Well, I got my PSA pistol upper today, and completed the pistol build.

I got out to test fire it, and put a 40 yard zero on the irons. Sun went down on me, and I lost light quick.

JBM suggests a 40 yd zero should keep bullet path within about 2" of LOS out to about 230 yards with M855 at 2600 fps.

I gotta say. it was a lot of fun to shoot. I was sitting leaning against the truck tire, Just getting some 40 yard 5-shot groups to get a zero.




Feel free to share your AR pistol stuff here.

That is impressive as hell. May I be so bold and get a price check on the upper ?? Did it come with a BCG and charging handle ?

The upper was $219 shipped from Palmetto State Armory. BCG, CH, and Magpul handguards included. I added the rear sight.

Looks like that upper is now out of stock, but there are others here:

https://palmettostatearmory.com/ar-..._multi=2304&upper_barrel_length=1352

Good for you! Looks good!

https://palmettostatearmory.com/psa...ockwave-pistol-kit-black-5165449130.html

You just might be surprised how much time this little guy spends with you.

Love mine.

I'm already feeling the love.

I'm probably going to add some type of optic. My eyes and bifocals just aren't cutting it anymore. I can't get a clear front post at all.

I'm thinking probably a 3X prism style from Primary Arms.



What kind of optic are any of you using on your AR pistols?

I can't imagine a Red Dot not being the right idea. I'll find out soon enough.

I was looking at the red dot option. The thing with most red dots is they don't appear to have a diopter adjustment.

Things I like about the Primary Arms prisms (have two already), they do have a diopter, and the reticle is etched, so it shows black if the battery is dead, or turned off. Of course the downside to the PA prism is the weight factor. Every option is a compromise of sorts.

Mine has a 1-4 Leupold VX-II.

Wife's has irons.

Third which I put together for the kids for plinking is mounted with a cheap red dot. So far all I've done with it it zero it. I'll probably throw together another lower for it and add a .22lr sub cal adapter over the holidays.

If I was looking at something from Primary arms for one, I'd consider one of their 1-6x or 1-8x's.

Of course, if money wasn't an issue I'd take Formidilosus recommendation and go with the Nightforce 1-8.

Load wise, the best I found for the PSA barrel was 53gr Nosler Varmageddon over a max load of TAC and CCI 450 primers.
5 shots just over an inch at 100 with the above 1-4 VX-II, but it never broke an inch.

Yeah a NF would be nice, but looking for something in the Primary Arms price range, $300 or so.


I have been considering the PA 1-6x24 as a possible. If one of those didn't work out on the shorty, I could migrate it to a carbine or rifle pretty easily..

sadly my eyes and red dot's don't go together anymore. Waiting on NF to release their NX8 with capped windage and elevation before I buy it, I have knocked SWFA 1-4 turrets off zero more than once pushing them behind a seat, or why even in the gun safe.

Checked the irons at 100 yards. Pretty close. 10 rounds off the bench. Fired them all in under 1 minute. Good enough for irons and a fuzzy front sight.

Shane, they've got them on sale now in gray color.

Price must be really good. Crashed the site.

Old eyes, iron sites, and milspec ammo,

No bad.

local dirt, thanks for the heads up.


antelope sniper, I was kind of surprised they all hit the black. I was just holdin' and squeezin'. I would imagine an optical sight would easily cut that group in half.



I probably need to adjust the impact up one click via the front sight. That should be about 1.75" at 100 yards on the carbine sight radius, and give the relatively flat 200 yard trajectory I'm looking for.

Just ordered an upper from PSA.

That looks like too much fun!!

It is a fun gun to shoot. I don't know what it is about it, the small size with the big boom, but no recoil to speak of.

This evening I ordered a Primary Arms 1-6x24 with the ACSS reticle for 5.56

This could be a fun little rig for well beyond 100 yards.

you may want to shoot heavier bullets.

I was looking at the heavier bullet ballistics in a 10.5". Looks like 2400 fps is realistic with the 75/77gr bullets.

This is a JBM calc on the Sierra 77gr TMK at 2400 fps, in local atmo,

I am curious if you have a round house figure for rounds down range and have there been any functioning issues.

Not many rounds at all. Maybe 100 or so.

The only ammo I've used so far is PMC X-TAC 62gr green tip LAP. Roughly an M855 equivalent.

So far no malfunctions or stoppages at all.

When I put it together I did throw in an H3 buffer from the start. Tested it for positive bolt lock-back on the last round and it worked fine, so I ran with it.

A standard carbine buffer probably would be fine too, but I didn't try that.

I have a kit on order from PSA with the standard carbine buffer. I’ll report out on any stoppages, if I get stoppages.

I think the trouble most commonly associated with the 10.5" with the carbine gas system is the short dwell time, causing an under-gassed condition.

If that is the case, the lighter buffer would probably be better than a heavy buffer.

Anyhoo, I'm going to run with the H3. If I run into any cycling issues down the road I'll share the info. With the H3 and the ammo I'm using, I don't feel any thump from the buffer hitting the back of the extension tube. It's real smooth.

MM,

I going to get the 7.62x39 carbine upper from PSA when they are back in stock.

What buffer do you run in yours?

I've got an H3 in the 16" 7.62x39.

It ran OK with a standard buffer, but I could definitely feel it hitting the back of the extension tube. The H3 smoothed it out real nice.



Another reason I went to the H3 in the 7.62 was because I figured delaying the unlocking a bit, should help reduce or eliminate the chance of losing a bolt lug. Apparently that has happened with the 7.62x39 in the AR.

Thanks

some of the pistol uppers are over gassed, the H3 makes some sense. I think the heavier bullets do better at longer ranges.

The heavies with the higher BC always win at distance.

Muzzle velocity numbers impress sometimes, But high BC is the gift that keeps on giving.

I see they have a chromed version as well, probably not as accurate.

The nitride barrels do seem to shoot a little better, on average.

You're assuming the underlying barrels are equal. They are not.

Most of PSA's chrome lined barrels are made by FN, their nitrites are made by some second tier producer.

I trust FN to make a good barrel.

so your saying that an FN chrome lined barrel would be more accurate than a second tier nitrided barrel? I don't dispute that they would be more durable.

You can nitride a turd and it's still gonna be a turd.

You need to start out with a good barrel and they seldom come as the cheapest option.

Yep.

This:

Yep I owned an FN double chromed barrel, in one of the early Noveske guns, it was a 2.5 MOA barrel with xm193 did not shoot much better than that with Hornady 55 grain Vmax factory ammo. They replaced the barrel with a new one when I complained that the barrel seemed a bit rough and the new one shot about the same. They are milspec barrels. I have spoken to a Knight armament dealer and he said the Knight barrels are about the same until you get 1000 rounds down the tube and they smooth up a bit. Again I am no expert here as many others are, but have owned a few chromed barrels. Colt has made a decent barrel.

Did you try any 75/77gr match ammo? M193 is 3.5 MOA at best, and usually between 4 and 5 MOA.


Every FN Double chrome lined barrel I’ve seen (100-125) has been a sub 2 MOA for ten rounds with 77gr Blackhills.

It was about 2.5 maybe 3 MOA for 5 shots with an NXS 1-4 in a LaRue Mount.. I never shot any 77’s. It was a reliable gun, sold it for too little. These days a PSA upper with an FN barrel which I assume is the same as what Noveske offers and a PSA premium bolt would be my choice over any intruded barrel

I'm don't understand your logic.

I feel the reason as to why 7.62x39 breaks lugs on bolts is that the lugs on the bolt have to be much smaller than the lugs on a .223 sized bolt. Also, The pressure on the 7.62x39 bolt is much higher than the pressure on a .223/5.56 bolt. (7.62 Case has a larger bolt surface area than a .223 bolt area hence more load is applied to the bolt). I understand 7.62x39 does not have an issue with breaking lugs in an AR10 or similar platform. I am not comfortable running 7.62x39 loads in an AR15 sized platform due to the smaller bolt lugs and increased load on the bolt.

I haven't done the math on bolt thrust between 5.56 and 7.62x39. But 5.56 operating pressure is around 62K psi, and 7.62x39 is around 45K psi. The bolt thrust might be closer than we think.

My thought on losing a lug might be all wrong, but I think rotating the bolt out of it's locked position is easier on all moving parts when pressure has subsided even a little bit. So the heavier buffer delays unlocking by a few milliseconds, and in that same short time, pressure is dropping in the chamber/barrel. I could be wrong.

Did some math to compare bolt thrust between 5.56 and 7.62x39

5.56 NATO,
Case head diameter .378"
Case head area .112 sq-in
Max pressure 62K psi
bolt thrust: 6,944 lbs

7.62x39,
Case head diameter .447"
Case head area .157 sq-in
Max pressure 45K psi
bolt thrust: 7065 lbs

Measured the rear lug surface of both bolts. They are the same.

Based on surface area calculated by rim diameter of 5.56 case, at 62k psi, the force on the bolt will be 6,974 lbs.

7.62x39, using SAAMI spec pressure of 45k psi, will have a force of 7,058 lbs. on the bolt.

7.62x39 military loads have an operating pressure of 51,400 PSI and will place a force of 8,062 lbs. on the bolt

The caveat, most American 7.62x39 AR barrels are cut with a .308 diameter bore. Pushing .311 diameter military loads down the .308 diameter barrel will produce a pressure in excess of 51,400.

Ruger's mini 30 also uses a .308 diameter barrel.

This is all valid. Now consider the difference between force on the lugs in a barrel with all bolt lugs seated evenly, and one where the barrel is not square to the bolt and one or two lugs take all the pressure.

That, combined with less support of the lug bases on the 7.62x39 bolts, is what really breaks bolt lugs. Squaring up the receiver (and therefore the barrel extension) goes a long way to making the bolt live. Getting the rifle properly gassed to prevent premature unlocking during high pressure (as you were saying) is a good thing as well. If you do those two things and use a good bolt, you can expect good bolt life.

Who chambers the 7.62x39 in the AR10?

That makes sense.

The CMMG “Mutant” is reputed to have a 308 sized bcg with a 7.62x39 sized boltface, which means a lot more metal around the case head, and much bigger locking lugs, and the increased mass probably helps to keep the bolt locked during the highest pressures.

Measure overall lug size instead.

There is no dimensional difference in the lugs.

The 7.62x39 is milled out more in the bolt face to accommodate the larger rim diameter. So the front of the lugs on the 7.62x39 do have less steel below the lug. If tested to failure it would appear likely to let go before the 5.55 bolt would.



5.56 left, 7.62x39 right,

Well, I stand corrected.

Two of the lugs on the 7.62x39 are narrower than the rest. The lug beside the ejector, and the lug just below the extractor are only .090" wide.

The rest are .100" wide, as are the 5.56 lugs.

I wonder if sending the 7.62 bolt for cryogenic hardening would help extend the life and prevent lugs from shearing off?

I don't know, but I'm just going to run mine as is, with either an H3 buffer, or a rifle buffer.

Probably not a bad idea to keep a spare bolt around.

Does PSA sell 7.62 bolts?

I searched and did not find them.

They have them listed in in 'AR15', 'upper parts', 'bolt carrier group', but currently out of stock.

These guys are out, too, but the reviews are better.

I signed up to be notified when they are back in stock.

https://www.primaryarms.com/bear-cr...omplete-bolt-carrier-group-black-nitride

https://palmettostatearmory.com/psa-ar47-762x39-bolt-assembly.html

This looks like a fair deal with good reviews, on a spare bolt assembly and enhanced firing pin.

https://www.righttobear.com/7-62x39-AR15-Bolt-Completion-Kit-Enhanced-Firing-p/762ekit.htm

Armorally bolt carrier groups are in stock, and have 26 reviews and all are 5 star.

I'll get one for T&E.

Nice.

It's easier & cheaper to relieve one of the bolt lugs a la Armalite.

http://demigodllc.com/articles/the-armalite-m15a2-infantry-rifle/

I put the Primary Arms 5X prism sight on the pistol to see how much it would shrink the 100 yard 10-shot group with M855, from the one I shot with the iron sights.

Whataya know, it didn't shrink the group any appreciable amount.



I did use the group to refine the zero.

I'll try some hpbt match, and 53gr VMax to get a better feel for the accuracy potential.

I might just put the irons back on it, and just keep it short and light.

I was shooting from a good stable position.

Seems about par for the course with M855 in some guns. I sold a rifle to a buddy that shot well for me, but he tried 855 and it shot like that. Once he tried my 75gr HPBT match loads though, it put 5 in a tight little cluster mostly all touching. Good ammo matters.

The one exception I've seen was the Steyr Aug I bought when Obummer got elected; for some reason that rifle shot pretty much everything into about 1.5-2 moa, including M855. I considered that really good for M855, but was unimpressed that it wouldn't do better with match loads.

Next time out we'll see how she does with three different handloads I have put together.

- 53gr VMax over 26.0 gr XTerminator

- 75gr Hornady HPBT over 24.5 gr XTerminator

- 77gr Nosler HPBT over 23.5 gr XTerminator



Those loads all shoot around 1.5 moa or so in the 16" and 20" ARs.

MM, What is the reticle or dot in the prism?

Suggestion - try that 75gr HPBT over 23.4gr of 8208XBR or Benchmark. It's not quite as fast, but consistently accurate in a lot of rifles, and more temp stable.

it's the Primary Arms ACSS reticle. Etched. Shows black, illuminates red or green. The center dot is 1 moa.

That looks like a nice set-up. Do you like the reticle or feel it holds you back at 100 yards?

I like the reticle. It's not a handicap at 100 yards at all. 5X with a 1 moa center dot. It is very easy to center in the round bullseye I drew on the target.



I originally had that sight on this 14.7" rig, the reticle tracks m855 very well. I have shot watermelon size rocks out to 600 yards or so with no problem.

The weak link in my opinion is the pistol brace (along with the ammo I'm shooting). The back end below the extension tube is fairly soft and rubbery. Probably not the best for consistency, and of course the LOP is maxed out at 12.5"

I understand there are some inherent limitations with the AR pistol concept. Mainly a close range hammer. I'm enjoying the journey so far, learning new things.

MM, check out the replacement strap for the SBA3 by lunar concepts. I put one on mine and it took a good bit of the "flop" out of the bottom of the stock and keeps the rubber pieces at the bottom from sliding off to one side. Still not a great stock for punching tiny groups from the bench but then again it's meant for pistol barrels. Works great though.

I m waiting on my palmetto upper as well. Trying to find a spikes to build the lower Going to throw a bcg from bravocompany in and will try an h2 or h3 buffer. Hoping for another sale on the geisselle ssa e trigger and slapping a red dot on this thing like a burris fastfire.

That's interesting.

You're so right, these pistols are not meant to be bench guns.....grin

Sometimes it's just in our nature to see haw far they can be pushed.

It seems like you have been pretty satisfied with the PA prism type sights. I am guessing you feel they are rugged and hold zero well? I have had the money sitting in my safe for a NF 1-8 but the A--holes will not sell me a capped windage and elevation model, so they have just lost a customer. How long have you had the PA prism?

jimmyp,

I bought the 5X prism with the 5.56 ACSS reticle a couple years ago. No complaints.

Since then I also bought a 3X prism with the 7.62x39 ACSS reticle for the 7.62x39 carbine.

The prism sights are a very clear optic, and the reticle is also very clear, with the diopter adjustability.

In the last few days I received the PA 1-6x24 with the 5.56 ACSS reticle. I mounted it up on the AR pistol, but it just seemed ridonkulous on there. Size and weight-wise.

The 1-6x24 plus the mount, weigh in at almost 26 ounces. Added considerable weight to the pistol. So I put the 1-6x24 on the 14.7" 5.56 carbine. Zero'd it in yesterday, seems nice.

Thanks

I believe I have this thing dialed to my liking, after trying a few things.

The carry handle keeps it light, but still has some longer distance capabilities, despite a fuzzy front sight with my eyes.

I set a 40/200 zero with the rear drum set at 3/6 minus 5 clicks (bottomed out). Midrange trajectory at 100 yards is only 2" above LOS.

I know the velocity is only about 2600 fps, but with the shorter sight radius, and local elevation, the rear drum is surprisingly very close. did some rock plinking out to 577 yards, and the rear drum was good to go.

I won't keep the bipod on there, but used it to get a solid zero.

I have a 16" M4 I built (tax deductible guns are cool) a few years back with a PSA CHF/CL upper. I've probably put 4-5k rounds through it at this point and it refuses to do anything but run like an ape.

If it weren't for finding a couple smokin deals on Colt barrels for a block 2 M4 and my wife's "early GWOT" M4 clone, I'd have probably done PSA again.

They're still the first place I'll look for something in stock when I'm looking for parts for a build, and one of the first places I'll send friends looking for stuff for their first build.

I've only had good experiences with PSA. That would include:

14.7" CHF/CL 5.56 upper
16" 7.62x39 upper
10.5" 5.56 upper
a few stripped lowers.

Just got my 10.5” pistol upper.

For general fun and anti-AntiFa, what’s best? 55 SP, 62 green tip, or 75/77 JHP?

All I've shot through mine so far is 62gr green tip. The PMC XTAC variety. I think that or any of the fmj economy stuff hits the mark for fun/practice.

For serious defensive use, I believe something poly-tipped, or OTM would be a better choice.



I do have some 53gr VMax, 75gr BTHP, and 77gr BTHP loaded up, haven't shot any through the 10.5" yet.

Understood.

Based on momentum and formidilousis 75-77 grain, the Speer gold dot 75 is something

David, is that the recent sale kit with everything except the stripped lower, 1-7 nitride barrel?

Yes sir.

I added an optic and a rear sight and changed the grip.

I have the KS-47 - 7.62x39, that takes AK mags, and their AR-10 in 6½ Creedmoor. The Creed needed some gas block tuning, but now runs well and shoots very well. The KS-47 has run perfectly, and shoots pretty well.

Interested in hearing how yours shoots.

I need to get back out there with mine, and make some more empties.

That KS-47 looks like a nice setup.

Is there a reason why you didn't include Mark 318 ammo as an option?

Oversight.

I listed what I have lots of in the ammo Vidmar.

I just lubed the BCG with Lucas lube in the hope of sending some rounds down range this weekend.

They come from PSA with a minimum of lubrication, in my experience.

I’ll report out when I get some shots fired.

Cool, I ordered the OD kit a few days ago for 269 shipped, it's hard to pass on at least one at that price when it gets you a complete AR for ~325 depending on the lower.

I thought my spare NIB lower was an Aero but it's an Anderson and was cheap so a good fit on the PSA.

Now I need to learn to shoot these tinker toys


I do like the handguard and stock that MM has on his pistol a lot better but doubt I will swap parts.

I ordered the MOE upper, and it came with a black MOE handguard, I already had the FDE brace and black A2 grip...……………..my OCD was working overtime....grin

So I ordered FDE furniture to get my head to cool off......grin

PSA apparently does not offer an 11.5 inch pistol upper with the FN chrome lined barrel.

I haven't seen that offered.


They have some 10.5" FN CHF/CL uppers in stock though.

https://palmettostatearmory.com/psa-10-5-hammer-forged-ar15-upper.html

If I needed another 10.5 to run with straight irons, I'd order that along with one of their premium BCG's they have on sale for $60.00

Tried out a few handloads today. Wanted to see how they would compare to the 62gr green tip I have been shooting.

I shot these groups at 51 yards. Temp 30F.



Groups are all 5-shot.

Top Left: PMC XTAC 62gr LAP

Top Right: 77gr Nosler, 23.5gr XTerminator

Middle Left: 75gr Hornady BTHP, 24.5gr XTerminator

Bottom Left: 53gr VMax, 26.0gr XTerminator

Bottom Right: 53gr VMax, 24.0 gr XTerminator

So my takeaway is that these short barrels definitely have the potential to shoot well. Saw a clear preference for the 75gr Hdy, and the 53gr VMax.

The short LOP and flexy nature of the brace are disadvantages, along with having the bipod so close in.

I'm going to put the carry handle irons back on it. I put the scope on today just to give all the ammo a fair chance to perform.

Shane

Nice shooting MM.

I'd say those Vmax have some potential in that rifle.

It does seem to like that 53gr VMax. Probably not a bad bullet for a defensive load in this shorty.

I was going to chrono, but no place to really attach the Magnetospeed. I'm guessing the 26.0 gr load must be in the 2700 fps ballpark.

Gratuitous pic. Probably going to stay in this guise for a while.

That looks good, MM.

I put mine together this afternoon and fired a test round with 24grs of Lever and a 75 BTHP. I was thinking the same about the Magnetospeed and remembered having a DPMS Levang compensator, it's not optimum but works. That load was running about 2580 our of a 16" earlier this morning at 49 degrees, 2260 out of the little booger.

I would not have expected 53 fps per inch but that is what it is for the single shot.

That's good to know.

Well, I can see when you get closer to the chamber, there would be more loss per inch, since the barrel pressure is a lot higher between 10-16" than say 16-20 inches.

Here is a comprehensive velocity test of many 5.56/223 commercial ammo types, in 10.5, 11.5, 12.5, and 14.5 barrels.

It is a little bit of a nut-roll to go through, but the links at the end of the first post have the 10.5" velocity data.

https://www.ar15.com/forums/AR-15/S...-11-5-12-5-and-14-5-ALL-DONE-/16-714088/

The Black Hills 77gr TMK and the IMI 77gr both break 2400 fps in the 10.5".


The IMI stuff in 55gr, 62gr, and 77gr is all pretty snorty compared to the others.

Thanks for the links, I am shooting for 2650-2700 fps in my 16" barrels and whatever I get in the 10.5" with 75's.

I was able to shoot one five shot group at a 100 yrds after bore-sighting that was about 1.5" and then jammed that booger up tight. One live round ended up stuck between the top of the bolt and the frame.

I had 40 rounds each running 24-25.5 grs of Lever and 75 gr BTHP's for testing in all three and to have some fun shooting. SS 10X's mounted on both and probably didn't shoot one five shot group better than 1.5", most 2"-4". One a Faxon Pencil and the other a BHW mid-weight but I don't remember the name of the profile.

I am close to parting out four and keeping the LE6920 that is completely stock and the PSA pistol.

That may indicate your rifle is severely overgassed with that load, as I've mentioned in the other thread. Weird stuff like that starts happening when the action is violently overgassed.

~23.5gr of Benchmark will get you to the velocity you want in your 16" guns, with a lot less gas and blast, and is right at a good accuracy node for 16" ARs. Save that Lever powder for the bolt guns, it's just mis-matched in the ARs.

I played around with JBM to work out a decent zero for M855 in the 10.5" barrel, at MV of 2570 fps.

Came out to a 40/200 zero in local atmo. That's what I put on the irons.

Here's what it looks like on paper.

I've been using an H3 buffer, no cycling issues with any of the commercial or handloads so far.

Cool, I have a few pounds of Benchmark but never used it with 75's so I will give it a run.

I checked PSA and neither the pistol kit or the Shockwave kit indicated what buffer is used other than "carbine" so I weighed it at 2.9 oz.

If it's overgassed from the start, why would PSA sell the kits with a 3.0 oz buffer?


If this information is correct start with an H3?

Car std 3.0oz
Car H 3.8oz
Car H2 4.6oz
Car H3 5.4oz
RRA 9mm 5.6oz


And on that same subject, what is the recommended buffer tube for a 16" barrel?

I don't know what I have now and can't get to the safe before heading out for the daily grind but I will weigh them this afternoon.

If it's overgassed from the start, why would PSA sell the kits with a 3.0 oz buffer?

They think most people will use underpowered ammo and won't shoot it much anyway. Or they just don't care.

I believe PSA err's on the large size for their gas ports.

Probably something to do with the amount of steel cased ammo folks shoot through them, it is a bit softer on performance, probably less port pressure with that stuff.

As far as buffer tubes for 16", I have used carbine and rifle recoil systems and never had issues with either. I think either is fine.

Because 99% of buyers are going to shoot the cheapest crapiest ammo made. It’ll be underpowered and cause issues if the barrel has the correct gas port size. There are almost no 10.5’s (all the way to 14.5”, and even then they tend to be over gassed for 5.56) uppers/barrels made for the above reason.

Start with an H2 buffer in pretty much every 14.5” and under.

Is an adjustable gas block a reliable solution to overgassing or would you recommend changing the buffer weight only? I have a Faxon 11.5" barrels with midlength gas. Thanks.

I'd imagine you could approach it either way.

I haven't used an adjustable gas block myself, but it would seem to give great latitude in adjustment.

I have a 14.7" mid-gas that was/is seriously overgassed, to the point the extractor was jumping the case rims. I added the o-ring under the extractor, and an H3 buffer, that settled it right down.

I was referring specifically to the Leverevolution load that RDW was shooting, not anything else. Lever works well for bolt guns in 223, but produces a lot more gas than typical 5.56 loads and as a result, it's a poor choice for an AR unless you tune the gas specifically for that load. Even if your rifle is gassed correctly for commercial 5.56 loads, it'll be overgassed for full charges of Leverevolution.

I do have one load I use it for in a Grendel, but have to open up the Bootleg adjustable carrier one notch to compensate for the gas when using that load.

Adjusting the gas is a better tuning solution, but changing a buffer is easier for most people.

Some guys are concerned about adjustment screws coming loose in adjustable gas blocks, but there are ways around that too.

Thanks. I've got my eye on a Superlative Arms gas block.

Either way is fine except if you are going to use a silencer. Then the adjustable gas block is preferred.

Gents, professing my ignorance, I have a dpms brand AR and want to do the conversion to what MM has here. You guys have covered well the sources to do that but what I need to know is what does it take to do this and remain “legal “ in the conversion from the existing 16” bbl to the 10.5” bbl ? DeFlave well advised that you cannot just simply cut the barrel down.

Any and all guidance and advice would be very much appreciated to get this right and legal from the start.

Thanks in advance, Gents.

OT

Yes, that's a consideration as well for me. Thanks.

If it's a rifle, and was sold as a rifle originally, you cannot legally change it to a pistol configuration. You can file SBR paperwork and then shorten the barrel after receiving approval, but that's pretty much it.

Or change the receiver for one not sold as a rifle. yes, it seems silly since the parts are functionally the same in every way, but that is what the almighty ATF has decreed.

Personally I'd suggest something else, but some people disagree. I don't agree with the hype about the bleed off system Superlative uses. My preference is for Seekins adjustable gas blocks (the version that is ~$60 or so). Seekins also has a newer version that is field adjustable and looks like a good idea, but I haven't used one.

Much appreciate it. Thanks for the info.

To keep it legal, don't build on a rifle receiver.

Use a pistol receiver (per 4473).

Or, use a virgin receiver transferred as 'other' on the 4473.

Use a pistol brace, not a stock.

There might also be state laws depending where you are.

Thanks MM. my state laws are good (Louisiana). I did find a complete article on this online in the American Rifleman .

Much appreciate you guys.

FWIW and you guys may already be all over this .

CDNN has pistol uppers advertised for 199.99$. Fits for AR-15, 300BO, 556, 7.62x39.
10.5” bbl, pistol gas system, match grade precision upper, A2 birdcage flash suppressor.
All NFA rules apply.

800/588-9500

Just FYI

Buy a Saint.

Much easier.

Have entertained that. Sweet looking rig, they are. Legal, too and with future rifle upgrades and back to pistol. What’s not to like.

I see Bud's sells the Saint for $819.00. That's always a solid name product.


My kitchen table build cost $475,

upper with bcg/ch (PSA) - 219
lower w/trans fee (PSA) - 49
lower parts kit (Midway) - 49
SBA3 brace (Midway) - 129
buffer (Midway) - 20
castle nut (Midway) - 4
end plate (Midway) - 4

total - 475

7.5's, yeah. But, haven't seen the 10.5's for that price.

No, I just took a quick search. I didn't even look at bbl length.

7.5" work too.

That's a deal.

No brainer if I was buying right now.

10.3" is $1,384.

If a man was really going to use something in competition, hunting or self defense, would you still shop the cheapest?

Not slamming anyone's choices, just had a bad deal on a Faxon barrel bought on Black Friday and it made me start looking again at better quality.

I do use mine for hunting and self defense.

Competition is different. That tends to kill everything.

For Iguanas’n chit.

Grins

That's what I mean. That's almost twice what I paid for any of my Colt M4's.

so the DD Mk18 pistol is expensive, wonder how it would stand up?

Crappy cell phone pic of a Pistol kit I put together last night.
PSA complete upper and parts kit I put into a new lower. I did upgrade to a Geissele SSA-E trigger though. I had the carry handle laying around so decided to try that for now. I like it and think it'll probably stay on there.
I like this little beast. It's seriously nose heavy, and the blade sucks, but I'm thinking it's going to be a whole lot of fun to shoot.
It's probably going to make me go get a SBR stamp though.

Looks good!

Mine balances at the magazine well. Not sure how the weights compare between the SBA3 and your brace.

The SBA3 weighs 7.2 oz, and I'm using an H3 buffer that weighs 5.3 oz.

7 lbs, 10.7 oz. That's with 28 rounds of M855 in the magazine.

I have a H3 buffer on the way. I was going to shoot it first to see how it goes, then replace it and see what the difference is. Did you shoot yours with the supplied buffer? Overgassed I'm betting?
I'll have to weigh it tonight and see what it comes up at.

I just bought the upper alone, so no included buffer.

I started off with the H3, thinking if it was too much, I'd put a standard buffer in there. But it has ran great with the H3 from the first round. And I've shot factory and a few different handloads.

H2 in mine, but havent gotten around to shooting it

I bought several hundred Fed Gold Medal Match 69gr SMK's to baseline my 223 AR's including the PSA. I have tried this in the past with Black Hills 75 BTHP and was not happy with the results. I used my Lilja barreled Montana that has proven to be 10-shot MOA at 100 to test the GMM and even though these groups are strung vertical the GMM was well under 1".




PSA Un-suppressed




Suppressed





Although this is a 10.5" thread I will post the 16" Faxon Pencil results since I have played hell trying to get any of my AR's shooting decent. I will save the 16" BHW results for an appropriate thread, those groups split the difference between the PSA and Faxon and I am very happy, this seems to indicate my loads are the issue rather than my equipment, assembly or technique.

Faxon Un-suppressed




Suppressed

I realize this is a side note to the point of your post, but maybe helpful info - the two groups shown above represent a pretty typical POI change between suppressed and unsuppressed. The easy way to deal with it is using a mil/mil optic, and noting the POI change on your dope chart. For example, maybe the suppressed group POI is 0.7 mil down and 0.1 mil left. With that info recorded on your dope chart, when shooting suppressed you can simply add 0.7 mil to your drop values at any distance and dial the 0.1 mil right, and you'll be zeroed for the suppressor.

Note that in this example we are not recording POI change in inches, nor do we care. That changes with distance, but the mil offset does not.

That may be already obvious to you, but some guys struggle with it so hopefully that helps.

That Faxon pencil barrel is a shooter too!

Well dang , I went and read this a week or so ago and got one of the $239 uppers. It came in yesterday and soon as I held it I knew I knew it is going to be a fun gun to shoot. My better half said she thinks it's the perfect size for her to shoot. Dang , may have to order another.

Two is one, one is none.....grin

Laighing. Yep.