Home Forums Hunting & Shooting AR and Tactical Rifles 6.8 SPC options

You don't cut the mags out to add powder, you cut the mags to get the bullet closer to the rifling

But some folks don't get that....

Yup, totally in agreement.

Along those lines, I should clarify that some of the brass I used (S&B and some Hornady) was from factory new 6.8 ammo, and worked fine in 6.8, but not in the ARP 30 Herrett. The issues were loose primer pockets and case flow into the ejector and extractor holes.

It doesn't matter to me whether the issue was the barrel or the loads in general, but the comparison tells me pretty clearly that pressure was too high in that barrel at least. My new barrel, that I made and chambered, shoots fine with the same loads.

Regarding chrono readings, my basis for comparison was shooting my 300 Blk over the same chrono with the same bullets.

I have seen the same thing in FC 223 brass, but at least in that case you can compare it with known good loads in other brass and realize it's just a brass issue.

I agree as well about some of the scary load practices that are promoted on the 68forums. The membership there seems to be generally less experienced though, and tends to just believe whoever is popular. Rost, some of those guys are loading long specifically to increase powder capacity and velocity. They will expound at length on the magical virtues of that extra .080" of length when given the chance.

I don't trust much on other forums and not nearly all I read here..... to many idiots out there.

RE chrono, I meant its possible there is a big difference between yours and his.... you'd have to shoot a known ammo over both to have a clue if his data was relevant to yours.

There supposedly have been a lot of brass issues over time with 6.8 stuff.

I got 100 rounds or so of SSA when I had my hunting gun in 6x6.8 done. I can go a lifetime with 100 rounds of hunting brass typically, the gun gets fired only 1-2 times a year if that...LOL

How do you like that 6x6.8? I was thinking of trying one of those myself; the concept looks good.

Its ok.

I"m still of the opinion that there isn't a lot out there that I can't do just perfectly fine with the 223, and that being the case the 6 sits in the vault unused most of the time.

Most of the time I just grab a 223 with tsx or 75 bthps.... and its never let me down.

The other calibers are fun, but simply not needed mostly.

Bought a 50 beowulf because I had a bullet issue on a vine with a 223 once... figured go big.. hell the deer run as far or farther with that round than they do with the 223.

I keep coming back around to the same conclusion, at least for the sub-30 cal stuff. I've wanted to do a 204 Ruger or 20 Practical in an AR as well, but come back to just using the 223 for all of it.

The 30 and 35 cal wildcats (and I guess the 300 Blk too) do offer some performance that you can't get with the 223 though. The Herrett based stuff in particular duplicates the old 30/30 and 35 Rem lever gun ballistics, but in a modern AR, so I see some real advantages there for a woods rifle.

There's some degree of AR pressure issues that can be mitigated by heavier buffers too.

if you think you can kill it with a 30-30 and can't with a 223, you need to learn to pick the right bullet and then learn how to place your shots.

I've shot deer to the far side of 550 with the 223 and no issues.

Anyone that has ever played with Quickload for 30 minutes can explain why increasing the OAL increases usable case capacity and lowers pressures. Those that wish to get as much velocity as possible can add a little powder to bring pressure back up to the maximum suggested.
There are several members on 68forums that own or use pressure test equipt. and have tested the above. Since 2006 many of the members there have been involved in correcting all of the mistakes on the original 6.8 design. Many have been involved in increasing the performance by tweaking designs and perfecting loading combinations and procedures.
There are probably more wildcat guys developing cats on that forum than any other forum, so many that they have now started a wildcat forum.
If there is anyone still following this other than the 2 this article explains more of the peak pressure problem solution.
The effects of engraving force and bore area on pressure-
http://www.dtic.mil/dtic/tr/fulltext/u2/a431357.pdf
CONCLUSIONS
1. The baseline heptagonal barrel will exhibit peak chamber pressures about 15 to 20%
higher than the same cartridge loaded in a standard M240 barrel. This is due primarily to
the increased resistance pressure early in the in bore travel of the projectile.
2. The increase in peak chamber pressure could be reduced by either increasing the free run
of the projectile prior to the start of engraving or by reducing the forcing cone angle in the
barrel.
3. A slight decrease in resistance force was observed for the 2.5 deg half angle forcing cone
compared to the 1.2 deg half angle forcing cone found on the M240 barrel baseline. It is
believed this difference is due to a reduction in the plastic deformation of the M80
projectile in the 1.2 deg barrel.
4. The addition of lubrication to the M80 projectile exterior increased the engraving force in
the baseline M240 barrel with 1.2 deg half angle forcing cone, while it decreases the
engraving forces in the 2.5 deg half angle forcing cone barrel. Likewise the push force
standard deviation increased with lubrication in the 1.2 deg half angle forcing cone, and
decreased in the 2.5 deg half angle forcing cone.
5. Projectile construction and elastic modulus appear to play significant roles in the
resistance pressure of small caliber projectiles.
http://68forums.com/forums/showthread.php?56136-Reloading-and-pressure-something-to-ponder

That made my head hurt...

Sorry to the OP but I'll bet after the first few posts you aren't reading this anyway.
Dan(Yondering), I don't chase you around the internet talking [bleep] but if you open up the conversation I'll explain.
This is the email chain between Yondering and I. Notice he wants a refund right off the bat? Start at the bottom and read up as the email chain would progress.
**************************************** END and refund given.

OK I will do that, thank you. It’s possible that lip or groove was there before too, and just wasn’t visible before you polished the chamber.



One other thing you can look at in the meantime, if you’re interested, is to check the brass you fired in this chamber after polishing. If you haven’t sized it yet, you’ll see a ring halfway around the middle of the case necks. You might see it even if they’ve been resized already, mine still show it.



Thanks,

Dan




--------------------------------------------------------------------------------

From: tech]
Sent: Wednesday, October 07, 2015 5:30 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



Something in there is reflecting light. We use a 800 grit flex hone to smooth the sticky melonite surface. Return it and a copy of the invoice to the PO box so I can borescope it. If there is a groove I will refund the purchase price.



From: Dan

Sent: Tuesday, October 06, 2015 11

Subject: RE: 30 Herrett barrel issue



Constructor, looking this barrel over last night, I noticed a sharp lip in the chamber neck, that appears to be a result of your polishing the barrel. The lip extends a little less than 180 degrees around the neck, with black nitride in front of it but bare steel behind it.



It looks like the chamber was lapped with a case that had a short neck, and wasn’t held in alignment during the lapping. It must have been fairly aggressive to cut through the hard nitride surface, and only cut through on one side.



It’s hard to make out but you can see it in the attached pictures, and also in the fired case. (The case is neck turned per your suggestion, bump in the case only appeared after firing in this chamber.)



Would you please consider letting me return this barrel for a refund?



Thanks,

Dan




--------------------------------------------------------------------------------

From: tech@
Sent: Wednesday, September 02, 2015 5:21 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



Sorry, I don’t know what else to tell you. Everyone else can shoot 29.5gr 1680 with 125gr bullets and get good accuracy with that load. Try some different things.



From: Dan

Sent: Tuesday, September 01, 2015 9:45 PM

To: tech@

Subject: RE: 30 Herrett barrel issue



Also, the brass I sent you was fired with only 28.5gr of 1680, a full 2 grains lower than what your website says is safe. I wanted you to see how it was getting swipes at only 28.5gr.




--------------------------------------------------------------------------------

From: Dan
Sent: Tuesday, September 01, 2015 6:10 PM
To: 'tech
Subject: RE: 30 Herrett barrel issue



I don’t adjust my dies that way, because all my AR’s will close the bolt on a fired case before any resizing. I made my own bushing for checking headspace, although you can use a deprimed 9mm case if you don’t have anything else.



The .340” neck is why I don’t think neck turning will have any effect on pressure of my loads, maximum neck diameter of my loaded rounds is only .336”.



Re-using the same brass work hardens it, which might explain why you don’t have issues. I bet if you tried new brass you’d get bad swipes as well; general wildcatting wisdom says to always use new or once fired brass for load development.



The primers certainly don’t indicate high pressure, but something weird is going on with the brass in this chamber and I can’t figure out what. The same brass, using the same bolt and rifle, works fine in my 358 Herrett AR wildcat barrel, using the same loading practices.


--------------------------------------------------------------------------------

From: tech@
Sent: Tuesday, September 01, 2015 9:17 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



The shoulder is .411, the neck is .340. In order to check the headspace measurement on a fired case a .375” bushing is needed. I do not have a precision ground .375” bushing to fit a Hornady set.

The shoulder is short enough that any other bushing size is too close to the radius at the neck or body. I checked them but with the size I have it could have been in the radius area.

I set the size die by screwing it up until the brass will not chamber then screw it down 1/16th turn at a time until it just chambers by dropping the bolt catch.



I did see slight swipes on your brass about like what I see on M193 ammo. I have no idea why you get loose primer pockets. I have used the same 50 pcs of brass for all of the testing I have done in all of the barrels and I am still shooting the same brass. I do not get swipes or cratered primers. Again I have tested the loads with Pressure Trace and posted the results. The loads are not high pressure.



From: Dan

Sent: Tuesday, September 01, 2015 11:25 AM

To: tech@

Subject: RE: 30 Herrett barrel issue



With the gas shut off, brass still flows into the ejector and extractor cutouts. It doesn’t swipe until I have to mortar the bolt open to rotate the bolt past the brass flow.



I sent you both sized and unsized brass fired in this barrel, so you could verify that I’m not bumping the shoulder back too far when sizing, since you’ve been saying this is a headspace issue. Did you verify that?



I’m happy to change the way I’m loading, but what? The only thing you’ve suggested that I’m not already doing is neck turning, and I will try that. I am using the same components as you, as I’ve described.




--------------------------------------------------------------------------------

From: tech
Sent: Tuesday, September 01, 2015 5:39 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



How does it create swipes when the bolt does turn because you have the gas shut off? The headspace/chamber size is going to be a little different since I used one of my bolts.

The barrel you sent, the barrels I have tested and the barrels everyone else is shooting handles that load fine. You need to change the way you are loading or the components you use to get better results. There is nothing wrong with the barrel.



From: Dan

Sent: Tuesday, September 01, 2015 12:13 AM

To: tech@

Subject: RE: 30 Herrett barrel issue



When you send my barrel back, could you include a couple pieces of your fired brass from testing this barrel?



Adjusting the gas won’t help; as I said it does this even with the gas shut off. I polished the chamber several times as well.



You still never commented on headspace measurements of my fired and resized brass; did you check that and compare it to yours?



I have a hard time believing the pressure signs I’m seeing are normal, regardless what the primers look like. Brass flow into the bolt cutouts and loosening primer pockets says otherwise, and none of my brass will hold a primer more than two shots with your load.








--------------------------------------------------------------------------------

From: t
Sent: Monday, August 31, 2015 6:38 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



As I said before turning the necks would help. Adjusting the gas back a little may help and polishing the chamber may have helped . The brass you sent didn’t look bad other than the swipes on the bottom. The primers were not flat or cratered.

I’ve shot hundreds of rounds loaded with 29.5 gr and even run them on the pressure trace so I know they are not over pressure.





From: Dan

Sent: Friday, August 28, 2015 8:15 PM

To: tech

Subject: RE: 30 Herrett barrel issue



OK, thanks.



Did you compare headspace of my sized brass to yours or fired brass? Do you have any conclusion on why my loads don’t work but yours do?



I did use 450 primers, but still couldn’t get anywhere close to 29.5gr 1680 without severe pressure signs. Only difference I can see with your load is SSA brass instead of my Hornady and Nosler. I’ll try backing the die out more, but without bumping the shoulder back as it is, I’m not sure I can expect much there.



I feel like I’ve tried everything you suggested, with no success, so I’m not sure where to go from here. Thanks for looking at it though.



Dan


--------------------------------------------------------------------------------

From: tech
Sent: Friday, August 28, 2015 8:58 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



Shot more today. 29.5gr 1680 with both 125TNT and SST. Both average apx 2540fps. No signs of pressure using SSA brass, CCI450 primers. I cleaned the gunk out of the cone area of the chamber and polished the chamber just to make sure the melonite treatment was not causing the cases to stick a little. Try adjusting the size die up until the cases will not chamber when the charge handle is released then screw the die down 1/16th turn. Also swap to CCI 450 or 41 primers. You will not get good accuracy by leaving half the neck one thickness and the top half another. 29.5gr of 1680 is a safe load and hits apx 2550. We will return the barrel to you on Monday.



From: Dan

Sent: Wednesday, August 26, 2015 11:30 AM

To: techar1

Subject: RE: 30 Herrett barrel issue



To be clear, new cases sized with that .008” crush fit (referring to headspace at the shoulder, not neck or body diameter) will not chamber if the bolt is eased forward gently. They do chamber when cycled from the magazine. My reason for mentioning it was to illustrate that I think the same thing happens to correctly headspaced brass as well, but I’m not sure why, other than the chamber is slick, or how to prevent it.



The Nosler brass is definitely thicker in the bottom half of the neck, but still only about .336” diameter. As best I could tell from slugging the chamber in that barrel, the chamber neck is around .340”, so there shouldn’t be a clearance issue to pinch the bullet and raise pressures. That was one of the first things I suspected. My loaded rounds (in fired brass) plunk into the chamber and fall back out again, so I don’t think there are any binding issues.




--------------------------------------------------------------------------------

From: techa
Sent: Wednesday, August 26, 2015 5:22 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



I should have more time to dig in today but it may be that the bottom half of the neck is just large enough to touch the walls in the chamber and pinch the bullet in place. I turn the bottom half to match the thickness of the top half. In a semi auto any amount of “crush” should not fit in the chamber and definitely not extract.



From: Dan

Sent: Tuesday, August 25, 2015 9:03 PM

To: techar15

Subject: RE: 30 Herrett barrel issue



Do you think dimensions of my dies might be wrong? Two of the cases I sent you were resized (with no shoulder bump); maybe you could load them without any additional sizing and see if you have the same issues I did. That might help me determine if it’s from how my brass is sized.



I fired some with the gas system turned off completely (mounted a spare gas block backwards to block the hole) and still got brass flow into the ejector and extractor holes at 28.5gr 1680, so in this case I don’t think any of the gas system parts are the issue.



Just to confirm, are you testing these by cycling from the magazine? Mine seems to set the headspace back just from feeding from the mag, without firing; enough that new brass sized for a +.008” crush fit still cycles and chambers from the magazine.



Does Hornady or Nosler brass work for you? I’m using all the same components except maybe the brass, which you didn’t specify what brand to use.



The only other differences I can think of are the dies and the bolt. My bolts don’t have any burrs, and both of them work in my 358 Herrett with the same brass up to 2,100 ft-lb without pressure signs.








--------------------------------------------------------------------------------

From: techa
Sent: Tuesday, August 25, 2015 7:25 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



A lot of times it is the way we load and the brass. Like I said before Xman could not get within 100 fps of what I was getting and had been using for 3 years until he started sizing like I do and using the same components. Sometimes swipes are a product of being slightly over-gassed. A heavier buffer, spring or an adjustable gas block will tone it down and remove the swipes.



From: Dan

Sent: Tuesday, August 25, 2015 10:09 AM

To: techar15performance.com

Subject: RE: 30 Herrett barrel issue



You fired it with the same loads I was trying but without any pressure signs? How can that be?



Did you check headspace of my fired and sized brass?




--------------------------------------------------------------------------------

From: techar
Sent: Tuesday, August 25, 2015 6:07 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



Yes, I’ve inspected it and shot it in the shop without issues but have not had a chance to shoot it for accuracy at the range yet.



From: Dan

Sent: Monday, August 24, 2015 10:15 PM

To: techar15performance.com

Subject: RE: 30 Herrett barrel issue



Hi, just thought I’d check to make sure you received the 30 Herrett barrel already; it should be there by now.




--------------------------------------------------------------------------------

From: tech
Sent: Monday, August 17, 2015 6:23 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



The PO box is safer. Not a great neighborhoor behind this industrial area.



From: Dan

Sent: Sunday, August 16, 2015 11:45 PM

To: techar15

Subject: RE: 30 Herrett barrel issue



I’ll mail the barrel to you tomorrow. Should I send it to your P.O. Box or the 8 address?



I’ll include 4 pieces of brass – 2 are as-fired using the 125gr TNT over 28.5gr of 1680 and CCI 450 primer. The other two were fired (at lower pressure) and resized, you can check my headspace setting, per my my measurements the die is just touching the shoulder without bumping it back.



Thanks,

Dan


------------------------------------------------------------------------------
from Dan
Sent: Friday, August 14, 2015 4:08 PM
To: 'techar15
Subject: RE: 30 Herrett barrel issue



I will send a couple fired cases and a couple sized cases with the barrel for you to check out.



Trim length is 1.570”. I’m not neck turning the cases, didn’t think I needed to with this one, and slugging the chamber indicated the neck is large enough that it isn’t necessary. Fired case necks measure .339-.340”, loaded case necks measure .335-.336”, and bullets slip into fired case necks easily.



Using new Hornady and Nosler brass, but have tried some S&B as well.



Dies are an older Pacific Durachrome set. It’s possible dimensions are slightly different than new Hornady dies, but I’ve done a bunch of measuring and haven’t found anything obvious.



I’m loading on a Forster Co-ax press, and loading pretty much the same as other semi-auto rounds. I’ve got the dies set back to not bump the shoulder (started with .004” bump at first), and newly formed cases are a .008” crush fit in the chamber for the first firing. Other than that, I’m following the same size/prime/powder/seat routine as everything else.



Seating depths are mostly 2.290-2.300”, although I tried 2.260 with the 125gr TNT to make sure they weren’t jammed in the lands, but that didn’t help.




--------------------------------------------------------------------------------

From: tech@
Sent: Friday, August 14, 2015 10:23 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



I’ll test the one you return first to see how it shoots for me. I shot 40 rounds this morning 29.5gr 1680 with 125gr TNTs and SSTs and both were under MOA with no pressure. Tell me exactly how you prepare the cases and load. Are you turning the case necks to a consistent thickness from mouth to shoulder? trim length? what brand of dies?



From: Dan

Sent: Friday, August 14, 2015 2:37 A
to tech

Subject: RE: 30 Herrett barrel issue



I agree that it sorta looks like excess headspace, but as I said, I’m not bumping the shoulder back at all at this point. That’s not guessing, but measuring with a digital caliper and an adapter that contacts the middle of the shoulder. New brass is sized to +.008” crush fit at this die setting. I understand the reluctance to believe there’s something wrong with this barrel, but I’ve tried everything I can think of to get it working right, and have wasted 100-150 rounds through it just trying to find a decent load with no success. Sending it back is my last resort, but I don’t know what else to do with it.



I’ll get the barrel packed up on and mailed back to you on Monday. Will you refund it, or swap for another? I’m OK with a swap, as long as you test the replacement barrel as well to verify it doesn’t have the same issues. Even if that means you send me a known good used barrel, I just want something that delivers the advertised performance in this chambering.



Thanks,

Dan




--------------------------------------------------------------------------------

From: techa
Sent: Thursday, August 13, 2015 5:16 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



You can return the barrel and we will check it out. If there is nothing wrong with the barrel and it shoots well you can not return it for refund or swap. If we find something wrong we will swap it out. From your emails it sounds to me like excessive headspace from pushing the shoulder of the case back too far but, send it in and we’ll check it out.



From: Dan

Sent: Wednesday, August 12, 2015 8:12 PM

To: tech@

Subject: RE: 30 Herrett barrel issue



I fired a few rounds using CCI 450 primers today, using 28.5gr of A1680 under 125gr TNT bullets at 2.295” OAL in Hornady brass; trying to duplicate your posted load as closely as possible. Velocity was 2508 fps (3 shot average). You worked up to 30.5gr with this combination, but judging from this brass I’d consider this well over max, and would back down at least one full grain.



See attached pictures of the brass from this load. You can clearly see where the brass flowed into the ejector and extractor cuts on the bolt. It does this with Nosler and S&B brass as well, and the 450 primer didn’t seem to change anything.



Can I return this barrel? I realize sometimes there may be an unexplained bad barrel out of a batch, it seems like this might be one of those; it certainly doesn’t come close to the advertised performance capability.



Thanks,

Dan

(




--------------------------------------------------------------------------------

From: tech
Sent: Tuesday, August 11, 2015 9:29 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



No, it’s not normal, you are the only one that has contacted me with these issues. Are you sizing the brass(shoulder) .002-.004max below the chamber size? Xman on the forums use to have a hard time getting the velocity on his 6.8s until told him to make sure he sizes the cases .002-.004 under. CCI primers will pierce and crater long before a 450 or 41. How far above the groove are you measuring for case head expansion?



From: Dan

Sent: Tuesday, August 11, 2015 11:36 AM

To: tech@

Subject: RE: 30 Herrett barrel issue



Thanks.



I am using new Hornady, S&B, and Nosler brass, with the same results in all. I’d be really surprised if loosening primer pockets is due to using CCI 400 instead of 450 primers, have you experienced that? I’ll certainly give the 450’s a try if that’s the issue. The pressure signs I’m seeing are mostly in the brass, not the primer though. I’m seeing brass flow into the ejector and extractor cutouts in the bolt, large case head diameter measurements, and loose primer pockets in one or two firings, depending on the load. I’ve tried most of the powders between H110 and 3031, focusing mainly on A1680 and A2200.



You’ve listed 2650+ fps with 125’s for this barrel with A1680, but I can’t get a safe load above 2450 fps regardless of powder, at ~2 grains lower than what you list. Is that normal for these barrels? I’m getting 2300-2350 fps with the same bullet in the Blackout. I bought this barrel because the numbers you listed looked really good, so I’m frustrated that I can’t get anywhere close to your results.





Thanks,

Dan






--------------------------------------------------------------------------------

From: t
Sent: Tuesday, August 11, 2015 5:21 AM
To: Dan
Subject: Re: 30 Herrett barrel issue



The barrels definitely have a shorter throat than a 30 Herrett pistol because it was designed for use in an AR with a mag limitation of 2.3”. The 110, 125and 147gr bullets all fit in the mags and are not jammed into the lands of those barrels. I’m not sure what brass you are using but SSA and Hornady will give the best results. Rem large primer and Fed are softer, can not be loaded hot and will not last as long. You should not use CCI 400, Rem 6 1/2 or Fed 205 match primers as noted on our website. CCI450 and 41 or Wolf magnum primers will not show pressure signs as early.

The 30 Herrett pistol was designed to operate at a much lower pressure and can not come close to the velocity of these AR barrels. Everyone I have spoken to is getting at least 200fps more than the 300BO.



From: Dan

Sent: Monday, August 10, 2015 11:52 PM

To: tech

Subject: 30 Herrett barrel issue



Hi, I purchased one of your 16” 30 Herrett AR barrels back in June. The barrel looks nice, and has a shiny smooth bore, but I’m very disappointed in the performance I’m getting out of it. Using the combinations you tested for these barrels, I’m getting pressure spikes bad enough to loosen primer pockets a full 2-3 grains lower than what you list as approaching max.



For example, with the 125gr TNT bullet over AA1680 and CCI 400 primers, I’m seeing pressure signs in the brass at 28.0gr/2475 fps, and loosening primer pockets at 28.5gr/2500 fps. Your data lists 30.5gr at 2655 fps “and I think there is more room to go up.”

I found similar results with AA2200 and the same bullet, with pressure signs and loosening primer pockets at 31.0gr/2500 fps.



COAL of these loads is 2.295”. I get similar results with other bullets, or pressure signs even earlier, like with the 125gr Nosler BT. I originally was bumping case shoulders back .004”, moved to .002”, and now not bumping back at all, with the same results.



I’m not new to handloading, have been doing it and experimenting with wildcats for over 20 years, so I don’t think it’s my bad handloading practices causing the problem. For example, I’ve also been working with my version of a 358 Herrett AR, machined two barrels from blanks and am getting great results from those; 180gr @ 2300 fps (over 2,000 ft-lb!), etc, using the same brass and shoulder dimensions as this 30 Herrett.



The bullets are not seated into the lands, but I have discovered, partly through trying to work up a cast bullet load, that this barrel has a shorter throat than any of my other 30 cal rifles, including 300 Blk, 30/30, 308, and 30/06. Is the throat in these production barrels shorter than the barrel you worked up loads with? I’m wondering if the standard 30 Herrett has more freebore, allowing higher velocity.



Can you offer any suggestions on what to do about this barrel? At this point it’s not much use to me, being barely faster than a 16” 300 Blk.



Thanks,

"Just to confirm, are you testing these by cycling from the magazine? Mine seems to set the headspace back just from feeding from the mag, without firing; enough that new brass sized for a +.008” crush fit still cycles and chambers from the magazine."

"I agree that it sorta looks like excess headspace, but as I said, I’m not bumping the shoulder back at all at this point. That’s not guessing, but measuring with a digital caliper and an adapter that contacts the middle of the shoulder. New brass is sized to +.008” crush fit at this die setting. I understand the reluctance to believe there’s something wrong with this barrel, but I’ve tried everything I can think of to get it working right, and have wasted 100-150 rounds through it just trying to find a decent load with no success. Sending it back is my last resort, but I don’t know what else to do with it."
"I’m loading on a Forster Co-ax press, and loading pretty much the same as other semi-auto rounds. I’ve got the dies set back to not bump the shoulder (started with .004” bump at first), and newly formed cases are a .008” crush fit in the chamber for the first firing. Other than that, I’m following the same size/prime/powder/seat routine as everything else."
Dan in the emails above in 3 separate places you say you use a .008 crush fit. How exactly do you get the brass .008 larger than the chamber in the chamber?

"Just to confirm, are you testing these by cycling from the magazine? Mine seems to set the headspace back just from feeding from the mag, without firing; enough that new brass sized for a +.008” crush fit still cycles and chambers from the magazine."

Above you say you are using new unfired 6.8 cases in this barrel correct?
Feeds and cycles from the mag with a .008" crush fit?

Maybe you missed this part, which you quoted: "and newly formed cases are a .008” crush fit in the chamber for the first firing."

That means cases with the shoulders bumped back from 6.8 SPC, but not fireformed yet. Your chamber was so slick that it did some of the sizing just cycling the action.

That does not mean I was trying to run full power loads on the fireform load; don't take it out of context.

Didn't you say something about me using fireformed cases to develop loads in a post up there somewhere? Kind of seems like you are changing your story.

You pointed out that you did give me a refund, but didn't say why. If you hadn't ground the nitride out of one side of the chamber when you "polished" it, I probably still would be stuck with that one.

Again, it's not that your barrel didn't work as expected. That stuff happens, no harm no foul. It's the way you responded about it, and acting like anyone not in your fanboy circle is an idiot.

Nope, but you're still looking for excuses.

Big difference between fireformed or once-fired brass, and brass fired 4-5 times or more. It's called "work hardening. Brass does it. Most wildcatters understand this.

If your loads work in work hardened brass, but not once-fired or fireformed new brass (that works fine in standard 6.8 SPC) your loads are probably too hot for that chamber. I don't know if that was just my barrel, or all of your barrels.

since we're quoting stuff here, yours from above:
"I have no idea why you get loose primer pockets. I have used the same 50 pcs of brass for all of the testing I have done in all of the barrels and I am still shooting the same brass. I do not get swipes or cratered primers. "

Truth is, if you'd responded without the "customer is an idiot" attitude, I probably would've bought a bunch more of your barrels, just like other people on the 68forums. Too bad for both of us I guess.

Also, what's up with posting my name online? You only have it because I made a purchase on your website. Doesn't your website have the standard agreement "to keep your information private" etc? Not to mention private emails between us, which don't help your arguments anyway.

I don't have anything to hide in this discussion, but that seems a little out of line.