Home Forums Hunting & Shooting AR and Tactical Rifles Somewhere between 223 & 308

"I'm shooting a 30 Herrett in an AR15."

Yondering,

I've looked at the 30 Herret; Which version are you shooting? Black Hole's, the HRT or AR Performances (which I don't know may be the same as one of the others?)?

Whose dies are you using?

And what kind of velocity (what barrel length & bullet weight)?

Thanks,

Jerry

Jerry,

Mine is an actual Herrett chamber, rather than a variation of it. The 30 HRT is the closest. The ARP version has a shorter throat, and BHW's version (30 American) has more capacity with the shoulder bumped forward. I just used a 30 Herrett reamer for mine though.

Regular 30 Herrett dies work with no modifications. With the Herrett chamber, you need to either neck turn the brass or open up the chamber neck as I did.

At some point I may bump the shoulder forward with a 30 American reamer for a little more case capacity, as the neck is long enough and shortening it won't hurt any.

I'm pushing the 125gr Nosler BT to 2740 fps, and a 150gr SP (Sierra I think) to 2500. This is from a 20" barrel.

6.8 SPC

The Herrett is a very hard hitting round out of an AR15 but it is a wildcat. The original 30 Herret pistol chamber had zero freebore. The lands start sloping up at just in front of the case mouth.
This is a little data including some pressure trace tests from the ARP 16" version.
Suggested loads-
125gr Sierra prohunter loaded to 2.240-30.5gr 1680=2610fps CCI 450 primer
125gr Nosler Ballistic tip loaded to 2.3"-30.5gr 1680=2680fps CCI 450primer
110gr Barnes TSX loaded to 2.295, 31gr 1680=2678fps
110gr Barnes TSX loaded to 2.295, 32gr 1680=2796fps
130gr MK319 bullet loaded to 2.295 30.5-30.7gr 1680=2600fps

The Hornady 125gr SST is not as accurate as the bullets above.

Added- Using SSA brass. Federal brass has .8gr less capacity.
28.5gr 1680 behind a 125 TNT hit 2500fps out of a 16" barrel.
29.5gr 1680-apx 2570- Very accurate with 125gr Speer TNT and Hornady SST
30gr 1680=2594fps--54925psi
30.5gr 1680 =2655 --57053 psi max(meaning do not try or use more powder than this)
30.5gr 1680 is pretty much max with 125gr bullets. The 125 Sierra prohunter hit 2600+- and the 125 Nosler hit 2680 with the same charge. The Sierra has more bearing surface, may be why it was slower.

Here is an interesting comparison between my current 308 Win and 6.8 hunting loads:

18" ARP 6.8, 120SST @ 2590, .400 BC:


24" 308 Win, 165GKHPBT @ 2630, .363 BC:

Ha! Agreed!

Similar BC's at similar velocities will have similar results regardless of how you launch them.

That's not what you get when you order a 30 Herrett reamer these days, in my experience. Of course, being a wildcat, there are a number of variations of it under the same name. My understanding was the original concept was throated for round nose bullets though, most of which require a little more freebore. The reamer I used matches that, with more freebore than your ARP barrels.

No AR at this time. I have all the parts and its in process again, only to use to track deer with my dog as a finisher.

The ONLY point in shooting a 300/221 IMHO is suppressed for quiet. Action noise ... makes noise... Same on my 10-22, wiht it I often hold the bolt closed when suppressed to make it like a bolt gun as I don't have a bolt thats threaded for a can yet.

50% of the other deer still run when I shoot suppressed.... and while I've yet to shoot more than one pig at a time with the bolt gun, I'm sure all pigs will run....so why make even more noise ALA AR?

I can run a bolt awful fast if needed.... not like an AR obviously, but years of match shooting and playing with bolt guns along the way in rapid fire strings you learn to run em fast, though I think I will add a knob to the 700 in 300/221.... will be going SBR with it as soon as I remember to fill the forms too, and will SBR the AR upper too....doesnt' take much barrel to get 900 or so FPS out of a 194 with a short tube.

Having shot pigs past 200, a couple of deer around 170ish, and a yote at a bit over 500, I forget the exact rangefinder reading, the X39 does just fine easily to 200 for me. I wouldn't even think of passing at 300 either...

So, you like 7.62x39 for hunting but see no use in supersonic 300 Blk loads... What am I missing?

I never said that I had any problem with the 300 BLK this is just another choice
I like the x39 also because its a great plinking round with a bit more punch. for plinking its a great value

Hank

Hank, Yondering's comment was directed at Rost. Rost has voiced his disdain for anything supersonic in the .300 B/O many times here.

6.8 SPC

My question was for rost.

I am in agreement with what you said, except I prefer the 300 Blk instead of the x39 for the AR platform, for a number of reasons. The ballistics are close enough to not matter for this discussion. the 6.8 seems like a great option too though, and ammo is getting pretty cheap (relatively).

Yes, RE the supersonic thing.

I like full cases of powder. Or I'd run x39 sub.

For that size round the X39 works just right at super and the 300 works just right or a bit too large of a case for subs.

So if I"m going to go super, i"ll just run the x39, and git a bit more speed out of the thing, and the ability to run a bunch of surplus if I had to for whatever reason.

Just my way of thinking, right or wrong.

I'm still not seeing it. 7.62x39 and 300 Blk supersonic loads do essentially the same thing, and 300 has several big advantages if you load your own.

You've said several times you see "no use" for the 300 supersonic. What does the x39 do for you that a supersonic 300 doesn't?

Just trying to understand something that doesn't make much sense to me...

no forming brass. cheaper and surplus ammo if you want to blast and if I'm going to go supersonic, I"ll take all that plus a bit of speed advantage to the x39 from what I've seen over the years.

Granted that may all have changed now... I know you can get formed brass for the 300/221, and its cheaper ammo now. But for years it was teh case.

if going super, why not take the speed advantage?

Yes the bolt is different... and requires a different mag, but other than that, and thats something I can deal with easily enough.

Given lets say a 125 grain bullet, what super sonic speeds are you getting out of the 300/221 these days?

A 16" AR will do ~2350 with a 125gr Nosler Ballistic Tip, in my experience. The better selection of .308" bullets is valuable IMO.

Making brass isn't a big deal for me, and it doesn't need to be fireformed. (Don't know if that's what you're referring too, but some guys still insist it has to be fireformed from 221 Fireball instead of sizing down 5.56 like everyone else.)

Factory 300 ammo is certainly more expensive, but I wouldn't know much about that, I've never bought any. Cost for reloading 300 is a little cheaper than x39.

It's not that both don't work well; my question was why the disdain for 300 supersonic when you're happy with x39 supersonic? There isn't enough ballistic difference to worry about.

when going supersonic I take all I can get... extra 100 fps is happily taken. Extends my range, helps with wind drift. At least thats my thoughts.

I didn't fireform my formed brass. It was just more work to form, cut off, trim etc... until I just bought some Lapua to see if it would be more acccurate than formed... have not tested yet. In an AR I would not waste the time.

Some of this is just like my thoughts on the suppressed rounds and not having an AR that way yet.... trying to get quiet, but you deal with action noise...why? there are obviously some good reasons, but at that point, I'm not so sure that going supersonic with a suppressor wouldn't be the better trade off.

BTW its not a disdain for the 221 round super, just that it doesn't make sense to me when I can grab the X39 stuff and run without any issues and get a bit more speed.

FWIW a loose buttoned bore my nephew has shoots ball x39 in a.308 diameter barrel just fine, and shoots 125 ballistics around an inch at the same time.