Hornady 750gr. AMAX & M82A1

[cruzie27]

So just for kicks I picked up a box of the Hornady AMAX for my M82,. The plan was to single load them to see what kind of accuracy I could get with them. I was very happy when I found that the newest lots of this ammo fit the m82's magazine,.

So I go to zero my scope with this load and I am loading one round in the mag at a time and getting my scope zeroed I get a group that has two out of three touching @ 100yds,. So I pile three rounds in my mag and fire away to confirm zero,. This is where it gets a little odd.

I had my first round hit where it was suppose to,. The second went quite a few inches left,. The third was on top of the first. no biggie I just figured I really screwed up on the second shot.

So I dial up for 300yds,. And I got the same exact thing,. Only I know I did my part and I should not have pushed the second round that far to the left.

Why is it every other round of this "match grade" ammo going native on me? Both American Eagle xM33 & Barrett M33 shot well,. And single loading produced a super group,.then two out of the three AMAX's shot really well when loaded in the mag,.. With the one apparently doing it's own thing when fired.

What's causing that? And how can I fix it? My gun seems to have alot of potential with this loading so I would really love to figure this out.

[davidedale55]

Sounds like the familiar story of all of us with the semi-auto Barretts. To a lesser degree this is what happens with an "untuned" M1A (civie version of the M-14). The big Barretts seem "sensitive" to a variety of factors including our shooting position. I have experienced exactly what you describe with my "most perfect" loads of every projectile from surplus to Lapua (yes, that includes the A-max). The big gun will likely shoot better in the new configuration (the M-107A1). I would be interested in "dispersal" data from an instrumented "gun tunnel" with the gun in a machine vice. Somehow I doubt we will see this kind of information anytime soon. Any of you military guys with extensive "gun time" should "enlighten us!

[Rangerat]

It is possible that under recoil the bullet is recessing into the case. This will happen with most semi's to a certain extent if the crimp is not correct. Try this, measure the overall length of 3 rounds as you load them in your mag. Fire the first round then clear the chamber and measure the remaining two rounds. If they move then you know the crimp is not holding.

[kevint82a1]

Sorry, but I've been out of touch for several months.

Are you writing that the AMAX round may not fit into the magazine?

Also, what are the changes between the 107 and the A1 variant that improve accuracy?

Respectfully,
Kevinol

[Shadow]

Sorry, but I've been out of touch for several months.

Are you writing that the AMAX round may not fit into the magazine?

Also, what are the changes between the 107 and the A1 variant that improve accuracy?

Respectfully,
Kevinol

kevint82a1 - Reread his post - his AMAX rounds seem to fit into his magazines - Many/most AMAX rounds don't, cuz the Projos are seated such that the OAL is too long for the magazines.

Specific to your second query - I'd suggest you repost in the proper section and ask you question there. You may get more activity to your question. Plus, It's unlikey ANY forum member could answer your question, unless they actually work for Barrett.

Besides, accuracy/precision is rather specific to a shooter's capability. It's unlikely anyone is shooting significantly better than 1.0 MOA with any of the Barrett semi's. What kind of accuracy would you expect with any of the Barrett .50BMG semis?? There NOT precision/match rifles (right?).

You may get a more direct answer by sending Kevin @ Barrett an email with your specific question. His email address is:

kevinf@barrett.net

Good Luck

[kevint82a1]

Thanks, Shadow:

I have shot 50 caliber rifles in both bolt and semi-auto styles over the past 35 years, but no longer reload. Hopefully my large amount of AMAX will fit and feed!

My practical accuracy standard for my 82 with XM33 is between 1.75moa. and 2.5moa. I can shoot well, but accept the tradeoff's wiith the semi-auto 82. My goal with the AMAX is to reduce spread by 25%. Eliminating the wide/high/low hits is the quest. Once the mechanical aspects are managed, the nut behind the but is the real variable. Placing between 50 and 100 record shots into 1.5 moa. with our 50's takes skill and good conditions.

Respectfully,
Kevin

[cruzie27]

Sorry, but I've been out of touch for several months.

Are you writing that the AMAX round may not fit into the magazine?

Also, what are the changes between the 107 and the A1 variant that improve accuracy?

Respectfully,
Kevinol

kevint82a1 - Reread his post - his AMAX rounds seem to fit into his magazines - Many/most AMAX rounds don't, cuz the Projos are seated such that the OAL is too long for the magazines.

Specific to your second query - I'd suggest you repost in the proper section and ask you question there. You may get more activity to your question. Plus, It's unlikey ANY forum member could answer your question, unless they actually work for Barrett.

Besides, accuracy/precision is rather specific to a shooter's capability. It's unlikely anyone is shooting significantly better than 1.0 MOA with any of the Barrett semi's. What kind of accuracy would you expect with any of the Barrett .50BMG semis?? There NOT precision/match rifles (right?).

You may get a more direct answer by sending Kevin @ Barrett an email with your specific question. His email address is:

kevinf@barrett.net

Good Luck

to be clear they where factory Hornady rounds that came in a black plastic 10 round box.

i'll pick some up on this next payday and bring something along to measure the rounds with.

[Shadow]

Sorry, but I've been out of touch for several months.

Are you writing that the AMAX round may not fit into the magazine?

Also, what are the changes between the 107 and the A1 variant that improve accuracy?

Respectfully,
Kevinol

kevint82a1 - Reread his post - his AMAX rounds seem to fit into his magazines - Many/most AMAX rounds don't, cuz the Projos are seated such that the OAL is too long for the magazines.

Specific to your second query - I'd suggest you repost in the proper section and ask you question there. You may get more activity to your question. Plus, It's unlikey ANY forum member could answer your question, unless they actually work for Barrett.

Besides, accuracy/precision is rather specific to a shooter's capability. It's unlikely anyone is shooting significantly better than 1.0 MOA with any of the Barrett semi's. What kind of accuracy would you expect with any of the Barrett .50BMG semis?? There NOT precision/match rifles (right?).

You may get a more direct answer by sending Kevin @ Barrett an email with your specific question. His email address is:

kevinf@barrett.net

Good Luck

to be clear they where factory Hornady rounds that came in a black plastic 10 round box.

i'll pick some up on this next payday and bring something along to measure the rounds with.

Cruzi27
Sounds like a plan.

FYI - You probably know that the standard OAL spec. for .50BMG is 5.45" OAL - Thats XM33, AP, API, etc. I don't have any non-AMAX to actually measure against the published spec. Do you have any non-AMAX that you can measure?

Anyway, I just went out and measured a bunch of my "factory loaded" 750g AMAX (Aluminum Tipped/Match) which are not handloads, BTW; and out of 20 plus rounds measured, they ALL measured between 5.442 and 5.444 inches. So.... my AMAX is between .008 to .006 of an inch shorter than what the std. spec indicates for .50BMG.

I'd be curious to see what your AMAX measures out to. Please measure all of them (or at least 10), not just one or two.

Maybe someone else who shoots AMAX can measure theirs so we can see whats up?

[Shadow]

Thanks, Shadow:

I have shot 50 caliber rifles in both bolt and semi-auto styles over the past 35 years, but no longer reload. Hopefully my large amount of AMAX will fit and feed!

My practical accuracy standard for my 82 with XM33 is between 1.75moa. and 2.5moa. I can shoot well, but accept the tradeoff's wiith the semi-auto 82. My goal with the AMAX is to reduce spread by 25%. Eliminating the wide/high/low hits is the quest. Once the mechanical aspects are managed, the nut behind the but is the real variable. Placing between 50 and 100 record shots into 1.5 moa. with our 50's takes skill and good conditions.

Respectfully,
Kevin

Hope this isn't toooo far off topic.......

Kevin
I understand and agree with your points, my brother.

What I was trying to say, is - the mechanical dynamics of the Barrett semis (in my opinion), should not be viewed as typically being able to shoot better than 1.50 MOA (at long ranges). The weapon's actual firing dynamics include the buffer stops, springs, the backward movement of the barrel in the upper, etc. IMO there's just too much going on to expect it to benefit (significantly) by shooting 750g AMAX. Maybe your 25% improvement is possible, given your setup, etc.

I always viewed the 82A/107 as a great "hard target" eliminator, but not the best tool in the LAV-25 for hitting TFTH's at long ranges.

To be precise, I don't own a 82A1/107 semi, but I've shot them many, many times. Never shot them using 750g AMAX, so my experience is flawed. Anyway, the best I've been able to do (with the semis) at long ranges is 1.25 MOA (Minute of Angle) to 3.0 MOCD (Minute of Car Door). Which I feel is completely adequate based on the intended purpose for the weapon. If some can do better, well then.......


Now on the other hand, with my M99 Barrett (single action/bolt) shooting 750g AMAX, match ammo, I usually shoot between .45-.50 MOA at 750yds; and .85 MOA (or better) at 1000yds. I hardly ever miss the 8" COD (circle of death) at 1000yds. BTW- That's shooting 10-15 round groups (not 2-3 round groups). But again, my experience is flawed, I've never shot XM33 or other ammo types in my M99. I've also hit "metal stuff" out to 1750yds, but don't have a clue what the my actual accuracy results were. Probably pizzpoor...

I'd sure be interested to see how the 750g AMAX ammo works for you guys shooting your semis. IMO, the significant metric is shooting at, at least 750yds and, even better at 1000yds, not at 100-200 yds. Unless shooting thru block walls/buildings, etc., shooting the .50BMG at the shorter ranges is just punchin $4.50 holes in paper.

So, anyone shooting AMAX at long ranges (with the semis), please post results, etc. so we all can learn what's possible.

SF, Shadow

[cruzie27]

i have the XM33 & some AP at the house,.. i should be able to get at least a box of the 750's tomorrow or friday.

i wish i still had the 690gr. PMC ammo i was getting 2.5 - 3.75 groups @ 300 with that ammo (i'll post that picture when i get home),.. and it was even cheaper than the American Eagle stuff,.. but the 750's made a cloverleaf just about 3/4" @100 when single loaded,. i'll pay the extra $$$ for that kind of performance out of my M82,. but i have to get this issue figured out before i go out and buy any large amounts of the ammo.

the shooting position being diffrent is unlikely,. i never break my cheek to stock weld,. and then take my time reseting my position,. adjusting the mono-pod,. and restarting my breathing / trigger squeeze ritual,.. all without moving my cheek from the gun.

i dont know lf the feeding is too rough on the soft alum tips,. or if sitting in a warm chamber while i get reset has some effect on the rounds point of impact,. or even if the recoil has some effect on the COAL......

ETA: it's $5.70 holes in paper at the shorter ranges

[Ridz]

rangerat I think is on to something. I was just looking at the Desert Recon Scout website and they have a special design on the magazines that prevent the tips of the round from making contact with the mag during recoil.
http://www.deserttacticalarms.com/srs-3 ... ersion-kit

"shoulder retention" feature that prevents the projectile tips from slamming into the front of the magazine during recoil. In traditional magazines the projectile tips slam against the front of the magazine, deforming the projectile, and in turn diminishing accuracy

good call rangerat.

[kevint82a1]

My Hornady 750 AMAX is all from lot number 3090689 with a headstamp WCC 08. The loaded round OAL for 20 cartridges ranged between 5.412" and 5.417" with 5.414" being predominant. Other Lake City ammo. with headstamp LC 09 had a nominal OAL of 5.43".

Speaking with Gunny Cook at Barrett yesterday he indicated that the factory AMAX should fit into 82/107 magazines because they should accommodate up to 5.455", if I heard that dimension correctly. What he shared was that the AMAX aluminum tip can batter and shorten while in the magazine, which reduces accuracy. He suggests single loading the AMAX round by pushing it fully into the chamber with ones finger and then letting the bolt slam into battery from the half way back position to achieve UNIFORM shoulder crush.

Respectfully,

Kevin