M1a Vs. Ar-10

[TRNinTX]

Since USPSA MOR is just about dead, I was wondering if a semi-auto could be made to work out to 1000 yards for matches like ITRC or Snipers Paradise Challenge. I was wondering if an M1A with an Armscorp receiver or an AR-10 from Armalite, DPMS or GA Precision would work better. From what I read on Fulton's site about M1's is bullets tend to go sub-sonic at around 900-1100 yards, but the gun will beat itself to death with hot loads. Anyway to counter this? And just what do the rear-lugged, and double lugged receivers do as opposed to a normal one?

Edit:

Guess I need to look at who is signed in before I post..

BJ

[Zak Smith]

For whatever accuracy you want (under 1.5MOA), it's going to be cheaper to build an AR10 that does it vs. an M1A. And mounting optics on the AR10 is a lot cleaner.

I think you'd want a 24" barrel. Loads from my 20" AR10 seem to lose their legs after about 600 yards. Not sure how 22" works.

I find spotting hits much easier from a bolt rifle without a brake vs. my AR10 even with a brake.

-z

[Scooter]

There are oversized gas plugs and also adustable gas plugs you can buy to help control the gas pressure to run heavier bullets. Most have said 175gr is pushing it on the M14/M1A. But by being able to adjust the gas pressure, you can prevent the op-rod from destroying the rifle.

[George]

Here's the skinny. The M1A is pretty well developed for High Power work out to 600 yards from years of use and it's pretty much a three quarter to one MOA gun. Yes, it can get tighter, but even the best bedded M1A/M14 will shoot loose in a few k and need re-work to be tight again.

An AR based rifle though, when equipped with a free float hand guard and assembled properly is capable of half MOA, or better and will shoot that until the barrel wears out.

Reliability is equal when both are set up properly. Accuracy and POI stability over the long haul go to the AR based rifle.

That should pretty much say it all for what you are thinking.

Of course, now that the AR-15 in .223 rules the roost in CMP service rifle class, there are an awful lot of good shooting M1A's sitting in High Power shooters safes and good deals can be had on rifles that used to cost 3k+ to build up.

Funny how the world works ;-)

--

Regards,

[B.J. Norris]

Wow, I guess you learn something everyday. From what I have seen in the past, it always seemed like it was easier to get an M1A to shoot better groups than AR-10s. Choices, choices... the GAP AR-10 is using a 1-11 twist, isn't this a little fast for 175 or above? I ran some numbers, and it seems as though a 190 gr SMK will perform at 1000 yards quite a bit better than a 175, why aren't more using these? Are they too long for the magazines? Is there anything else I should look at, including going with a semi vs. a bolt gun?

[Zak Smith]

The most common answer for long range is the 175SMK since it can be fired at a decent velocity (2700fps from 24"'s). There are other lighter bullets with nearly as good or better BC's that may work better at long range:

_Bullet_           _BC_ _MV_         0     200     400     600     800    1000 | YARDS
190 SMK           0.53* 2560 >   -0.00    0.00    6.22   14.17   24.10   36.54 | drop (moa)
175 SMK           0.51* 2675 >   -0.00    0.00    5.75   13.22   22.67   34.70 | drop (moa)
155 Scenar        0.508 2850 >   -0.00    0.00    4.94   11.32   19.30   29.33 | drop (moa)

190 SMK           0.53* 2560 >    0.00    2.81   12.05   29.21   56.01   94.16 | wind (inches)
175 SMK           0.51* 2675 >    0.00    2.85   12.23   29.69   57.25   96.76 | wind (inches)
155 Scenar        0.508 2850 >    0.00    2.53   10.83   26.17   50.19   84.66 | wind (inches)

190 SMK           0.53* 2560 >    2560    2244    1949    1678    1437    1237 | velocity (fps)
175 SMK           0.51* 2675 >    2675    2328    2007    1713    1452    1238 | velocity (fps)
155 Scenar        0.508 2850 >    2850    2498    2171    1871    1600    1366 | velocity (fps)

I just guessed at the 190gr velocity, but the 175 and 155 loads are still moderate.

-z

[GeneralChang]

USPSA MOR is dead? Did I miss something? Who? What? When? Details on MOR's death, please

Sheldon

[bgary]

Since USPSA MOR is just about dead

I don't think USPSA MOR is dead....Quite the contrary.

I think that in the next year or so you may see a *separate* USPSA MOR Nationals. We're already seeing rifle-only USPSA matches.

Yes, it is true, there will be no MOR side-match at the USPSA 3-gun Nationals in Vegas this year. That's due to a scheduling constraint, created by the larger-than-ever number of shooters who want to shoot the main match, *not* a lack of commitment to MOR.

Bruce

[codyb]

Since USPSA MOR is just about dead, I was wondering if a semi-auto could be made to work out to 1000 yards for matches like ITRC or Snipers Paradise Challenge.

The AR 10 works well indeed, I recently had my GAP rebarreled to a REM 260 when punching paper at these matches I think it is the way to go less recoil and a better BC have made my optics more efficeint, and it came shooting under 1/2 moa from George.

Cody

[Larry White]

Jerry M. seems to do quite well with his DPMS.----Larry