[schaz42]

Hope this hasn't been beat to death but I'm just trying to find out what the max weight one should kep in mind when shooting out of a USGI standard chrome lined and standard NM barrel, thanks

James

 

[Visigoth9]

The issue of bullet weight has less to do with the barrel variety

and more to do with the gas driven operating system pressures

and the imposition of additional stress upon the op rod

the general rule is to not go above bullet-head weights of 180 grains

less is better, in the case of the m14 from a wear and tear perspective

given that the original design was arrived at using bullet-heads in the 147 grain weight range

 

[Bamban]

My standard slug for 600 yards and beyond is the Berger 185 BTHP Long Range for my number 1 gun. Number 2 prefers the Berger 175 BTHP Long Range. The key is moderate velocity with these big slugs. Don't hot rod them in the 14.

 

[KYShooter]

I agree with Visigoth in that it is more of an issue with the gas operation/design than with the barrel. I put nearly 8k rounds through my NM M1A and 95% of those rounds were standard loads with 168g SMKs. The other 5% were 175g SMKs for 600yd shooting. The 175s shot so well I never found any need to look for something better. They did punch harder so I never considered shooting them any more than necessary. The rifle is still running strong.

 

[bd111]

You don't gain anything any more to test the gas system by loading 190's. I've never shot Bamban's 185 gr. Bergers (bear in mind that's his pill for a heavy double-lugged M1A), but I used to shoot a lot of 180 gr. SMK's. Good bullet but that was before the 175 SMK, which is better. The 168 gr. SMK is still the gold standard to 600 yds.

 

[BigBill]

We must remember the heavier bullets take a higher peak breech pressure to get them to move. This higher peak pressure also relates to the action in the force of the ejection/extraction cycle too. The case rim will tell the story if there is a problem with too much gas pressure. Its also the fired primer will tell if the powder charge it too high also. These are the mechanicals that we can inspect too. Its ok when we see which bullet weight and powder charge will preform better but we also need to be sure there safe to shoot too. The twist of the rifling matters if we go to the higher speeds too(Feet per second). the bottomline is to besafe too and enjoy. Bill

With my saiga's its recommended that we stay at 168gr bullets and under and with my m14 i'm going to stay 175gr and under too. Remember to read your brass too that tells the real story on whats going on too.

 

[Ted Brown]

I don't like to shoot anything over 180 grains, but the 185 grain Lapua bullet has been used with great success in the M14.

 

[Rubline]

I get great results using Nosler 168 Custom Comp bullets sitting on top of 39 grains of IMR 4895 with CCI mil spec primers. M1A Standard shimmed.

 

[30Caliber]

I stop at 175grs and use them only for 300+yds. No sense beating the gun more than you need to and the lighter bullets are easier to shoot.

 

[MesaRifle]

So I'll assume it's A-OK to load bullets heavier than 180 gr if you compensate by reducing the powder charge and thus the breech pressure and o coure velocity.


But then, what's the story on retaining supersonic velocities as long as possible? (which would mean starting the bullet as fast as possible, within reason, from the muzzle.) I assume (I'm doing a lot of that I see...) that it has to do with the behavior of the bullet when it goes trans- and then sub-sonic, since apparently it goes into a de-stabilizing flight condition as it passes through it's own shock wave. (Just like Chuck Yaeger experienced in Glamorous Glennis, right?)

http://www.google.com/imgres?imgurl...1&ndsp=15&ved=1t:429,r:1,s:0&biw=1219&bih=600

Right? Wrong?

 

[gas_gunner]

My standard slug for 600 yards and beyond is the Berger 185 BTHP Long Range for my number 1 gun. Number 2 prefers the Berger 175 BTHP Long Range. The key is moderate velocity with these big slugs. Don't hot rod them in the 14.

What speeds were you running these projectiles at?. I just got done chronographing some 1000 yard loads with the 185 and safely got up to an average of 2595 fps with them, ahead of RL 15. I haven't tested for accuracy yet, just max load and speed. I don't know if I'd run them at that speed even for a 1k load. My previous load used the Berger 175 VLD, or whatever the new name is now. I have some older bullets on hand. I was/am running those at 2620 fps ahead of Varget.

Danny