308 bushmaster

dallas.com

Any of you guys reloading for the bushmaster 308 yet?
I have reloaded for my remington 700 308 for years with very good results. I have never reloaded for a semi auto 308, anything I need to watch for?

Pearyw

The main thing I watch out for in the 308 ammo I load for semi-autos, is to use a medium burning rate powder such as IMR 4895. I don't have experience with the Bushmaster. Is it a 7.62 x 51 NATO or a true .308? I load for HK 91, FAL, and M1A. I usually load for the NATO cartridge which has a lower pressure limit than the .308. I use 147 gr to a maximum of 175 gr bullets in a fmj or a spitzer style soft point to aid in feeding reliability.

dallas.com

mY UNDERSTANDING IS THAT IS A TRUE 308, WHAT WOULD BE AN EXPECTED VELOCITY FOR A 165 GRAINER KNOWING IT HAS A 16 INCH BARREL.

sandwarrior

dallas.com,

I think what Peary is pointing out is that while a .308 and a 7.62 Nato are totally interchangeable in a bolt action they are not interchangeable in a semi-auto action. You need to use a medium burning powder so that the powder will be burned by the time it reaches the gas recovery/operating sytem. Too much powder still producing expanding gas into the gas operating system and it will slam your bolt back and possibly crack your reciever or damage part of the gas system itself.
Delayed roller blowback type actions face the same kind of dilema with 'high pressure' .308 rounds. There are two little rollers that aren't made to take the same kind of pressure as the two big heavy lugs on a bolt action.
In a nutshell while the two rounds are interchangeable size-wise, 7.62 Nato has a couple of specs the .308 doesn't; fast/meduim burning powder and pressure limited to 48,000 cup. .308 has the full range of powder to use and limited to 52,000 cup.

I would recommend staying with 4895, 4064, AA2520, and nothing slower burning than 4320. With a 16" barrel I wouldn't even go as slow as that. What you will see instead of pressure signs on your case is damage to your rifle.
You should get about 2450-2500 fps using 165-168 gr. bullets. Work up to these velocities and I would recommend stopping at that as there will not be a way to determine how much stress your rifle goes through until the bolt slams back too hard once and breaks something.

-good luck with your endeavor.

We have the second amendment so that all the rest are secure....UNK>

dallas.com

Thank you for your reply, I was out of town and didn't see it until today. I used varget 43gr behind a 147gr fmj with a cannelure by remington. Got 2400fps. No signs of elevated pressure. How much can i push it without damaging the gun?, when using a 165 grainer soft point got a similar velocity by the way??

sandwarrior

Dallas,

I would stay where you're at with the 165's, maybe add a pinch, but you can push the 147's up to 2600-2700. Varget burns pretty quick so it shouldn't be a problem.

We have the second amendment so that all the rest are secure....UNK>

Hunter375

I use IMR 4350 behind 150 gr. FMJ and 162 gr. AP for my Armalite AR10A2 carbine and have had no problems with 90%-95% loads. I tend not to push the envelope in autoloading rifles. My only advise would be that you don't stray too far from military-type loads for which the rifles were designed. 150-165 gr. bullets at normal velocities. Had a couple jams with 180 gr. spitzers in factory winchester ammo.

Save the seals-club a liberal instead.

dallas.com

Hunter, that is very good advice.
I just came back from the range and I'm very please with the results.
the core lock with a cannelure was pusshed at 2500 fps by varget 44.5 grains using a large rifle federal primer. it group sub moa at 100 yards.
very please!