Have experience reloading in bolt action rifles and several handguns. Anything special about the ar's---crimps,lands,dies,sizing,powders,bullets----anything to make it run smooth. Both 308 and 243 target rifles. Is there a die made that will FL size ALL the way to the base? Faster powders? Better luck with ballistic tips or spitzers? Thanks

Forgot to mention both are 20" heavy tube.

try an rcbs small base sizing die. They size cases to 'minimum specs" and do seem to run to the base.

I load Hornady AMAX in my AR10 in 308(which is back home because of Kommifornia). The best load in mine is the Hornady 155 gr AMAX with 42 gr of Reloader 12(now discontinued but I have a 4 lb. jug) and it shoots an inch or less @ 100 yds.
Sometimes the Spitzer's seemed to get a little beat up going into the chamber. Guess I'll have to look for another load when the RL 12 is gone but that should be a looonnnggg time.

Steve E........

I load for the M1a, AR15 and M1 Garand. All semiautomatic gas guns. Reloading is different for gas guns than bolt guns.

As you surmised, use faster powders in gas guns. In 308 use powders that are close to IMR 4895. That includes H4895, AA2495 and AA2520. About the slowest I recommend is IMR 4064. My lot of Varget is too slow for my M1a’s, so I don’t recommend that powder. I have fired a couple of pounds of IMR 3031, it worked well and functioned the rifle. That may be the fastest powder you should use.

I have no opinion on which powders to use in a .243.

If you do not have a cartridge headspace gage in 308 and .243, get them. This is an important and critical gage to have for a gas gun. An excellent site which explains their use is http://www.realguns.com/Commentary/comar46.htm

I do recommend the use of small base dies, but regardless of die type, size your case to gage minimum. At the very least, set your shoulder back .003†less than the chamber headspace. Sizing to gage minimum is simple to do and simple to gage.

I recommend reaming pockets to depth. Even if you do this always inspect each and every primer to ensure that it is below the case head.

I recommend the least sensitive primers you can get. Your AR10 should have a spring loaded firing pin, but slamfires have been reported with FAL’s and LC ammo, so even spring loaded firing pins have a small probability of a slamfire. The only company advertising that they are making a “Harder†mil spec primer is CCI. It is their #34 primer. Avoid Federal primers. Lots of slamfires have occurred with Garands and M1a’s with Federals, Federal is proud to tell you that their primers are the most sensitive on the market. Federals are excellent bolt gun primers, but more sensitive is not something you want in a gas gun.

Seat your bullets to a little less than magazine depth. Good 30 caliber bullets are not jump sensitive. The Sierra matchkings can skip a country mile and still land in the X ring.

The typical 308 gas gun will shoot 125's through 175 grain bullets very well. Bullets heavier than 175 cause high gas port pressures and accelerate the action too much. Use whatever bullet works best for your rifle. You will have to determine the size, brand, type.

Bullet crimping is absolutely un necessary, and the Lee Crimp die will damage your bullets. these are 6.5 mm SMK bullets damaged by the Lee Crimp die. The only way you find they are damaged is by pulling the bullets

I was planning on starting with IMR4320 using the Hornady 95gr SST which has a cannalure for a slight crimp. Guess I'll try the standard FL sizing die getting the small base die to save on brass stress. Do you think the 85-100gr sp's would be more reliable than the SST?