Best MV from a gas gun?

Quicksilver

Sergeant
Full Member
Minuteman
Feb 3, 2013
156
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38
College Station, TX
Well, I finally bought a Beta Chrony and will be going out to the range this weekend and was wondering,
those of you with gas guns, how hot are you getting?

Im shooting a .308 out of a 20" barrel, using Winchester brass and 175 SMK's, normal sizing, flash holes deburred, generous bullet chamfer on the case mouth, BR CCI large rifle primers and 43.2g of H4895. No clue on how fast the bullet is moving, all I know is I can make 3/4" groups at 200 yards with that combo. bullet drop from 100 to 200 yards is 3.5 inches, which must be pretty decent since the normal shelf gold match federal has a 4.5 drop at the same range in my gun, but again until I shoot thru the chrony I have no idea how fast its moving.

The reason I bought a chrony is because I wanted to possibly develop hotter loads to "try" to keep the bullet flying further down range before going transonic. I know I can't match the performance of say, a 300 Win Mag in terms of MV, but I would like to go as far as I can before showing pressure signs. I also ordered an adjustable gas block in anticipation of all this. Right now, I would say the bullet probably goes transonic about 600 or 700 yards from some of the targets I've shot, but again, just a guess.
 
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I find my new DPMS LR308 likes to shoot the 168gr bullets at 2550 FPS give or take. When I get over 2600 FPS, my groups open up quickly... like, really quickly.

My former armalite AR-10T I could push another 50-100 FPS faster and maintain good groups, but I'm not sure why exactly. You will have to push yours to see what it will do, they are all slightly different.

Below is the pic from todays workup on my new LR308 @ 200 yards. If I did the math right its around .6moa center to center with the 2550 FPS group (41gr IMR 4064) and .75 moa at somewhere just under 2600 if I remember right (41.5gr). If you are shooting 10 shot groups half that size, WOW is all I can say. Got any targets you can post up?

http://img7.imageshack.us/img7/4061/20130527132320.jpg