What are the ballistics tables like for the combination you are shooting? If you're getting to 1,000 M with a 20" barrel, is the load still super-sonic? How far is "well beyond"? Are you running high pressure loads with tight match chambers?
In the context of the original post we're talking about factory 20" barrels here, not custom match aftermarket barrels. I certainly don't hear people recommending 700 LTR's for anything beyond 700-800. As I mentioned earlier, I would cut down a varmint barrel to 22" to retain a little extra velocity over a 20" without sacraficing handling.
Rick, here's a question for you. What velocity gains (if any) are you getting with a match grade barrel in .308 Win. over a conventional 700 factory barrel, assuming the lengths are the same.
I know it depends on the load combination you're shooting and a host of other variables to be taken into consideration. Generally speaking, what are we talking, 100 fps. increase?
TPS5071: Thanks for the link, I'll take a look at it.
All my rifles have minimum tolerance match chambers. The loads definately are on the edge, we all ran them hotter, but brass life suffered so we backed the loads down a couple of grains to where the accuracy was still excellent but casings were not taking a beating. Interestingly the velocity loss was marginal, as in about 25 fps.
Glock , Blackcloud and C4 are, last I heard all shooting 175 gr bullets. If I remember correctly , and I hope 1 of the guys chimes in, they are seeing 2700 plus fps. I am running 208 gr Amaxs out of mine and get 2640 fps
I need 33.5 moa to make 1000 yards, according to exbal the bullet is still travelling at 1353 fps.
The furthest I have taken my 308 out to is 1400 yards for which 63 moa is required elevation over 100 yard zero and the bullet is still going 1064 fps.
As for any velocity difference with a factory barrel, I honestly do not know, I have never run a factory barrel on a 308 personally. Maybe someone with a factory barrel can supply chrono info for us. I have found that the Rock and Krieger barrels do seem to give higher velocities than what seems to be normally expected. My 300 win mag with the new Rock barrel on it spits the 208s out at 2950, which I think for a 300 win is pretty fast given the bullet weight. I believe this may be due to them being slightly smaller internal dimensionally than what I see many factory barrels to be.
The other part of the question is how much my religious use of Gun Juice effects the velocity.
I have several clients who shoot LTRs with good success out at the 1000 yard mark, so I know it can be done. The biggest problem I see is that many guys get hooked on the 168 gr SMK which is a great bullet, but does not seem to work well beyond the 600 to 700 yard mark as reliably as the 175 gr SMK, Berger or 178 Amax does.
Years ago there was an article published "tales of a texas warehouse" or something like that,I think it was called and the guys wer experimenting in a near perfect environment. Someone posted it on CGN some time ago if I recall correctly. Certainly a worthwhile read if you can find it.
One of their findings was that 308 thrived on 21.75" long barrels, the author firmly held that that was the optimum barrel length for 308 win caliber, my findings though far less scientific seem to arrive at the same end result.
