Velocity Difference between 20" and 26" Tube??

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hbar2

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What can I reasonably expect to suffer in velocity loss between a 700P with a 26" tube and a LTR with a 20" tube? In .308, and Im not interested in hypothetical situations when it comes to performance. Is there a table or chart one can go by somewhere, or is there an accepted standard of xfps loss per inch of barrell?? Thanks
 
Velocity differences can be expected from barrel to barrel, but maynard's numbers are what you could expect. Longer barrels are about the easiest way to boost velocity. One of my TRs with a 30+" barrel has sent 155 Amax bullets through the screens at 3050 fps, with a standard load. 154 Scenars run about 2950. 155 Sierras through the 27" Rock barrel on my precision rifle run 2850.
 
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If you read Precision Shooting, there is an article in the current issue about a new sniper rifle being supplied in limited numbers by Iron Brigade Armory. It has an 18 3/4" barrel - to permit use of a suppressor without the rifle becoming ungainly - and it has been successful past 800y. The barrel has a 1:10 twist, faster than on most .308s, and apparently this allows use of the shorter barrel without sacrificing long range performance.
 
Thanks, I was thinking that 40fps was the number, but its been a long time since i really checked into it. I know the Savages shoot very well too, but it goes back to the old moped analogy..............:ninja:
 
hbar2 said:
Thanks, I was thinking that 40fps was the number, but its been a long time since i really checked into it. I know the Savages shoot very well too, but it goes back to the old moped analogy..............:ninja:
Click to expand...

As in: "Mopeds are like ugly girls, they're really fun to ride but you don't want your friends to see you on one."?
 
I have shot the same handloads through my 20" Barrelled M70 Compact and my 26" M70 Stealth. The average velocity was 2628 fps and 2694 fps respectivley for a difference of 66 fps or 11 fps per inch. Definately not enough to worry about.
 
Zulumike.....66fps difference in 6 inches? Obviously chronographed, thats interesting. I may try the same .223 loads in my CZ527 varmint, and buddies Handi rifle, see what I come up with, thanks! Never would have thought it could be such a slight difference.
 
tiriaq said:
If you read Precision Shooting, there is an article in the current issue about a new sniper rifle being supplied in limited numbers by Iron Brigade Armory. It has an 18 3/4" barrel - to permit use of a suppressor without the rifle becoming ungainly - and it has been successful past 800y. The barrel has a 1:10 twist, faster than on most .308s, and apparently this allows use of the shorter barrel without sacrificing long range performance.
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Tac Ops has been building custom rifles with 18" barrels for years. Their Tango 51 is an outstanding rifle.
 
40 fps per inch is the highest I've ever seen suggested. Most estimates state 20-35 fps depending on the cartridge size and which inches are cut, e.g. six inches cut from 30" to 24" would not decrease the same as six inches from 24" to 18".
 
Not to hijack this thread but, just asking this to all you long range shooters regarding barrel length and load.
Does anyone here find that the ball powders such as WW748 or BLC-2, do these "hotter" powders as opposed to the IMRs (4064, 3031) get any significant velocity advantage in the longer barreled rifles? (24-26 inch pipe)

Cheers
 
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