Will 4 inches on a barrel make much difference?

[In_Waters_Deep]

Hello,
this question is in reference to the rem 700 sps tactical 308. It has a 20 inch barrel, while other models have a 24 inch barrel. Will it affect power or accuracy at all? Thanks alot for the help.

[mauser06]

velocity will be somewhat lower (want to say 10-20fps per inch of barrel out to..24 or 26")

accuracy...less rifling..i guess it could, but i really dont know..

whats your intended purpose/shooting style??

when i was shopping for a long range rig, i found right away i liked a LONG heavy barrel..why? that extra weight helps stabilize and steady things...atleast for me it does. that 26" full heavy barrel is long and heavy...leaving the gun way front heavy(so bad i have to sling it upside down because it wont stay upright!) but when on the bipod or laying prone, im much more steady with it than any of my other rifles...

but i bought the rifle with 1 thing in mind...long range groundhogs from a sitting location not far from the truck...didnt buy it to walk..didnt buy it to stalk..didnt buy it to hunt the woods...i bought it for sitting ontop of the highest hill with the best view of the most groundhog holes and making it happen from that spot..usually sitting not far from the truck...i have carried it and done walking with it...its doable..but gets old..lol..made alot of standing, freehand shots with it too..

[bigbulls]

All other things being equal..... a shorter barrel is stiffer than a longer barrel of the same diameter. A stiffer barrel "vibrates" less and should be the more accurate barrel. The down side is that you do loose a little bit of velocity.

From my experience with that cartridge and those combos, on average you would lose 100-150fps. Some people say thats nothing, but basically, to me its alot.

[eldeguello]

ORIGINAL: In_Waters_Deep

Hello,
this question is in reference to the rem 700 sps tactical 308. It has a 20 inch barrel, while other models have a 24 inch barrel. Will it affect power or accuracy at all? Thanks alot for the help.

As a rule of thumb, we say that a standard round such as the .308 would lose about 25 feet per second for each inch cut off a barrel like yours. So you'd lose 100 FPS from the MV of a 24" barrel vs a 20" one. However, this rule has some notable exceptions;some .308's starting with a 24" barrel might even give a higher MV with 4" less barrelthan at 24". EACH RIFLE IS AN INDIVIDAUAL.

Now, as to acuracy, the only barrel length requirement here is that the barrel has to be long enough to ensure the bullet receives the required spin. A 20" barrel will certainly do that. And, in many cases, a 20" tube, being stiffer than a regular size 24" barrel, it is often found that a 20" barrel will shoot more consistently than a 24" or a 26" barrel.

Summary: Cutting 4" off your .308 barrel will not significantly affect the MV, and it might even improve accuracy! Certainly it will NOT degrade it! Many benchrest rifles have quite short barrels.

[CZ2506]

ORIGINAL: eldeguello

As a rule of thumb, we say that a standard round such as the .308 would lose about 25 feet per second for each inch cut off a barrel like yours.

Would the loss of velocity be noticeably different for cartridges that work best with slower burning powders? for instance the 300 mags or 25-06 rem?

[Ideaman]

You know, this question brings up a point I have struggled with. I truely in my heart belive that a gun should fit the shooter first and foremost, but am torn with wanting every performance advantage I can get. I know that 200FPS in not really an issue for 99% of my practical shooting, but I sure hate knowing it is not available.

In my opinion a tactical rifle should be even more ergonomic for the shooter. We all think about the spectacular 400 yard shot that saves a life, but have you failed in your mission if you have to take a 400 yard shot? Would you want to have to shoot a guy from 400 yards that was holding your kid? Well what if the shorted gun would help you to crawl undetected to 200 yards then take shot? 400 yards at 2900 FPS or 200 yards at 2700FPS?

If the shorter gun really feels better at 20 buy it, 200 FPS means little if you miss.

But yes the 20 will probably on average be a little slower, with slightly less power/energy.

[eldeguello]

ORIGINAL: CZ2506

Would the loss of velocity be noticeably different for cartridges that work best with slower burning powders? for instance the 300 mags or 25-06 rem?

Well, the final MV of that type of cartridge might be less becausethose big charges require longer to accelerate their bullets. So you might lose more MV when you cut them off, say 35-50 FPS/inch of barrel cut off.

Butwhen speaking only of the type of powder which is best,the slower powders will still produce more MV. For example, IFyou get the maximum possible velocity from a given cartridge and rifle using a slow powder likeH4831 with a 26" barrel, if you cut that gun to 20", your NEW (lower)maximumpossible MV will still come from that same amount of that same powder.

Many people think that to get the highest velocity from a given cartridge with a shorter barrel, they should use a faster powder. The idea is that "more of the faster powder burns in the short barrel. Sounds logical. However, what actually happens when you fire the gun is that ALL of the powder, regardless of type, is completely burned up by the time the bullet has travelled 3" to 5" up the bore. In order to get a higher velocity from a faster powder, you would have to load it to HIGHER PRESSURES, and this is a very limited option-limited by the strength of the brass cartridge case and the structure of the gun!

The slower powder, on the other hand, has to be usedlarger amounts to produce the higher velocities,but it reaches a peak pressure within safety limits which LASTS LONGER, thus applying MORE PUSH to the bullet for a longer period of time until the bullet exits the muzzle. Faster powders, even if loaded to higher peak pressures, drop off in pressure much more dramatically, thus pushing the bullet for a much shorter period of time and consequently achieving a lower final velocity at the muzzle.