Barrel length and velocity question

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Greg Duerr, Jul 26, 2013.

  1. Greg Duerr

    Greg Duerr Well-Known Member

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    I hear a lot about barrel length and velocity. For every inch increase in barrel lenght their is approx 35 fps increase in velocity, is this true or does it vary from barrel to barrel or from cartridge to cartridge? I saw a report a few years ago in Guns and Ammo that took a Rem 6mm and a Rem 280 both with 24 in barrels and ran a velocity check at the 24inch lenght then cut off one inch recrowned and recheck the velocity.........it was surprising that the hightest velocity was with the shorter barrel lengths.................for me it was food for thought that often we are set in one way of thinking when in reality that might be wrong.

    Its a lot like the thoughts about premium bullets over standard. I alway compared bullets to the Nosler Partition. When at the Elk Foundation in Reno, Nevada I talked with some hunters from South Africa and asked what bullets they prefer hunting to come with all of them did not recomend the Partitions as they have seen to many failures with frontal core seperation. We all have our experiances but coming from hunters who guide and who see hundreds of kills that caught me off guard. I get set in my way of thinking and then all of a sudden somthing comes along and redirects it.

    Greg
     
  2. highridge1

    highridge1 Well-Known Member

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    Velocity and barrel length varies from gun to gun. Never really heard of higher velocity in a shorter barrel though. Usually it seems like about 15-35 fps per inch velocity gain with barrel length increase.It's just like how some guys believe a .338 300 gr SMK is just a target bullet and not good for hunting ,when in reality it flat hammers game with great performance.To many people seem to read something on the internet or outdoor life and just think that's the way it is and they don't have the hands on experience.It's all about what works for a guy and what his own results really are.
     

  3. Greg Duerr

    Greg Duerr Well-Known Member

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    In reality your right ..................my brother in law has killed a lot of Elk with a .270 and cant understand why anyone would need anything else. It works for him. He did change this year to a .280, for him that was going bigger. I hunted some years ago that hunted with a Remington MDL 1 I think, it was one of the first auto's with the fat barrel. He shot the 30 Remington and had all kinds of Deer and Bear to its credit. Even though there were better ones out there he never Changed. It worked for him.
    If we beleive in somthing its because it works for us...................
     
  4. ol mike

    ol mike Well-Known Member

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    I read an article on Remington's site about velocity and barrel length.

    In the nut shell extreme velocity rounds like a 220 swift 257 weatherby etc. will lose a lot more velocity if you go from a 26" barrel to a 20" barrel.
    The more "over bore" a cartridge is the more FPS you will lose w/a shorter barrel.
    You could build two rifles alike both set to use the 308win case design -chamber one up to 358win the other 22-243 [308win. case] .
    Put 26" barrels on both -start taking length off 1" at a time --the 22/308 would lose a lot more velocity than the 358win. would.
    Mike
     
  5. Mikecr

    Mikecr Well-Known Member

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    It depends on the cartridge, bore capacity AND the amount of what powder to burn.
    Following previous example a .358WSM would also lose higher rate in shortening of a barrel.

    Also, IMO, insufficient length for what you can burn is a bad effort.
    Did the magazine mention muzzle pressures or of slapping the back of boat tail bullets with excess pressures? You know, a great big ole fireball that knocks your hat back, ain't good for accuracy.
    Better to burn the powder INSIDE the barrel.
     
  6. Trickymissfit

    Trickymissfit Well-Known Member

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    like Mike said case volume verses barrel length is the key factor here. A 6mm Remington is probably about done in a 26" barrel, but with a powder burn rate adjustment, it will shoot similar velocities in a 24" barrel. An example here is with H414. I can see little difference between the two using something like an 80 grain bullet. Yet I think moving up to a 105 grain bullet will show some difference. With my 6/250 improved, I doubt there's much difference between a 24" barrel and a 26" or even a 28" barrel. I know for a fact that I lost about 75 fps going from a 26" barrel to a 20" barrel in a .223. I'd also say a 22-250 is similar in that we normally think of them with a 26" barrel shooting 50 thru 55 grain bullets, but probably very little difference with a 24" barrel. yet the same round in a fast twist barrel might show more gain using 75 grain bullets verses the samething in a 24" tube. When we start moving into the .277 and larger bullets the advantage of a longer barrel often comes to the front as they also often have much greater case volume. But if you took a .250 Savage case and necked it up to 7mm, and compared it to a .280; you'd find a need for the longer barrel length. The .250/7mm probably would do nicely with a 23" tube.
    gary
     
  7. Greg Duerr

    Greg Duerr Well-Known Member

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    The Article left a lot of variables out....................it was more general. Both Rifles were factory and the ammo was also factory.