Question about shotgun barrel length???

[NYH1]

It's always been my understanding that with rifles (and even pistols) barrel length doesn't have a lot to do with how accurate a gun is. Example my Remington 7600 carbine (30-06) with an 18 inch barrel would shoot the same size groups as my friends 7600 rifle (30-06) with the 22 inch barrel. Both were zeroed at 100 yards with 150 gr Core-Lokt ammo. Even at 200 yards they shot the same size groups. The difference being his rifle was 3 inches or so low at 200 yards where mine was about 4 to 4 1/2 inches low at 200 yards. His rifle's trajectory was better but the accuracy was the same. My other friend has model 7 and model 700 308 Win. His model 7 actually shoot better groups then his model 700.

So me and another friend were talking about shotgun hunting. Our hunting camp is in the "shotgun only" part of the state. I'm going to get a 21 inch fully rifled barrel with the cantilever scope mount for my 11-87 20 ga. He said I should get a 24 inch barrel instead of the 21 inch barrel. I told him I can't because Remington is the only one that makes a rifled slug barrel for the 11-87 20 ga. and they only make it in 21 inches. He said my gun isn't going to be as accurate as a gun with a 24 inch barrel. I told him that I had a 21 inch rifled barrel on my 870 and I sold it and went with a 23 inch fully rifled barrel and my groups were the same. I personally didn't gain anything but an extra two inches in overall length by going to the longer barrel. He told me my 23 inch barrel should have been more accurate.

I'm just looking for a little clarification on this. Am I right in my thinking about the rifle barrel length? Do these newer shotguns need the added barrel length with the new sabot slugs out there today? Thanks!

[Phoneman]

With rifles a shorter barrel is supposed to be more accurate because there is less vibration in the barrel. But you do loose some speed with a shorter barrel. I have a 24" rifled barrel on my 870 and at 50 yards I can put 3 shots touching everytime useing brenicky KO's or Hornady sst. A friend has the same setup as me but with a 20" barrel. His shoots just as well except he has a little more drop at 100 yards than mine. I don't think on a slug gun a couple of inches is going to make enough of a difference to matter. I have seen a few barrels that wouldn't group for anything though. But I've always been able to send them back for replacement. I wouldn't worry about the 21" barrel. It should do just fine.

[NYH1]

Phoneman, Thanks! 

[PHATINJUN]

Ok I kind of understand what you are saying about bbl lenght but why then is the T/C Encore  PH barrel 28" ? Anybody got any input on this new encore barrel?

[SDS-GEN]

If its a longer barrel all it can do is keep the projectile in the barrel longer.  This allows the gas, from still burning gun powder, to push the projectile longer, resulting in higher velocity.  The new slugs on the market may have enough podwer that in a shorter barrel it is still burning after the projectile leaves the barrel(huge muzzle flash)and is wasting energy.  I don't know if this is the real reason, its just speculation.

[Busta]

The new High Performance (+ 1800 fps) saboted slugs are chronographed out of a 30" tube by the manufacturers of the slugs to get the maximum velocity. Too long of a tube will actually start to drag on the bullet once the powder is burned, too short of a tube will result in slower speeds than indicated by the manufacturer due to the bullet leaving the bore before all powder is burnt as stated above by SDS-GEN.

A 30" tube may be the best length for velocity, but might not be the most practical in the field. In a tip-up shotgun, you can have a longer barrel without adding as much overall length, as is the case of the Encore. With the Encore, a 28" barreled gun can still be shorter than a 23" or 24" barreled auto-loader or pump gun, due to the length of the receiver.

[IOWA DON]

I have several Thompson Center TCR-87's.  I use one with a custom 20-gauge fully rifled barrel which is 23 inches long. I had another barrel built for my son to use. He wanted one minimum legal length so I had it made 18-1/4 inches long. With Winchester sabot slugs his is slightly more accurate than mine. I doubt if there is much difference in velocity as the ratio between powder and barrel volumn is very high. The disadvantage of the short barrel is that it produces more of a blast and the gun rocks back a lot more during recoil. - DON

[jy951]

i may be way wrong on this, but i thought i read several places max velocity is reached with a short 18" or so barrel.   the longer barrels are actually slowing the slug down.

[kyelkhunter3006]

Generally, longer barrels lead to higher velocity, but every round has a point of optimum length.  For example, in the .22lr, the highest velocities are usually recorded in barrels of 18-20".  That's because the pressure curve of that round tops out as the slug reaches that distance from the chamber.  Longer barrels on .22's usually have lower velocity, because the pressure is dropping before the slug leaves the barrel, leading to the "drag" you are talking about.   With high velocity centerfire rounds, there is almost no length that is too long, because of the pressures you're dealing with.  The longer the gas pushes on the bullet before release, the faster it goes. I know that if someone did a controlled test, they could determine which length is best for a cartridge velocity wise, but it really isn't worth the trouble.

As for the Encore, I think the barrel is 28" because all of the other barrels are too, and that's one of the big selling points of the Pro-Hunter.     It will lead to less muzzle flash and less jump than a shorter barrel.  I can almost promise a shorter barrel would be more accurate. 

I had a Remington 7400 with a 22" barrel, and I had it chopped to 20".  Groups shrunk by about 1/2" inch.  Was is the shorter barrel, or was it a problem with the lands in the last 2"?  The barrel looked like it had a bad spot about an inch from the muzzle, one of the reasons I had it shortened.  Who knows, but I won't complain either way.   

Most benchrest guns have short barrels, and those guys know what works, that's for sure.  If a short barrel wasn't more conducive to accuracy, you can bet that they'd all have long tubes on the guns.  The Remington 700 LTR is considered by many to be the most accurate out of the box factory gun you can get, and it's got a 20" barrel.  Other than the one I had (the barrel was a real dog, how did it pass QC?) most of these that I've seen shoot less than .5 MOA with factory ammo, usually several different kinds.

As thin as the barrel walls on shotgun barrels are (exception for the Encore), I don't see how it's possible that a long barrel will be more accurate, the short barrel should be much stiffer.

[jy951]

i'm convinced that 18-22" is best for a slug gun in terms of accuracy and velocity.  here is one link, i know i've read it several other times: http://www.whitetailfanatic.com/html/rc_go_slug.shtml  also, fyi on high powered rifles, the best length seems to fall around 24"-26" if you go alot longer, you definitely begin to lose velocity.

[NYH1]

jy951, thanks for the link. The best part about it was the bottom paragraph (which I cut and pasted below). I just bought the same shotgun, I'm using the same scope and I'm hoping the Remington Premier Core-Lokt Ultra Bonded Sabot Slugs shoot good in my gun. I really want to use them. I'm going to try as many different slugs as I can though. I also want to have the trigger worked on as well. Thanks again! 

My personal slug gun is a 12 gauge, Remington 11-87 SP, with a Monte Carlo composite stock, cantilever scope mount fully rifled barrel toped with a 2x7 Leupold VX II Scope. The trigger has been worked to remove the creep and is set at 4 lbs. I shoot Remington Premier Core-Lokt Ultra Bonded Sabot Slugs. The projectile is a .385 grain bonded bullet. At 100 yards the bullet is traveling at an amazing 1648 fps and has 2325 ft-lbs of energy. The gun is zeroed at 150 yards. (TF)

[jy951]

i've done a little more research on this.  in Dave Henderson's book "Shotgunning for Deer," he states that the powder burns in the first 16-17" and there is a slight increase in velocity up to 25" but anything beyond that will slow the slug down.  imho T/C prohunter barrels being 28" are purely for marketing purposes.  everthing i've read on shotguns states a shorter barrel is better.  also, i've read tests showing certain certain calibers, especially .223 perform better from shorter barrels.  a 28" barrel might give you slightly better velocity from magnum cartridges, but that's about it.  i'd like to get an ultra slug hunter and hack the barrel down to 18".  I think that would save some weight and be pretty compact.

also, the book stated, 1:28 twist barrels seem to handle high velocity slugs better than 1:36 twist.

[NYH1]

also, the book stated, 1:28 twist barrels seem to handle high velocity slugs better than 1:36 twist.

Mine has the 1:36 twist.