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nekshot
04-14-2014, 10:12 AM
How much differance in performance is a 28 inch vs 20 inch shotgun tube with same choke? Got to thinking about this and wondered if it is a balance thing for follow thru or a real issue with the shot column and how much would a ball be affected in this sceneria? I understand the powder burn issue but I am thinking of the hit of the payload.

too many things
04-20-2014, 04:55 PM
well guessing you are doing a slug/ball. if the long barrel worked better why does all the slug barrels have a 20in length.

FullTang
04-20-2014, 10:47 PM
I'd always heard that barrel length didn't matter much in shotguns, that all the powder was burned up in the first 12" or so. Then I got a chronograph, and I was surprised that the longer barrel really does give significantly greater muzzle velocities. My 28" trap gun consistently gets about 100+ fps more than my 18.5 inch tactical gun, and the 24" slug gun is right in between, with the same loads. Haven't tried comparing patterns, since they are such different guns, but patterns vary a lot with velocity, too.

jmort
04-20-2014, 11:07 PM
10 fps per inch is essentally nothing. Thinking powder like Steel might bump that up some.

FullTang
04-21-2014, 01:32 AM
I think you're right---the slower burning powders will show an even greater difference. There is a reason for 30" barrels on goose guns!

Themoose
04-21-2014, 06:59 AM
What will you be shooting, slugs or shot? If you are interested in accuracy, the edge will probably go with the shorter barrels... they will be more rigid and flex less than a longer barrel.. remember that most shotgun loads are slower than centerfire rifle loads...Many top .22 rifles are now sporting shorter barrels touting accuracy...I don't think there is a direct link, but most .22 lr ammo is around 1200 fps where most factory loaded shotgun(using shot) shells are loaded... it may be folklore, but the claim was that over 1200fps with shot and the pellets became deformed and blew the patterns... of course, today there is a whole array of specialty loads, buffers, wads, that are built to improve shotshell performance. I think my slug barrels are 22" and 26" in length.

dverna
04-21-2014, 07:10 PM
The main reason for longer barrels is to increase the sighting distance to aid in better pointing. It is why trap guns have longer barrels. There is no effect on patterns and minimal impact on velocity unless you are using very slow powders.

Don Verna

nekshot
04-21-2014, 10:07 PM
thanks for your input, I thought it would not make much differance but I don't want to cut off and then regret it. As far as powder it is for black powder. I looked at the barrel closer and noticed it has screw in chokes, now I must wrap my mind around that! I can not in faith cut this barrel now. I will live with it as is.

sirsloop
04-21-2014, 11:07 PM
Black powder is going to benefit from the extra barrel length. Having shot plenty of BP out of a 18.5" barrel... I can tell ya there's still PLENTY burning... big ol fireball coming out the business end.

petroid
04-21-2014, 11:28 PM
I agree that BP will benefit from extra bbl length for velocity. Trap guns usually have long barrels to aid in tighter patterns and more weight to keep it swinging through the target. Turkey guns have long barrel for tighter patterns with a slight velocity gain. I would suspect goose guns are the same. Slug barrels would not show much benefit from a long barrel, maybe a little less recoil but slightly less accuracy I suppose. But I've been wrong before.

RMc
04-22-2014, 12:03 AM
An additional thought:

Longer barrels reduce muzzle pressure when firing heavy loads with slower burning powders. What's the big deal? Well, some plastic wads have a very weak gas seal section. Particularly those with air vents along the outside of the gas seal. I have fired loads that worked perfectly well from a 26" barrel and then string patterns randomly when fired in a 21" barrel. The gas seal would often flare out on one side, tipping the wad on bore exit due to higher muzzle pressure.

southpaw
04-25-2014, 11:30 PM
Barrel length has more to do with balance than patterning. Any velocity gained will be lost (or insignificant) by the time the shot reaches 30-40 yards. Not sure about bp but thats the way it is with smokeless. I am not that familur with bp to know how much velocity can be gained or lost with the shorter or longer barrel. But the faster the shot starts off the faster it slows down, to a point anyway.

Jerry Jr.