The answer that you're seeking probably doesn't exist. It probably doesn't exist because how much velocity you get isn't just influenced by barrel length alone. The bore diminsions, rifling style, chamber diminsions, leade or freebore, and the smoothness of the bore finish all influence velocity, too. None of these diminsions are exact, but are made within a range of tolerance. So, you can have two 20" 336's shooting the same load from the same lot and if you expect them to both chronograph the same, you could be very surprised when they don't if you didn't consider everything else that could influence velocity from one rifle to the next.

You can also have a "fast" short barrel come very close to duplicating the velocity achieved by a "slow" longer one.

There are just too many variables involved. Which is why you get "general rule" type answers to the question of how much velocity difference you can expect between a barrel of x length and one of y. And in general, a shorter tube gets less velocity with more muzzle blast than a longer one does, as you already know.

I've typically got higher velocity from my 336 from a given load than I've seen chronographing the same load out of Winchester M-94's. It's never been enough for an animal getting shot to fret over the difference. I have assumed that Marlins' use of the Microgrove reuslts in a more effecient gas seal, a smoother bore, and less friction due to shallower lands. Then again, the difference could be due to my rifle having a fairly tight or minimum diminsion chamber while the chambers on the Winchesters I've chronographed were far more generous (my fired cases fint in them but their didn't fit in mine). A smaller combustion chamber is like higehr compression in a car engine in the sense that you get more power from the resulting bang.

So, I think the answer that the original poster is looking for may not exist, but I'd like to see it if it does!

T-C

 

I don't know about the velocity but I've got a 336 LTS, 336 Marauder and a Winchester 94 trapper all in 30-30. All have the same barrel length and about the same weight. The LTS and the Marauder have no more muzzle blast or recoil than any other Marlin 336 in 20 or 24 inch barrels. The Winchester, however, kicks like a mule and is very unpleasent to shoot.

 

The answer that you're seeking probably doesn't exist. It probably doesn't exist because how much velocity you get isn't just influenced by barrel length alone. The bore diminsions, rifling style, chamber diminsions, leade or freebore, and the smoothness of the bore finish all influence velocity, too. None of these diminsions are exact, but are made within a range of tolerance. So, you can have two 20" 336's shooting the same load from the same lot and if you expect them to both chronograph the same, you could be very surprised when they don't if you didn't consider everything else that could influence velocity from one rifle to the next.

You can also have a "fast" short barrel come very close to duplicating the velocity achieved by a "slow" longer one.

There are just too many variables involved. Which is why you get "general rule" type answers to the question of how much velocity difference you can expect between a barrel of x length and one of y. And in general, a shorter tube gets less velocity with more muzzle blast than a longer one does, as you already know.

I've typically got higher velocity from my 336 from a given load than I've seen chronographing the same load out of Winchester M-94's. It's never been enough for an animal getting shot to fret over the difference. I have assumed that Marlins' use of the Microgrove reuslts in a more effecient gas seal, a smoother bore, and less friction due to shallower lands. Then again, the difference could be due to my rifle having a fairly tight or minimum diminsion chamber while the chambers on the Winchesters I've chronographed were far more generous (my fired cases fint in them but their didn't fit in mine). A smaller combustion chamber is like higehr compression in a car engine in the sense that you get more power from the resulting bang.

So, I think the answer that the original poster is looking for may not exist, but I'd like to see it if it does!

T-C

Well your Right! I have a Marlin, Win And a Rem 788 30/30. When I Run Factory ammo over my Chrony they are all Close the Marlin is on average 30fps faster than the 94 the 788 with it's 22' Barrel is 30 fps faster than the 30 Glenfeild Marlin. But it ends with Factory ammo! the 788 is King with reloads, but it aint sexy like my old Glenfeild. The 788 is a honest 1/2'' gun with a Serria 170gr it loves that slug.
Now going with my own tests and chrony results I would say a a 30/30 is best with a 20-22' barrel just my O.P I tried a 26'' Win and it was slower with factory ammo. But that is part of the fun mix burn rates of powder to your barrel. But really the 30/30 is good at burning up all the powder in 20 to 22'' of barrel at least that is what I have found.
But that dam .308Win give it 24'' of barrel will = a 06 with slugs up to 165gr ;D
That's just part of the fun of reloading.And a good amount of 748!

 

I don't like barrels shorter than 20" on any guns. Then seem really stubby and unbalanced to me. Get what you like, but if you are going with the shortest, make sure it's 16.25".

 

I have to agree with Halwg on the barrel length. I find 18 1/2" the best balanced for several reasons. The 16" feels pretty good but backheavy mostly because of the buttpad. I put a buttplate on my son's and it felt real good.

The velocity loss per inch is about 21fps for LeverSolution and 10fps for regular ammo.

 

On the average you gain about 30-45fps per inch of barrel to the optimum point.
Like the AR-15, the 30 WCF round was based on a 20 inch barrel.

 

My Glenfield 30A had a 20 inch barrel when I got it. Did some chronoing with
factory 170 gr. and my own 170 gr. reloads.

After shortening the barrel by 2 inches, I lost between 40 & 45 f.p.s with the same ammo as above. I don't believe that is enough to make much difference. Accuracy
remained about the same. Possibly a little better with the 18 inch barrel.

 

I think that 20' is about ideal for me.But Im tall,The 16 seems stubby and its harder for me to find the front sight quickly. Ive thought of the youth guns a time or two. But more for the short stock with heavy clothes,than the shorter barrel. Gunrunner,,

 

Thanks for all the good replies, folks.

 

Gabe, at normal rather short ranges the 30-30 was designed for the velocity differences won't make a hill of beans difference. Felt recoil would very slightly increase with shorter barrels as the total rifle weight goes down. Neither are probably at all noticeable. The biggest difference, in MHO, is that shorter barrels have less rear to front sight distances and we all know that a short sight radius dimension is more difficult to shoot very accurately than a longer sight radius. Radius is the correct term if you think about the rear sight being the center of the circle and the front sight as a point on the circumference. The longer the radius the less movement at the target a longer barrel and sight radius will have. That's one reason why peep sights are more accurate than barrel mounted open sights. Note the old 'Creedmore' competition photos from the late 1800's with LONG barrels and tang sights mounted far back. Shorter is lighter, maybe faster handling, but probably less well ballanced. Too long is total rifle and muzzle heavier but probably with more repeatable accuracy.