barrel length and burn rate

[gator378]

Normally the slower powders that give you the highest velocity in a longer barrel will give the highest velocity in a short barrel. The only difference is the short barrels will have more muzzle blast.

Look in the Lyman reloading manual at rifle loads and then look at the same loads for the Contender pistol. You will see what powders provide the highest velocities. I have a 16 inch barrel on my Winchester 94 Trapper model and a 20 inch barrel on my .308 Savage. And the slower powders still give you the highest velocity.

That being said you can download any cartridge using a faster burning powder to practice with. "BUT" you will reach max pressure at lower velocities than with slower powders.

I am one of those people who believe a barrel can never be too long but they can be too short. I like long and heavy barrels and have the slings to carry them. After spending a decade or so diving with twin 72 scuba tanks, everything seems light.

 

[gator378]

cape cove you are right-- I forgot to mention this the heaver the bullet the slowers powders do work better.. the 25/06 is a great example you know it is a magnum.. In the old days we took the case dipped it into 4831 knifed off the top and put a 100 gr. bullet and she would kill the whitetails as far as you could see. and I am sure that 7828- h-1000 - and reloader25 will do better with the heaver bullet. . so you have two varibles bbl length and bullet weight.. I am close to Cranbrook BC.

Daughter lives in Vancouver BC, I like BC

 

[jellyjam]

I should say I don't know which powder Remington loaded in that ammo, but we have found slower burning powders in larger cases to be the best. with long barrels. in my .270 with a 28" barrel I shoot 60 gr of mag pro with a 150 gr. accubond long range at 3104 fps.

 

[montana west]

Jelly jam in your 7mm you should get an increase of 50 FPS per inch" and you did .. and the Montana man sure can build good Barrels

 

[jellyjam]

I am one of those people who believe a barrel can never be too long but they can be too short. I like long and heavy barrels and have the slings to carry them. After spending a decade or so diving with twin 72 scuba tanks, everything seems light.

I would agree 100%

 

[jellyjam]

Jelly jam in your 7mm you should get an increase of 50 FPS per inch" and you did .. and the Montana man sure can build good Barrels

only problem with 7mm ultra mag is by the time you get a load worked up your barrel is shot out

 

[DJ Fergus]

Sorry I wasn't as clear as I should have been. A shorter barrel is better with faster powder and a longer barrel is better with a slower powder. I also picked up that the smaller caliber in the same barrel (30-06 vs 6.5-06) is the smaller bore builds pressure faster because it is more restricted so it would run a slower burn rate than the larger diameter bore. All other things being equal.

I'm trying to determine what length barrel to order and what powder. Most load data is for 24 and 26 inch barrels. If I better understand the correlation or a formula, I can save time and money. If I go from a 24" load data to a rig with a 30" barrel for example.

Sorry if I missed it but what cartridge did you have in mind?

 

[jellyjam]

that particular rifle just got converted to a 7mm wsm with a 29" bartlein in 7.5 twist so I could shoot the 197 gr. sierra matchking. load development is still occurring but i'am right at 3000 fps

 

[jellyjam]

it was fun while it lasted maybe 500 rds would never shoot berger 180s they would keyhole flying all over the place.

 

[DJ Fergus]

My personal preference on bolt action barrel length is sort of an all or nothing mentality. I want at least 26" I have one 28". If I want compact then I want 22" & no less than 20. I have one 24" barreled rifle and I always wished it was a 26" I've got two 22" rigs and the are handy knock around rifles. I guess I see 24" as a compromise, this is just my preference, different strokes for different folks.

 

[jellyjam]

My personal preference on bolt action barrel length is sort of an all or nothing mentality. I want at least 26" I have one 28". If I want compact then I want 22" & no less than 20. I have one 24" barreled rifle and I always wished it was a 26" I've got two 22" rigs and the are handy knock around rifles. I guess I see 24" as a compromise, this is just my preference, different strokes for different folks.

a pack around barrel for me is 28" 26" minimum long range guns are all 30" as you are generally spotting from truck or atv then get set up for shot. only problem in Idaho is making 16lb limit

 

[Calvin45]

Normally the slower powders that give you the highest velocity in a longer barrel will give the highest velocity in a short barrel. The only difference is the short barrels will have more muzzle blast.

Look in the Lyman reloading manual at rifle loads and then look at the same loads for the Contender pistol. You will see what powders provide the highest velocities. I have a 16 inch barrel on my Winchester 94 Trapper model and a 20 inch barrel on my .308 Savage. And the slower powders still give you the highest velocity.

That being said you can download any cartridge using a faster burning powder to practice with. "BUT" you will reach max pressure at lower velocities than with slower powders.

Very true, has been my experience too. In rifles anyway, no experience with pistols, whatever powder gives the highest performance does so regardless of barrel length, the advantage of faster than normal powder having to do with muzzle blast on shorter barrels. My 270 has a 22 inch barrel and does it's best work with full or even compressed loads of Rl22, 7828, 7977, rl 25 even. Haven't been as impressed with the usually recommended 4064, 4350, 4831 powders but I do sure notice how much brighter the flash and louder the ka-BOOM! is with my 7828 loads compared to 4350. I like that though, if one doesn't enjoy a fireball and a big kaboom it seems odd to be centerfire rifle enthusiast.

 

[TheDeicide]

6.5-06 maybe AI but haven't decided but it's load data I found is a 24" and I want 28-30"
30-06 AI at some point perhaps, but who knows.
338-06 My data is 23.5 and 24" but I might do 26 on this one so it's not a huge deal.

I'm researching now so I better understand.

 

[DJ Fergus]

6.5-06 maybe AI but haven't decided but it's load data I found is a 24" and I want 28-30"
30-06 AI at some point perhaps, but who knows.
338-06 My data is 23.5 and 24" but I might do 26 on this one so it's not a huge deal.

I'm researching now so I better understand.

RL26 would be the first powder I would try in a 24" 6.5-06 with 140& up bullets. Im not experienced with the 30-06. I do have a good friend who pushes a Berger 200gr out of a 30" 308 win. FTR rifle at about 2800 with h4350.