barrel length and burn rate

TheDeicide

Well-Known Member
Joined
Dec 18, 2011
Messages
97
Location
Eastern Clearfield County PA
I have read a ton of posts and all I've learned is shorter = faster and longer = slower. Can anyone point me at some good articles or videos on the subject. I am tempted to buy QuickLoad but I don't really wanna spend $150 on it.


Edit: 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.
 
Last edited:

bigedp51

Well-Known Member
Joined
Dec 10, 2010
Messages
1,022
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.
 

entoptics

Well-Known Member
Joined
Jan 16, 2018
Messages
486
I can't supply any more definitive sources than "a ton of posts", but my understanding is that until you get to the extremes (e.g. pistol length rifles, or rifle length pistols), there's no significant difference in behavior.

As bigedp51 states, the burn rate that gives the fastest velocity in a particular cartridge will do so regardless of barrel length. For example, if H1000 is faster than H4350 in a 26" 243 Win for a particular bullet, it will also be faster in an 18" 243 Win.
 

Gord0

Well-Known Member
Joined
Jan 3, 2017
Messages
749
Location
Michigan
I can't supply any more definitive sources than "a ton of posts", but my understanding is that until you get to the extremes (e.g. pistol length rifles, or rifle length pistols), there's no significant difference in behavior.

As bigedp51 states, the burn rate that gives the fastest velocity in a particular cartridge will do so regardless of barrel length. For example, if H1000 is faster than H4350 in a 26" 243 Win for a particular bullet, it will also be faster in an 18" 243 Win.
And probably faster in a 10" 243 win. Maybe if you got down to something like a 3-4" faster might help...
 

djfergus

Well-Known Member
Joined
Dec 25, 2015
Messages
1,281
I have read a ton of posts and all I've learned is shorter = faster and longer = slower. Can anyone point me at some good articles or videos on the subject. I am tempted to buy QuickLoad but I don't really wanna spend $150 on it.
My personal findings May differ from other people's findings. What I have observed is sometimes slower burning powders in short barrels leaves alot more powder fouling in the barrel. I can't prove it but I have my suspicion that this speeds up carbon fouling. I have observed increased carbon build up on the muzzle face when running a muzzle brake and more build up in the muzzle brake itself vs running faster burning powders in short barrels. If you are shooting later in the evening, you will notice the muzzle flame upon firing will be more lenghty vs a faster burning powder in a shorter barrel. You get a more complete burn in a shorter barrel with faster burning powders vs something like retumbo or n570. All that being said, there are plenty of folks running slower burning powders in shorter barrels with success but bore size has influence on this also. Let the rifle tell you what it likes. But if you are trying a slow powder in a short barrel and find yourself having to clean it quite often to maintain accurracy, then you may consider stepping to a little faster burn rate.
 

entoptics

Well-Known Member
Joined
Jan 16, 2018
Messages
486
...If you are shooting later in the evening, you will notice the muzzle flame upon firing will be more lenghty vs a faster burning powder in a shorter barrel. You get a more complete burn in a shorter barrel with faster burning powders vs something like retumbo or n570...
I need to remake this video, now that I have an iPhone with 240 fps - 1080P capability, but I still get a kick out of it (pun intended).

I based my original comment, at least partially, on my experience with magnum handguns. I have loaded a huge variety of ammo for 357 mag, 44 mag, 454 Casull, and 475 Linebaugh in barrels ranging from 3" to 24". The slowest burning pistol powder out there (H110, Lil' Gun, 300-MP), ALWAYS proves the fastest for any barrel length.

As you go faster in burn rate and lower in case fill, speed decreases (and fireball size :oops:). Whether it's a 3" or 18", a max load of H110 is faster than a max load of 2400, which is faster than a max load of Blue Dot, which is faster than a max load of Unique.

This holds true for rifles in my experience also. Whatever powder has the heaviest max charge, while resulting in max SAAMI pressure, will be the fastest velocity for the caliber. Of course, if the burn rate is too slow, then you can fill the case to the brim, and never reach max SAAMI pressure.
 

RICHARD PERRETT

Well-Known Member
Joined
May 23, 2019
Messages
135
Location
texas
I have read a ton of posts and all I've learned is shorter = faster and longer = slower. Can anyone point me at some good articles or videos on the subject. I am tempted to buy QuickLoad but I don't really wanna spend $150 on it.
HELP ME OUT,shorter what equals faster what? Longer what equals slower what? Just not sure what your saying. thx
 

djfergus

Well-Known Member
Joined
Dec 25, 2015
Messages
1,281
I need to remake this video, now that I have an iPhone with 240 fps - 1080P capability, but I still get a kick out of it (pun intended).

I based my original comment, at least partially, on my experience with magnum handguns. I have loaded a huge variety of ammo for 357 mag, 44 mag, 454 Casull, and 475 Linebaugh in barrels ranging from 3" to 24". The slowest burning pistol powder out there (H110, Lil' Gun, 300-MP), ALWAYS proves the fastest for any barrel length.

As you go faster in burn rate and lower in case fill, speed decreases (and fireball size :oops:). Whether it's a 3" or 18", a max load of H110 is faster than a max load of 2400, which is faster than a max load of Blue Dot, which is faster than a max load of Unique.

This holds true for rifles in my experience also. Whatever powder has the heaviest max charge, while resulting in max SAAMI pressure, will be the fastest velocity for the caliber. Of course, if the burn rate is too slow, then you can fill the case to the brim, and never reach max SAAMI pressure.
I've had two rifles where I couldn't get enough powder into the case to reach max pressure. Barrels were shorter than I would have considered optimum for the cartridge. In both cases e.s. was highly irratic. At some point as I reached a threshold, velocity seemed to fall off a bit as I increased charge. If a fellow wants to try a slower burning powder in a short barrel, I see no harm in it and it might work out nicely. Tell tale signs will eventually show if indeed it's not going to work out in the long run. I just let the rifle tell me what it likes. I do know that with any type of combustion, the more complete the burn is, the less carbon is produced. All that being said, my personal powders are mostly slower burning. I start out slow and gradually go to faster one step at a time if needed: N570, retumbo, h1000, rl26 so on and so forth.
 

Buttermilk

Well-Known Member
Joined
Dec 19, 2005
Messages
615
Location
Good Ol' Oklahoma
I shoot a lot of short barrels. Typically, I’ve gotten my fastest velocities with some slower burning powders for the specific cartridges.

There are some exceptions but typically same powder that gets velocity in long barrels does the same for shorter barrels.

I’ve shot a lot of 14”, 15”, 16.5”, 17.5” barrels in specialty handguns over the past 27-28 years.
 

djfergus

Well-Known Member
Joined
Dec 25, 2015
Messages
1,281
I can push 80gr bullets out of my 24"bbl 25-06 faster with rl17 than I can with retumbo. With more barrel length, I do believe the retumbo would produce higher velocity with those same bullets.
 

RICHARD PERRETT

Well-Known Member
Joined
May 23, 2019
Messages
135
Location
texas
poke me with a stick if I'm off topic! Does not slower powders generate more velocity in longer powder column's (i.e. 30-06 step child cartridges vs. 308 or 6.5 creed based length cartridges) then faster burning powders? The longer powder column's require more time to burn to build up pressure. Inversely a shorter powder column (308 or creedmoore) needs a faster burning powder in a shorter case to build pressure. Does not the % fill of the case also influence the most desired burn rate? Please don't be to harsh on my ignorance.
 

djfergus

Well-Known Member
Joined
Dec 25, 2015
Messages
1,281
Another example I have is in a 22 creedmoor that I loaded for. H4350 would run just as fast as h1000. Now the question is, if the barrel was longer would the h1000 been faster? I think it's a possibility. Don't get me wrong, I love slow burning powders, but there are some situations where they work better than others. I'm not trying to prove anyone wrong one way or the other but just implying that every situation is different and never rule out anything without trying it first.
 

josip89

Well-Known Member
Joined
Apr 23, 2014
Messages
95
In my case ,some old 3006 that have 65cm (nearly 26") barrel and 200gr Gamekink have max velocity with n560 (cant remeber what velocity).
Then we chop barrel to 50cm or (little bit under 20") and still have more velocity than the faster powder.

What I dont know is what happen if we put 150gr or 130gr bullet on the same test with same powder.
 

Trending threads

Nightforce has great tracking capabilities, they are rugged, a bunch of elevation, holds zero forever, and reticles are designed for long range shooting. So if you are looking to shoot long distances constantly, then you need a scope that can take the abuse. -- gilmillan1


Culture Of Excellence At Nightforce Optics
By Len Backus

A high level of quality both in production and in service. Read More


Nightforce is such a solid combo of reticle, available elevation, glass that is good enough to shoot at the longest range you can dial. Nightforce has bullet proof construction that can handle the incidental horse rolling or some other rodeo action. -- bigngreen


Nightforce ATACR Scope Review
By Jeff Brozovich

The new NightForce ATACR is for sure a top choice for any long range shooter. Read More


The total package. Nightforce is the best I have used as far as turret feel and solid detents. I have never had one that didn't track right on and always return to zero. Nightforce NXS is the best value for everything I need. -- Broz


Nightforce Velocity 1000 Reticle Review
By Scott Shreve

I think Nightforce knocked it outta the park with this reticle! Read More

NightForce


Top