Short barrel powders

[larryh1108]

Many times logic and physics don't match up very well.

Talking in general terms for powder burn rates, it seems to make sense to use a fast powder for the short barrel (under 3" barrels) semis to get as much powder as possible burning in the shortest time.

Today there are a lot of snubbies and pocket pistols with short barrels. I know there are other things to consider due to pressure spikes, etc. However, is the theory that the shorter barrels need the fastest burning powders to do the best job or does physics say otherwise?

I like and use Bullseye for many reasons. Is this the best for the pocket pistols like the LCP, Solo, PM9 and snubbies?

 

[cfullgraf]

Generally, a powder that gives a higher velocity in a longer barrel will do the same in a shorter barrel.

 

[Blue68f100]

^^^^^ this and the bigger issue is loss of velocity required for expansion in SD.

Then every barrel and gun is unique. What works well in one does not necessary mean it will work in another.

BE is a dirty powder. I have been using WST it burns cleaner at the low end too. But not good for the upper end.

 

[rcmodel]

As stated above, whatever powder gives the highest velocity in a long barrel will also give the highest velocity in a short barrel.

And fast burning Bullseye ain't it!

For example, in a .38 Special snub-nose revolver using Speer 135 grain (Gold-Dots)
Relatively slow burning Power Pistol (medium burn rate powder) will give over 1,000 FPS at standard +P pressure.
Without pressure peaking and suddenly going off the charts.

Bullseye would have to try real hard to get 900 FPS before pressure spiked and bad things happened.

For your listed guns?
Unique would be a much better powder then Bullseye if you are looking for best velocity.

rc

 

[ArchAngelCD]

Nothing left to do here...

Don't forget the range report...

 

[zaphar]

Generally, a powder that gives a higher velocity in a longer barrel will do the same in a shorter barrel.

Why is that? I've had powders that would theoretically give the best velocity, but ended up plateauing due to barrel length. A slightly faster powder actually did better. BE is fast compared to Unique, but I can usually go faster than that with even slower powders like HS-6 and Longshot, but will be sending a lot of pressure/gas out of a short barrel after the initial pressure spike.

 

[Swampman]

Originally posted by:zaphar

Why is that? I've had powders that would theoretically give the best velocity, but ended up plateauing due to barrel length. A slightly faster powder actually did better.

That hasn't been my experience.
Would you mind posting actual data of work-ups where this occurred?

 

[PowerPistol]

As stated above, whatever powder gives the highest velocity in a long barrel will also give the highest velocity in a short barrel.

And fast burning Bullseye ain't it!

For example, in a .38 Special snub-nose revolver using Speer 135 grain (Gold-Dots)
Relatively slow burning Power Pistol (medium burn rate powder) will give over 1,000 FPS at standard +P pressure.
Without pressure peaking and suddenly going off the charts.

Bullseye would have to try real hard to get 900 FPS before pressure spiked and bad things happened.

For your listed guns?
Unique would be a much better powder then Bullseye if you are looking for best velocity.

rc

That simply is not always true. It depends on the powders. A max Power Pistol load will equal or surpass a Max H-110 load out of a 2' barrel. I have tested and proven this for myself.

 

[ArchAngelCD]

That simply is not always true. It depends on the powders. A max Power Pistol load will equal or surpass a Max H-110 load out of a 2' barrel. I have tested and proven this for myself.

I find that very hard to believe. Is it possible your tests were in error? I have tested HS-6, Longshot and H110 and the H110 loads always generate the highest velocities in both a 4" L frame and a 2" J frame.

 

[PowerPistol]

I find that very hard to believe. Is it possible your tests were in error? I have tested HS-6, Longshot and H110 and the H110 loads always generate the highest velocities in both a 4" L frame and a 2" J frame.

I have tested several times, results are always the same with h-110, not so much with 2400. Using 14.0 2400, compared to 8.0 PP, with a 158 JSP, the 2400 load did outperform the PP load, but it was by such a small margin, it would not be worth the extra powder / blast, and recoil. About 30 FPS as I remember

PP

 

[jmr40]

Generally, a powder that gives a higher velocity in a longer barrel will do the same in a shorter barrel.

With rifles this is absolutely true. All of the powder burns within the first few inches regardless of burn rate. A slow powder may need 4-6" where a fast powder will burn in 3-4". All the longer barrel does is give the pressure behind the bullet more time to work on it.

With pistols I'm not so sure.

 

[larryh1108]

...and that is why I mentioned logic vs physics.

It would seem that you want all of your powder to burn before the bullet leaves the barrel. Otherwise, why have that much powder if it gets pushed out, unburned? Since there is no barrel to allow the bullet to accelerate, the fastest powder would seem to be the most logical choice.

Now, remember, this is just logical thinking, not experience. This is what I am trying to learn from guys who know. This is not arguing, just asking. I want to learn so I can apply my craft as best as possible to my short barreled handguns.

 

[zaphar]

Originally posted by:zaphar

That hasn't been my experience.
Would you mind posting actual data of work-ups where this occurred?

I don't have the actual work up data anymore, but it was using Longshot and HS-6 with 100gr .355 projectile in a 38 Super with 4.5" barrel. The loadings seemed quite linear in velocity gain with .2gr increments. At one point the Longshot stopped gaining velocity, i.e. plateaued, HS-6 did not and could achieve higher velocities.

On the other hand, I have found Longshot to work very well with heavier 158gr bullets in the same gun:

I guess what I'm trying to point out is that from my experience certain powders are better suited for certain barrel lengths with certain cartridges when bullet weight is a consideration.

Another thing to look at would be the data here They list several different cartridges which probably don't use the same exact powder, and some of them do vary at the top and bottom of the chart.

 

[ArchAngelCD]

I have tested several times, results are always the same with h-110, not so much with 2400. Using 14.0 2400, compared to 8.0 PP, with a 158 JSP, the 2400 load did outperform the PP load, but it was by such a small margin, it would not be worth the extra powder / blast, and recoil. About 30 FPS as I remember

PP

Please give me more information, this sounds interesting...
Caliber?
Powder charges of each?
Bullet construction and weight?
Primers used in each?
Handguns tested?

Now you have got me wanting to test some stuff! LOL (I have PP, 2400 and H110 on hand)

 

[kcofohio]

My short time of experience has been this:

Shooting from an LCR-38, most of the loads were using Titegroup and Hp-38. After shooting, the barrel was usually fouled by either powder or lead. The bullets used were 125 gr. LRN and 158 gr. SWC. And accuracy was doable at best.
Then this week, using Ramshot Silhouette, at max load with 158 gr. SWC's, the barrel looked very clean. And hit the target very well. I will back if off .2 gr. and see if I get the same results.

I had the train of thought that the faster burning powders would give best results for short barrels. My thinking was that the butt of the bullet would seal quicker thus less chance of leading. But I have a lot to learn.

BTW, Silhouette is the same powder as what was once Winchester's WAP, according to a published magazine article I read a few months back.