Same pressure; lower velocity, with a different powder

[chemo]

Hi y'all

I'm looking for a pistol powder that can generate equal or higher pressure as Unique but I'm aiming for lower velocities.

In theory, do I need a slower burning powder or a faster burning powder?
to be honest I'm a bit mixed up, I think I would need to use a faster powder?


thanks alot

 

[SandRoad]

Hi y'all

I'm looking for a pistol powder that can generate equal or higher pressure as Unique but I'm aiming for lower velocities.

In theory, do I need a slower burning powder or a faster burning powder?
to be honest I'm a bit mixed up, I think I would need to use a faster powder?

???

What are you trying to achieve? Just lower velocity?

 

[H4831]

If you want lower velocity, just use less Unique. Unique is an excellent pistol powder, well adapted for reduced velocities.
The theory you brought up is much more aplicable to rifles, than it is to pistols. In bottle neck rifle cases we'll say the maximum working pressure is 50,000. A slow burning powder that requires a full, or nearly full, case to develope that pressure with a suitable bullet, will be the best, most effecient powder.
A small amount of Unique could easily raise that same amount of pressure, but the velocity could be little more than half of what the slow powder developes.
This is beacuse of the length of duration of the pressure. Fast powder, short duration.
Slow powder, much longer duration.

 

[chemo]

???

What are you trying to achieve? Just lower velocity?

Lower velocity without changing the spring #, currently using a #9 recoil spring, anything lower and chambering isn't constant

If you want lower velocity, just use less Unique. Unique is an excellent pistol powder, well adapted for reduced velocities.
The theory you brought up is much more aplicable to rifles, than it is to pistols. In bottle neck rifle cases we'll say the maximum working pressure is 50,000. A slow burning powder that requires a full, or nearly full, case to develope that pressure with a suitable bullet, will be the best, most effecient powder.
A small amount of Unique could easily raise that same amount of pressure, but the velocity could be little more than half of what the slow powder developes.
This is beacuse of the length of duration of the pressure. Fast powder, short duration.
Slow powder, much longer duration.

Thank you H4831, as usual your insight is mighty
I'll see what I can do to download it, but I'm already in the lower spectrum of the load

 

[saskgunowner101]

Are you trying to keep the pressure up for a cleaner more consistent burn?? Maybe a faster powder such as Clays or Bullseye IIRC would be more in line for what you need, more pressure with lower velocity.

I do agree with H4831 on Unique though. Just like the Franks red hot (hot sauce) commercial.....I put that s**t on everything. Unique, a very versatile powder.

 

[SandRoad]

Lower velocity without changing the spring #, currently using a #9 recoil spring, anything lower and chambering isn't constant

Sorry, having higher pressure won't make any difference. Assuming your gun is recoil operated, then it depends on the total kinetic energy, not pressure.

Pressure will slightly change the recoil curve, but not the total kinetic energy required to operate the mechanism. If you want lighter loads to cycle your gun, then you need a lighter spring.


Using a fast powder wouldn't even make any difference in a gas operated gun, since with a fast powder in a small case 9mm, 40, or 45acp, peak pressure occurs by the time the bullet has moved about 1/4". Meaning it hasn't even cleared the case!!! After that point, the pressure keeps decreasing all the way to the muzzle.

 

[chemo]

gotcha SandRoad thanks.

I also remembered I didn't update my load after begining to roll crimp (it's a bottleneck pistol cartridge). Maybe that can allow me to downgrade a bit