Powder compression?

[kenneth carlson]

So min charge is 34.1 gr. And Max charge is 39.0 gr of imr 3031. I am compressing the powder at just 36.3 gr. Just curious as to if this will spike the pressure to much or not. I am currently wanting to do a test batch at 36.5 as I have done a few different loads starting at minimum charge and working up to where I am now. There is only one other powder listed for this load and I am fresh out of 4198.


I am loading 550 gr fp in 45-70 new starline brass for my marlin guide gun.

 

[Spawn-Inc]

only if it breaks the sticks of powder will it change the burn rate which will change the pressure. that being said i don't know how you know if you've broken the sticks of powder.

 

[Eagleye]

Sheesh! You would have to break a lot of powder into smaller pieces to make any appreciable difference in the burn rate.

IMR 3031 is not sensitive to being compressed somewhat. Go ahead and use those loads without fear.

Regards, Dave

 

[kenneth carlson]

Awesome. Thanks guys. That's what I was thinking. But just wanted to confirm it. That being said Tommorow after work is gonna be a fun day.

 

[Ganderite]

Other things being equal, compression slows the powder burn a bit. Work up to what ever pressure level you want.

 

[Bassmaster]

Awesome. Thanks guys. That's what I was thinking. But just wanted to confirm it. That being said Tommorow after work is gonna be a fun day.

I'm thinking those are gonna beat you up pretty good...please let us know how much 'fun' you really had

 

[Andy]

Shouldn't be an issue in the 45-70 with that heavy bullet, but compressed loads can sometimes cause the bullet to be pushed out some from its as loaded OAL. A crimp can prevent that.

 

[Seagull]

1 1/14 oz chunk of lead, impressive. Your poor shoulder thou. Let us know how they shoot

 

[LouF]

I called Sierra bullets years ago on this very issue http://www.sierrabullets.com/ and they told me a slight compression is allright with a good crimp.

 

[Chinbullco]

K C
If your barrel is 1:20 twist the 550 FN might not stabilize. I've never seen compressed loads "jack" bullets up from set seating depth. Joked about it a few times.

 

[sharp shooter]

Those look mean. I know with my bottle neck cartridge reloading, the slower i pour the powder into the case, the more i can fit. I don't know if thats the same for straight walled cases.

 

[Ganderite]

Are you familiar with a drop tube? use a McDonalds milkshake straw between your funnel and the case. The powder will settle deeper.

 

[sunray]

Isn't unusual for compressing to start long before the max load is reached. Compressed loads are nothing to worry about anyway.
Guy on Reloader's nest worked up an IMR3031 load with a 510. Says the recoil is brutal out of a Handi-rifle. And that it would not cycle through a lever due to the OAL. Screams double rifle to me.
Breaking the granules does nothing to the burn rate.

 

[jethunter]

Mostly extruded rifle powders aren't overly sensitive to compression.

Some powders are quite sensitive, for instance Trailboss and Unique produce abrupt increases in peak presssure when they start to compress.