300-MP for 357 140 Gr. Zinger (MBC)?

[kcofohio]

Over the course of time, I have takin' a liking to the 140 gr. in 357. With 2400 (the only magnum powder I have used) being in short supply. I have begun picking up a pound here and there of 300MP.

My only data source is from Alliant. They don't list the powder for 140 gr. And the 125 & 158 gr. data is two different bullet types.

In 300-MP:
125 gr. GDHP max is 22.3c @ 1450 fps.
158 gr. UCSP max is 18.6 @ 1690 fps.

So my thinking is setting the max for the 140 gr. LCN load at the max of 19 gr. And for 140 gr. XTP at 20 gr.

The crimp groove for the lead (Hi-Tek II coated) sets the COAL at about 1.590".

I'm starting at 17 gr.

My only barrels are 2 1/4 & 4".

Does anybody see any problem with my thinking?

Thanks!

Kevin

 

[RealGun]

Over the course of time, I have takin' a liking to the 140 gr. in 357. With 2400 (the only magnum powder I have used) being in short supply. I have begun picking up a pound here and there of 300MP.

My only data source is from Alliant. They don't list the powder for 140 gr. And the 125 & 158 gr. data is two different bullet types.

In 300-MP:
125 gr. GDHP max is 22.3c @ 1450 fps.
158 gr. UCSP max is 18.6 @ 1690 fps.

So my thinking is setting the max for the 140 gr. LCN load at the max of 19 gr. And for 140 gr. XTP at 20 gr.

The crimp groove for the lead (Hi-Tek II coated) sets the COAL at about 1.590".

I'm starting at 17 gr.

My only barrels are 2 1/4 & 4".

Does anybody see any problem with my thinking?

Thanks!

Kevin

I would cut them both back 1 full grain.

 

[kcofohio]

I would cut them both back 1 full grain.

Okay, I'll start at 16 gr. and work up to 18 gr. Thank you!

 

[ArchAngelCD]

Okay, I'll start at 16 gr. and work up to 18 gr. Thank you!

I would not try to guess the powder charge for a 140gr bullet using 125gr and 158gr data.

This is an easy one, write Alliant and ask them. Much of the time they have the data you need.

 

[Rule3]

OK lets take this in steps.

One can actually used jacketed bullet data for HARD CAST bullets.

If one does not have data for a lighter bullet they can use the next higher bullet weight so for 140 you can use 158.

BUT you are not using the same type of bullet so it's a little trickier.

Alliant list only the MAX load of 18.6 for the 158gr ( assume that is a jacket bullet) so you would start with .90 of that.which is 16.4.

But since you are using lead you can even reduce it a but more and I would drop it another 10% which would be 15.1

So as mentioned above 15 to 16.00 would be good.

You can use this in other calibers and bullet weights you use to figure out a load.

Especially with slow powders like 2400 there is less chance if any of blowing up things. It is the super fast ones that can cause you a problem.

Forget the data for the lighter bullet as it serves no purpose,

 

[RealGun]

OK lets take this in steps.

One can actually used jacketed bullet data for HARD CAST bullets.

If one does not have data for a lighter bullet they can use the next higher bullet weight so for 140 you can use 158.

BUT you are not using the same type of bullet so it's a little trickier.

Alliant list only the MAX load of 18.6 for the 158gr ( assume that is a jacket bullet) so you would start with .90 of that.which is 16.4.

But since you are using lead you can even reduce it a but more and I would drop it another 10% which would be 15.1

So as mentioned above 15 to 16.00 would be good.

You can use this in other calibers and bullet weights you use to figure out a load.

Especially with slow powders like 2400 there is less chance if any of blowing up things. It is the super fast ones that can cause you a problem.

Forget the data for the lighter bullet as it serves no purpose,

I stuck a bullet in 44 Mag with getting too low in my extrapolation with 300-MP. It is not just another powder.

 

[kcofohio]

Thanks all for the advice.

Arch, I attempted to take your advice about contacting Alliant, but my phone's keyboard app kept freezing up. (My phone doesn't seem to like those contact forms). Got busy and didn't get the chance to get on the computer. Maybe today.

I started the loads at 16 gr. This powder looks to be more potent than 2400. I hope to have the chance in the next few weeks to test them.

Again, thank you all for the input.

 

[kcofohio]

I stuck a bullet in 44 Mag with getting too low in my extrapolation with 300-MP. It is not just another powder.

Realgun, did all the powder burn, do you remember?

 

[RealGun]

Realgun, did all the powder burn, do you remember?

It was not a squib but rather a low charge. 300-MP burns very dirty but I don't recall any evidence of unburned powder. Just trust me, there is no good source for loads that pair lead bullets with 300-MP.

 

[kcofohio]

It was not a squib but rather a low charge. 300-MP burns very dirty but I don't recall any evidence of unburned powder. Just trust me, there is no good source for loads that pair lead bullets with 300-MP.

Okay, thanks! The 1st sign of "something not right", and I'll put the powder back for jacketed and give Blue Dot a whirl for the lead.