Help with developing a 9x25 load

[Grey Morel]

I am trying to develop a 9x25 Dillon loading that uses a 71 grain bullet.

I only have access to ONE of the rare THV bullets that will be used in this load, so I need to develop a functional load before I test the bullet in question.

I don't care about accuracy or brass longevity at this point, I just need to develop a load that will propel the bullet safely, and at higher velocity than a 9x19.

* The 9x19 propels the 71 grain THV at 1,500 fps.

* The 9x25 propels a standard 90 grain ball at 2,100 fps.

The only bullet i could find for the .355" that approximates the weight of the THV is the 77 grain bullet offered by Magtech. My current plan of action is to develop a load using the 77gr Magtec bullet that replicates the 2,100fps found in the 90gr factory load, and then switch over to the THV bullet once I am satisfied with its consistency.

I need to know a lot of things before i begin loading:

1) I suspect that using a lighter bullet over a charge intended for a heavier bullet will increase the chamber pressures generated. Is this correct?

2) What powder would be well suited to this project?

3) I am assuming that the same 2,100 fps could be reached with a lighter bullet using a lower chamber pressure than the 90 grain load. is this correct?

Any and all help is greatly appreciated.

 

[rcmodel]

If I had a THV bullet, I certainly wouldn't waste it by shooting it.
I would love to have one in my cartridge collection.

They were outlawed for importation under the "Cop-Killer Bullet" ban years ago.

As to your questions>

1. Lighter bullet with same powder charge will give less pressure.

2. I would suspect best velocity would be obtained with that light a bullet using a fast to medium burn rate powder like WW231, AA #5, Blue Dot, or Auto-Comp.

3. Not with only one bullet to test.
I wouldn't even attempt it without having enough of the same bullets to work up a load over a chronograph.
You can't do that with one bullet.

rc

 

[bobotech]

Why were these outlawed?

 

[rcmodel]

Cop Killer handgun bullets.

Able to penetrate a Kevlar vest in one fell swoop.

http://en.wikipedia.org/wiki/Cop_killer_bullet

rc

 

[ReloaderFred]

I have all the original notes from Dillon when they were developing the loads for the 9x25 Dillon. The lightest they went in their testing was 115 grains, which was the bullet weight they settled on.

The 9x25 does best with slow burning powders in the 115 grain weight range, but you're in unknown territory with a bullet that light, so I can't help you there.

Ballistics and pressures are also different for solid copper bullets vs. lead core/copper jacket bullets. They don't compress like lead does, so the bullet weight to powder charge formula will be different.

It also may be a violation of Federal Law to load that bullet into a cartridge..........

Hope this helps.

Fred

 

[Grey Morel]

Thats a maximum load? Double tap sells 90 grain ammunition that is rated at 2,100 fps from a 6" barrel, with a 90 grain bullet.

This bullet is being launched at over 1,500fps by a 9x19 from a 4" barrel. 200 fps gain just seems very low for a dillon maximum load.

 

[Afy]

Using a 6 inch barrell and a 90 grain bullet... Tubal SP7 16.6 grains will get you there in thoery.. as would 15.4 of H 4350 in theory..

 

[NCsmitty]

Thats a maximum load? Double tap sells 90 grain ammunition that is rated at 2,100 fps from a 6" barrel, with a 90 grain bullet.

"Rated" ballistics compared to real world numbers over chronographs often vary widely.
Let us know what you can safely achieve should you load some rounds.

NCsmitty