What best primer for 44 Magum subsonic using Trail Boss

[drew2]

I've got a heap of Large Rifle Magnum primers and I'm wondering if I can use them in my 44 Magnum cases?
It's for a Ruger 77/44 with standard barrel (ie. 18.25" long with 1:20" twist).
I'm wanting to load some Trail Boss and 240gn cast projectile, I'm looking at starting with 9.0gn of Trail Boss and going from there.
Just not sure if i can use the large rifle magnum primers.
Thanks,
drew

 

[ants]

Nope

Go check out the height dimension of large rifle primers versus large pistol primers.
Rifle primers are taller.

 

[Floppy_D]

In a rifle, it's probably a non-issue, as you won't see cylinder binding or anything. Just make sure the primer seats fully. My main concern would be your start load... it seems a little high. Trailboss is for slow loads. 7.3g should put you at 21k psi with a pistol primer. Is this 9.0 published data, or are you guessing?

Given your primer choice, I'd start closer to 6.5-6.8 and work up. They'll still be subsonic.

Edit: Welcome to The High Road!

 

[zxcvbob]

It doesn't make any difference what large pistol primer (magnum or ortherwise) you use in this case, but large rifle primers are too tall.

With small primers, you can sometimes use SR's in pistol cartridges. I use small rifle primers in some .357 Magnum loads -- but all my guns have good strong hammer springs.

 

[Floppy_D]

You're right, LR primers are about 1/100th of an inch taller; but this is a bolt gun. Generally, I'd shy away from it. But, I know Jeff Quinn runs a 320g cast WFN over 8.0g of Trailboss for 890 fps out of a 77/44... so pressure isn't gonna be the issue. If the bolt locks up properly, and the load is reduced (which 6.8 would be) I'd call a LR primer safe. Hopefully one of the gurus chimes in on this.

 

[nastynatesfish]

If you decide not to use them and want to get rid of them pm me and ill buy em from you

 

[rcmodel]

I would suggest you prime a few cases and see if the rifle bolt will close on them before you load them.

If they stick out of the case much at all, it will decrease the headspace and the bolt may not close on them.

Other then that, I don't think you can get in too much trouble using Trail Boss.

starting with 9.0gn of Trail Boss and going from there

FYI: Hodgdon lists 7.3 grains Trail Boss with a 240 LSWC as a max load giving 917 FPS in the .44 Mag.

rc

 

[buck460XVR]

Other then that, I don't think you can get in too much trouble using Trail Boss.

I agree. On the Hodgdon site they give a recipe for developing loads with TB. Seems the volume it takes to fill the area beneath a seated bullet without compressing is a max load in virtually any caliber......even rifles using jacketed bullets. 70% of this is your starting load, but I've found with my .460, even filling the case is quite mild compared to full house magnums.

 

[drew2]

Thanks for the input everyone, I went and bought a 1000 CCI large pistol magnum primers, I'll use these instead.
I saw Hodgdon's data, it seems I was looking at starting off too high. I saw on Gunblast website's 77/44 review that they load 8.0 grains Trail Boss with the Cast WFN 320gn projectile and it gives 890 FPS. I'd like to see if that big heavy slug will stabilise at 900 FPS in the Ruger 77/44 1:20" twist!

 

[counterclockwise]

I use CCI 350's with my TB in 44 mag. In my Vaquero 4 3/4 bbl, 7.5 gn TB with 240 gn Hdy LSWCHP comes out at 1042 FPS, 6.2 gn TB comes out at 885 FPS. With a 9.0 gn TB, and 19" bbl, you are going to be zipping along pretty fast. Probably should use gas check or hard alloy cast.

 

[Kernel]

Probably should use gas check

I don't think gas checks are needed. I always thought leading wasn't a problem under 1,300 fps, assuming the bullets are properly sized. These Trail Boss loads should be well under 1,300 fps, even in the carbine length barrel.