RCBS-357-180-SIL for cowboy rifle silhouette

[Sixgun]

I shoot Cowboy Rifle Silhouette with a Rossi 92 carbine.  

I would like to work up a load that will reliably take down 200 yard rams.  These rams are at the Blacks Creek Range at Boise and are usually hard to knock down.  I have had good, center hits with my 30-30 using a 150gr jacketed bullet starting out at 1700fps that rang a ram with 3 hits in a row.  I have also rang them using the same 30-30 with 190gr bullets going about the same mv.

I have a RCBS-357-180-SIL mold that throws bullets at about 195gr using my alloy.  They are a bit heavier using a gc.

I also have some LC 180gr bullets  and a few LBT cast bullets that run about 190 gr.

I figure I need a load that will get over 1800fps mv and is reasonably accurate to boot.

I was thinking maybe trying Lil Gun, for the first time.  I was also wondering if a slower powder, like 4227  or AA1680 might be a little better from my 20 inch barrel than 296 or H110.

I don’t want to go out and cause cases to separate or ruin my rifle.  I just want to kill them rams with a 357 mag.  The guys at Blacks Creek claim it can’t be done.  Now it is a challenge.

Any ideas???

Let me know your thoughts,
Sixgun

[ajj]

Just to remind you of what I'm sure you already know, it's the momentum figure that predicts target knockdown ability, not "energy." If the 180 and the 195 arrive at the target with the same kinetic energy figure (meaning the heavier bullet is going a little slower) the 195 will take more targets down. I think I would concentrate on the heaviest, accurate bullet and go from there. Good luck.

[Jason]

Anyone have a general idea of how much momentum it takes to knock down average 200m rams for cowboy silhouette? I have an old Marlin 336 that I am going to shoot that match with, and it shoots the only load I've tried so far (factory Win 150gr Powerpoints) extremely well. I grabbed some Winchester brass and a bag of those bullets to get started loading for the gun, but am starting to wonder if the 150s are going to knock down the rams reliably. My initial plan was to just try to work up a load with info from my reloading books and try to duplicate factory velocity through the chrono. I'm starting to think I might need to go with a heavier bullet for the rams. If someone can throw out a guess at how much momentum I'll need to knock down the average rams reliably (I know different shooting ranges will differ a bit), I can eliminate a lot of loads on paper before I go to the trouble of loading them up to test accuracy.

This post caught my attention because I have a friend who wants to try out the long range match, but is only interested if it can do it with the .357 lever gun he uses for the pistol cartridge matches.

Thanks for posting this, Sixgun.

[ajj]

Assuming this is the regular, HP rifle ram set closer, the figure you see most often is 1.0 lb-sec. for pretty reliable takedown. Most rifle shooters get by with something a little less. Hits in the heart and low belly take more momentum than hits high in the back or in the horns. Even a little wind will hold them up and the range-to-range variance may be higher than you would think. I know that my 140 gr 6.5's arriving at somewhere in the area of 1700fps are pretty reliable. The 150 from a 30-30 should be fine but if it will shoot 170's accurately...

[B_Koes]

The places where I've shot cowboy rifle have been doing double duty with IHMSA so the rams are not set "full foot".  Basically what I'm saying is that it depends how the rams are set since it generally takes about .77 lb-sec for an "IHMSA" ram to be taken over (your mileage may vary).

[Sixgun]

I got a pound of lil gun and tried some of it last night.  I loaded 15 gr of lil gun with the rcbs sil bullet and a cci std small pistol primer.  I had to crimp the 357 cases over the front driving band to get them short enough to cycle.  I was not too impressed with the results.  I got 1703 avg fps with an extreme spread of 59 fps and a Standard deviation of 25.  I didn't shoot for groups because the light was fading fast and I wanted to shoot some over the chrony before the light was all gone.

The was no pressure signs, in fact the cases soot around the very end of the case mouths.  I may be able to get 15.5 gr of lil gun into the cases but not much more.  I don't think I can get enough lil gun in these cases with this bullet to cause any danger of too much pressure.

Sixgun