Rainier Copper-plated Wadcutter .357 Loads

[5hundo]

I want to load .357 Magnum Brass with 148gr copper-plated wadcutters from Rainier. I was thinking about using approx 4.0gr of W231 powder but the load data I have in my manuals don't give me much info on the loads I want to do.

I'm thinking it would put them around about the 1000fps range. Is that too fast for the copper plated bullets? Any chance of these coming apart like older wadcutters sometimes do?

[RaymondMillbrae]

5HUNDO,

remember that Rainier Ballistic bullets do NOT have a copper jacket - it is more like a VERY THIN copper skin. They should be treated like lead bullets, or if data for lead bullets is absent, load to plated bullets specifications...MINUS 10%.

Rainier Ballistics also recommends keeping their bullets under 1,200 FPS.

Another thing to keep in mind is the amount of pure lead in the bullet. If it is purer lead (softer), then it will deform a bit more, give a tighter seal in the barrel, hence increasing the pressures. But if the lead is mixed with another material (antimony?), there will be less distortion of the bullet, less seal in the barrel, which equates to less pressures.

Anyhoo, here are a few loads I dug up.

In Christ: Raymond


IMR POWDER

Bullet: 148gn Rem SWC
COL: 1.580"
IMR 4227 - 15.3gn @ 1075 FPS
Hi-SKOR 800X - 8.6gr @ 1,080 FPS
SR 4756 - 7.5gn @ 940 FPS


HODGDON POWDER

Bullet: 148gn HDY LHBWC
COL: 1.290"
Universal: 3.5gn @ 880 or 4.0gn @ 989
HP-38: 3.0gn @ 845 FPS OR 3.4gn @ 908
TiteGroup: 2.9gn @830 FPS or 3.3gn @ 909 FPS


WINCHESTER POWDER

Bullet: 148gn WIN LBBWC
COL: 1.590 max
231: 3.4gn @ 880 FPS


RCBS BULLETS

Bullet: 148gn WC
231: 2.8gn @ 634 FPS or 3.3gn @ 731 FPS

[5hundo]

5HUNDO,

remember that Rainier Ballistic bullets do NOT have a copper jacket - it is more like a VERY THIN copper skin. They should be treated like lead bullets, or if data for lead bullets is absent, load to plated bullets specifications...MINUS 10%.

Rainier Ballistics also recommends keeping their bullets under 1,200 FPS.

Another thing to keep in mind is the amount of pure lead in the bullet. If it is purer lead (softer), then it will deform a bit more, give a tighter seal in the barrel, hence increasing the pressures. But if the lead is mixed with another material (antimony?), there will be less distortion of the bullet, less seal in the barrel, which equates to less pressures.

I don't honestly think that 4 grains of W231 would put the velocity over 1200fps, but I can see what you're saying about the deformation causing an increase in pressure.

Per the Hogdon website, 3.0gr of 231 will give a 148gr lead bullet 845fps. 3.4gr of 231 will give the same bullet 908fps at 17,600 CUP. So, if .4gr gives you an extra 63fps, then an extra .6gr should still keep velocities under 1000fps.

I'm sure that the ratio isn't that simple, but in regards to pressure, some .357 loads put pressure up into the 40,000 CUP range, so I don't think that it would be "dangerous". There's no way than an extra .6gr of powder can make another 20,000 CUPs of pressure. Plus, the Rainier bullets are not "hollow base" wadcutters, which is what the hogdon website is giving info for...