8x56r loads

[chevyiron420]

hi folks, i want to work up a higher velocity load than what i have been useing. i have been useing 12 or 13 grains of unique with a 205 grain GC from a lee mold. im thinking about imr4198 or h4895. what do you think?? what velocity do you think i can reach without leading and maintaning good groups? what kind of groups do you think i can get? both me and my son have m95 steyrs and we love to compete with each other. the recoil and muzzle blast is all part of the show, and we love it, but we cant afford to keep buying the hornady j word bullits.

[dromia]

Slower powder are best for higher velocities, try it with the two you mention.

The real trick to higher velocity with accuracy though is good throat and barrel fit, concentric chambering, consistent ignition, a hard enough but not brittle alloy, appropriate lube Carnuba Red or LBT soft blue work for me.

[Buckshot]

................."im thinking about imr4198 or h4895."

Well that's quite a spread in burn rates there :-) 4198 is a historicly superb powder for cast in full size military cartridges. Around 23-24 grs should get you about 1600 fps or a tad more. If you're wanting more 'fun' then 1600 fps provides (as Dromia suggested, slow powders) I'd for sure switch to the mentioned 4895.

In addition for the best results with the slower powder I'd also suggest a solid filler such as a Grex type material. Grex is no longer available as a reloading component, and it was used as a shot buffer in shotgun loads. However similar products are available such as Super Sam, which is a finely divided polyetheylene material. Graf & Son sells it and I'm sure the other suspects stock it or similar.

I'd start with about 35.0grs of 4895. Dump the charge and then fill the case to the top with the filler. Use a wood dowel to compress the filler as much as possible, then fill the case to the top again and seat the boolit. Increase your charges a grain at a time until you reach the enjoyment level you're looking for, or accuracy begins to suffer. You CAN drop to an even slower powder, but keep using the filler.

................Buckshot

[jonk]

PSB (Precision Shot Buffer) is a pretty good substitute for Grex. Pufflon is still my favorite but is pricey. For most filler applications, dacron (polyester) fluff is cheap and works fine.

[DanM]

I am still using COW filler in my 8x56r loads. Haven't tried a PSB or Grex type filler yet, and don't feel any need to. The COW works just fine for me. There is ligitamate concern that COW absorbs moisture over time, and might deteriorate or harden to a plug. I can't really speak to this, as the longest any of my COW filled loads have set on the shelf is 4-6 months. I know that COW does harden a little when compressed, but that has yet to effect my loads. I am getting excellent results with 35-38.5grs IMR4350 topped off with a case filling dip of COW that is compressed by the seated boolit. The Lee .338-220 boolit sized to .334" maintains good accuracy to about 1850fps with this load. Some of our most respected members don't reccomend Cream O'Wheat filler, and their views certainly have merit, but I haven't had any problems with it yet.