Barrel twist qustion...

[twoworms]

I'm going to have a barrel made for my Encore in 500 S&W, as I can't seem to get my TC barrel to shoot lead boolits.

My load for plinking is the Lee 440cast with WW and Gas Checked at around 1000fps. I would like to be able to shoot near max loads with the same barrel and would expect 1700 fps from warm loads.

My question is what twist should I get it made in? The guy at MGM said he would pick the twist for me but wanted to know if I was going to be shooting lead or J bullets. He also said I would be more than happy with how it shot lead boolits at 100 yards.

Do I let them pick the twist rate or not? I would also add that this barrel will cost over 400 does and I'll be one sad guy if it don't shoot well.

Help!

Tim

Link to the barrel maker is below.

http://www.matchgrademachine.com/gunshop/pages.php?pageid=5

[felix]

What weight and shape? LFN, WFN, K? Distance, wind, velocity?

[Frank46]

I think that the twist for the 50BMG is something like 1x15". But they launch bullets between 650 to 750 grains. Or something like that. They said (MGM) that they use shilen blanks. Why don't you call shilen and see what they suggest?.
Frank

[felix]

The machine gun uses 16 twist, with either 650 or 750 grainers, either at 2700 or 3200 depending on application. All bullets are spitzers for one mile or more. ... felix

[twoworms]

They come out at around 455gr with the GC on them. I shoot them from my TC Encore with a 20" barrel anywhere from 1000 fps to 1700 fps. The low end is what I want for the most part. Just a good plinking load out to 100 yards or so. I'll run them a little hotter if I hunt deer or T Rex with it.

Tim

[felix]

I would go for 24 twist, 500 groove depth, 7 lands at 488, in 60/40 percentage configuration with land angle at around 85 or so. Have the leade configured at the angle giving maximum boolit contact withOUT any cartridge insertion force (match the ogive). This would work well with soft boolits. ... felix

[wonderwolf]

The JR .500 has a 1x10 twist...he claims it shoots well with everything from the 365's- 725gr bullets...food for thought. Greenhill formula?

[felix]

Won't hurt to over-twist at this low of a velocity requirement, but my preference is to make the boolit reach the maximum target distance with as little twist as is necessary for the ambient conditions. The torque on the pistol is heavy duty enough with a 50 caliber, and we don't need to add more with excessive twist. I am very sensitive to any kind of recoil. In purely hunting conditions, recoil is of no concern, but beer cans will laugh all the way to the bank. Well, to the river bank, anyway. ... felix

[crowbeaner]

I'd go with 1-18.5" twist.