Boolit sizing for .357 revolver

[got_lead?]

Hello all:

OK, another boolit sizing question. My Ruger Security Six bore slugs at .358, and the cylinder throats are reamed to just a wee bit over this (you can push the .358 slug through them with just a little finger pressure).

What diameter should I size the boolits?

Thanks

Dave

[Piedmont]

Size them .358, but .359 will work too, if they chamber at that size with the crimp you use.

[subsonic]

Try .358 first, then .359 if they fit in the gun, and lastly .357. Shoot for groups and see which the gun likes best. If you work with a different powder or boolit alloy, test again.

[got_lead?]

I have .356, .357, and .358 sizer dies in the Lee, and a .357 Lyman H&I. I am going back to old skool lubing with the lubrisizer after my experiences with LLA only. I found that LLA just wasn't enough lube, and bullets would start streaking the bore about 1/2 way down. Filling the grease groove with 50/50 stopped the leading. LLA has it's place, but I'm going back to the old time proven 450.

So, I'm debating on which H&I to get, the .358 or the .359. I also have a Marlin 1894 in .357, and would like the larger sizer on its account. I'm just wondering about how running a .359 boolit through the revolver throats will act.

Here's a tidbit of interesting information: I was working up loads for my Smith M52 a few months back, and also shot some of them through my Security Six. The Security Six shot very well with 2.7 grains of BE behind a 148 grain WC. Grouping about 1" at 25 yards. I had both .356's and .358's loaded at the time, and grouped both from the security six. There was no difference in accuracy, however, the .356's shot at 740 fps, and the .358's shot at 780 fps.

I have also found that a spankin clean gun will shoot about 70 fps slower than after I run 2 or 3 cylinders full through it. The throats, even though sized slightly larger than the boolit will foul with a thin layer of lead (which is pretty stubborn to remove). However, this lead in the throats is probably what accounts for the velocity increase (more initial resistance, and more efficient powder burn). The fouling in the throats does not affect accuracy at all, the gun will still shoot 1" groups, and the barrel runs clean (except for a bit of leading in the forcing cone).

This fouling in the throat probably sizes the boolit down a bit anyway, regardless of it's initial sizing. I just don't know if it would be hard on the revolver to shoot .359's. With rifles and autoloaders (guns without cylinders) the convention is to size one or two thousandths over bore diameter. With revolvers perhaps it is better to size at throat diameter?

[bobthenailer]

Ive only used cast bullets sized to 0.358 dia for over 40 years in the 357/38 in over 10 different revolvers , 2- single shot pistols and 1- marlin 357 , with ballard rifleing with excellent accuracy in every one