Starline 375 ,Winchester a no go wish they could !

[dgr416]

I.talked to the guys at Starline brass at the NRA show here in.Atlanta .I am.glad they are making.357 rem max brass and 444 marlin brass .I asked about them making.375 Winchester brass because there is none being made now ! They said the rear cup thickness was the problem but I.Hope they work it out .Their brass is some of the best brass I.have used .so also soaked them.about making.405 Winchester brass I.hate the hornady brass it's too thick and hard to load .I guess I will try to fix the 300 pieces of 375 win brass I.have .It was flared by someone trying to load lead cast bullets .I haven't ever used 38-55 brass for It I didn't know if it would hold my hot loads !

[earlmck]

38/55 brass will do you just fine as long as you keep loads to 38/55 pressures. That "rear cup thickness" problem the Starline folks mentioned is where the extra thickness in the base area is provided to the 375 brass to handle the 375 pressures.
The same thing is true for us 218 bee shooters: we can make fine "bee" cases from 25/20 or 32/20 brass but the resulting cases are not really up to full 218 bee pressures because of the lesser base web thickness in the 32/20 brass. Still wonderful for cast bullet loads but not so wonderful for full pressure loads.

[KWK]

... cases from 25/20 or 32/20 brass but the resulting cases are not really up to full 218 bee pressures...

Earl, how long does 25-20 brass last at those pressures? Just a shot or two? Where does it fail?

I have to admit I've never understood why thin brass doesn't work as well. It's supported by the steel chamber and breech and need only bridge a small gap.

[earlmck]

Earl, how long does 25-20 brass last at those pressures? Just a shot or two? Where does it fail?

I have to admit I've never understood why thin brass doesn't work as well. It's supported by the steel chamber and breech and need only bridge a small gap.

Hah -- you got me . You'd think I would know the answer to that good question since I spouted off about it. But my limited observations are the other direction -- I have an elderly 25/20 (like black-powder era) so a moderately generous chamber and probably softer steel. Upper level 25/20 loads lead to case head separations somewhere around 5 loads. But if I make my cases from 218 bee brass -- well I haven't had one of them even get to the detectable stress groove inside the case that I try to find before the case actually separates-- so I only know that in that situation the bee brass lasts lots longer.

Like you are suspecting, a good tight chamber and tight lock-up may well allow 32/20 brass to do fine in a 218 bee, and 30/30 brass last fine as a 375. I know that the 30/30 brass I use to make Improved zippers lasts quite well in an application where pressures are quite a bit above 30/30 level. What I find is that the 30/30 brass begins to give that sticky extraction feel at pressures that should be only around the 50k psi level (as estimated by the QuickLoad program). The factories make the brass thicker in the web area when higher pressures are going to be generated, and I think it is an extraction thing rather than a brass-life thing they are addressing with the thicker brass.

[KWK]

Interesting, Earl, and thanks for the forthright reply. Karl