Month: January 2008

Case Conversions

Posted by on January 15, 2008

One of my buddies is one of those “get things done” types. He made successful 50 BP Express cartridges from brass tube soldered to lathe turned heads, and 375H&H bullet jackets from 5.56 fired cases. That included making all the dies.His latest foray into case conversion is 45 Auto Rim. For those who don’t know the 45 Auto Rim is the 45 ACP with a rim for use in revolvers. In WW1 the Americans couldn’t produce enough 1911 pistols so both Colt and S&W made revolvers for the 45 ACP. To confuse matters both are known as Model 1917. Half moon clips were used, but later brass was made with a rim. It is a very thick rim because headspace needed for the 45 ACP case rim plus the half moon clip.45 Auto Rim is not easy to come by so my buddy decided it was time to make some cases for his S&W Model 1917. This is how he did it. He turned a plug to be held in the three jaw chuck, so dimensioned to be a close fit to the inside of the case, ie the case is pushed on tight enough to be secure for light machining. The rim is turned off, in fact the head of the case is turned to 10mm diameter for a length of 2.29mm that being rim thickness. That’s all there is to the preparation of the 45 ACP case.To make the rims a piece of brass rod is chucked in the lathe and faced off. The OD is turned to rim diameter. A 10mm hole is drilled down the middle, and the rims which are no more than washers of a particular size are parted off. Thickness is not so critical that it can’t be controlled with a vernier caliper.The rims are then soldered to the cases. I am somewhat confused about that. I know that fabricating cases is done by soldering head to tube but I would have thought that solder temperature especially silver solder is so far above the annealing temperature of brass that it would leave the head too soft for safety. But it seems to work as the cartridges he showed me were on their fifth loading.As he didn’t have a shellholder he made a simple Lee Loader type die, so we don’t yet know whether the soldered rims will resist pulling off in the loading press. He is also quick to concede that it is not a precise job at this point, although the cartridges shoot well enough and looked pretty good to me. He says that for bigger volumes it would be worth making better and more precise tooling, which is easy to make.But there you go, a real live example of what can be done.[Originally posted to SATalkGuns -- Admin]