by BD1 » Tue Jun 09, 2009 4:05 pm
Getting a good crimp is definately an issue with this cartridge. On calguns I learned a technique some other guys had developed. This basically involves cutting down a Lee 45-70 factory crimp die so that it will emboss a crimp on the body of the bullet, leaving the case mouth at the proper diameter to head space the round in the chamber. I also turned some length off the crimp section of the collet to narrow up the crimp band. I used this technique with limited success on the Nosler 250 grain JHP 43013, and the Hornady 250 grain FTX. It helped significantly. However, I'm still getting velocity ES over 150 fps, and SD of over 50, which IMHO indicates pretty poor start pressure consistency.When I drew the 300 grain cast RNFP boolit I wanted to try in this cartridge, I placed a lube groove at a point just .01" below the case mouth to give the "body crimp" an edge to stop against. This has worked out well. Velocity ES on the initial testing was 58, and SD was 18. This is more in the range I'm used to seeing in something like the .44 mag. With luck, the attachment will be a photo of the boolit and a loaded cartridge showing the crimp. i have to say that it takes vice grips to pull the boolits when they've been crimped like this, (don't ask why I know that).I also feel that the expander in the hornady die is a bit to large for the .4505 and .451 jacketed bullets. It works better with the cast boolits sized .452, but if I could get at it, I'd still polish it down a mite. In my opinion the jacketed bullets would benefit from greater neck tension, and a real cannelure for the body crimp to "seat" into. I have yet to see a factory loaded round, but I can't imagine thier as loose as what Hornady's dies are producing for me. Maybe if we could standarize what we're using for a body crimp, we could get Hornady to put a cannalure on thier bullets? BD
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