Converting 30-06 to 8mm Mauser

[gpidaho]

I'm somewhat new to case forming. I do the easy things like necking up and down, I also make my own 300 Blackout cases from 223Rem. I just bought a very nice 8mm Mauser and want to convert 30-06 and 270 to 8mm. I have the Harbor Freight 2" mini chop saw to cut down cases. My question is, is there any advantage to buying a trim and forming die for the conversion or should I just cut the cases down on the chop saw and form the brass in a full length sizing die. All comments welcome. Thanks GP

[troyboy]

The answers to your questions and many more are in a new section one more down.

[Maven]

gpi, I've reformed '06 brass by trimming it first and then running it into a FL 8 x 57mm sizing die as I didn't yet own a trim & form die in that caliber. Since I acquired the latter (Redding), I've used it exclusively. Can I tell the difference between the cases reformed by either method? Not really. Are there differences in accuracy between the two? Not at all. Do what's easier for you, but be sure to anneal the reformed cases before loading them. Btw, the expander balls in the FL dies vary a few thousandths not only between die manufacturers, e.g., Lyman v. RCBS, but also by the FL dies produced by the same manufacturer. That's not likely to present a problem, but you should be aware of it.

[gpidaho]

Thanks guys! need to look a little more when an idea pops into my head as troyboy pointed out the answer is just below and it's got good recommendations. GP

[xvigauge]

By all means get the form and trim die either by Redding or RCBS. It will make your case forming almost effortless. I anneal the .30-06 brass first, them run it through the form and trim die, saw off the brass sticking out the top, file it smooth, trim to proper 8x57 length (by whatever method you like), run it through the 8x58 FL die, check again for proper length, and then reload. The results, perfect brass. From .30-06 brass, I form .25-06, 7x57, .257 Roberts, and 6.5x55. I always put a little case lube on the brass before running it through the form and trim die. I also make .300 Savage out of .308 brass the same way.
xvigauge

[EMC45]

My method is a bit more time consuming, but I am cheap err...Frugal, and I have not a trim die. I first select my 30-06 brass to use (have the -06 brass, but no rifle for it....yet), I then apply the Imperial to the body of the brass being careful to not get it gobbed up on the neck area. I size all the brass so that it looks like a giraffe with a long neck. I then take my Brown and Sharp calipers and make a scrape/scribe mark on the case to where I need to cut. I then cut the long neck off with a brake line tubing cutter. I go from there to the RCBS case trimmer to get down the last several thou and then clean everything up with chamfering and a rub with fine steel wool. I bump them back through the size die one more time and they get wiped off and put up. I guess I do that due to the OCD, but I get to check my length one more time and ensure that all is good with the cases.