Re: 7mm wildcat
I just formed with COW, never have tried the Malt-o-Meal. It just seemed like more guys were satisfied with COW (less grainy) than grits or anything else, so that's just what I used. Some guys cut another chamber in an old short barrel or what ever just to fire form with... I may even do one down the road too, but I see no wear on mine from the 60 rounds or so I formed with the stuff. Wear is wear though, I doubt any is good, and probably best to save everything you can for practice and the perfect hunt.
I had .006 errosion in mine at about 300 rounds checking it with the 210 JLK, .000 with the 178 AMAX, .002 checking it with the 200 Accubond, 360 rounds if you include the COW loads.
I used 26-30gr of IMR800X, CCI200 primer, then funneled in COW to the top of the neck. On a hard surface, I used a drill bit upside down just small enough it fits in the case neck to pack in the COW. You can drill a hole in a golf ball half way and use the ball as a handle, I just used a 416 WBY case upside-down for one (I'm not a golfer). I pack it in pretty tight a couple times, re-fill to about half way up the neck and pack again. Top that with 1/4 square of toilet tissue ( fold a bunch and cut with scissors folks [img]images/icons/wink.gif[/img] ), which I work in and pack on top with a bit about half the size as the other one.
After about every 5 I stop and go shoot 'em, trim the weeds in the back yard with COW, [img]images/icons/grin.gif[/img] keeps the barrel from heating up so bad doing them all at once.
Pressure on the Oehler M43 was about 30,000 psi, pretty low really, and I was even getting fully formed shoulders at 22-26k psi. Because I pushed the shoulder back with my design, it left a little donut on the inside bottom of the neck. You could measure about .001 smaller diameter on the outside over this point on the base of the neck too, about .002-.003 smaller at lower 20,000 psi. Once I had the pressure up enough that the base of the neck was within .001 of the rest of the neck I stopped there and formed the rest, turned and reamed with the K&M tool and was done. I think I just went with 28gr 800X, as 30gr or more didn't make any more difference, shoulder lines were nice and crisp, every one blew out perfect.
I really had no choice but to use COW before loading, necks were too thick for the .335 chamber but, they were still far from straight enough to neck turn and ream after first running the 338 Lapua brass into my 30-338 Lapua 40 deg Improved FL die. Pushing the shoulder back to make the .400 long neck, and it going to 40 degrees really left the base of the neck several thou smaller in diameter, .010 or so smaller if I recall.
[ 05-08-2004: Message edited by: Brent Moffitt ]