boolit seating depth

[hornsurgeon]

i am working on getting a wildcat 375 to shoot the lyman 274gr fngc descently. i am using ww with tin added. this is a chase gun when guiding for black bear, and i might use it for deer for the fun of it. my question is with boolit seating depth and crimping. i have been seating it as long as possible and still crimp it in the crimping groove. i think it is just too far from the rifling. with j-bullets, it needs to be within 0.020" or less of the rifling to be accurate. i assume i need to crimp to avoid bullet creep within the magazine, but could i crimp in a grease groove without causing problems? could i force a crimp in a band? or is it something else like the alloy needing to be wq or ht?

mark

[docone31]

Just my opinion, and I can be a butinsky, I would not crimp the case. I like mine long enough to almost engage the rifling without putting pulling pressure on the bullet if I retract it after putting it into battery.
A lot of factors here, magazine cycling, bullet width, neck tension.
As an aside, I have never had a bullet move in a case without crimping it. I have had unburned kernels however. Could have been the need for filler, or the powder needed back pressure. Don't know. I also water quench all my castings. Kinda of my routine. Works so far.

[Ricochet]

It's not necessarily true that even J-bullets need to be within .020" of the rifling to be accurate. I've had very accurate .300 Weatherby Magnum loads that were about 3/8" off the rifling origin.

[hornsurgeon]

with j bullets, THIS GUN needs to be seated within 0.020" of the lands. i can get there by using a roundnose hornady as opposed to a spitzer. i do need to crimp these as i have had them creep when in the magazine. if i am having problems with j bullets creeping, i assume that cast will creep as well. i just have been hesitating to try crimping elsewhere on the cast boolit. also, incase there is any question, i have been using bac for lube.

mark

[dromia]

What you say sounds reasonable Hornsurgeon, how ever I would try different oal's with Cast Boolits first so that I know what the rifle/cartridge combination likes with cast.

Sometimes theory and practice don't speak to each other. :veryconfu