300 win mag seating ?

[XWrench3]

i bought a new mold for my 300 win mag, and just now realized that i would have to go against something i was taught not to do. [smilie=b: i was taught NOT to seat a cast bullet deep enough that the gas check could fall off inside the case. well, as it turns out, these 200 grain boolits definitly seat deeper than that. these shells have a rediculously short neck. actually, almost half of the bullet is hanging inside the shell if i crimp at the crimp groove:holysheep. i can not seat these so that the gas check is at the bottom of the neck. they are just to long and fat, and i can not close the bolt. should i only fire these w/o the checks?

[bowenrd]

I load and shoot 210 gr. cast GC from a Lyman #311284 mould. I shoot them in a Ruger M77 Hawkeye 300 WM. My rifle has enough free bore to allow me to seat long. The GC is right at the base of the neck. Your GC should never fall off if crimped on correctly.

The best I can offer is experiment with overall length. The short neck is a pain to work with. I am thinking of reducing expander a bit to get a tighter grip.

[XWrench3]

i was thinking along the same lines, that the check should not fall off that is. i did throw a micrometer across them before and after. there is a .009" reduction in size on the gas check after it is crimped on.

[Keyston44]

The problem I had with seating the GC boolit so it is in the neck is, it wouldn't fit in the magazine then. I had plenty of free bore but no magazine room.
My loads are light enough that I don't use the gas check.
I'm still working on the higher velocity gas check loads.

Key

[XWrench3]

i do not mind shooting light loads a lot of the time. in fact, that is one of the things i like to do is down load it to other calibers. as far down as the .30 carbine. but sometimes, i really want it to be a 300 magnum. actually, my cut off point for gas checks is 1800 fps (planned). if i want to faster than that, i run gas checks. i have a 160 grain boolit that i have no trouble with. but i wanted to try a heavier boolit in this rifle.

[63 Shiloh]

I am just getting into the .300 win mag cast myself Xwrench3, so I will follow your progress.

I too plan on using a heavy boolit 200gn+ with GC. Due to the short neck I have pondered the issue of a GC falling off. The crimp on style shouldn't in theory, I think I will be adding a drop of super glue or similar to the GC just in case.

I have set myself a goal of 2 MOA at 100m with a 200gn GC boolit at 2650fps.

Should be fun getting there [smilie=2:

[XWrench3]

i have a dozen made up and crimped in place (hornady checks that snap in place and when measured after crimping have been reduced in size by .006", i would hope they are getting at least a .002" crimp on the boolit). these are not hi powered rounds by any means, somewhere between a 30 carbine and 30-30. basicly i just grabbed a lee scoop, and chucked in some powder (of course making certain with a load book they would be fine). i am going to shoot them loading them singly, and checking the bore after every shot. if none of them come off, i will load up a dozen that should produce in the vacinity of 2600 fps, and try that. if none of them come off in the barrel, or on the way to the target, i will call it good and not worry about it unless something does not seem right. i will re-post with progress. i am not going to worry about any kind of accuracy or leading issues, or anything else (unless it rears its ugly head and forces me to). just concerned with the checks staying in place at this point.