gas check seating

[flounderman]

I made some 7.7 jap cases from old military 06 cases, so the necks are probably thicker. cast bullet is 311. I sized the cases in a backed off 8mm sizer and expanded the neck with a 310 die for the 303 brit. I don't have a 311 or bigger sizer. bullets are tumble lubed with lee alox. I'm going to try the bullets unsized, but am wondering if the gas check will crimp from the case neck pressure when the bullet is seated. check fits the base snug. probably be best not to seat the check below the neck. has anybody tried putting the check on the bullet and seating it without sizing first?

[stubshaft]

In the olden days of yore the Lyman GC's were only a press fit. They don't have to be crimped but do not seat below the neck.

[runfiverun]

those old ideals took some oomph to seat, i think they are/were quite a bit taller.
i still have a few thou and have to seat them on the boolit before i can size/lube them on the star.

if i were doing it your way i'd buy a bottle of superglue.

[Calamity Jake]

The copper material of the GC is thicker than the brass case neck and will not crimp the GC to the boolit it will buldge the neck, they need ti be crimped on.

[flounderman]

I won't know until I try it, but the cases are reformed 06 brass and should have thicker necks. necks were annealed, or attempted anyway. 30 cal checks, hornady, 31 caliber jap. do they make a 311 gas check or are they all 311? is tumble lubing with lee alox sufficient lubrication? never tried it before. how fast can you drive a hardcast gascheck tumble lubed without leading? shooting them as cast, measure about 311.

[popper]

Crimp the GC on by running tail first through your sizer, just to crimp the GC. I assume you have a .309 Lee sizer. Use a stick to push it back out. I've done that for my 30-30 and .311 bullets, seats the GC without sizing the entire bullet. If the jap is going to be a standard reload, get a Lee sizer that fits. Condition of the bore probably will determine the amount of leading. Is that a 7.7 or jap 7.62? I and many others use the 45/45/10 alox/JPW which should work fine. I shot a 7.62 jap brought-home after WWII last year and was amazed at it. Accurate and low recoil.

[Char-Gar]

To start with, I will confess, I don't shoot unsized gas check bullets and do not use LLA. So I am talking from what I think is the way to go and not what I do.

The old Lyman slip on gas checks had parallel sides. Todays crimp on gas checks are slightly wider at the top to allow the sizing die to force them onto the shank of the bullet.

So, if you don't crimp the new gas checks and seat them in the case neck, the wider top part of the check will expand the neck as it goes down and botch up the neck tension on the bullet. I would think nothing good could come from this.

I would crimp the gas check on as popper suggested or just size the entire bullet and crimp the check on a the same time. If you still want to use LLA, that could be done after the sizing and crimping of the gas check.

Just my thoughts on the subject at hand.

[popper]

I use the hornady 30 cal GC on .311 and .310 CB without a problem. I don't have a crony but several here have posted that 2200fps with 45/45/10 works fine. Pea sized gob in a pan or baggie, let dry, do again. Load and shoot. I don't know what bullet you are casting, but I think it helps to get lube on the nose, at least the bore riding part. I didn't find the 7.7. fired cases to check the neck thickness - I'd load a dummy and see if it chambers OK. I assume you slugged the barrel with a soft lead bullet you cast? 303guy here may be able to get you more info.

[1Shirt]

I use a Lee push thru sizer to seat and crimp. Works better than anything else I have used over the years.
1Shirt!

[TNFrank]

I use a Lee push thru sizer to seat and crimp. Works better than anything else I have used over the years.
1Shirt!

I've often wondered about this, do you run the bullets thru the sizing die gas check first or bullet nose first? Thanks.

[geargnasher]

I use a Lee push thru sizer to seat and crimp. Works better than anything else I have used over the years.
1Shirt!

+1!

Less than 20 bucks and a "free" bottle of LLA included too!

Gear

[cf_coder]

With the Lee sizer, the boolits go through nose first.

_codeer

[TNFrank]

With the Lee sizer, the boolits go through nose first.

_codeer

And it crimps the gas check on ok that way? Reason I'm asking is that it seems like if you'd feed it gas check end first then it'd start at the small end of the gas check and work toward the expanded end and squeeze it onto the bullet better. Going nose first with a gas check you're having to go from the largest part of the gas check, unless there's a good taper in the sizing die that I don't know about that would allow the gas check to squeeze down as you sized it nose first.

P.S.
For "normal" cast bullets I feed em' nose first.