Boolit base

[DeanWinchester]

I've been noticing the bases of my boolits (after seating a gas check) are not as good as they used to be. Something has changed in my mold or technique and I think it's one of the reason I'm having fits with grouping. I'll get a 3/4" group at fifty yards then shoot the same load and get three boolits touching and two fliers a couple inches off.

I'm a pan luber mainly because I'm too darn cheap to do it any other way but that's gonna have to change. Using my lee push through (.311) sizer sometimes I get a perfect pressure ring on the base of the check, sometimes I don't. Obviously it's my fault but I think the gas check shank being too tight is the culprit. Because I'm sizing down very little I'm thinking there's not enough pressure to sets the check squarely. An out of square base turns a rifle into a shotgun.
On my boolits with a meplat I use a pair channel lock pliers I ground smooth (jaws) to seat the check firmly but with a spitzer I really need to be using a nose punch and a press. That's why I think I'm gonna HAVE to break down and buy a lubesizer. That, and I'm shooting in such volume now that pan lubing is becoming a pain.

Any thoughts, am I on the right track?

[CIBCasting]

well you could use a ball bearing to open the check up. That way it woud fit on the base all way and then your push through would seat/crimp it square.

[Pb2au]

You might want to consider annealing the checks.
I ran into a batch 32 cal checks from Hornady that were harder than the hinges of h#$% and was experiencing a similar issue. I annealed them and the issue was no more.
I played the flame of torch over them (in a metal pan) briefly and then dumped them into a pan of water.

[Tom Myers]

You might try what I found to work well when using the Lee push through sizer and seating gas checks on slightly oversized shanks that do not set all the way into the bottom of the check.

Start the check on the bullet base and place the bullet on the ram and run it up into the die until just before the gas check starts into sizing portion of the die. Then back the ram down a little and smartly, but lightly, move the lever up and down, tapping the check firmly, and squarely, onto the shank. The bullet is held paralell to it's axis and is into the die far enough so that no deformation is taking place. For me, doing it that way really makes a difference in the uniformity of the checked bullet bases and doesn't take all that much extra time or effort.

Hope this helps.

[Tatume]

If you can visually detect gas check crookedness, you will not get good accuracy. One cure is to manually seat your gas checks as a separate step. Use a flat steel bar to block entry into the Lee bullet sizing die, and raise the press handle to push the bullet and gas check against the bar (I prefer the gas check to be up, but it probably doesn't matter). Then move the bar out of the way and push the bullet through the die. Once you get used to it, it is very quick and easy.

[Shiloh]

What does your base look like before you seat the check. Flat and smooth??

Shiloh

[DeanWinchester]

Pretty decent. I do have to remove a bit of flashing if I let the mold get too hot.

After setting the check, sometimes I'll get a flat base, sometimes a little wrinkle. Sometimes a perfect ring, sometimes not.
I believe that inconsistency is a problem.

[Shiloh]

Inconsistency is a problem. When I let the pour set for a few seconds, I get an even shear of the sprue. Whe I didn't I got a raised smear that interfered with seating the gas check. You could see a bump on the check where the lead was.

Shiloh