Lapping a bullet mold to accomidate pop can thickness?

[git_dr1]

With all the information that has been shared on how to make a checkmaker, I was curious if anyone has considered lapping the base of a gc bullet mold to be able to use pop can material.

Is there a reason to use thicker material other than matching final bullet diameter on the base of the bullet?

Pop can material is abundant and I was wondering if anyone has done this and/or if there is a reason not to.

Thanks,

git_dr1

[fcvan]

The soda can material is thin enough that you can seat a check on a boolit with a plain base, or a boolit without a gas check shank. That is the basic premise of the PatMarlins Plain Base CheckMaker dies. I have made plain based checks as thick as .010 thick and they've worked fine. Soda can is generally .004 and some energy drink cans are .006 and either make great checks with good dies. I have 35PB and 45PB dies, and have made/fired thousands of rounds with PB checks.

No need to remove a check shank for use with PB checks if you can get the mold as a PB design. I have one 35 GC design mold that I don't use often but m not going to modify to a PB. I made a bunch of PB checks for a friend who sent me a bunch of standard checks in exchange.

A regular CheckMaker uses aluminum flashing which I buy reasonably from Ace. If you like regular checks that is the way to go. If you just want to use pop can go ahead and ream out the check shank. If you don't feel confident in doing so, there are a couple of guys who will do that for you. I believe Buckshot is one of the usual suspects, and I know there are others. I'm sure other members will chime in with their names.

[hickfu]

fcvan, that is good to know... I have some PB gas check makers on order with Pat and if they work good on my .35 rem and 405gr 45-70 boolits then I will be asking Buckshot to ream out the other molds I have to make them plain base..


Doc

[338RemUltraMag]

My only concern for using .004 metal is wondering if the check also provides some structural support to the base of the boolit. When shooting high pressure rifles, I would almost bet that a thick check be it aluminum or copper necessary to keep accuracy.

Now this is only theory as I really dont know!

[hickfu]

At this point I am also looking into the freechex III check maker so maybe I will have both just in case.....


Doc

[git_dr1]

Thanks for the replies.
My main interest is in rifle velocities.

Doc, if you do get both please post results.

git_dr1

[longbow]

I have been curious about high velocity rifle cartridges using PB checks myself. I do not believe that gas check is necessary for structural reasons because paper patched smokeless loads can run at "J" bullet pressures and velocities with PB boolit and no gas check. The gas check does provide a smooth consistent base though which is good.

What I do wonder about though is to whether the thin pop can material will shear or fail in some way at higher pressures. You wouldn't be getting "J" bullet pressures and velocities with any gas checked boolit in most small bore bottleneck cartridges but I have not seen any posts of comparisons between max. velocity with standard check and PB check. Since I am too lazy and fumble fingered to paper patch boolits for my .303's and I have several PB moulds, I am wondering what those pressure/velocity limits are.

Someone posted good results with .35 cal checks (Hah! fcvan did above too) but I think they would be easier to get good performance from than .30 cal. or smaller. I find larger than .30 cal. bores easier to get good results from but that may just be me.

Just curious.

Longbow