Modifying blocks

[earthquake]

Hey guys,
I have a set of NEI blocks that cast a .430 bullet at about 335 grains, I think its a J D Jones designed bullet.
Its a plain based bullet, I would like to have a gas check on it. Would it be possible to machine it a bit deeper to add a GC? Does a bullet this heavy even need a GC? I shoot them in S&W 29's and my Super 14 Contender mostly but I have loaded them up in a .444 marlin at about 1500fps, I cast them pretty hard.

Casey

[country gent]

In the mold the gas check section would be a smaller dia than the bullet dia. ( mold is a mirror image of the bullet) Gas check grease grooves are the smaller rings driving bands are the grooves in the blocks. Cast hard at 1500 fps in the marlin shouldnt be an issue if fit is there

[SciFiJim]

Catshooter did just the thing that you are thinking of. He wound up adding a plate between the mold and the sprue plate. He posted about it in this thread.

http://castboolits.gunloads.com/showthread.php?68205-An-interesting-experiment-in-adding-the-gas-check-feature&highlight=gas+check

[runfiverun]

I'd just try it as is.
then as an alternative to changing he mold.
I would then look for some plain base gas check.
then look to have the mold duplicated [with a gas check] if the first two options didn't work.

[Walter Laich]

Catshooter did just the thing that you are thinking of. He wound up adding a plate between the mold and the sprue plate. He posted about it in this thread.

http://castboolits.gunloads.com/showthread.php?68205-An-interesting-experiment-in-adding-the-gas-check-feature&highlight=gas+check

Now that is a great way to add a GC shoulder. Would never have thought of it