Using the Checkmaker™ PB “Plain Base” Dies
The Checkmaker™ “PB” (plain base) version dies are made to use with thin inexpensive metals to form your own gas checks for plain base bullets. This allows you to use one plain base mold and have the best of both worlds with a plain base cast bullet, and a gas checked bullet all in one.
Your old plain base molds can now go where they’ve never gone before- a whole new frontier never explored. It’s like getting a whole bunch of new molds to try.
I’m going to some extremes here show what can be done, but everyone has to work within the limits of their alloy hardness, metal thickness, sizing die process, and how far you are sizing down in diameter, etc. Just takes some experimentation to find out what works best for your bullet and setup.
I’m starting with 2 styles of bullets used for the 45 ACP.
On the left is the well known LEE TL-452-SWC that I had cast up a long time ago and lubed with LBT blue soft (.452). The ones on the right are a LEE group buy mold for the 45ACP I believe (.454 dia).
Below shows gas checks formed with .004 beverage cans, and .010 1/2 Hard copper. Both bullet styles were cast few years ago, and are air cooled WW alloy.
I decided to PB check these for my 1911 and size to .452. I use the old Lyman 45’s lube sizers, and this one has Bullshop Speed Green in it. Everything was cold, so I fired up wife’s clothes iron on high and set it on the Lube Shelf of my ROCKdock™ while I searched for sizing dies.
The heater plate works real slick. Real fast. I set it on high, and as it warms, I progressively turn it down until it heats the lube up where I like it, then I shut it down and remove it. If you run really hard lubes, you can leave the iron running and set on low to the consistency you need.
I noticed one of my .452 dies was missing, and the one present I had picked up used somewhere and had not tried it. Incrusted with old hard lube, I set it next to the iron and warmed it up enough, so I could clean it up.
A shot shell case makes a great storage container for these H&I style dies. After a good cleanup with an old bore brush and a wipe down with Ballistol, it was good as new.
Starting out with the LEE GB bullet, I knew I was pushing it as they were pretty hard and I was sizing down from .454 to .452 with .010 half hard tempered copper.
It’s best to size on the same day or so after you cast while the alloy is still soft. With PB checks you can take advantage of using pure lead or a deadly expanding 50/50 mix as well. Still I was able to size these with the thick, relatively hard .010 copper.
First I wipe the bullet with Ballistol on a cloth- I’m a big fan of Ballistol, but you can use bullet sizing lube, etc., and use your normal sizing process. I wipe the mouth of the die also.
The harder your bullets are, the more your try to down size in diameter, and the thickness and hardness of gas check metals all make a difference in the ease of the process. What I’m showing here is about the limit. You will not be able to get away with using .010, on hard old WW cast every time. The best check metal performance will be between .004 and .008 thick, on freshly cast.
Here’s the copper .010 formed check on the LEE TL bullet that had been previously sized at .453. It was considerably easier to size.