Hello, I have been casting with some lee molds quite some time and recently bought some lyman Gas check molds listed above for my Ruger Revolvers because of the acclaimed accuracy of the above mentioned molds.

My 45 vaquero shot about 5 inch groups with the lee bullets(reamed the throats, over sized base pin, trigger/action job, just waiting on the firelapping manual from btb so I can fire lap the barrel. I guess they were out of stock, I received the kit, just want the manual so I know I am doing it right)

Never had 38 dies or molds so I shot standard 38 special rounds out of my ruger police service six with excellent results (2 inch groups at 25 yards)

Bought some dies last week and I first cast some of the 358156 in WW and water dropped them. Loaded them at 38 special load in 357 cases with different weights of WIN231, no gas check. Best I could get was 5.5 inch groups. Decided to try with gas checks even though they are not needed at these velocities, the groups opened to 9 inches. I am sizing them to 358, they come out of the mold at 357-359 so they are not sized completely just basically at the parting line. Using the lee sizer, tried some gas check first, some nose first. Do you think the bullets are to hard? I have Air cooled a few but have yet to fire them. Another possibility is using mag primers with light loads? Really don't want to have two types around but?

Also have cast the 452490 in ww both water dropped and air cooled. I have measured them and noticed that the water drop are 451 to 452 and the air drop are smaller at 450-451. Are they supposed to do that? Should I only shoot these with gas checks in magnum loads(the purpose I really bought the mold for) or do you think that they will be alright in light loads?

Thank you, for an inexperienced cast such as my self help would be very welcomed.
Jay Moyer

Howdy Firebrick, I wouldn't use a mag primer with a fast powder like W231. I shoot air cooled ww in my 38 specials, quench hardened ww may be too hard for your application.
Let us know how the air cooled ww shoot.
What are the confidence limits of your measurements?

Howdy Firebrick, I wouldn't use a mag primer with a fast powder like W231. I shoot air cooled ww in my 38 specials, quench hardened ww may be too hard for your application.
Let us know how the air cooled ww shoot.
What are the confidence limits of your measurements?
Thanks for the reply. I probably should just pick up a hundred or so of the standard primers, I just would like things to be simple. I figured that they needed to be softer, just had to many variables starting out and didn't want to chase my tail round and round.

By confidence limits I take it as How sure am I that the measurements are correct? Pretty sure, I am a machinist and random sampled 15 to 20 of each type of bullet. My calipers are above average in repeatability, could use the micrometers but I don't want to spend that much time.

Thank you

Your main problem might be making the bullets too hard by water quenching them. As you described it, and as I understood it, you are water quenching the .38 bullets and then shooting them in .357 Mag cases using .38 Special equivalent loads. That shoudl mean a very low pressure load, which could result in poor obturation of the hard bullet, and poor accuracy.
Try water cooling.
I have used the Lee .38 SWC bullet without the gas check in low power loads without any problem, and good accuracy.

A rookie bullet caster report:

I cast for several revolvers using air-cooled wheel weight metal. Lee moulds. No sizing. No gas checks. Lee Liquid Alox for lube.

Accuracy is "as good" as hand loads that used commercial cast bullets that I was using before(good).

Cleaning was the biggest change. No leading and and much less smokey residue to deal with.

Note that the commercial stuff WAS NOT Beartooth!

Cheezywan