sans gas check

[tuckerdog]

finally got to get out and use some of the many boolits i've cast with mihec's 433-300 mold. I've had this mold for about 4 months and have only plinked a little. This time I sat down and got serious.
Started at 17.5 grn IMR 4227 and made 5 steps up to 18.6. Sized .429 and shot without gas checks using 50-50 alox bees wax. from a sand bag rest at 25yds the 18.6grn load seemed to be the sweet spot,groups seemed to just suck right together.

Using a fairly soft alloy, ww and adding pure lead until I got 295 grn (hollow point) I figured I'd get bad leading at the higher pressures but groups went from 2.5 - 3" to 1.75 avg for 3 5 shot groups! Anyone else have this experience.

Thank you mp molds for making such a high quality product in a time when the other guys are letting quality go out the window

[rintinglen]

Actually, no, my experience with Gas-Checkless, Gas-Check mold designs has never been been very good, in fact it has been pretty bad. But. mayhap there is something to it. I'll have to try and make up some loads with 4227 and give it a look see.
I have in the past tried the RCBS 358-162, the Lyman 358-156 and the 311-291, none of which worked all that well, sans checks.
I will join you in commending the MP Molds that Miha Prevec Makes--they are dandies.

[geargnasher]

You didn't mention what gun you were using, but I've had lots of good luck shooting without checks. The key to maintaining accuracy and minimizing leading is the same as PB boolits, balance the peak pressure, pressure curve, alloy, and lube to the pressure and velocity being used. Treat the boolit as if it's a raw egg, so everything you can to protect it. That means quality lube, low pressure, long pressure rise time (slow powder), standard primers, and often a filler might help. Many times a person tries to achieve the checked level of performance with an unchecked boolit, and that can sometimes be done without leading, but not often with the same accuracy.

Gear

[tuckerdog]

5.5" superblackhawk alox beeswax 50-50 + 1tablespoon transmission fluid boolit seated on 2nd (middle) crimp groove