Home Forums Reloading Bullet Casting Powder coated grooved vs grooveless.

posted 05 July 2021 16:19
Any one have experience with powder coated bullets at higher velocity in 30-06, 375-55, 45-70, 405 Winchester?
Adding to that question is there any thing gained using grooveless bullets vs standard grooved cast bullets with grooves?
Another question: When using gas check bullets, am I correct that the gas check goes on then the powder coating is applied? Thanks for any advice and experience offered.

I've shot 170 gr.powder coated cast lead bullets at factory velocity in my 30-30 which is around 2100 fps. and in my 30-06 I pushed the same bullet or bullets to 2300 fps. with excellent accuracy at the ranges I shoot at. Bullets are cast from 50/50 alloy, powder coated, water quenched after curing and gas checked if needed. Depending on the coating thickness and the gas check shank diameter, some bullets benefit from applying the gas check before coating, I have a few bullets that are easier to work with applying the gas check first. The PC will stick to the gas check just as well as the bullet, so when you apply the gas check it going to be more of a matter of personal preference or necessity, the PC also bonds the check to the bullet so it's no coming off.

The only true grooveless bullets I cast an shoot are for handguns, I can tell no differance between them at least with my shooting skills as to accuracy, but the grooveless bullets do drop from the mold much more easily without any fuss. I don't really shoot any grooveless bullets in rifles, but I do shoot a couple of tumble lubed designed bullets in rifles that once they are powder coated and sized there pretty much grooveless and they shoot the same as they did when I used them with the old Alox TL process but I've only pushed those to around 2K fps. or less.

Most all my rifle and handgun bullet molds are of the standard grease groove design, it's basically the only option for those bullet designs and I can always use my RCBS lubesizer in the event I can't powder coat.

res45 summed it up pretty well! memtb

With my cast bullets, it's apply the gas check first or you can;t get it on after PC.

why do you need the gas check if you powdercoat?

I have read that since the base of the gas check designed bullet will be a smaller area than the shaft of the bullet. It may deform upon ignition of the powder. Having the gas check on protects the base.

In my limited experience, a gas check designed bullet is more accurate with the gas check than with out. I have been shooting 45-70, 305 grains to 420 bullets. When using a gas check design but without the gas check, my shoot groups at 100 yards open up from 3" to 4"-5".

That's because the base determines the accuracy of the bullet.

Funny, because almost every mold has the sprue at the base.

Because the base of the bullet is what steers it as it exits the muzzle, powder coating doesn't remove the gas check shank, therefor you have an imperfect base and it's why it's important to have a flat of a base as possible without imperfection regardless of if it's a gas check or plain base bullet. PC does allow you to shoot a slightly softer alloy and a slightly higher velocity, but it doesn't replace the need for the check once you reach a certain velocity pressure range, I shoot lots of bullets designed for gas checks with the check left off but I don't push them hard i.e. pressure wise or fast regardless of if they are powder coat, traditional lubed or Alox / JPW lubed.

Rez45,

I just started casting again and powder coating. My Lee 44 cal 310g mold has a base for a check. I ordered some gator gas check but haven't got them yet.

Yesterday a loaded so 44 mag with powder coated 310 grain bullets without a check. I tried 4 different powders from mid burn speed Longshot to magnum slow burning pp300mr. I didn't do any accuracy testing just ran them over the chrony but they all made it to the target ok. Velocities ranged from about 1000fps to just over 1100 fps.

I'm not running them very fast but I an using a pretty heavy full charge of magnum powder. Do you see any need for checks based on the powder being used or is it all about velocity? If so what is a good general velocity at which a check is recommended?

I've also heard that some gun powders can react with the powder coat potentially degrading the coating and possibly the gun powder charge too. Some have theorized its the nitro glycerin in double based powders that causes the degradation. Does anyone know about that? The use of a check after powder coating would prevent powder contamination.

Bb