Home Forums Reloading Bullet Casting gas checks. when are they necessary?

I would like to get into casting bullets for the cost savings, with bullets as expensive as they are these days. Also I like the idea of being as autonomous as I can, and while stocking up on powder/primers being ALOT cheaper than stocking up on the slugs themselves. However, I do not like the idea of having to stock up on another item like gas checks.

So the question is, if a mould is set up for gas checks, do you need to use them? And at what point pressure/velocity wise do they become required. I like the look of the rcbs 30-180-FN for my 30-30 but I don't like the gas check. Would I be able to load those with out the gas checks to say 1800-1900 fps without running into problems? I saw a article that listed I believe 29 grains H4895 as a max load for that bullet but it didn't give a velocity or pressure.

dunno, shooting GC bullets with no GC sometimes works sometimes not.

why don't you just get a mould with no GC on it?

or have one cavity "honed" out to make it a plain base?

Honestly, I wouldn't know how. Does RCBS have a custom mould department? The reason I like that mould is from what I have read it normally drops at 195ish grains with lube and gas check, and that is the only 30 caliber flat point mould I have found in the 190 grain range. I am looking at that range because full loads seem to be just under 2000 fps which seems to be the ceiling for cast bullets.

there are people around who can hone out a mould to a plain base but you'll have to pay for it of course.

If you are serious let me know via PM and I'll tell you some options.

Mortre 2000fps is NOT the ceiling with cast bullets. I run a 350gn gc bullet in my 404 at 2365fps that has shot into under an inch at 55yds with aperture sight.I also have a source who says he runs a 22 cal cast bullet at 2800fps. The cost of gas checks is negelible when you look at per bullet cost and as most times a gas check bullet will shoot more accurately with than without a GC, it makes sence to use them. The only thing to watch out for with casting your own is the addictive aspect of the practice. I started casting from the cost savings aspect but now cast for the pleasure of shooting my own bullets

Von Gruff.

Vongruff is right, the ceiling is not 2000fps.

Use the gas checks when speeds are 1200 fps and over. Of course there are some exceptions, type of metal, etc.

You can heat treat your bullets and use plain linotype.

I shot a load for many years in a 357 Mag with the Lyman 158g with gas check with 15.0g of 2400. I used the #2 mix and it leaded the barrel in my 357. I figure that the158g Bullet bullet was going 1200 fps.

Lots of variables.

Gas checks come in a box of 1,000. That is enough for a lot of shooting!

One of the things that makes cast bullets interesting, and also frustrating, is there are no hard and fast rules.

There are many factors that have an effect on weather or not a cast bullet will lead the bore. The condition of the rifles bore, the barrel twist, the throat of the chamber vs. the bore dia, the dia of the bullet after sizing, the lube that is used, the alloy of the bullet, the hardness of the bullet, and the peak pressure of the load.

For some ballpark guidelines, gas check bullets shot w/o gas checks tend to have problems with leading at lower velocities/pressures than a plainbase (not bevel base) cast bullet. With a not too hard bullet sized 0.001" over bore dia (if the chamber allows) and using a good lube you'll likely find that your gasless checked bullets shoot fine at 1200 fps, plainbase can be driven 1500 fps (maybe 1700 fps if everything is perfect), and if you run a gas check on the gas check mold you should have no problems with 2000-2200 fps.

The RCBS 180 gr 30 cal mold is about as good as they get, just spend the extra couple cents per shot to run gas checks, and use a good lube like LBT blue. Cast from wheel weights and air cooled will outstanding from a 30-30.

458 lott
That agrees with everything I have read/heard; I am new to casting myself and am looking for info.
Thanks

I shot these long ago at 100 yards with a TC contender 30-30. I ran out of gas checks so I tried them without. All shots at 50 yards went through the paper sideways.
The gas check was designed to take the rifling at the rear of the boolit if high velocity or soft lead skidded past the base. That opens a channel for gas. As long as the check will keep the land and groove size on the base of the boolit the same size as the bore, all is well.
But leaving a check off will also reduce the drive area so a boolit no longer matches the twist. In other words the boolit is now too short.
Yes it will work in some guns at certain velocities and the only way to know is to shoot them.

I have found that 1700 FPS is the fastest that plain based bullets can be reliably fired without a gas check.
So all of my faster rounds include a gas check.
Frank

I see the adds for, and the write-ups about the Freechex II. It is a die for making your own gas checks and in NZ$ is about the same price as a 1000 GC. Have only seen good things about it. Have not long bought 1000 of the 44 and 7mm cal although have only seen the 30, 312 and 44 cal so far.

Von Gruff.