I am presently studying all I can on the subject of cast bullets for hunting. I an interested in casting bullets for my 30-30s, and in the future for the 45-70. I understand the reasons for gas checks, but what determines the need for them, pressure, or velocity, or both? Are there any really good websites for learning about casting? I am still in the beginning stages of this ( obviously ), so any help would be appreciated. Thanks

DGK

375hnh,
Bullet design, speed and alloy usually decide if I need to use GC's. Most cast bullets with GC shanks haven't shot that good with-out the gas checks. Over 1800 fps I use GC's and for softer alloys I like gas checks also. They help to keep the leading down. Buy a Lyman #3 cast bullet book as it has some good knowledge in it. There are several cast bullet forums. One is Aimoo.com and lots of us hang out there also. Feel free to ask questions. Also find out if there are any casters near you who could help you learn. Mark

Thanks Mark. I'm off to find the Lyman book. There aren't too many places around, that I have found that cater to the cast bullet crowd in my area. I have become friends with an older gentleman in my home town that used to do a lot of casting, and he has sort of offered to be my mentor.

DGK

You might have to check used book stores or hopefully you have a gun book seller who goes to gun shows and usually has older books like that. Good that you have somebody for a mentor. Mark

I don't think anyone has come up with a substantative formula of when gas checks become required. Factors that effect the nead for them are: combustion pressure, barrel tist rate alloy sheer strength, bullet fit to throat/groove, and possibly velocity, but I think the velocity issue is related back to alloy sheer strength vs barrel twist. The faster you push the bullet, the greater the sheer forces on the bullet.

IMHO, unless you are working with plinker loads in a rifle, ie 800-1400 fps, you're better off starting out with gas checks. The only advantage to not using checks is lower cost, and less labor in crafting bullets. I can't think of any instance where I've found checks to detract from accuracy, provided the bullet had a good check shank.

Thankyou gentlemen for the info. My friend Herb brought me some old Lyman manuals last night, and a coffee can full of .30 cal cast bullets. I am going to play around with them for a while in my 30-30, and an '03 sporter I have. I have a lot of studying to do now.



DGK

Yet another factor is powder burning temp. I know, the exposed surfaces of the bullet bases don't melt from the powder gas, but the temperature of the gas slipping between the bullet and the barrel sure affects "gas cutting." I still have quite a few swaged .44 bullets, soft like .22 LR bullets and similarly wax-lubed. Some are from Speer, some from an unknown maker that I bought off eBay, and I still have a few of the old Winchester-Western 240 gr. SWCGC bullets as well. With 2400, Blue Dot or Unique (hot burning double base powders), I can't shoot the plain-base swaged bullets faster than about 1000 FPS in my Super Blackhawk before the leading gets really heavy. But with 296 or WC820 (Ball powders, despite containing about 10% nitroglycerine, burn very coolly due to the large amount of nonenergetic deterrent), I can load right up to the max and get rather minimal leading with the plain bases. BTW, no longer being able to buy those factory 240 grain lead SWCGC bullets was a big motivation to start casting. Those are the finest factory bullets ever made for the .44 Magnum!