CoW or PC Cast Bullet

[WardT]

Hi
I'm getting ready fireform some 30 Alaskan Mag (30-338).
I have always used J-word before, but I do not want the barrel wear.
Is one better than the other , Cream of Wheat or powder coated cast bullet ?

Wardt

[popper]

I decided not to use CoW in bottleneck 30/30. Lots of PCd rounds, pistol & rifle, no wear I can tell, no lead either.

[WardT]

How did your shoulders form ?

[Mk42gunner]

I haven't done a lot of fireforming, but I never got the shoulders to fully form when trying the cream of wheat method. I have had good luck with using a j-word jammed into the lands though.

I see no reason a cast boolit wouldn't work as well.

Robert

[popper]

Ward I don't fireform anything, just read a lot about CoW and decided against it as filler. Lube dents on 308 & 308MX disappear with stiff load, PC cast not jammed to the lands..

[leadman]

I use COW to fire-form most of the time. The key to getting the shoulder to blow out is to use a stiff charge of a fast burning powder. I use 20 grs of Unique to fire-form the cases for my T/C Encore in 7mm Rem Mag. If I don't fire-form these the cases are only good for 2 to 3 loads, after FFd I can get 6 or 7 loads. All the new 7mm RM brass I have tried is short from the belt to the shoulder. I had some that is short from the base to the top of the belt also but I head-space it to .001" to .0015" so the belt is irrelevant.

For my 7mm RM I prime with whatever primer fits the hole (usually from deprimed cases), add 20grs of Unique, fill case to half way up the inside of the neck with COW tapped on the bench to settle, then put a plug of wax or boolit lube in the neck to hold everything in.

[WardT]

leadman
have you used a false shoulder to keep the head against the breach face ?

[mart]

I'm making an assumption here but if you are using 338 brass why not just neck down the case with your dies set for zero clearance, i.e., no headspace, and start your load development? I don't see the need for COW in this case. It sounds like an extra step. From what I can tell the dimensions for the 338 and 30-338 are identical except for the neck diameter so it would seem that fire forming would be a moot issue. That is unless your using a wildcat version with noticeably different dimensions.

I've formed a lot case with COW but its always been to go up in bullet diameter and to change the case dimensions. The 400 Whelen is a good example. I made my first cases for it by fire forming with COW because I didn't have a set of dies yet. After fire forming, I just neck sized the cases in a 41 magnum die until I got my dies.

I also wouldn't be too concerned about barrel erosion with either jacketed or cast bullets. You didn't specify how much you'd be shooting this gun nor its intended purpose. If its going to get a lot (I mean an awful lot) of shooting, barrel erosion might be a concern. Is this going to be a cast bullet gun or are you going to shoot jacketed and just use it a few times a year for hunting. It would take a lifetime of shooting to wear out a 30 caliber barrel, even a magnum. Of course any barrel can be eroded by shooting too fast and too much without letting it cool. With normal shooting and load development it would be very difficult to ever wear out a 30 caliber magnum barrel. My 300 has had a bucketful of j word bullets down the pipe and is still as accurate as the day I bought it and the throat and barrel still look great. My thought has always been one should be lucky enough to either live long enough and/or shoot enough to wear out a rifle barrel. Either way you've probably had a lot of fun shooting.

[WardT]

Thanks