.3o8 into .338 Brass Problem

Norm99

CGN Regular
Rating - 100%
468   0   1
Location
Newfoundland
Reformed some .308 brass into .338 federal by running the brass through my FL resizing die. Now, after trying to reload some .338 with the same brass, I'm finding that some of my cartridges are not chambering in my .338 TK3. Of 10 reloads, 3 will not chamber, despite being will under the recommended COL. What gives? Is it normal to run into this problem when changing brass to a different caliber? Any suggestions.
 
Try the brass in your gun before you load it. Sounds like you will have to give it a good crunch to make it fit your chamber. I'd be inclined to use some method to make positive headspace when fireforming.
 
Tried several pieces, after reforming and before loading, all chambered so I didn't try anymore. Most of the brass was once fired, some was virgin. I didn't trim, and I guess I should've. I may have to go back to square one again. Might as well do it right the first time, eh?
 
Did you full length resize the brass after fireforming? I've personally had that same problem with the m96 swede that I've converted to 338-08.

Full length resizeing does the trick for me. I'm not bothered by OAL as the chamber is from a custom reamer, made long before Federal decided to legitimise it. Absolutely awsome cartridge out to 300+ yards with 225 grain hornady interlocks.

bearhunter
 
Did you full length resize the brass after fireforming? I've personally had that same problem with the m96 swede that I've converted to 338-08.

Full length resizeing does the trick for me. I'm not bothered by OAL as the chamber is from a custom reamer, made long before Federal decided to legitimise it. Absolutely awsome cartridge out to 300+ yards with 225 grain hornady interlocks.

bearhunter

Any idea on the velocity of your load with the 225gr IL?
 
I ran Winchester .308 cases through RCBS dies for mine. I trimmed the case mouths even and some were still a little stiff to close the bolt. I did give it a little force, (Loaded ammo, pointed downrange at the shooting range) and they did close and opened and rechambered much better. (This was using once fired brass) Upon fireforming the case to the new chamber, they go in and out perfect. I think you will find the same thing with your rifle. Good luck.
 
Well, the unfired brass chambered perfect, it was only the onced fired stuff that was causing the problem. I deprimed and ran a couple through the resizing die again and they chambered pretty good after that, a little stiff, as you said. It looks like I'm going to have to deprime my 40 or so brass, and run them all through a second time. Something must have went wrong the first time.
Sure helps to get input on this stuff. Thanks.
 
The once fired stuff was already fire formed to fit the .308 chamber it was fired in. When you full length size, your die might be set so that you are not bumping shoulder at all. This wouldn't matter on the new brass, and you wouldn't notice any problem, as it's likely already at spec. The once fired stuff though may have a wee bit higher shoulder...just enough so it won't chamber, or will only do so with more than normal force. You could try adjusting the die downward a very little bit at a time and see if you reach a point where the brass chambers easily...course if you start to buckle the brass before you get a fit, you'll definitely know that's not it! Also, if you set the shoulder back too far, there's a chance you'll start to get either get head separations, or at least see signs of stretching brass just above the head...a mistake I made with some 7mm R mag a while back. To see if you are/are not hitting the shoulder, you can blacken the outside of the neck and shoulder with something like a Bic permanent marker, then run it through the die. It will be obvious from the markings on the blackened area where the die touched and where it didn't. Once it's been fired in your .338, you can used the same Bic marker method to set your die so that you are just neck sizing...as long as you keep it trimmed, it will fit your chamber perfectly, and you will maximize the life of your brass. I make all of my .358W from .308 brass...no grief so far. Apologies for being so long winded, especially if you already knew this.
 
Back
Top Bottom