Elkhunter1983
Well-Known Member
What he said. The IT die is a life saver with belted mags.
7 mag brass problem
- Thread starter BW64
- Start date
Help Support Long Range Hunting Forum
ment2bfree
New Member
Try Larrywillis.com he makes a collet die for belted magnums when you have this problem. Hope it helps Mike MAs you can see there is a pronounced ring just above the belt. If I adjust the die to remove it the shoulder gets bumped .005-.006. I have read that is way too much. Solutions please? I'm about ready to pull this barrel & replace it with a non belted caliber!!! Thanks. BW
sureshot21
Member
- Joined
- Aug 7, 2009
- Messages
- 22
Hi ive just read through all the replies.
1st there is an issue with either barrel fitment and headspace
2nd chamber dimentions
or 3rd die undersize.
So please dont just go buying the larywills die until you fix the underlying issue.
If you have a new unfired Win case set your headspace off it instead of the headspace guages. Take your firing pin assembly out before you do it if its loaded ammo.
This should allow you to set the barrel back further so the belt of the actual cases you are using wont have clearence in the belt groove.
The headspace for a belted mag is sometimes a lot more generous than is required with the brass. And as you have a Savage you can adjust it out.
This should allow you to size the case by pushing the shoulder back .002" max as if it was a non belted case.
Also remember Win brass is always undersize at the case head so they will look like they are bulged in a max size chamber.
2nd try to obtain another full length sizing die just to compare to your die. If you set the headspace to Minimum on the Win cases and with 2 different brand cases you get a burr forming as you size the cases it could be an oversized chamber. That will lead to case seperations.
The larywills die is helpfull to use occasionaly if you are getting cases sticking on the case head. That is not your problem at this stage and it wont fix the issues your having only mask the problems until you get seperations. The Forster Co Ax is an amasing press and switching the shell holders around wint work as the other side is to small.
Please try this when we build belted mags we always try to shorten the headspace to suit the actual cases being used its the same thing we do with rimmed cases.
Hope this helps
Cheers Bill
1st there is an issue with either barrel fitment and headspace
2nd chamber dimentions
or 3rd die undersize.
So please dont just go buying the larywills die until you fix the underlying issue.
If you have a new unfired Win case set your headspace off it instead of the headspace guages. Take your firing pin assembly out before you do it if its loaded ammo.
This should allow you to set the barrel back further so the belt of the actual cases you are using wont have clearence in the belt groove.
The headspace for a belted mag is sometimes a lot more generous than is required with the brass. And as you have a Savage you can adjust it out.
This should allow you to size the case by pushing the shoulder back .002" max as if it was a non belted case.
Also remember Win brass is always undersize at the case head so they will look like they are bulged in a max size chamber.
2nd try to obtain another full length sizing die just to compare to your die. If you set the headspace to Minimum on the Win cases and with 2 different brand cases you get a burr forming as you size the cases it could be an oversized chamber. That will lead to case seperations.
The larywills die is helpfull to use occasionaly if you are getting cases sticking on the case head. That is not your problem at this stage and it wont fix the issues your having only mask the problems until you get seperations. The Forster Co Ax is an amasing press and switching the shell holders around wint work as the other side is to small.
Please try this when we build belted mags we always try to shorten the headspace to suit the actual cases being used its the same thing we do with rimmed cases.
Hope this helps
Cheers Bill
WalksLikeADeer
Well-Known Member
Try adjusting the die per instructions. The Lee FL sizer die will bump the shoulder back to SAAMI specs so a .006 bump would be totally normal. You can't use that die to only bump the shoulder .002 consistently. If you want to only bump the shoulder .002 then get a Redding Body die which is what I use and then the Lee Collet die to size the neck to .002 tension. The neck collet die does not push/pull on the neck like an expander ball die which can cause inconsistencies in shoulder bump.
WalksLikeADeer
Well-Known Member
Just for comparison, my Remington 7mm RM brass just ahead of the belt, fired out of a Remington factory barrel measured .514" and .513" after sized with the Redding body die.
Something to keep in mind also, is that even good calipers can be off +/-. I just realized mine were off .001" when compared to micrometer that measured to 1/10,000". I realized this when my calipers kept measuring .242" for .243 bullets. When measured with a micrometer they all measured .243-.2432". Good luck!
Are your dies brand new or did the problem start after a while of use? 7mag is a great gun. Stick with it you'll figure it out. So I just resize to the bottom of the neck because I know I'll be using the brass in the same gun time after time but I can alwaya tell when my lube pad is getting low on lube on because the handle gets harder to pull up and I actually get a dry sounding sqeak pulling the hande up from resizing stage. I can always tell if I have too much lube because the neck will push down and swell the shoulder or put dimples in the shoulder. Either way stick with it. There is a great much of guys on here that will see you through the complete issue. Good Luck
BW, a friend and I recently purchased 7mm Mag barrels for our TC Encores. I have a factory TC barrel and he has a EABCO custom heavy barrel. We are both experiencing a similar issue. I'm using Lee FL die and he, Hornady. We are both reloading Winchester brass and the problem visible expressed itself after the third reload. However before we realized the issue we both had case separation above the belt and ended up with cases stuck in the chamber. We've only been reloading cases two times now. Just purchased Hornady brass, thinking it was the Winchester brass. But after reading these posts and others on the net I'm thinking the Larry Willis solution may be the answer. So thank you for sharing your problem and others for your experience.
greenejc
Well-Known Member
Some 7mm Remington magnum rifles have long chambers. Since they don't head-space on the shoulder, sometimes they will stretch the brass on the first firing and expand the brass above the belt. (they head-space on the belt) Have a gunsmith check the chamber. Also have him check it just forward of the belt to see if it is possibly too wide at that point, which would allow the brass to swell excessively just in front of the belt. If that is not the problem then try a different set of dies. Also, there is a company out there that makes a die designed just to size belted magnums and remove the bulge that eventually develops in front of the belt. Most commercial dies won't remove said bulge because they won't size far enough down on the casing without bumping the shoulder back too far. I think it used to be sold by E. Arthur Brown Inc. I don't know if they still have it in their inventory. And I won't ask if you're using case lube because if you haven't stuck a case in the sizing die, you're obviously using lube. Keep your powder dry.
Stiletto150
Active Member
- Joined
- Jul 25, 2013
- Messages
- 31
Send it in. Have them check the chamber. I just checked 4 different brass. Remy 7Mag and 300 WM(Same parent case) Win, R-P, Fed and ADG Brass. ADG once fired .512. RP and Win 2x and 3x fired-.513" Fed 2x fired with second sizing just the neck .513" I have the LW die and it can be a pain to do every load every time. Your chamber sounds like it's .516" + and no brass will hold up to that. It must be a Friday afternoon assembly....have them check it on their dime. They might just set it back and the headspace won't grow that much anymore. Or you might get a properly cut chamber back from them. If you think about it set your caliper for .003"-that's how much your die is shaving off your case.
johnnyk
Well-Known Member
Appears from the photos that the resizing die is not bored to true center or kinda offset or maybe in the shell holder.
Is the brass true to spec?
Is the brass true to spec?
