head space issue with 7mm rem mag reloads

tinymike66

tinymike66

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hello, I have been having issues with my 7mm rem mag reloads.
seems that they will not fully go into chamber and can't close bolt. get stuck in there.
I know 7mm rem mag measures the headspace from bottom of case.
May be I am not setting up my resizing die properly.
I usually screw die in until it touches the shell holder. then I give it one quarter more turn.

Any ideas?
 
Head space for a 7mm mag is on the belt so that is not your issue. Maybe you aren't sizing completely and the shoulder needs to be pushed back. Are they used brass from another rifle? It could be the bullet not seated deep enough like chappy said.
 
Of course you've made sure that your chamber is clean and dry?

For this test, lightly lube your chamber with a slightly oily patch. Look into your chamber for any imperfections, nothing? Great...

Now take one of your cartridges, wipe it with a clean and dry rag and then colour it with a sharpy-type marker. The whole thing, bullet included. Make sure that you are feeding the cartridge from the magazine and try to chamber it (keep everything pointed in a safe direction, this is live ammo, remember!)

Now have a look at the marks in the ink. There should be marks from the magazine, and marks from the chamber. And on the bullet, maybe marks from the leade.

*Note* the reason I suggested feeding from the mag, is because the OP doesn't specify the rifle, and some controlled-feed actions don't like to be single fed.
 
OP, how many times have you fired and resized that brass?. If you're FL sizing every time, there's a reasonably good chance you've pushed enough brass down against the belts that the diameter just ahead of the belt is now preventing you from chambering fully.

This has been discussed here several times and is well known otherwise. I've encountered this problem in as few as three firings in a .300 WM. The link below shows a tool to solve the problem and also gives a brief description of what happens - this may be your issue. Scroll down to the third section.

Edit: click on Articles about our die in the sidebar to the left. This is a more comprehensive explanation.

http://www.larrywillis.com/

Yes, eliminate the most fundamental of variables, but don't over complicate things. KISS!

Rooster
 
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Its not a headspace issue, its a sizing issue. You can try screwing the die in a bit more, that might work if the press flex is enough to cause the casing to be not completely sized. Watch carefully when you size the case, is there a sliver of daylight between the shell-holder and the die? If so there is room to screw it down a bit more. 1/2 turnpast the contact isn't crazy, its actually the recomended setting with the Redding competition shell-holders. In any case, it wont cost you anything to try. Another is just try another die if you have access to one.


More than likely though its the die. years ago I had to buy a SB .300 mag die because they didn't have anything else in stock at that moment. Turns out that it was accidently the best money I ever spent on a die, because with the guts removed I can put a little extra squeeze on practically anything with a belt. I'm tempted to get another one and cut it in half so I can do the rest as well.

I've also got the Willis tool, which works as well. It has the benefit of working on all the belted cases regardless of length.

Anytime small base dies are brought up there is always a chorus of guys saying that they never needed them so they are useless. In actual fact, all it proves is that they haven't seen everything. Maybe if they hang around for a bit their turn will come.
 
Splatter said:
Of course you've made sure that your chamber is clean and dry?

For this test, lightly lube your chamber with a slightly oily patch. Look into your chamber for any imperfections, nothing? Great...

Now take one of your cartridges, wipe it with a clean and dry rag and then colour it with a sharpy-type marker. The whole thing, bullet included. Make sure that you are feeding the cartridge from the magazine and try to chamber it (keep everything pointed in a safe direction, this is live ammo, remember!)

Now have a look at the marks in the ink. There should be marks from the magazine, and marks from the chamber. And on the bullet, maybe marks from the leade.

*Note* the reason I suggested feeding from the mag, is because the OP doesn't specify the rifle, and some controlled-feed actions don't like to be single fed.
Click to expand...




its a Remington 700 xcr ii
 
358Rooster said:
OP, how many times have you fired and resized that brass?. If you're FL sizing every time, there's a reasonably good chance you've pushed enough brass down against the belts that the diameter just ahead of the belt is now preventing you from chambering fully.

This has been discussed here several times and is well known otherwise. I've encountered this problem in as few as three firings in a .300 WM. The link below shows a tool to solve the problem and also gives a brief description of what happens - this may be your issue. Scroll down to the third section.

Edit: click on Articles about our die in the sidebar to the left. This is a more comprehensive explanation.

http://www.larrywillis.com/

Yes, eliminate the most fundamental of variables, but don't over complicate things. KISS!

Rooster
Click to expand...

brass was not fired from my rifle, bought off CGN'er and assume once fired.
20 out of 50 reloads were bad, the rest are good
 
358Rooster said:
OP, how many times have you fired and resized that brass?. If you're FL sizing every time, there's a reasonably good chance you've pushed enough brass down against the belts that the diameter just ahead of the belt is now preventing you from chambering fully.

This has been discussed here several times and is well known otherwise. I've encountered this problem in as few as three firings in a .300 WM. The link below shows a tool to solve the problem and also gives a brief description of what happens - this may be your issue. Scroll down to the third section.

Edit: click on Articles about our die in the sidebar to the left. This is a more comprehensive explanation.

http://www.larrywillis.com/

Yes, eliminate the most fundamental of variables, but don't over complicate things. KISS!

Rooster
Click to expand...

Belted Magnum Collet Resizing Die, wow its $98 for that die!
 
tinymike66 said:
brass was not fired from my rifle, bought off CGN'er and assume once fired.
20 out of 50 reloads were bad, the rest are good
Click to expand...

And there is the problem. It is not at all uncommon for cases fired in one chamber to not chamber in another chamber, even after being FL sized. That is one reason that I never bother with used cases.

Belted Magnum Collet Resizing Die, wow its $98 for that die!
Click to expand...

Exactly, way more than 20 used cases are worth.
 
A headspace gauge won't help you. It measures the distance between the boltface and the belt recess in your chamber. Well, measures is probably too strong a word, more like ball-parks the distance.

Where are all the people who wanted to pillory the gunsmith in the other 7mm thread? If you really, absolutely need your cartridges to fit in your gun, it stands to reason that you start with cases that came out of your gun. Oh, sure the range pickups and bought once fired cases will probably work, but maybe not. The maybe nots do happen more often with belted cases.

I've got a large herd of rifles chambered to belted cases, and have found and fixed most of the quirks more than once. There is probably not a thing wrong with the once fired cases you bought, but the combination of his chamber, your chamber and your die doesn't get along. There's ways around it, but might not be worth it.
 
I had that happen to some brass when i ran them through a redding FL body die. The die shaved off some of the brass when they were being sized and the brass piled into the belt.
 
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