Belted mag bulge?

[jryoung]

So, it's time to reload my Mashburn as I've finally worked through my loaded rounds. Running them through the FL die I'm getting pretty heavy friction and even a little scraping of brass off right above the belt.

I've never had this problem with my 7RM, and am wondering if my load was too hot and the case bulged a bit.

Any thoughts? Should I keep running the ram and figure my case life is limited but cross that bridge in the future? Should I get a neck size die, and use a belted mag collet die like the one from Innovate Technologies?

 

[WapitiBob]

If you full length size and set it according to directions it'll bump the shoulder back about 20 thou. That'll cause the case to stretch right ahead of the belt when fired, thinning it and eventual (like 2 reloads) start cracking the case. I no longer run the correct full length die on my belted 7stw, I use a 7mm mag, which is .002 over case dia, and use it to bump the shoulder about .002. I would look at how far you're bumping the shoulder back and go from there. If you light a wax candle and run the case shoulder thru the flame, it will soot the shoulder so you can then chamber it and gage where you're at. I set mine so the shoulder just touches the soot. They also make gages that go on your calipers and reference off the case shoulder. That middle case is already split so I'd guess you're bumping too far back. And that donut on top of the case belt isn't going to do you any favors.

 

[jryoung]

I haven even really bumped the shoulder yet, I'm hitting resistance with the bulge above the belt. I have the Hornady Lock and Load Comparator and I was only able to bump the shoulder on the case on the right where I was cammed over by a half turn on the die.

 

[mtmuley]

I think brockel has loaded the Mashburn a bit. mtmuley

 

[Blacktailbc]

What lube are you using?
Are the cases only once fired?

I’ve had plenty of cases with a little bit of “chatter” kind of like your pic. But the brass scraping is different

 

[jryoung]

Imperial sizing wax, they're like 1.5x fired. Fire formed with COW, then fully loaded.

 

[Blacktailbc]

Hmm
Might try “one shot” from Hornady . It’s super thin & very slick. My dies seem to like it better than other lubes.

 

[MThuntr]

oversized chamber?

 

[jryoung]

oversized chamber?

I had to explain that to a girl one time.

Seriously, I don't know. Didn't have issue when fire forming. I have the reamer, I could try and measure it.

 

[ol_spark]

Did you lube near bottom of case and not just the upper portion? Is the cartridge all the way in the shell holder and in line with die prior to ram movement? Is this first time loading this cartridge or just first time with this problem?

 

[brockel]

What was your load?

 

[antelopedundee]

What did your primers look like? After the COW fire forming I think I would have loaded the next rounds with the bullet lightly jammed in the rifling just to make sure that everything that's supposed to be moved forward has been moved forward. Pretend like the belt isn't there. As one poster suggested it could be an oversize chamber. I wouldn't expect the COW method to have the same pressure as tho you had used a bullet which is why you didn't see it when fire forming with COW.

 

[brockel]

When I had my mashburn I got away from the COW fire forming just because it didn’t seem like it completely finished out forming like it should have. Just found it better to seat a bullet and use it for barrel break in

 

[Don Fischer]

Seem's to me most problem's run into have a really easy fix but we are so used to guages to measure thing's we end up over looking the obvious! I had trouble with a 7mm Rem Mag years ago, couldn't figure it out. Kept seeing the ring around the head after just a few firings. Turned out a really simple thing and fix was partial sizing. BTW, back them we didn't have the cool measuring tools we have today. I think in the OP's case I'd start with the case lube. He's using Imperial wax. I was never confident I could put that stuff on properly. Did I get enough or not enough? Who knows? Well One Shot solved the problem. Spray it on the whole case from 45* angle and get inside the neck too. The old lube pad some guy's love but there I found I never really knew how much lube on the pad was enough! Well not quite true. Soon as I'd stick a case I'd figure the pad was to dry! My first though is change your lube to a spray on type, my choice is One Shot. If you develop a ring around the head after 3 or four firing's, partial size the case's although I doubt partial sizing will help the problem you have.

 

[Ben Lamb]

I thought this was going to be another food thread.

Sad.

 

[antelopedundee]

When I had my mashburn I got away from the COW fire forming just because it didn’t seem like it completely finished out forming like it should have. Just found it better to seat a bullet and use it for barrel break in

The COW is also messy and a PITA from what I'm told. Better to half fill the case with Bullseye, top it off with some TP to keep the powder from spilling and fire it by shooting straight up. Never tried either one since I prefer to use a bullet.

 

[antelopedundee]

Seem's to me most problem's run into have a really easy fix but we are so used to guages to measure thing's we end up over looking the obvious! I had trouble with a 7mm Rem Mag years ago, couldn't figure it out. Kept seeing the ring around the head after just a few firings. Turned out a really simple thing and fix was partial sizing. BTW, back them we didn't have the cool measuring tools we have today. I think in the OP's case I'd start with the case lube. He's using Imperial wax. I was never confident I could put that stuff on properly. Did I get enough or not enough? Who knows? Well One Shot solved the problem. Spray it on the whole case from 45* angle and get inside the neck too. The old lube pad some guy's love but there I found I never really knew how much lube on the pad was enough! Well not quite true. Soon as I'd stick a case I'd figure the pad was to dry! My first though is change your lube to a spray on type, my choice is One Shot. If you develop a ring around the head after 3 or four firing's, partial size the case's although I doubt partial sizing will help the problem you have.

Partial size just enough so that the case chambers in the rifle.

 

[cahunter805]

Jr
Seems like your load might be a bit hot and causing case head expansion.
Have you measured a fired case just above the base?
What brand of dies?

 

[jryoung]

What was your load?

74gr H1000 and a barnes LRX 168, it's a hot one, and I'm planning on backing off to 72 gr as it was similar in accuracy and only modestly slower.

 

[jryoung]

Jr
Seems like your load might be a bit hot and causing case head expansion.
Have you measured a fired case just above the base?
What brand of dies?

The load is hot.
Are you saying to measure the width of the case above the belt?
Redding, type S bushing.