I helped a buddy put together some rounds for his M-98 mauser. These were 180g sierra with 77grains of IMR 4831. It looks like we screwed-up by loading for H4831 instead of IMR-4831 at 73g. A couple of these rounds were shot and some very severe pressure signs were seen(sticking bolt,flattened primers, one blown primer). We are pulling the bullets and reducing the loads now.

I attempted to resize the cases that were shot in his gun but found that I was unable to set the shoulders back so they would chamber in his gun. This has me puzzled. I'm now questioning where my problem is (dies, chamber, brass) He is taking the rifle back to the shop where it was chambered to get it rechecked with some gauges. The dies are some older RCBS in new condition. Is it possible to stretch a case to the point where it can't be resized? Or am I looking at issues with the gun or dies? We would like to reload this $$ Norma Brass.

I'm feeling lucky that nobody got hurt with with these loads. It's been a lesson and I plan on working loads up and paying attention to the details from now on.

quote:

Is it possible to stretch a case to the point where it can't be resized?

No....you should be able to resize the cases regardless of the amount of stretch in the chamber.

If you had that much pressure the brass might be history anyway. Normally if I've gone to the point of blowing a primer the head has expanded to the point that it doesn't want to hold a primer.

Just curious if you had worked up to that load and then used the wrong powder or simply started at that point?

I've had a couple of other belted mags that the factory die wouldn't allow me to bump the shoulder. I took a second shell holder and filed the top edge. Didn't take much.

My sierra manual shows from 67.2 to 73.2 grains of IMR-4831 and from 70.1 to 77 grains of H4831.
I would strongly reccomend that you start at the bottom end and work up by half-grains or so.
Chambers and barrels vary, your rifle might show pressure way before the max and might be at its most accurate well below max also.

Paul
I didn't work up the load. It was stupid and I should know better. He insisted he wanted some Maximum loads and we looked up the data and then screwed up between the different 4831 charges. My buddy didn't say anything about the sticking bolt. I asked to take a look at the cases for pressure signs and found that it took two hands and alot of force to open the bolt. Thats when I saw a blown primer.

I'm using LEE shell holders with the RCBS dies.
Is this a possible reason for my inability to correct the shoulder on these rounds?

quote:

I'm using LEE shell holders with the RCBS dies.

I've never tried or measured the lee holder. So it would only be a guess on my part. In my cases it was a RCBS holder and RCBS die. You might try a rcbs holder just a couple $$.

I have a 308 Norma. While I have more experience with the 165s my Load for a 180 Nosler is 71grs of IMR 4831. I happen to load for 2 friends 300Wmags and the accuracy load for them is less than your 73grs of IMR4831.

Remember friends must always protect friends from themselves.

I understand, friends are good to have and it's kind of hard to say no when they're dead set on something. But, there's more than one way to lose a friend.
If he is properly impressed with what happened, "work up" a load" starting at the bottom. I realize that that rifle might be not too much fun at the range, but that's the only way to protect your friend from himself.
Speaking of protection, the law could be kind of rough on someone who knowingly provides dangerous ammunition to a dead person. A bereaved widow and a couple of poor little fatherless children could cost you a lot in the courthouse, and any judgement there can be renewed for many years. You could lose everything you've got now, and will accrue in the future. The question might well be whether you knew better, regardless of what the corpse insisted upon. Just because he was dumb doesn't give you an out. You can't get out of that sort of thing in a bankruptcy, by the way.
My advice is to not load for your friend unless he plays by the rules. Factory ammo will maybe let you keep a live friend. If he goes berserk over you not loading for him and you lose a friend, well, that's better than letting some bull-headed yo-yo destroy your life out of a desire on his part to be the biggest ker-banger in Oregon.

Toss the cases, they're junk. Before you load any more for that rifle, take a good look at it and talk with the gunsmith yourself. I suspect that those two rounds might have been over 60,000 psi and that rifle could be dangerous junk.

I think the 308 Norma Mag is designed to have some freebore like Weatherby rounds. If your chamber was cut with no freebore, there lies your problem.

I have one without freebore and starting loads yield close to the velocity that full power loads should yield.

I found out my problem shooting Norma factory 180 grns loads and getting close to 3200fps over my chronograph. I had to pry my bolt open.

I pulled the bullets and loaded a starting load of H4831(69.9) and Hornady 180 gr.bullets and got 2980fps.

Always start off low and work your way up.

Rojelio

A point not mentioned...the Norma Brass I found to be on the "soft side". I had issues with soft brass expanding too much with hot loads...and then the bolt had to be hammered open with a leather mallet, etc. What happens is the brass flows just too much...being softish. When I changed to stronger, normal brass...the problem stopped, even though the same hot load.
I shoot a .308 Norma Mag too. If you can get another brand of brass...I don't know if RWS makes .308 Norma brass...that would be the way to go. I don't like to use Norma brass unless I have to, I suppose you could probably form .338 Win Mag brass to .308 Norma, then size it...might work better than Norma brass.
The soft brass issue had me stymied at first...too much signs of overpressure...but was the lousy soft brass, not the load.
Best Regards,
Tom

quote:

The soft brass issue had me stymied at first...too much signs of overpressure...but was the lousy soft brass, not the load.

I found that in my wildcats the 280 Norma brass would start to expand "around" 67000+(at least on our stain guage). So I always used that as my stop point since I had no other data.

quote:

Originally posted by mcbob:
I helped a buddy put together some rounds for his M-98 mauser. These were 180g sierra with 77grains of IMR 4831. It looks like we screwed-up by loading for H4831 instead of IMR-4831 at 73g. A couple of these rounds were shot and some very severe pressure signs were seen(sticking bolt,flattened primers, one blown primer). We are pulling the bullets and reducing the loads now.

I attempted to resize the cases that were shot in his gun but found that I was unable to set the shoulders back so they would chamber in his gun. This has me puzzled. I'm now questioning where my problem is (dies, chamber, brass) He is taking the rifle back to the shop where it was chambered to get it rechecked with some gauges. The dies are some older RCBS in new condition. Is it possible to stretch a case to the point where it can't be resized? Or am I looking at issues with the gun or dies? We would like to reload this $$ Norma Brass.

I'm feeling lucky that nobody got hurt with with these loads. It's been a lesson and I plan on working loads up and paying attention to the details from now on.

Scrap the brass that was fired with the overload (IMR 4831 77Gr. 180 Gr Sierra), it is now UNSAFE to reload.

quote:

Originally posted by vapodog:

quote:

Is it possible to stretch a case to the point where it can't be resized?

No....you should be able to resize the cases regardless of the amount of stretch in the chamber.

Well, i would say there are times when the case can NOT be resized to fit a chamber with standard dies.There is more than the shoulder that has to be resized (pushed back). The area around the belt is not touched by the sizing die. This part of the brass can be the problem.

Per the Hornady Handbook Of Cartridge Reloading 6th Ed page 439, 178-180 Grain Bullets...the maximum load of IMR 4831 is 64.0 Grains.. The Max load for H1000 is 79.9 Gr..The Max load for RL 19 is 72.4 Gr.. I have had a 308 Morma Mag rifle since the 60s. That was one hot load, You are luckey. Dont try to make that 180 Gr bullet go over 3,000 FPS out of a 308 Norma Mag..

Thanks to all for the suggestions and comments.
In trying to set the shoulders on this brass I adjusted the FL sizing die down until I was just camming over the lever with full contact against the shell-holder. As mentioned the dies were RCBS and a Lee shell-holder. I always assumed shell-holders were pretty generic. We will be trying a RCBS holder to see if there is a difference. After that loading some reduced loads. Thanks for the help!