Bulging brass

axialmillipede

axialmillipede

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Hello,

Wondering if anyone on here can help me out a little bit. I got a fast twist 22-250 custom made by a very reputable gunsmith. Remington 700 action, 1:8 twist, bedded into an hs precision stock with a timney trigger and a nightforce nxs 5.5-22 scope. I'm shooting 75 grain berger vld's. This is my first try at longer range shooting, and The darn thing thing shoots like an absolute dream. One hole groups. I've shot some amazing groups at 500,700, and 900 yards, and the rifle is always under 1 MOA, and generally always under 0.5, I'm sure it's me, not the rifle if a bullet strays. The problem I have with it is that it keeps bulging the brass. Now I want to make it very clear, I'm not trying to throw any mud here, hence leaving names out. I'm looking for advice or if anyone has had a similar problem, and how did you fix it. These guys are very willing to work with me, I'm just trying to educate myself a little bit before I go back again. I brought it back to the gunsmith after I tried to fl resize my first lot of fired brass and noticed the die was shaving metal off the case. I left the gun with them a couple weeks, and they told me that they couldn't find any problems and that it was probably my reloads that were too hot. I was puzzled because I've yet to load anything even close to a max load. I found a couple good loads about half way between minimum and maximum. The gun does the exact same thing with everything even all of the absolute minimum book loads, no matter what bullet or powder. So I decided to get some remington 50 grain factory loads, and check what the cases looked like after firing. Same deal. Swells the case. It does it in the same spot, 0.100 above the extractor groove. I shot the same hand loads and factory loads from three other rifles(two factory stock remington 700's and a Montana rifle), the cases all measure the same diameter 0.464 +/- 0.001, which I checked against the saami spec and it's bang on . Mine on the other hand are always 0.006-0.010 bigger and have the same bulge I get anywhere from 0.468-0.474. You can see the bulge with your naked eye. I bought a headspace gauge and checked the cases as well. It seems like the fired brass from my gun is usually 0.001-0.002 longer than fired brass from the other rifles. Anyhow, I'm getting very frustrated. I'm sure this can't be good for the life of your brass, and I bought all brand new lapua brass, which I'm being told is now garbage after one firing. I want to start neck sizing, but with that bulge in the case, I'm thinking that's not a good plan. I've tried winchester and remington cases, I get the same result. I've tried all kinds of powders too. The heavier bullets need a touch slower powders, so I've been trying Imr 4831, h4350, imr 4895, superformance, and a few others. I was using the hornady reloading manual, the nosler, and the berger manual to compare loads. I get really great performance with the superformance, but it swells the cases the worst. So I tried a more conservative load with the imr 4831 and get one hole groups, but at 300 fps less velocity. So I'm a little disappointed that I'm forced to run 200-300 fps shy of most of the book loads, especially considering all the book loads use a 24" barrel, and I have a 26". It's costing me a small fortune in wrecked brass and used components and I really want to get this all figured out. Any advice would be appreciated.
 
Chamber was cut to big. It's the only thing left. You've tried different brass bullets loads and rifles and it goes back to an oversize chamber. The brass probably looks like 303 british brass out of an old lee enfield.
 
Possibly the chamber is a bit large but if you are using American made brass it is most likely undersize brass as well... get a custom die made for your fire formed brass. Virgin brass measuring .464 is undersize. A chamber measuring .472 is common and acceptable. Quality pictures may help with opinions... is the bolt ever harder to lift after firing?
 
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Is extraction difficult at times?

Get access to Go & No-Go gauges for your chamber. While the Go gauge should slide in like daddy into mommy, you should encounter restriction with the No-Go. I bet your chamber fully swallows the No-Go gauge, meaning oversized chamber. See if you can do that and report back.
 
Do a chamber cast and measure what you get. Compare your measurements to cartridge spec. Then check your brass. Your solution will depend on the outcome of your analysis.
 
Who cut the chamber? I had a rifle poorly chambered by Julien at Downrange Precision, the chamber was cut 0.013" over all the way down the case and the headspace was 0.019" longer then max sammi spec. After I ruined 12 lapua brass due to bulging, I sent the rifle to a qualified gunsmith. What reamer was used for the cut?
 
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The issue I wanted to fix was that it was eating my brass. Lapua brass isn't cheap, so it's hard to pay that much for a custom rifle that wears out brass faster than it should. It did show some pressure signs that were very odd, like very flat primers, even at minimum book loads, but I thought that could have been due to either loading too close to the lands or just not liking certain powder. I started backing it off 0.015" from the lands, and it seems to have gone away. Again, I'll try the same loads and see how it reacts this weekend.

Anyhow, I brought it back in and the guys were very willing to help me out, and were very very good about it. They were as stumped as I was and made sure I was taken care of. The end fix was cutting a few threads and rechambering it. They test fired a few rounds of the same factory brass, and it looks like the issue is gone. I'll take it out this weekend and update. Again, thanks very much to all the guys who helped me with constructive feed back. Much appreciated. Like I said before, I'm not going to start finger pointing, just wanted to hear some feedback from people who know more than me.
 
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WHY are you full length sizing your brass? You are using a bolt action rifle, and only using this brass in this one rifle. When you fire a cartridge, it expands to fill the chamber then contracts slightly. You now have a cartridge case that gives better alignment because it has expanded to fit your individual chamber.

If you full length size your cases, you now introduce an alignment error into the rifle because the case is undersized for your own individual rifle. A bolt action rifle should be able to chamber cartridge cases that have been fired in it without full length sizing. For maximum accuracy, you should just neck size only, and then only neck size the case neck down just enough to provide a bit of tension to hold the bullet.

From what you originally wrote and described, you have a very accurate rifle that shot very well in the original condition. The full length sizing of your expanded cases was really not necessary.
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