Last weekend I went off to western Nebraska on a varmint hunt with two good friends.

One guy had a H&R 25-06 break open rifle. He has used this rifle as his deer gun for a few years now, and has never had any problems.

For the trip, he brought along some Winchester factory rounds in 90 grs. While my friend was merrily shooting the p dogs, I noticed that ALL the primers from the factory loads showed gas leaking by and massivly cratered. We talked him out of shooting the rest of the box ( he only had 2 out of 20 left anyway), and convinced him to break out his new .17 HMR anyway.

My question is this. I have a few pieces of brass from the same gun that were fired last year. They show no signs of over pressure or bad headspace. But these shells look like they were way over loaded and almost blew apart. Could this be a recently developed head space problem (can you even get that in a single shot)? Or did the folks at Winchester make a really hot batch of rounds.

My friend is (hopefully) taking the gun to a smith to get checked out. I told him that I would not fire it until it is inspected, but this has me real curious.

Whether it is the rifle or the ammo is a secondary issue. The primary issue is that you clearly recognized the signs of an overpressure load and acted to prevent him firing any more. You get the gold star for that one. Your friend has a lot to learn and from your description is lucky he is not another statistic.

Back to some thoughts and questions on the secondary issue.
You said that you were varmint hunting. Were a lot of rounds fired in a short time (did he get the rifle too hot)? Were there other loads fired that day prior to you noticing the problem with primers that looked OK?
I don't think headspace is an issue, but you could answer that question and eliminate it as a possibility simply by measuring the unfired vs. fired cases.
It is possible that the loads were simply too hot for that rifle. A load that is fine in a strong bolt action might be too much for the cheap single shot he was using. What was the ambient temperature? Sometimes that can push a hot load into the unsafe range.
Maybe they were loaded too hot at the factory, but that seems rather unlikely considering how lawsuit-happy the world has become. Do you have a strong bolt action in that chambering in which to test the remaining rounds? If they were overpressure, you would probably see flattened primers there, too, with less risk.

The temperature was around 95F, and pretty dry. It wasn't a very active town, and we fired once every 10 to 15 minutes or so that morning (according to my range notebook).

When I saw the spent case on the ground, he had already shot 18 out of that pack of 20. All the shells had signs of high pressure, from the first shot out of the pack (prior to the trip) to the last one fired. He still has two rounds from the box, and I told him to hang on to them and take them to the smith.

The neck of the fired case is very "rimmed" on one side where the neck bulged, but pretty smooth on the other. Almost like the gun didn't lock up right. I looked at the fired round I have here at home (I like odd caliber cases, and have a collection of them), and it looks pretty good. I will measure the two (last years deer round and the recent varmint round) and see.

The temperature might be the biggest factor. I will give my friend a call Monday and see if he has had a chance to have the gun checked out.

Were the rounds in the direct sun? 95 degrees air temp plus direct sun and that brass will get really hot pretty quick.

Thinking back, I think that they were in the direct sun.

I also dug up my other piece of brass from that rifle last night. There is some signs of neck seperation, but not as bad as the recent varmit rounds.

My armchair opinion is that there is nothing wrong with the ammo. It's the gun. Either sloppy headspace, the action is stretching (very common on break-opens), the action is partially opening (again very common), or the firing pin may be a sloppy fit in its bushing.

Repeat after me:

Primers are not a reliable indication of pressure.
Primers are not a reliable indication of pressure.
Primers are not a reliable indication of pressure ......

I had a 25-06 that copper fouled really badly and to the point of increasing pressure.

quote:

Originally posted by NEJack:
I also dug up my other piece of brass from that rifle last night. There is some signs of neck seperation, but not as bad as the recent varmit rounds.

It's unclear what you mean by "neck separation". Do you mean a longitudinal crack, or some circumferential feature? A problem with the neck on first firing would indicate either brittle brass or a grossly defective chamber. Excessive pressure has little effect on the case neck.

It does sound as if the action is either stretching and creating excessive headspace (were the primers excessively flattened?), or that the fit between the firing pin and firing pin hole has become enlarged, thus allowing the primers to crater. You don't mention any signs of difficult extraction. Firing a round that was creating excessive pressure would likely manifest itself in making the NEF action very difficult to open.

That action was origially designed for shotshells generating 10,000 LUP of pressure. It is marginal for rifles generating 55,000 CUP.

NEJack,

It's most likely head space. I loaded for a H&R 25-06 that did the same thing w/ every load you ran through it. Even mild loads flattened the heck out of the primers. Some of the H&Rs have terrible chambers w/ improper headspace and some are even off center slightly. Somehow many of them still manage to shoot descent.

Reloader

i find 25-06 and 270, as well as ALL wsm/RUMs, to SPLAtTEr primers, probably more than 60% of the time, even with factory guns.

was shooting with my nephew one august in shreveport, probably 100deg .. and I was popping off a some 257+p (found at the local wally world on sale.. 5.99 a box!!) and he was shooting greenbox 270 130gr ...

mine looked normal, even "light" (think 30-30 accelerator) pressures, and his looked like 3 grains over!!

he switched to some barnes 110 reloads and we kept shooting...


btw, hot and shaken FULL coke cans are great reactive targets.. we scattered them while driving around on a 4wheeler and had to pick them out and off at various ranges

jeffe

By slight pressure signs in the head, I meant that you can see a shiny line near the case head where the case has pulled apart some. Interestingly it only goes about half way around the case.

Haven't heard if the gun went to the smith yet, but I will update eveyone when it does.

quote:

Originally posted by NEJack:
By slight pressure signs in the head, I meant that you can see a shiny line near the case head where the case has pulled apart some. Interestingly it only goes about half way around the case.

I take it that by "pulled apart some" you mean exhibits stretching, not that there is actually a fissure or crack in the case.

If so, what you describe in this comment sounds like the pressure ring. This is the point at which the brass case becomes thick enough as you move from the neck toward the head that it is strong enough to resist the internal pressure and does not expand out to meet the walls of the chamber. From this point forward, the fired case reflects the dimensions of the chamber (minus spring back) and from this point rearward remains more or less at its original dimensions. If the pressure ring is more prominent on one side of the case than the other, then the chamber may be "egged" or canted in relation to the bore or bolt face, or otherwise is dimensionally out of spec.

This rifle is sounding more and more like an excellent piece of "trading" merchandise for the next local gunshow.

quote:

Originally posted by Stonecreek:


If so, what you describe in this comment sounds like the pressure ring. This is the point at which the brass case becomes thick enough as you move from the neck toward the head that it is strong enough to resist the internal pressure and does not expand out to meet the walls of the chamber. From this point forward, the fired case reflects the dimensions of the chamber (minus spring back) and from this point rearward remains more or less at its original dimensions. If the pressure ring is more prominent on one side of the case than the other, then the chamber may be "egged" or canted in relation to the bore or bolt face, or otherwise is dimensionally out of spec.

This rifle is sounding more and more like an excellent piece of "trading" merchandise for the next local gunshow.

Yes! Pressure ring! Man I need more coffee.

I have been trying to convince my friend toeither get a new barrel or scrap the rifle. He won't trade it in, since it has problems. Sad thing is he bought it used from a well known gun store in Lincoln, NE.

Determing if it's a pressure ring or insipient case seperation is just a grinder away...grind the head of a fired case half off and look for thinning inthe brass. 'Stretchy' actions are very prone to this...