Help! I think my 700 chamber just let go!

I have been reloading for this particular 700 SPS chambered in 7 mag for about 4 yrs, bought it new. It has had some where around 1500 of my reloads through it, all using RL22 and never any sign of excessive pressures. Anyway, my brass has recently been showing what appears to be a radial fracture transfer from the chamber. Since I inspect my brass after each round fired, I saw the extrusion transfer on the brass from the initial point of origin as it quickly grew in radial size. I have not had a case head separation, ever, and can't imagine how, or why this could have happened. During the last 20 rounds the radial extrusion on the brass has increased in length from one round to the next. If I had been having head separations I could see how I would have damaged the chamber with gas cutting, but this is not the case at all. All my brass has always been clean and in good condition following each firing.

I'm bummed.

The common load I run, and the one's that I was running when this occured was 64.5 grains of RL22 and a 139 gr Hornady with necked Win brass, OAL at .010" off the lands, same load I have been shooting for ever in all my 7 mags. without incident. My brass has always looked 100% normal without any incipient head separations or gas leaks any where. I'm extremely anal about my brass inspection process and never use brass that is in question of being worthy to reload.
Anyone else ever seen something like this happen without any probable cause on the 700 SPS 7 mag.?

No, I have not checked head space, this is just the first and initial point of inspection. All I have right now is a radial separation inside the chamber, and brass that matches such.
GS

No, it's not the same 700 as my April problem. That one was a very old ADL that had had who knows how many thousands of rounds through it, this one is a rather new stainless SPS.
And I will have it properly inspected when I get back from my hunting / fishing trip next month.
GS

Otto, do you think they would be willing to take care of my other older 700 one as well, the ADL.
I'll be honest here, if I thought for one moment if it was something I was, or have been doing wrong for the last 30+ years of reloading I wouldn't be advertising these catrostrophic failures knowing it was my stupidity that caused it. Additionally, I have never had a single problem with any of my reloads since I started doing this hobby. But I do load them full tilt most of the time, but only in a proper work up process, watching for any sign suggesting I'm breaching safe operating pressures. I don't encounter case separations, blown or leaking primers, or any case issues that indicate I'm beyond the limits. Do I use slow burning powders and push the envelope, yes, but again not to the extent that I ever, ever, separate or other wise breach the brass or primers. And the 7 mag is the only cartridge I've ever had a problem with at all, and the problem has been limited to these two awful incidents.

The only thing that comes to mind is that my Son bought several boxes of factory ammo when the rifle was brand new, and all but a few rounds of it would not chamber, and those that did would not eject without excessive force after being fired. Those were mixed brands, Remington and Winchester, so that leads me to believe that something was out of spec with the chamber from the get go?
GS

Same problem with two rifles in 30+ years of reloading but only months apart. I'm as baffled by this as most here in this regard. I had a friend come by earlier today and checked head space using a go-no go, all was fine.

As to brass and loads per action, I only use the brass that has been fired from the specific action that it originated from, and necked brass at that. The brass that I was using were well formed to each of those chambers, I know the brass was on at least it's 4th necking and had not yet been through the FL die. Either way, this is odd and does present a number of questions to address, especially for a long time reloader who has had nothing but uneventful years of reloading, that is until now. But I have not changed anything in the process in all those years.

Primers were normal appearing, CCI-250's, primer pockets were still in good condition, no leaks or loose ones.

Powder was from the same lot thoughout that load work up, up to that day. And I weigh each and every charge on my RCBS beam scale. And also, one of the first things I did was I checked the the scale using check weights.

And 64.5 grs. is not full tilt, although RL22 is a slow burning powder that produces upper to full tilt loads.

Seating off the lands .010" in that action is no problem at all and allowed for more than .284" of neck to bullet shank contact with those 139 gr. Hornady's, and yes, they fit the magazine with no problems. All my brass is maintained to within trim too lengths, I'm very particular about my brass in every aspect.

I've decided that when I return from my vaction I'm sending both of those rifles to Remington for inspection and proper diagnosis, even though the other one (ADL) is rather old and has had quite a few rounds put through it, RL22 loads at that. Nothing else looks out of the norm, the lugs are completely normal in appearance, and the bolt face isn't unusual looking. I'm no confirmed expert here, but I am very anal about my reloadong process and have never stepped outside the proper procedures since I began reloading in the late 1970's. I always use a scale for each and every cartridge and for every weapon I load for, except shot shells on my 600 Jr's. as they utilize powder bushings of course. But I use the scale to determine which bushing is throwing the desired charge.

I load for other older 7 mags, one is a custom M98 action / Douglas barrel, and load for family members 7 mags and a host of other high powered cartridges / rifles and all have been uneventful, other than the usual reasons for work ups and tweaking load specks to obtain improved accuracy.

GLOOB, I find your plausable cause to be a very possible explanation. This chamber is tighter than most 7 mags I load for. It is easy to get up to the lands without having to sacrfice any neck to bearing contact. I've had difficulty when I first bought the rifle getting factory ammo to chamber and or extract. Indeed I may have not been seeing signs of over stress, and especially loading full tilt as I do?

Thanks to all for your input, and I'll let ya all know what Remington has to say when I get their response.

GS

Kelbro, I'm going to see if one of my son's can assist me in gtting some picks posted. And no worries as to offending me, I'm just as capable of making a mistake as anyone.

As to what Remington has to say, I'm going to be 100% honest with them in that, both actions have had reloads almost exclusively put through them. And also that of the several boxes of factory that have been put through the SPS wouldn't extract, and most wouldn't even chamber. That right there indicates to me that something wasn't right with the chamber dimensions, and could be a major contributing factor.

As I had mentioned already, it has been no problem getting the bullets seated up to the lands while still providing plenty of neck to bullet contact and fiiting the magazine. Even 100 gr and 110 gr. bullets could be seated up to the lands and still maintain the recomended .284" of shank to neck contact.

Also unusual, when it became necessary to bump shoulders back, I had to adjust the FL die down as far as it could possibly go in order to bump the shoulders back at all.
GS