Wife and I went to the range today to get a little recoil exercise and me shooting a mark v 340 weatherby with just bought norma cases with handloads with 250 GR. sierra spbt using H4831 col 3.560" 82grs for 2700fps at the muzzle which is below max.
After shooting the 3rd shot, upon opening the bolt to load another round, the only thing that came back with the bolt was the belted end. Case was stuck in the chamber and even after pulling the bolt and attempting to extract the case was to no avail.
We bought the rifle to John (gunsmith) and he was able to extract the case, but since it was Sunday night when we bought it to him, he wants to do more measurements on the gun for head-space clearance.
He did use a Sinclair head-space tool for quick checks and every thing was in specs, he then dropped the loaded shells into a gauge and they checked out ok.
I will be going over there tomorrow afternoon to find out whats up. The empty brass I bought was from a well known online retailer and I have been reloading this caliber for almost 25 years.
Any ideas?

The first thought is also Head space problem..

Some gunsmiths uses one size fits all head space gauges for most similar calibers ,
I believe belted cases require different gauges.

Other reason might be that particular case had a fault line on it, but this is a very rare occurance

Keep us in the news!

My first thought would be that the cases are possibly being re-sized a bit too much and setting the shoulder back. I would adjust my sizing die to only touch the shoulder of the case enough for positive chambering. Yes, I know belted cases are supposed to head-space on the belts, but the shoulders do still expand to fill the chamber. Usually the first sign you see is failure or stress lines at the web-line. Readjusting the die to minimally size the case will also allow the case to head-space on the shoulder as well as the belt...and may well give you better accuracy. Belted cases often vary a great deal in shoulder placement. Head-space gauges for belted cases only show that the head-space is correct in regards to the belt location...they give no indication of whether the shoulder is where it belongs.

SSL,
I have only done neck sizing with this caliber using RCBS 2-Die Neck Sizer # 30602. I never had to do a full length resize in the almost 25 years reloading this caliber. Taking the day off work and heading to the smith, he already called me this am and wants to head out to the range using his gun instead of mine. He has checked chamber and shoulder measurements on my gun and every thing is in specs. His idea is to use his gun to fire my reloads and use my gun to fire factory loads to see what happens. The range opens up at 8am my time and will update as soon as I get back home.

OK, looks like you have my concerns covered. Will be interested in hearing what you find. Good luck!

Was this once fired cases you bought from this dealer? Could it be that one that was at the end of it's usefullness somehow sneaked into the once fired cases?

Just got back and my poor shoulder took a beating from firing 80 rounds of shots with 40 of them at full throttle. Here's what we did, at the shop before heading out to the range, we pulled the bullets and dumped and weighed the powder in each shell. Powder was at 82grs +/- 1/10thgr. Then assembled the cartridges and headed out to the range. I fired all 20 factory loads in my gun with out a hicup. I then fired my handloads in Johns gun and 7th shot was a hellava time getting the bolt open.
We eventually got the shell out of the chamber and and did some measurements. Immediately John said these are not new cases.
That being said, we headed back to his shop and we reloaded two times the factory ammo I shot in my gun to full house max using 250 gr sierra spbt ahead of 85grs h4831 at 2900fps using a chrony. Never had a problem.

Bushy
You nailed it, it was more then one but from now on I will only buy online from the business that begin with M's and C's.

Also, one thing that needs to be brought to attention, for people that shoot belted ammo, the very first time you shoot it in your rifle, the headspace is on the belt.
After you reloaded your empty brass and do a light resize using neck sizer only, then when shooting the reloaded shells in the same gun will headspace on the shoulder and not the belt. It will give more life to the brass.

That's what I do with my .30-30 brass. I set the resizing die so that the case headspaces on the shoulder of the case. Mostly because I do have a headspace problem with my 62 year old M94. Primers were backing out just a smidge (.030"). Moving the die out by .030" forcing the case head against the bolt face solved the problem...