Bigbill,
Yes, the fired Turkish cartridge looks healthy, the primer is indented in like it should be, there are no abnormalities with the case. I remembered that last year I had a similar problem with my Russian Model 44 Mosin Nagant carbine, no matter what source of ammo I shot through it, I had to use some muscle to open the bolt on it too! It was attributed to the fact that the 1891 Mosin Nagant has a really short bolt handle. I only shot brass and steel cased Soviet surplus through it (7.62 X 54).
Years ago I shot some really hot Egyption 7.92 ammo through my Spanish Mauser 98 Airforce Rifle, that showed all the signs of high pressure. The primer pushed out like a nipple and that rifle had a fierce kick with that ammo. I had the fired case inspected by a local ammo collector who confirmed that it was loaded hot from the signs.
I have owned 4 military Mausers and this Jugo made gun has an odd peculiarity about it when pushing the bolt into the first stage of closing the action, that is with the bolt in the vertical position, the second stage is to push the bolt down after it touches the rear of the receiver. In the first stage the bolt will not go down into stage 2 unless heavier than normal pressure is applied forward on the bolt pressing on the receiver rear. I suspect that it was machined very tight in regards to the contact of the locking lugs with the receiver indents, my other rifles don't need that much pressure applied. And this oddity happens either with or without a loaded chamber, so it must be sloppy machining, there are lots of tool marks on the end of the bolt knob where it sticks out from the receiver.
The Jugo ammo had gas leakage from the outer rings of the primer, it was old and I suspect that it was decayed. I used to shoot alot of the Jap 6.5 surplus ammo that came out of China back in the late 1980's and man, numerous case splits and primers that would punch all the way through. Strong action those Jap Arisakas!
I was wondering if anyone else had a similar experience. I will take the advice of the other writers and check the closing of the bolt without firing a round, with each of the brands of ammo to see if there is a headspace problem next time I go to the range.
Thanks