Thread: New rifle problem

My son Deereman who lives in Canada recently sold several rifles and bought a new Christensen Arms Ridgeline rifle in 300 Rum. Since it arrived he has had it to the range a couple of times, the first time out he broke the barrel in trying different loads which all shot well , an inch or smaller.
Today he messaged me saying he found a real accurate load ( one enlarged hole, sorry can't get picture off phone) but the problem is he has a major effort to get the shells out of the chamber.

Bolt lift is fine, but he has to all but hammer the bolt back to remove the fired shell. Primers look ok on fired shell. Load is 90 grains of H1000 or AR 2217 with the 212 gr Hornady ELDX, according to book .5 grain under book max.
He also tried some 190 gr LRAB he had loaded up from the first range visit which went off without a hitch but when he tried the same load today they were hard to extract. Rifle has had about 50 rounds through it and the first 40 odd on the first range outing went off without a problem.

I suggested the brass was getting old so he is going to load up some new shells and try them but he thinks the ones that were sticking had only been fired twice. He fired some old Nickel plated brass that has been loaded upwards of 7 times and these ( 2 ) extracted fine.
Temp today in Pentiction where he lives was 12 deg so temp should be an issue.

Does anyone have any ideas what it could be, strange why it started doing this on this outing. If it was a chamber problem it should do it all the time ? Any help, suggestions would be much appreciated.