Stuck case/bolt?

Hey guys, got a question. I took my rifle out yesterday (remmy sendero 7mm mag) for some range time. I dont even consider myself a newbie in precision shooting because I have no clue what to do or where to start. Anyways, I figured I’d try a different bullet and went with the Hornady 139 gr SST moly. I usually shoot remington140 gr but the store didnt have any. When I got to the range, I shot what I had left of my 140 gr from the last range trip (about 20 rnds), and let the rifle cool down. After that, I took out the box of Hornady and loaded a round. It went in fine, and after I shot it, the bolt would not move. After wrestling with it for a few minutes, it finally came unstuck. I inspected the case, and couldnt see anything wrong with it. It looked identical to a remington case that I placed next to it. So I figured maybe it was just that particular round. I loaded another in, and the same thing happened. I was not able to get this one free, and had to use a rubber mallet at home to knock the bolt back. So, at $45 a box, this kinda sucks for me. Is this the guns fault, or the ammo? What would cause the bolt to get stuck like that?

Thanks,
Mate

Don’t know but don’t shoot any more of that. Malleting a bolt open is not a good thing.

Excessive chamber pressure.

Sounds like you did get a little more pressure than you should have. I would call Hornady and give them the LOT#. If anyone else has reported problems they should replace the ammo. Should you have any concerns about the rifle take it to a guns smith. I had a Remington sendero in 300WM that would do the same thing and it ended up being a rebuild in the end.

If you or someone has calipers, measure the length of the spent case. That could cause the sticking and overpressure.

Trim length on the 7mm Rem Mag is 2.5".