Did some shooting at the range the other day with my .375.

I've had the gun since '94, but had not shot it for 5-6 years as it was in storage in Europe.

I had a box of RWS 300gr soft, and started firing away, nothing special. Then, I did a 5-rounds fast string (reload, aim and fire as fast as possible, stock on shoulder), no problem.

Reloaded the gun, fast fire again, third round was difficult to extract. Fourth a bit more difficult, fifth stuck the bolt. I got it out with a good pounding on the bolt handle by hand, holding the rifle on the bench.

If I chamber these cases, they stick - meaning that the brass expanded. Primers are quite flat, but not any more than what I use to see on RWS ammo.

Any idea of what happened?

Was the barrel a bit tight to start with, then got too hot? But then if the metal expands, the bore should expand as well.

Did not have the opportunity to shoot since then, I'd have tried some Federal that I have. Still scratching my head.

Philip,

It is almost impossible to diagnose problems from afar, so what you will get is just a personal opinion.

From the way you describe the issue, it sounds like you are experiencing high pressure. RWS stokes their cartridges pretty well, you were probably shooting in high temperatures (if your location is anything to go by), and with the extended fast fire exercise, your gun probably heated up pretty well. I think all 3 factors combined to gradually let your pressure rise to a point where first extraction and eventually bolt opening was a problem.

It is likely, that if you had left your ammo even longer in the hot chamber, you might have experienced the problem earlier. The hot chamber will heat up the ammo, and pressure will rise. The issue is not the barrel (chamber) expanding with the rise in temperature, rising temperature causes the ammo to develop more pressure.

What to do?? Try different ammo. As I mentioned above, RWS is known to be one of the more "optimistic" manufacturers when it comes to loading ammo to its "potential".

- mike

What Mike said.

Mike,

The shooting was indoor range, in Europe, air-conditioned and pretty mild temperature. The rounds were not in the chamber more than 2-3 seconds... I was not shooting from the bench, but practicing fast fire offhand. After firing, the barrel was hot but still within "hand holding" temperatures.

I shot once a .300WM in the heat of Mali's noon, a comfy 45C+ (113F), and with the gun left in the sun for a while.

The kick I received told me about heat and pressure issues...

But in this case, chamber heat can't be the issue. I'll try and get close pics of the normal and sticky cases. I did not notice any difference.

Agree that RWS cases often seem to have flatter primers than others when fired, and give that little kick above others that makes me think they load to the brim. In .375 I've not fired much factory ammo, most always reloaded and worked my loads with a conservative margin bearing in mind possible heat.

I had a similar problem with my Parker-Hale 375HH; ammos were reloaded with RWS brass and spent cases were sticky to extract. Switching to Rem brass cured the problem.

Hmmmm . . . is RWS .375 H&H brass a little on the soft side?