I am shooting a 300 rum, and shooting 93 grains of 7828ssc, 200 grain nos accubond. 3300 fps, <1" groups. Everything is going well, on about every 6th bullet I am seeing extractor marks, very light. Shot about 15 rounds through it on Saturday, on the 16th round the empty case got stuck??? Pulled the bolt back and the brass stayed?? Any suggestions on what caused this. Using Remington brass.
If you are getting a 200gr bullet to go 3300fps in a 300RUM this must be a pretty hot load. (So, in general I would watch for pressure signs -this sounds like possibly the first.) But I'm not particularly familiar with that round.
It sounds like the cases are overexpanding and fusing to the chamber? Maybe others can chime in here, but you might try a more robust case. I'm not as familiar with the Remington cases. But I know that the Winchesters (at least the ones I've tried in my 300wsm) are on the soft side, and I would guess the Remingtons are similar. I've just ordered a batch of Norma cases. I know from the ones I've used in my 270wby that they tend to be harder and stand up to more punishment. They're more expensive, but a stuck case while hunting could really suck.
I'd also be tempted to take it to a good gunsmith and have him check and, if neeeded, polish the chamber. I've never had it happen to me, but I've heard reports of burrs left behind by chambers that have been reamed by a sloppy smith. The soft brass can fuse to those burrs and get stuck, making extraction sticky or worse.
It would seem that you are very near or a bit over the max pressure for the load. FPS is directly proportional to pressure (well kind of) and any variation at all at the general pressure area you are shooting could put things over the edge.
I don't understand what you mean by "Extractor marks"? You didn't mention which action you are using, I would suppose its a Remington? If its a Remington it has a pretty poor example of an extractor if you pulled the bolt back and the case stuck?
I've had to "hammer" the bolt back a tap or two with whatever tool was handy and the case never stuck.
I'd recommend backing off a couple of grains of the 7828SC and get the velocity down to about 3100 max and go from there.
Just my thinkin......
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!
I thought the norma brass was softer? In my weatherby 30-378 w/ 210 berger VLD's, I get sticky results around 3300fps.(actually 3270fps.) using 110gr. retumbo. Not every shot, but if I don't wait long enough between shots it seems to happen a little more. I backed the load down to 108 gr. @ 3205 fps., plenty for me, and they group better besides! 5/8" consistently @ 108yards.(just happens to be where I set the bench up this spring,oops)
you cant dump'em if you don't pull the trigger!