I have loaded my 300 rum brass 3 times
and on the third fireing the neck starts to
crack right around the shoulder.This sucks,
I havent even had to trim the cases yet,
I neck size every one and no streching.
Ill be glad when some one else produces
the brass other than remington or iam i asking
for to much out of the brass. Reloaderlen

reloader len,
Try some slower burn rate powders.
RL 22 or 25 work fine in the ULTRA's.
IMR 7828 in my 300 & 338 ULTRAS takes the primer pockets out in 2 to 3 firings.
DAN

I've had the commercially loaded (180 gr. Nos. Part.) ones crack ON THE INITIAL FIRING. Two, out of about 100 cases. Seems a bit strange to me.

None of my reloaded cases have split the necks, though I'm only on the third loading.

Pertinax

If this is happening in Remington rifles, I am not surprised. The chambers I have seen recently on Ultra mags are on the ragged edge of being within spec -- and all are on the "too large" side. And, the roughness of the chamber walls doesn't help matters, either.

Quality control at Big Green is non-existent as of late.

I have gotten 9 reloads so far out of my 300 RUM brass with no cracking or loose primers and I am shooting 180 at 3375 fps. I find it to be excellent brass myself. Its flows pretty good and I have never had a singal cass blow yet. I've trimed the necks 2 times now. We will see how long it lasts though.

Markus,

What load, bullet and OAL are you using at that speed?

I got 3345fps twice with a 180 Scirocco with 86.5 and 87gr of RL25 at 3.660" but pressure measured 70,400 psi on the Oehler 43 doing it though. The factory loads were running 3200 at 59,900 psi and factory Partitions 3250 at 63,500 psi.

I have shot mine 3 times now. No problems, but wonder when I will get case head separation?

i have 300 ultra and 7 mm ultra that i have loaded several times with no problems yet 7mmrum conos at3587 140 grn barnes xlc 95.5 grns rl 25 and the 300 rum conos at3411 barnes 168 grn xlc at 97 grn rl 25 both shoot 3/4 in. groups

I had a good load with the 168XLC too, it was under an inch at 200 yards with loads between 97 and 99gr in 1/2gr increments. 99gr was upto 65,000 psi. The Oehler wouldn't read the velocity, it was too foggy and dusk also, but at the top end they grouped great.

The 180 Scirroco grouped the same 1/2 moa between 91 and 93.5gr using RL25 too.

I've only loaded them twice so don't have any idea how life will be yet.

Split necks are likely with the Rem cases though, casehead seperation is unlikely unless you have excessive headspace too. You can check them with a paperclip if you think they're getting thin.

I use 95gr of reloader 25 with 180 nos bt. I load them to fit into the magazine I think its just a hair over 3.6" but I can't remember off hand. I just have the die set and just press the bullets in now that its been set up.

I don't have any way to measure pressure other than by inspecting the brass by eye. So far the bolt has never been stuck. there is no cratering of the primers but they are starting to get flattened. I have tried 96 gr of reloader25 but that started to crater the primers and accuracy fell off so i stick with the 95gr load.

Markus,

I'll have to load some 180 BT's up and check them with RL25, I have tried them with 82gr IMR4350 and they grouped about 1 MOA at 200 yards with ten rounds. That was Noslers best powder and load in their book. The load I worked up with the Scirocco shot twice that good so I'll have to try RL25 with the BT too.