Just bought a remington 375 ultramag and am enjoying the rifle but having some troule working up a load. My first load was midrange per noslers book 98 grains imr 7828 with a 300 gr rn hornady interlock bullet. Recoil with this load was stout little circles on the end of each brass (ejector mark?) and flattend primers moderately. chrono 2 shots 2742 and 2754. Next I tried imr 4350 again per noslers book with the same bullet, same little circle on the end of the case head only very lite primer flattening with 91 grains both loads shot within reason for accuracy. Neither load made the bolt lift in the slightest bit sticky. chrono 3 shots with the imr 4350 at 2661, 2702, 2675. What are your opinions? Going to use this round elk hunting this year I don't need 2800 fps or faster but 2661 seems a little lite for this round.

Forgot to mention, using federal 215 primers.

What happens when you fire commercial ammo? I know it's expensive, but it sounds like it's time to buy a box and see. If it fires with expected velocity, and you're still getting the marks, see a gunsmith.

I can get 2660 out of my H&H with that same bullet (H-4350), so it does sound to me like those are on the light side. But be careful. There may be something seriously wrong.

Pertinax

[ 09-01-2002, 16:52: Message edited by: pertinax ]

I'll go with the box of factory. and then I would try another powder.
On my 416rem, I started with a bottom load to get 2250... and it chronoed 2396 (close enough to 2400 for ME). Pressure was there (i guess around 50k) but not excessive, HOWEVER, i think that if I had loaded it to the max book I would have had an issue.
the fed primers are the goods.

best of luck, and do a case head exspansion measurement,
jeffe

Your loads are all middle-of-the-road, so I doubt you are having pressure problems.

As suggested, run a couple of orounds of factory through the gun and compare the case heads.

Also, chamber a few rounds and see if the "little circles" show without firing. If they do, then your problem is nothing more than pressure from the ejector rod.

Thanks for the responses, i'll have to order in a box of 300gr factory ammo and see if i get the same results or not. Ricciardelli I will try to chamber and see if the light circles show next time i get some fresh brass right now only have 40 cases that have all been fired.

Tried another load yesterday seemed to work well. 92 grains imr 4350, fed. 215's, hornady 300gr rn bullets. 1 grain powder increase made a big difference is velocity chrono- 2801, 2777, 2760. No difference in primer appearance from 91gr load, primer very slightly flattend, no bolt stickyness, shot accurately enough. Think i'll stick with this load as it has enough speed and seems to work well. Loaded another box with same load today but backed the sizing die off one quarter turn to see if it makes a difference in this slight primer flattening i am getting. Primers look normal to me according to nosler's guide of high pressure signs and primers.

Try a slower powder....ie H4831, RL22, etc.

I have a remington 700 LSS in375 ultra,my best loads are 300gr nosler 97.5grs RL 19 win mag primer chrono's at 2833 fps for an average,without exessive pressure.270gr barnes X same primer 101grs RL19 3009fps.Both loads go under 1.5" @ 100yds.I don't know of a better caliber for any game anywhere at any reasonable range.my 270gr X shoots as flat as my 300 win with 180gr nosler, with alot more smack!

I would try a different primer. Several of us shooting magnum rifles as of late are having some strange problems with the 215's. A friend has some which are cracking and the gas is etching the bolt face. Its not being pierced by the firing pin either, I asked him. So federal is having some problems with these primers. It doesn't take much effort to try the win mag primer or the CCI , etc. FWIW.

Thanks for the suggestions, I'll probably try them all this winter when the range is empty except for me on those below zero days. (i'll just have to remember the difference in pressure than on those 95 degree summer days). I have a friend that really likes rl22 in his 340 mag., changing primers is easy enough, are all magnum primers around the same equivalent as fed. 215's, 215's originally made for 378 weatherby I thought they would be perfect for the 375 ultra. griz what manual did you get your reloader 19 info out of or did your just work up? I've got very good results out of reloader 19 and my 338 win. mag.