Pressure? Keep loading or not

[Snowrun]

I'm loading 285gr Hornady ELD Match bullets in my 338 RUM, 27.5" PacNor on a Browning Abolt. Only 25 rounds down the barrel so far with break in but not too happy with accuracy of these so far. Loading H1000 up to 91 grains, primer images are for those rounds. I seem to get random ejector marks even at starting load charges so I'm not sure what to make of these. Please check out primer photos, should I keep going up or try different powder/bullet? No heavy bolt lift whatsoever so far.

 

[Frank in the Laurels]

Your about there, that's enough..that about action won't get sticky, never saw one that did when every other sign said you shouldn't be able to lift it..try another bullet, no fan of the vld or so called long range bullets..

 

[LRSickle]

It doesn't look like the primers are all that flattened. It's hard to tell with those pictures though.
Are you resizing too much? Are you leaving too much lube on your cases?

 

[Trnelson]

It doesn't look like the primers are all that flattened. It's hard to tell with those pictures though.
Are you resizing too much? Are you leaving too much lube on your cases?

Lube on the case when firing will significantly increase bolt thrust and can keep the case from proper obturation to the chamber. This can give you a 'false' high pressure. It isn't really false, it's just the case isn't sealing to the chamber and is transferring all the pressure to the bolt face, but once the cases are cleaned of lubrication the load should be ok.

 

[Snowrun]

Appreciate the feedback.
Cases are full length sized & tumbled clean afterwards.
I agree that the primers do not look very flattened-Fed 215M- first time I've used them so not sure about thickness. The ejector mark with OK looking primers has me a bit puzzled. I might need to buy a .00001" micrometer to check case expansion near the base?

 

[Waynzee]

The picture where you are holding 3 cases with the primer in them has high pressure signs. I would back off the charge about 3 grains and look at the primers again. Also, make sure cases are clean.
To me it looked like the primers where cratered and flattened out.

 

[RockyMtnMT]

At 91g I think you are at a top end load. Did you work up? How did the brass and primers look on the lower charges? What velocity are you getting? Velocity is a very good indicator of pressure. High velocity means high pressure when it is in conjunction with other indicators like you are showing.

I looked at Hodgden load data and they show 91g h1000 as max load for 175g bullet. So my answer to your original question is: Do not keep going.

Steve

 

[J E Custom]

Another thought. seat the bullet a little deeper in the case. the RUMs like freebore and sometimes if you are to close to the lands you will get pressure signs.

As stated, make sure you chamber is clean and free of oil or cleaning solvent, and that the rounds are also clean.

J E CUSTOM

 

[LRSickle]

Appreciate the feedback.
Cases are full length sized & tumbled clean afterwards.
I agree that the primers do not look very flattened-Fed 215M- first time I've used them so not sure about thickness. The ejector mark with OK looking primers has me a bit puzzled. I might need to buy a .00001" micrometer to check case expansion near the base?

But are you just bumping the shoulder back or are you setting it back quite a ways?
I would be more concerned about the ejector marks than I would the flat primers. I've seen factory loads with completely flattened primers because of their generous headspace.
Like Steve, I looked up your load and it does look a little hot.
I didn't know RUMs typically like freebore. It might me worth checking that. JECustom has solved more than one of my reloading mysteries.

 

[270DT]

H1000 seems too fast of a burn rate for what you want. I would look at RL-33 or VVN570 with that weight of bullet.

 

[Snowrun]

I worked up from 85 grains with MV in the 2710s to 91 grains with MV 2850s.
Cases are taken down to the bottom out point as far as sizing, chamber is cleaned out with gun scrubber after bore guide is removed each time.
I will try seating a bit deeper.
Is RL33 temp sensitive? Also have a jug of Retumbo but I think I'll run out of case capacity.
Thanks again for all the suggestions
Shaun

 

[Predator 22]

If you are going down to the bottom out/cam over point you are probably sizing more than needed. Buy a headspace gauge and set your die up to just bump the shoulder just enough to chamber. I was making the same mistake and started sizing just enough to chamber with a very slight bit of resistance.

 

[LRSickle]

If you are going down to the bottom out/cam over point you are probably sizing more than needed. Buy a headspace gauge and set your die up to just bump the shoulder just enough to chamber. I was making the same mistake and started sizing just enough to chamber with a very slight bit of resistance.

That's kinda what I was thinking also. Just bumping your shoulder back help your brass life too.

 

[North Idaho Hunter]

You have plenty of case capacity for retumbo. I could even squeeze 101 grains of reloader 33 in there with a COAL of 3.600 (highly compressed load)

with 2850 with H1000 I would say your over pressure. that's high velocity for that powder out of a 338 RUM. Your getting 30 inch barrel edge velocities with the smaller RUM case.

If it were me I wouldn't push it any farther. if you want more velocity go with reloader 33. you'll likely gain another 100 FPS from it.