.243 WIN Pressure signs/Ejector marks

[bbutturff]

Hi everyone,

I've been reloading for a long time and reload for several different rifle and pistol calibers. Yesterday, for the first time ever, I noticed ejector marks on 5 out of 15 of my RP brass. I shot a mixture of RP and Win brass during the session but none of the Win brass showed any ejector marks. This is a bullet/powder/primer combination that I have shot for several years.

The specifics are:
Savage Model 10 in .243 Win
Nosler 95gr Partition
39.6 gr. Reloder 17
CCI 200 Primer
COL 2.676
Jump .020
Velocity 2828 fps
ES 6
SD 3
100 yd 5-shot group .625
Temp. 74 degrees
Powder trickled on a RCBS 505 beam scale

As you can see this is a really great load and not particularly fast. When working it up I stopped at the sweet spot. Bolt lift was a little stiff but not heavy (you Savage guys know all about Savage bolt lift). Recoil seemed mild. I've never found a published book max for this combination but for H4350 the max is 42.0 gr. of RL17 @ 3087 fps so I don't believe I'm close to max.

Anyone ever experienced anything like this? Is it possible some of the RP brass was a just little too soft? I'm stumped.

Thanks,
Bruce

 

[bigedp51]

Is it possible some of the RP brass was a just little too soft? I'm stumped.

Thanks,
Bruce

Remington brass is softer than Winchester which asks the question why are you using mixed brass with different case capacities and hardness.

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests

http://bulletin.accurateshooter.com...r-brass-5-56-and-223-rem-base-hardness-tests/

 

[bbutturff]

Only because, with this rifle, it doesn't seem to matter. It shoots bug holes with this load all day.

Bruce

 

[Bravo 4]

Only because, with this rifle, it doesn't seem to matter. It shoots bug holes with this load all day.

Bruce

Apparently with this load in that rifle it does matter. Maybe not in accuracy but in pressure. The difference in case volume between the Rem & Winchester brass may be enough to cause higher pressure or the Rem brass is softer and is showing the signs of over pressure. If you are only getting a stiff bolt lift with the Rem brass (along with the ejector marks) then I would say drop the load down a notch or only use the Win brass. If you are getting a stiff bolt on all the brass then I would ask if all loads (especially factory) did this or if only this load. If they all did it then I would probably call Savage and get the rifle looked at for a possible chamber issue. If it only happens with certain loads or certain brass then I would say you are over max pressure.
Also, have you checked brass length? May need trimmed.
Are you neck sizing or full length?
How many times has the brass been fired?
There are a lot of things that could be going on here, these are just a few possibilities.