So I go to the range to sight in my 375. I am shooting a 270 grain bullet with 69grs of RL15. CCI mag primer in new Remington cases. First shot bolt closes fine, goes boom! Open bolt case stays in chamber. Close bolt and open again case comes out. I have rcbs press and dies and camming over in size die. Tried one round from another press extraction was fine. What do I need to do to my sizing die. I did notice that when sizing case it stops sizing just short of the belt.
A good job is sometimes just a series of expertly fixed fark-ups. Let's see.... is it 20 years experience or is it 1 years experience 20 times? And I will have you know that I am not an old fart. I am a curmudgeon. A curmudgeon is an old fart with an extensive vocabulary and a really bad attitude.
Posts: 324 | Location: Too far north and 50 years too late | Registered: 02 February 2015
This is the 2nd barrel I have had on this action and prolly 30 rounds through the 375 and under 250 in previous barrel. Also I checked the extractor and no chips.
Since it comes out the second time, with what I assume to be normal "force", it has to be your extractor. Or very short brass, base to shoulder length. The camming over thing insures you get a minimum base to shoulder length case; not always a good thing. But it shouldn't cause extraction problems either. I think you are over sizing them; try to just size enough so that the brass fits the chamber snugly, ignore that useless belt. Check the extractor for springing in and out; it is it's own spring. dirt, rust etc.
Posts: 17549 | Location: USA | Registered: 02 August 2009
The camming over thing insures you get a minimum base to shoulder length case; not always a good thing. But it shouldn't cause extraction problems either. I think you are over sizing them; try to just size enough so that the brass fits the chamber snugly, ignore that useless belt.Check the extractor for springing in and out; it is it's own spring. dirt, rust etc
What dpcd said.
As usual just my $.02 Paul K
Posts: 12881 | Location: Mexico, MO | Registered: 02 April 2001
I'm thinking that you might not be getting enough extractor tension / engagement on the rim which will give intermittent failure to extract. The riveted magnum size Remington extractor can lose tension, can be a bear to install correctly, and may be installed in an incorrectly machined bolt recess (it happens) which prevents it from achieving full engagement. The best fix might be to have a Sako extractor installed... .. jmho.
A good job is sometimes just a series of expertly fixed fark-ups. Let's see.... is it 20 years experience or is it 1 years experience 20 times? And I will have you know that I am not an old fart. I am a curmudgeon. A curmudgeon is an old fart with an extensive vocabulary and a really bad attitude.
Posts: 324 | Location: Too far north and 50 years too late | Registered: 02 February 2015
I checked the extractor and its still very stiff. Will try sizing less and see where that takes me. Thanks for all the help. And by all means keep them coming.
Does it do it every shot or was it a one time deal? Is the extractor tearing up the rim when it fails to extract? Is the brass sticking in the chamber? That should be a fairly mild load.
Honestly, I doubt it has anything to do with your re-sizing since you said it was new brass. You also said it has a belt so I'm assuming 375 H&H. You can resize until the cows come home and the belt and rim isn't going to change.
With the current brass quality, I would look hard at it. Specifically the rim diameter and extractor groove diameter.
And make sure the extractor is clean and functions. There not much movement there, but it has to move as it snaps over the rim. Also, check that the extractor isn't cracked where the rivet goes through it.
Posts: 562 | Location: Mostly USA | Registered: 25 March 2011
Everyone needs to realize that the belted mag cartridges have a fairly Huge tolerance allowed between brass and chambers, (SAAMI specs allow .015, which is way more than most people realize) so, whilst, yes, sizing does not change the belt, it can and does alter the base to shoulder length. Which is why I always say, Ignore the belt and size your brass to fit the chamber just as you would on a rimless case. You will avoid several problems that way.
Posts: 17549 | Location: USA | Registered: 02 August 2009
