Primer backing out!

pjkaz

Well-Known Member
Hi All,
Have recently purchased a Marlin .444 lever action rifle, and have fired Hornady ammunition, lever revolution 265 gr ftx ammo. I have noticed that the primers have all been flattened, and the majority have backed out from the primer pocket, by up to 40,000th of an inch. Is this a problem with head space, or over/under pressure??. Has anyone else experienced something similar like this, I would be grateful for any advice...:confused:

Paul
 
why would headspace cause primers to back out? (asking for my knowledge bank as well!)
does this happen if the case is shorter from shoulder to bolt face than the chamber?
 
This is a straight walled case that headspaces on the rim. I would venture that it is a combination of things but in the end, not hazardous. I'd like to see the primers.~Muir
 
why would headspace cause primers to back out? (asking for my knowledge bank as well!)
does this happen if the case is shorter from shoulder to bolt face than the chamber?

Ed

I over resized some 260 Rem cases and set the shoulder back about 8 thou. After firing, this resulted in the primer sitting very slightly proud of the case head. If I put the case head on a glass plate or other flat surface and gently flicked the case neck, the case could be seen to rock gently on the primer rather than on the case head.

Regards JCS
 
There are a few things that can cause a primer to back out. Low powered loads, a less than perfectly smooth chamber, excessive headspace caused by reloading setup (as JCS illustrates), mechanical headspace issues, or combinations of all of the above. Usually in high pressure loads the cartridge slams back and reseats and flattens the primers. What I am curious about is Paul's note saying that the primers are both flattened and backed out at the came time. I suspect it's a light pressure load and some inconsequential headspace. ~Muir
 
In keeping what what Muir has said I will post some photos of cases and a "problem" I encountered when starting reloading, in the end it wasn't a problem at all.

This first photo is of some cases from some reloads and this was a very light (book) load indeed. As you might be able to see the primers are a little backed out but are not flattened at all

reload2.jpg


Here is what happened to factory ammo fired in the same rifle - the primers are flattened and a little backed out which might not be clear from the photo. I guess these might look a little like what you are seeing in your 444

factory2.jpg


Now that I only neck size my cases are growing to fit my chamber and so there is no "headspace" issue. This photo is of a full house home load that is sending a 150 grain 308W bullet away at 3000fps. As you can see the primers are fine and are neither flattened nor backed out.

primers2.jpg


I'm sure Muir will be better able to document what the pictures show than I but hopefully my comments are approximately correct and that they provide a little help and reassurance.
 
Hi All, many thanks for your replies. Thanks to CAORACH for posting the pictures, my primers look very similar to the 1st 3 cases on the 2nd picture, but backed out to 2000th of an inch!. I have tried another batch of ammunition which are 444 Marlin 265 gr fp interlock, and exactly the same thing has happened. The cases show no other signs of overpressure or under pressure, no sootiness around the primer or neck. Still not really any further forward, have reported the problem to the armourer at Edgar Bros, I shall keep you informed

Paul
 
pjkaz

where abouts are you as i have some Remington factory 240grs and some home rolled 265gr interlocks you could try in 444 marlin if it might help.
I have never had the primers back out on any of my reloads as yet and they are pushing it a bit.
is the rifle a new marlington or a old Marlin as the build quality is said to be lacking on the new riminton marlins!!

bob.
 
Hi All, many thanks for your replies. Thanks to CAORACH for posting the pictures, my primers look very similar to the 1st 3 cases on the 2nd picture, but backed out to 2000th of an inch!. I have tried another batch of ammunition which are 444 Marlin 265 gr fp interlock, and exactly the same thing has happened. The cases show no other signs of overpressure or under pressure, no sootiness around the primer or neck. Still not really any further forward, have reported the problem to the armourer at Edgar Bros, I shall keep you informed

Paul

How does the sides of the brass look. Any concentric, or linear lines present after firing? (Pic would be great!) It may be that you have a headspace issue. Not dangerous, but annoying.~Muir
 
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