XL650 Primer Disc: is this damage or wear?

[cohland]

During my most recent reloading session I ran into a spate of high primers. I could feel some difference in the primer seating at times, but I thought it might have been loose primer pockets. Of 600 rounds (.45ACP) about 30 had high primers.

I did the routine cleaning, removed the shell plate, and upon close examination I noticed some marks that either represent damage or wear on the primer disc, small dents around the edges of the holes in the primer disc. Here is a photo of the top of the primer disc (no wear was noted on the bottom):

The dents are roughly at the 1:00 position on the holes in the photo.

The machine was thoroughly cleaned, and I installed a replacement disc. All other adjustments were made, although nothing was really out of adjustment. I still wonder what might have caused this, and whether it played a role in the high primer episode.

The cleaning of the machine showed noting unusual, although I have to admit that until today I had never removed the primer system. I'd guess it has made about 4,000 rounds in total.

Does anyone have any idea how serious this damage might be, and what may have caused it? Your thoughts and suggestions will be appreciated.

Chris

Edited May 8, 2013 by cohland

[jlamphere]

That is odd, being on the top rather than the bottom where the primer ram might have nicked the edge somehow. I am not sure how something would have struck the top of the hole. I am sure that someone with an answer will be along shortly.

[Jaxshooter]

I don't see how that would have caused high primers. I could understand it if the primers were going in at an angle caused by catching on that edge.

[cohland]

I don't see how that would have caused high primers. I could understand it if the primers were going in at an angle caused by catching on that edge.

That puzzles me as well. I had only three primers flipped in the whole session.

Chris

Edited May 8, 2013 by cohland

[BMartens]

Can't explain the marks you are seeing on the primer disc but, flipped primers normally indicate a timing or alignment issue.

[cohland]

Can't explain the marks you are seeing on the primer disc but, flipped primers normally indicate a timing or alignment issue.

I took it all apart again, and it looks like the marks on the disc are coming from the primer indexing arm: it touches the primer disc at that point to rotate it. So, it might just be normal wear, or accelerated wear due to some extra friction. I cleaned up the entire primer assembly so the friction should be cured, if that was a factor. There is no apparent wear on the primer cam, but if I continue to see any marks appear on the disc, I'll change the cam.

In the previous day's session I loaded about 650 rounds, and I had exactly two flipped primers. That session was all new Starline brass, which sure does make a difference.

Today's session was mixed range brass. Even though it was very clean, there's always some drama when I have a mixture of brass that has been fired up to ten times and is fifty years old in the mix.

I was able to hand-seat the primers on the twenty-odd rounds with high primers with no problem.

Chris

[anm2_man]

It looks like wear. Here is a picture of one of my primer wheels. You can definately see the wear.

I think most of it is caused by the locking ball. I do flip them back and forth.

[cohland]

It looks like wear. Here is a picture of one of my primer wheels. You can definately see the wear.

I think most of it is caused by the locking ball. I do flip them back and forth.

How about the top side, where the primer indexing arm engages the disc? Is there any damage up there? I keep wondering if I have some strange timing problem here, so just for the heck of it I'm going to change the priming cam to see if that makes any difference.

Thank you for the photo, by the way!

Chris

Edited May 9, 2013 by cohland

[anm2_man]

The top side looks just like the bottom side. But take a look at the bottom of my picture. You can see the index arm in one of the holes. Make sure yours fits nicely inside the holes.

[cohland]

Follow Up:

I changed the primer disc, the primer cam, the ring indexer (that was fun...), and the index pawl, all of which were showing some wear. Not much, but some, and I thought that tolerance stacking might have been the culprit: too many things a little out of whack.

The result: a run of 300 rounds without a single primer problem. Zero. In fact, no problems of any kind. I did switch to Winchester primers for this run, I wonder if they just happen to work better.

The next run will be with CCI primers, I'll post an update if it turns out that the Winchester primers made a difference.

Chris

Edited May 11, 2013 by cohland