trimming the taper?

[tbirdman74]

During the last session of 450's, I noticed that the end of my cases are chamfered on the outside,(as if you were to debur the outside overwhelmingly...) and it made putting the taper crimp on a very special case of pain in the ear. I am just curious if others have this issue, or do I have an issue somewhere else. Brass was once fired factory(250 ftx) deprimed, washed, tumbled, resized, washed, and tumbled. No trimming, or deburring had happened when I got to this point. Thanks.

[Hoot]

During the last session of 450's, I noticed that the end of my cases are chamfered on the outside,(as if you were to debur the outside overwhelmingly...) and it made putting the taper crimp on a very special case of pain in the ear. I am just curious if others have this issue, or do I have an issue somewhere else. Brass was once fired factory(250 ftx) deprimed, washed, tumbled, resized, washed, and tumbled. No trimming, or deburring had happened when I got to this point. Thanks.

Had you been shooting reloads the last time, I would have hazarded a guess that you overdid the taper crimp and squeezed the mouth walls thinner than normal. That not being the case, it concerns me that your cases are seating a little past the chamber end lip and it is chamfering them. This is not a good thing. You really need to measure your chamber to put that concern to rest. Do you understand what I'm saying?

Hoot

[tbirdman74]

Yeah, I do. Its all gonna have to wait a while, packing up to go back to work, but next trip home, I've got a bunch of things to do to this gun, aside from this problem. Do you think this could also be a cleanliness issue? A little buildup at the end of the chamber wall? I'm just grasping... really hoping I don't have to get it reworked.

[Hoot]

Yeah, I do. Its all gonna have to wait a while, packing up to go back to work, but next trip home, I've got a bunch of things to do to this gun, aside from this problem. Do you think this could also be a cleanliness issue? A little buildup at the end of the chamber wall? I'm just grasping... really hoping I don't have to get it reworked.

No, I do not. Buildup will not shave the brass. It might make it stick or not go into battery, but not that. Sorry you have to deal with it in order to enjoy what you paid for. I'm not sure what is going on with Bushmaster / Remington, but they sure aren't making any points lately.

Hoot

[pitted bore]

tbirdman-

Do you have any issues like this when firing Hornady factory ammo? I read your posts all the way back to February and found no report of the problem there.

If the problem doesn't occur with factory loads, then the next question is how do your handloads differ from the factory loads. I'm more than likely missing a piece of the puzzle here. Because this isn't a problem I've experienced myself, I'd like to understand it better.

Thanks.
--Bob

[tbirdman74]

PB, thanks for making me reread my post. This was factory ammo that I had shot a couple weeks ago and was(were?) reloading. And when I said "like I had chamfered them" I may have mislead you. It was more like a hard taper crimp would have been. I'm thinking that this may be a result of the other problem(the bullet shaving from other post), possibly some of the rounds chambered with a sliver of bullet in the end of the chamber. I have one case that has a nice half moon imprint about half way down the side where a sliver stayed alongside the case when fired. If I can get a pic I'll post it in the morning.

Gonna call bushmaster in the morning and try and get it sent in before I head north again.

[Hoot]

I can't believe the case and that sliver both fit in the chamber at the same time. Seeing that sends a chill up my spine. That could have gone very badly. That having been said, clarify that the mouth constricting / shaving occurred with both the factory loads and the reloads, not just the reloads, right?

Hoot

[pitted bore]

tbirdman-
Assuming that this is happening with factory ammo, then the problem becomes finding where the shaving occurs while the ammo is cycling into the chamber.

If the chamber hasn't been altered or damaged, then the problem appears to be Bushmaster's to solve. If and when you ship the rifle to them, it might be helpful to include some fired factory ammo that displays the problem. Most manufacturers don't want to solve problems associated with reloads.

Keep us posted on how this works out. Good luck.
--Bob

[wildcatter]

TBM,
I'm wondering, have you tried the Thunk Test yet, for even more conformation data??

..t

[tbirdman74]

I have and do thunk test my reloads, and have never had any problems before, but after this last round, they thunk but stay stuck in chamber. Have to push them out with cleaning rod. I think I have one more box of factory, not sure if I have thunked them yet.