I notice a distinct crescent at the edge of primers on cases fired in my Miroku Win 86. Looking at the 'bolt' face, the only explanation I can see is that they have been made by the top of the weird, big ejector, which constitutes a large part of that face.

These marks don't seem to change, they are there on base-line reloads and factory ammo and may, for all I know only, be imparted at ejection.

Any thoughts?

Yes, carry on and shoot.

So, how do you like shooting the rifle?

Thanks, dpcd.

OK so far, thanks, CR. At old-time levels it is a pleasure to shoot; with steamier loads no big deal but I can see how that might change.

I have put a piece of closed-cell foam inside a slip-on recoil pad over the steel, crescent butt plate. This lengthens the shortish pull and gets my glasses away from the tang sight, but maybe not far enough. I have noticed the sight tilted forward after a shot but think that in the field, where action cycling should be more positive than at the range, the breech-block would push it back again.

As JFE has observed, use of heavy bullets may make recoil longer, if not harder, meaning contact with the tang sight happens more often. I intend to hunt with no disc in place, leaving a rounded contact point - but might investigate some form of rubber ring to cushion it.

To close down the aperture a little I have sawn the blind ends off a couple of grub screws. One has a smallish round hole, the other is pretty much a hexagon but the eye doesn't notice that. The thread is not exactly right but that means I can get these 3mm shanks two or three turns into the front end of the sight, where they bind. A target disc can then still be put in from the back when I'm at the range, though I'm not sure the POI is exactly the same.

it's from a strong ejector spring.
you'll see it on model 92's pretty frequently too.

Thanks Lamar, so you think it results at ejection? I guess it is important the face of it remains flat, not bevelled off, to prevent primer material flowing outward on firing.

I have an 86 just like yours; it follows the original Win bolt/ejector design. Nothing to worry about.

Great to hear, dpcd. Now, back to the reloading ...

OK, I confess.
All this chat about the subject finally worked its way far enough into my memory to reach the fact that 10-15 years ago, my then- new Miroku 1886 .45-90 also showed the same ejector marks on primers.

+, I just looked at some empties from Africa bullet testing and all have the little ejector mark on the primer edge.

BTW, on a Bison shoot, my guide noted that my 1886 was tossing empties 6 feet over my head. A little excited, maybe?

Do go back to your reloading and do let us know how that works out.

Well, CR, the only news on that front is that I have been widening the meplats on those cast 468-grainers to make them safer in the magazine. Some of the ones I squished in the vice (without being in a sizer) actually seem not to have expanded in the body or bore-hugging nose, so I have just gone around the forward end with steel wool, maybe removing one thou and some seam.

I have also filed a couple of mm from the front of some others in a makeshift jig and smoothed their edges with steel wool. I must weigh them to see how much weight has been lost.

These bullets will only be loaded when I've developed loads with the original bullets and then only used in the magazine, rarely to be fired. The full-length- bullet loads will be hand fed into the chamber.

I don't see how an ejector or extractor mark can be on the primer, It should appear on the case head in which case it means your load is too hot and looking for trouble. and you will get case separation in a few more reloads..

If Im reading all this right that is...ejector marks on a case head is serious pressure indications,and that's common knowledge I would assume...????????????

As an ignoramus, I can't say if the ejector did it, Ray - but it appears to extend within primer distance of the firing-pin hole. As to pressure, as I recall the mark appeared on all sorts of cases, including those from starting and factory loads.

And on Ultramax 300 grain cowboy action ammo (sissy loads)in my Miroku 45-90 1886.
Facts are troublesome things!

Well I don't know, but on a bolt action rifle or a Savage 99 or Win 94, that indention on the case head itself is normally the firt sign of pressure going into the red zone...the next step is to reload that case and see if the new primers are snug, probably not or barely and the following load and that loose primer can be a blown primer or case separation..I live in that zone and have experienced most of the failures out there short of a blown up action and Lever actions are the worst offender as they are not known for accepting pressure, they are springy for sure..

Just my take and a red flag to all, However to each his own, we sometimes do fly by the seat of our pants..

Thanks CR and Ray. I will certainly start by opening the action partially after shooting and taking the case out before the ejector flicks it. If there is no mark already I will feel a lot better.

Seriously; everyone needs to realize what an 86 bolt face looks like; it is NOTHING like any other design, NOT like any bolt action, Savage 99, or Win 94. Nothing.
The 86 ejector is huge and very close to the firing pin, and definitely well UNDER the primer, unlike any other ejector and closer to the firing pin than any other I can think of. Not a design we would do nowadays.
SO, it is normal for the primer to have a mark on it from the ejector, even with very low pressure loads.
Quite normal.

What dpcd said +1.

It takes a strong ejector to toss a fired 45-90 case 6 feet in the air like my 1886 does.

Going to the range Friday, so will conduct experiment mooted above. Watch this space.

Indeed - with breathless anticipation!

DPCD and Crshelton, thanks for the heads up, one never gets to old to learn..I had no idea.

Well, I tried taking out the case before the ejector got to it - very hard, because it seems to deploy the moment the case clears the chamber - but yes the damage does seem to be done on ejection, not before.

In regard to the reloads - so far, so good.

Both of my Mirokous leave that mark also, looks normal for those to me.

I have a Rossi ‘92 in 44 Mag, it leaves the primer cup in the ejector slot, when I worked up loads, anything over 24gr W296 with a 240gr SP, and cases would be stuck in the chamber u til the rifle unlocked.

I believe this is normal with levers and spring loaded extractors.

Cheers.