quote:

Originally posted by Triple4:
How much headspace is too much? To get a rough idea of the headspace in this rifle, following what you explained to me, I used a 444 Marlin case as a quick headspace gauge (case mouth diameter falls between Min and Max diameters of 9.3x62 shoulder) and results as follows...

Reminton factory - unfired: 4.275" fired: 4.295" = .020" headspace
Prvi Partisan factory - unfired: 4.280" fired: 4.295" = .015" headspace

I am a reloader but started with factory ammo for this particular rifle because it is available and reload components were tough to find... So, if the solution lies in reloading for this rifle, I can make it happen.

Then I recommend removing obvious causes on the bolt face and progress from there. The bottom line is that the primer problem is only cosmetic. Handloading is likely an option since factory loads aren't yielding accuracy results.

Headspace can cause flattened primers, but it is NOT what is causing the primers to be torn up in the shape of the ejector!

Fix the ejector problem. There are other things that can cause flattened primers besides headspace, I doubt that is what you are dealing with.

quote:

Originally posted by Wstrnhuntr:
Headspace can cause flattened primers, but it is NOT what is causing the primers to be torn up in the shape of the ejector!

Fix the ejector problem. There are other things that can cause flattened primers besides headspace, I doubt that is what you are dealing with.

How does the ejector have anything to do with the imprints on the case head and primer? It is spring loaded and provides no support the case. Just about every Remington bolt in recent history uses this type of ejector system and I don't see how the shape of the ejector or hole, even if it was out of spec, has anything to do with it.

Excessive headspace in any firearm will allow the primer to back out on firing and then flatten against the bolt face as the protruding primer is not supported in the primer pocket. The case is them forced back against the bolt face and the primer reseated in its pocket giving the impression of high pressure because we most often read primer flattening that way. In fact the pressure will be normal. The ejector hole must be ovalled as it looks to be in the photos as it is the only thing that can possibly provide a recess for the backed out primer to flow into. If the ejector hole is not itself ovalled and we are seeing the shadow of the ejector pin then it it is when the very rounded nose of the pin when it is pushed back into its seat that is 'causing' a recess in the ejector hole into which the primer metal can flow.

As the primer backs out on firing with the top edge being unsupported by the primer pocket it can flow into the ovalled ejector hole and as the bolt is opened the sharp edge of the ovalled hole gouges the 'flowed' metal of the primer. It is physically impossible to have cases showing the flowed metal effect on the primers that we see in all the photos without a recess on the bolt face for the metal to flow into.
No use trying to hedge around this obvious fact.

This phenomenon would not have shown up when the rifle was in 270W chambering as the headspace was likely perfect and the primers would have been supported in the primer pockets at all times when the cartridge was fired and not able to flow into the ovalled ejector pocket on firing.

I don't see why it is so hard to accept, the phenomenon is happening and something outside the ordinary has to be causing it. Again the only thing that has changed is a rechambering which has resulted in a case of excessive headspace. I would never expect to see the high pressure signs of flattened primers in factory ammo. There will not be hard extraction which most often accompanies high pressure because in this case there is no high pressure, just interpretation of it based on primer flattening, in error.

Either reload and neck size only to allow cases to fit the chamber, have the rifle rechambered and/or fix the ovalled ejector hole (which could easily only require flattening the profile of the ejector pin).

Forgot to add in:

Back sizer die out until it no longer touches shoulder, about one turn, then turn down until sizer just touches the shoulder and the case fits into the chamber with a slight "crush" effect.

Alternatively you can expand the neck to .375 then resize slowly until the case just fits with a slight crush in the chamber ensuring the case is tight against the bolt face.

I've done this process many times, over many years, on many wildcats and other rifles...it takes longer and sounds more complicated than actually doing it.

You're a reloader and probably have the stuff and knowhow to do this already.

The amount of fiddling is a function on how much you want to solve this problem simply and cheaply before sending to a smith.

Reload with a beginning load, seat the bullet out into the lands 10-15 thou so it is fairly snugged up against the bolt face. Put the round into the chamber by hand and hold the bolt and lock gently so it doesn't slam forward and reseat the bullet...fire and re-measure to see how much of the headspace is taken up.

IS that ejector button hole really elongated??? There isn't a "before and after" scenario.

I don't like partial sizing but in this case it is one simple way to check the problem. If this is just for hunting accuracy, once you get the headspace down to ~0.003" then you can lock the die there and it will probably work forever other than maybe needing to full length resize every now and then because the base will eventually expand and the cases won't fit. May or may not ever be a problem.

I use the oversized shell holders because doing so also eliminates some other accuracy problems, but that's another story.

To answer your question about the ejector button hole, with the gun in front of me, I agree with the comment from gzig5 "That ejector hole doesn't look out of round to me. I think that dark ellipse you see is the flat cut into the ejector pin that rides on the cross pin to retain the ejector. Normally that flat would not extend that far forward."
I'm taking notes on the competion shellholder and reload suggestions but I would prefer to have the rifle meet the appropriate specifications instead of owning a sort of "wildcat" that needs fire formed brass...that may be a little over dramatic but this will be a hunting rifle and I'd like to know that the rifle can shoot factory ammo without issues.
Took the rifle to a local gunsmith and he didn't want to touch it. I'll try another but I may just end up at plan B with all the great reload info you've offered. I'll let you know where it shakes-out. Thanks.

Since it has been rebored, has anyone slugged to bore to insure bore & groove diameters?

m4220

No. Honestly I was trying to avoid such things so this rifle doesn't nickel/dime me...

It don't cost much to drive a lead ball through the bore & measure. Then at least you would know FOR SURE what size bullets you should be using & that it is not undersize & causing HIGH pressure. Might help if you add a picture of a fired case side x side with a factory loaded round from the same box to see if the shoulder is fireformed out due to excess headspace?

m4220

quote:

Originally posted by Triple4:
To answer your question about the ejector button hole, with the gun in front of me, I agree with the comment from gzig5 "That ejector hole doesn't look out of round to me. I think that dark ellipse you see is the flat cut into the ejector pin that rides on the cross pin to retain the ejector. Normally that flat would not extend that far forward."
I'm taking notes on the competion shellholder and reload suggestions but I would prefer to have the rifle meet the appropriate specifications instead of owning a sort of "wildcat" that needs fire formed brass...that may be a little over dramatic but this will be a hunting rifle and I'd like to know that the rifle can shoot factory ammo without issues.
Took the rifle to a local gunsmith and he didn't want to touch it. I'll try another but I may just end up at plan B with all the great reload info you've offered. I'll let you know where it shakes-out. Thanks.

Good a bit more info on the ejector hole. I would now take the ejector rod out of the bolt and grind the face flat, stone the edge so it is not sharp and then put it back in. This might just cure the problem. I still think it is a head-space issue that has arisen with the chambering to 9.3 but a simple mod to the ejector rod could be the answer.

If you want to shoot factory ammo then you've just about ran out of alternatives other than a rebarrel...by a COMPETENT 'smith...or sell it...and if a gunsmith won't touch it then your alternatives are reduced to zilch.

I did a bad assuming the barrel was within specs but M4220 has a very good point and slugging is an easy thing to do.

Having factory ammo is a good thing...I guess...I haven't shot any factory ammo except 22LR and 223/308/Russian cheap military stuff in so long I get sticker shock every time I check prices...

I have half a box of Rem 180gr CoreLokts that is marked $6.99, the last box of '06 I bought.

Luck

I hear what you're saying. And you touched on one of my underlying thoughts. If I would decide to sell it...I want the rifle to function properly and don't want to pass on this problem to someone else. I'm on a search for a local competent gunsmith whose willing to give the rifle a check-up and look into a slug test. In the meantime, I'm buying a PTG No-Go gage (1) because I can't find anyone who has one laying around for 9.3x62 mauser (2)I want to understand the headspace issue so I have some information if I decide to send it back to the guy I know rebored/rechambered the rifle. I didn't have the gun rebored directly. I bought it from the guy's brother who apparently finds candidate rifles, has his brother do the conversion, then sells the converted rifles...so maybe I have a legitimate claim to have them take a look at it... Sorry to be long-winded with the backstory.

A 760 needs a little headspace to function.
With light loads the primer will stay pushed back.
What is happening here is the primer will flatten
out over the ejector. When the rifle cycles the
ejector will push the edge of the primer forward.
This can be most clearly seen in the middle
picture in the second series. I would think that
there is no danger in shooting the rifle as is.

I've never had a 760 apart nor do I know anything about the factory specific functionality so I can't speak to what is or isn't "a little" headspace.

I DO know that there are SAAMI/CIP tolerances to take care of the differences in manufacturing specs between brass, bullets, chambering specs, loaded ammo etc and EVERY rifle, be it bolt, pump, auto, single shot, etc, and ALL factory ammo has a manufactured in headspace/tolerance and that headspace can be positive, i.e. a plus anywhere from 0.001 to (usually) 0.008" but it can also be a negative number amounting to a few thou.

I've had factory rifles that were on the negative side and wouldn't chamber some brands of factory ammo that was manufactured on the positive side of the tolerance, but would chamber ammo on the minimum side, but it DIDN'T have anything to do with the brand, just a particular lot coming out on the high side of the tolerance.

I consider anything over 0.008" as excessive even thought the ammo "might" still shoot. This rifle has headspace over twice that amount...that ISN'T "a little" headspace. Whether or not it is acceptable is argumentative from many points of view.

To get around headspacing problems, I use a case sized in the dies that will stay with the rifle as the headspace gauge and set it up slightly loose on the bolt closure. I hardly use factory ammo so this ensures the reloaded ammo is minimally mashed in all directions and still gives me a couple thou slop in then chamber...the brass lives a LONG time. I also fiddle/polish the sizer if needed, just how "anal" I get with the total package depends on the rifles and caliber

Triple 4...I think you have a very valid claim for returning the rifle and getting your money back. The brother messed up bit big time.

I also think that it is a neat platform and if it were mine I would just do the reloading corrections and forget the factory stuff. This is a hunting rifle and you don't hose the world down with it...besides finding factory 9.3x62 ammo out in the boonies here in America is like looking for hens teeth. You can reload all the needed ammo and separate it so in case one lot is lost/misplaced you have another lot handy close by.

One other thing to consider...take a look just how small 20 thou is. Anyone who plays this game and builds rifles gets all anal over a few thousandths, and depending on the rifles use, those thousandths can be very significant. But, in a hunting rifle, as long as the accuracy is within your acceptability range and you hunt with factory ammo and NOT reload, all you do is end up with slightly ugly ammo that you wouldn't even bother with, leaving it on the ground and not looking back. But being a reloader and seeing something not quite right, causes concern. That amount of stretching is HARD on brass from a reloaders point of view and easily correctable, but who cares from a factory only ammo point of view.

Luck

Any decent craftman should stand behind his work if he wants to stay in business.

I've been wrestling with the idea of sending the rifle back to guy who did the rebore or just keep it and reload for it accordingly. I actually purchased the Redding competition shell holders to make up for some of the excess headspace AND I bought a PTG 9.3x62 No-Go gage to satisfy my curiosity. Well, the No-Go chambered! The action locked solid so I don't think it would've chambered if it were another thousandth or two. Stupid questions maybe... Is this a deal breaker? Should I definitely send the rifle back now?

I would at least investigate what the seller might do for you.
You can deal with the headspace with the die setting but there is no reason to tolerate the primer issues. It appears the guy that did the work did not test fire the rifle.

quote:

Originally posted by Triple4:
I've been wrestling with the idea of sending the rifle back to guy who did the rebore or just keep it and reload for it accordingly. I actually purchased the Redding competition shell holders to make up for some of the excess headspace AND I bought a PTG 9.3x62 No-Go gage to satisfy my curiosity. Well, the No-Go chambered! The action locked solid so I don't think it would've chambered if it were another thousandth or two. Stupid questions maybe... Is this a deal breaker? Should I definitely send the rifle back now?

...I was told he did test fire the rifle...but I'll talk to him about the primers, etc. and report back.

I talked to the guy who did the rebore and I quickly realized that sending the rifle back to him wasn't going to do much good. In a nut shell,(1) he said he's seen the marked primers before on spent cases from Remington 760's & 742's and it's from the ejector, (2) I told him I was able to chamber a No-Go gage and he told me he uses a factory case to headspace a chamber and stops when the case will chamber,(3) in his experience, if it chambers and ejects the spent case okay it should be fine...
I'll report back with my range results after I work up a load using the tricks I've picked up here...Thanks again!

Uh yeah...I don't think I'd be letting that idiot touch it again either. Good luck. Can you at least give a few clues who it is so I don't send any work his way?

I'm struggling with giving any clues at all because I have no interest in offending anyone here or starting a firestorm over it. On the other hand, if I would've been informed in the first place, I probably wouldn't have bought the rifle. All that said, I'll tell you the business name is three letters...

I just had JES Reboring bore out a .30/06 760 to 9.3X62. It should be here tomorrow. I hope that I don't have this problem. Some factory ammo is shorter to the shoulder than others, so I sent JES a pulled Hornady factory case to make sure that the gun will work with the ammo I have. Once I shoot some up I'll start reloading with Privi 286 grain bullets.

I would definitely be interestsd in hearing how your rebored 760 shoots. A friend had some 9.3x62 components and I shot a few reloads from new Lapua brass, 250gr. Accubond bullets and Varget powder. The primers didn't flatten like the factory Remington and factory Prvi Partisan ammo and there was only a small mark on the primer. So far my best "groups" have been with the reloads and the Prvi Partisan at ~3". I haven't given up on this project and will report back as I make progress.