Wierd chambering problem with Winchester cases........

[3006guns]

One of my favorite rifles is a Yugo 8 x 57 that I cut down to a "short rifle" configuration some years ago. It makes a good behind the seat pickup rifle and is accurate to at least 200 yards, using 17 grains of 2400 and Lyman's 200 grain Loverin style boolit, sized at .325. I've used reformed 30-06 government cases, PPU cases and Remington cases in the past with no problems whatsoever. Then I got this little batch of 50 new Winchester 8 x 57 cases and ran into a strange problem....

Basically, the empty case chambers just fine with no resistance at all. Once I assemble a cartridge though, I cannot put the bolt handle down and it stops in the same position no matter where the boolit is seated. The outside neck diameter measures the same as an empty case. In order, I've:

1. Full length sized, with my Rock Chucker camming over center. No good.
2. Trimmed to 2.221 (max. is 2.240) No good.
3. Left case mouth square. No good.
4. Adjusted die to gently crimp. No good.
5. Coated loaded case with bluing, trying to find any "tight" spots. Nothing...no marks on shoulder or neck at all.
6. I've tried many different seating depths, to the point that the boolit actually fell into the case! No good.

I thought the boolit ogive might be jamming in the throat, but my other loads chamber just fine. I even tried a commercial round with a rather fat, round nose soft point and it chambers easily also.

I'm really baffled as this is the first time in 47 years of reloading that I've run into this. As a last gasp attempt, I'm thinking of loading about 10 grains of Bullseye with a Cream of Wheat/glue plug in the neck and see if it fire forms, my thought being that possibly there's a problem with the shoulder configuration, even though the empties chamber. Again, no matter what I've attempted so far the bolt handle always stops in the same position and removing the round involves whacking the bolt handle several times with my palm.

Anything I might have missed??

Edit: I forgot to mention that I tried one of the loaded rounds in another Yugo, same thing.....yet it will chamber in my Gewer 98, 1888 Commission carbine and my VZ24! Again, this is the same load combo I've used for years, but with other cases, no problems.

[sawinredneck]

Have you tried an unloaded resized case? Might be a problem with an oversized sizing die, might be it's not setting the shoulder back enough?
I get I'm newish to this, but I'd take the deprimer/sizer ball out, resize a case and go from there.

[3006guns]

Yep.......that was my first action, since I always resize new cases. I also put bluing on a loaded case, then attempted to chamber it and found no marks upon removal. Weird, huh.

[country gent]

Could the extractor be binding in the groove or on the rim? Are cases and or chamber round. How is bullet dia in relation to the throat Dia? How does the shoulder dia compare to fired cases fired shoulder length. though this may show up with ink it may not.

[sawinredneck]

Yes! Other than trying another resizing die, I'm out of my depths, sorry!

[rking22]

May be the base diameter. I have mauser that needs a small base die to get the bolt closed on any of my brass. Compare dims to brass that chambers.
Nevermind, just reread your post ,,, interestinh

Perhaps the neck is being expanded to interference by the bullet. Measure the neck dia right at the shoulder transition and at the mouth. Do you have pin gages to check a sized case neck for consistent id?

[3006guns]

Yep.........the loaded round's neck measured the same as an unloaded one and no sign of interference at the shoulder/neck. By the way, the brass appears to be uniform at the neck......that is, not overly thick......as my other cases.

It is strange. Probably something basic that I've overlooked and I really think a fire forming "blank" might give the answer, but it will be a day or so before I can get to the range.........just to pop off a couple of blanks. If that doesn't provide any info, this whole lot of Winchester cases may be headed for the scrapper........sigh.

[sawinredneck]

Will a new, out of the bag, case chamber? I'm fishing here.

[3006guns]

Will a new, out of the bag, case chamber? I'm fishing here.

Yep, no problem at all, no resistance on the bolt handle. Load up a round and it sticks the bolt at about the two o'clock position every time, despite seating changes, running through the sizing die again (RCBS, used it for years), trimming, etc. Diameters (base and neck) all mike okay too. I'm stumped. Anyone need some nice, fresh 8mm cases? (kidding, I want to find the problem!)

What's driving me batty is that I've used this same configuration successfully for years......with other cases.......and I can't see what the problem with the Winchesters is.

Update: I just measured the neck o.d. of a functioning round (Lake City WWII) and the loaded Winchester. Both measure right at .351. The Lake City round chambers, but not the Winchester. Then I placed both rounds side by side and I think I see a slight difference at the neck/shoulder juncture. Not much, almost microscopic, but it's there. It could be that the Winchester brass is springy enough that even resizing it does not form that area correctly. In any case, fire forming should prove it one way or the other. If that does the trick I'll form all of them, then load and shoot. Annealing the neck/shoulder is a possibility too, now that I think about it. That would soften the brass, allowing it to conform to the sizing die more readily. Might try that first.

[3006guns]

GOT IT!

I pulled the boolits from two cases, dumped the powder, deprimed and carefully annealed the areas around the neck/shoulder, quenching in water afterwards. I then ran one case through my sizing die and compared it to the other one. There was a very slight, but noticeable sharpening of the angle near the bottom of the neck and the shoulder looked a little farther back. I seated one boolit, put it in the rifle magazine and closed the bolt with that satisfying "shu-shuck" of an easily chambered round.

My theory: When this brass was manufactured, the die that forms the neck/shoulder may have been slightly worn forming a gentle rounded area instead of a sharp angle (springy brass). It was so tiny it was virtually unnoticeable. Annealing that section and resizing moved the shoulder back a bit and sharpened the angle.

So why did the case chamber easily without the boolit? Simple. The boolit did not materially increase the diameter of the neck...no more than usual anyway...but it DID expand that rounded area so that the loaded case would not chamber. Had these new cases been annealed at the plant and then full length resized by me prior to loading, none of this would have happened.

Lessons learned: Load ONE round and test chamber it first, before proceeding. Even better, anneal an entire lot of new brass before loading.

Many thanks to all of you for the help, suggestions and encouragement. Perseverance was the key!

[sawinredneck]

Sorry I wasn't any help, but glad you got it sorted out.

[3006guns]

Sorry I wasn't any help, but glad you got it sorted out.

You WERE a big help! Ideas, suggestions, experience, etc. are what make this board great. By contributing anything at all, you add to the growth of an idea. Your suggestion to try another sizing die was what caused me to examine the cases more closely and THAT'S when I started to make progress. So, thank you!

[rking22]

Glad you got it figgered out! Puzzles are fun.....till they get aggravating! Your experience has been duly logged for future reference, thanks for posting the resolution.

[3006guns]

rking22, thanks for your help also and I hope the info can be useful to others in the future. As an update, I annealed all 50 cases, resized again then loaded. Every one of them chambers beautifully........now it's time to make them into "once fired brass"!

[John Boy]

Lessons learned: Load ONE round and test chamber it first, before proceeding. Even better, anneal an entire lot of new brass before loading.

Glad it has been resolved. There is an old saying:
* A European carpenter measures 7 times - cuts once
* An American carpenter cuts 7 times - measures once