Very interesting, thanks for letting us know about it. Mine seems to headspace Ok though. Not like that.
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Very interesting, thanks for letting us know about it. Mine seems to headspace Ok though. Not like that.
Last edited by Earlwb; 05-10-2020 at 10:37 PM. Reason: add more info
Earl, do you find that you split very many cases?Originally Posted by Earlwb
I hope to get it straightened out, mine is a very lower serial number first year hi-cap pistol. Maybe they have their act together now.
Well, for the cases that survive, an anneal and not setting the shoulder back as you are doing seems appropriate. The factory case may be headspacing on either the case mouth or shoulder depending upon how the chamber is cut. From the looks of things and assuming your fired and sized case length is about the same as the factory case length you are accomplishing cartridge shoulder contact with the chamber or close to it and at least reducing some of the slop the factory rounds have.
Fired cases and your correct appearing sized cases have a noticeably shorter neck than factory cases which means the fit of the factory case in the factory chamber is the problem as you surmise. There is some generous clearance it appears.
Not knowing their tolerances I cannot say what is proper but split cases are not good. A poor factory anneal may contribute.
If you anneal it can be overdone so proceed carefully. I have to exercise caution when doing so myself.. Some Tempilaq used judiciously is helpful in avoiding over doing it. If shoulder headspacing is being accomplished and the bullets and dies used allow a crimp that can help hold the bullets in place during feeding with a roll crimp into a cannelure being a good choice if you can manage it.
The reason I mention a crimp is that sometimes annealimg makes proper case neck tension a little more elusive depending upon how it is done.
Interesting I am glad you found the problem I hope thy take care of you.
I am curious to hear why a case fired in that chamber will not re-chamber I hope someone knows.
To solve that particular problem compare fired cartridge diameter at shoulder, midpoint and base above the extractor groove to a sized one that chambers. Then you will have your answer. If it only goes halfway in it is diameter that is causing it rather than anything to do with the shoulder or neck.
I have already submitted the RMA paper work and the same pics of an unfired and fired and sized round. The factory rounds are really hot, the primers come out looking pancaked and most of the firing pin hit is smashed out. In this chamber, I am not surprised that they split. This round is just so much fun, I just want to get to where I can shoot it regularly. It shoots cast very well, 2.5" for me at 25 yards, with my bad eyesight... I now consider that good given the black sights with no dots. If they get it going right, I will add dots to the front and rear sights.
One thing I do not like, the fireformed case do have some of the case wall exposed in the barrel. I am not sure that is a good plan, see the pic above and you will see what I mean.
With my caliper, I find that the fired brass is much closer to a straight wall case now. The formed round actually should have a decent increase in volume. Would have used a mic, but my daughter dropped my .0001 0-1 and it just is not right now. I need a different one at this point.
All 1911s have some amount of case exposed in the feed ramp area. Whether it is excessive or not depends on the working pressure of the cartridge used and how much brass is exposed. The area of the case near the extractor groove is solid brass and the first part of the case wall is usually pretty thick.
A sectioned case will show how much of the combustion area and brass thickness is adjacent to the relieved area of the chamber if you must know.
Excessive exposure with higher pressures leads to guppy belly brass, a problem sign to be heeded.
At one time they had real problems with the dimensions of the brass even on loaded rounds from the factory. Most were just too long (a lot) but who knows if the shoulder was pushed back or not. Try fire forming with lite loads and don't touch the shoulder when resizing.
That is what I did this weekend, I do have to touch the shoulder just a tiny bit, otherwise the neck will not allow the shell into the chamber. So, I am using Lee dies and for the case to fit the chamber I just need the base of the die to touch my RCBS shell holder. If I set the die with any compression, the shoulder is set back to far. I will put a Hornady lock ring on the die and leave it set now, the Lee lock rings do not lock and will end up to long or to short in this case.
Only a few with the first box of factory ammo I fired. After that factory or reloads I haven't had any neck splits. So at the time, I thought it was the brass not being properly annealed or something. At the time we were thinking it had to do with where the ammo was manufactured. They were making it in the Phillipines and in the USA. If you look at the boxes you can tell where it was made.
Last edited by Earlwb; 05-11-2020 at 11:41 AM. Reason: add more info
I think that my gun's chamber isn't as overdone as yours was. it still headspaces OK. I was going back through my pics when I had mine out at the range a while back. The case shoulder doesn't expand out like yours does but the case neck swells up some. But I didn't think of it as being a problem.
A fired case, a unfired factory round, and a unfired empty case shown here.
That looks reasonable. Note the neck does not shorten so much. Shorter neck equals shoulder blown forward upon firing due to slop between case and chamber allowing room for brass to move forward.
I really wish that my boundaries were that sharp. My shoulder to body and shoulder to neck boundaries are more curved than angular. My 2 cases of ammo are USA made.I think that my gun's chamber isn't as overdone as yours was. it still headspaces OK. I was going back through my pics when I had mine out at the range a while back. The case shoulder doesn't expand out like yours does but the case neck swells up some. But I didn't think of it as being a problem.
A fired case, a unfired factory round, and a unfired empty case shown here.
If the cartridge is not overloaded and the case is not bulging at the ramp and they can't unlock under pressure why will the fired cases not rechamber ?
Any one have any ideas ?
I am not 1911 guy I have one now and have had a few others but have never found them comfortable to shoot , they just don't work well in my hand so I have never spent much time messing with them.
In this case, I think if flat out have a bad chamber. Measuring with my calipers, I seem to have a slightly fat spot in the middle of the case. I am not having extraction problems and no marks on the brass. I might be able to force the case in by hand, but would have to drive it out with a dowel. I would expect a snug fit, but I would have expected it to fit as well. I did not try rotating in all around, it may be a chamber geometry issue, my fired cases are show below... I just do not have a good way to compare cases, other than visual and caliper at the moment.
An eccentrically shaped chamber would fit his description of what is occurring.
Is it even possible to do a measurable chamber cast on a 1911 . that was one of my first thoughts but when I thought about it I could not think of a good way to do it.
Thanks for the response guys .
I get something like this stuck in my head and I can't stop thinking about it.
Last edited by onelight; 05-11-2020 at 05:24 PM.
Sure. Get some Cerrosafe from Brownells or something similar. Exact measurements to “good enuff” are obtained 30 minutes after solidification.
With the barrel hood the only place the barrel is as long as the case how do you contain the Cerrosafe to get the full chamber casting ?
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