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anyone else ever seen this before, is on a original winchester barrel on a QHMC which means it had to get past their inspector, then get to QHMC and get past their inspector and then get approved by the ordnance inspector-kind of baffling to mehttps://www.milsurps.com/images/impo..._8065JPG-1.jpg
The back one looks correct but not the front one. Are you sure it wasn't done sometime after by ??? It wouldn't line up with the gas vent either. That's how the vent was drilled.
It's not a vent. It's the hole made by drilling the gas port into the barrel. There would be no other way to get a drill in position to drill a hole going from the front wall of the piston chamber into the bore. Look at a vertical section through of the gas block and it will be obvious. Anyway, there's already a pretty big gas vent right under the front sight - it's about 10x the area of this hole. Also, the bullet has already exited the muzzle by the time the piston gets going good, thereby dropping system pressure to atmospheric.
I would guess the forward hole does not penetrate into the bore. Would be interesting to know the distance on the inside from the front edge of the forward hole to the front wall of the piston chamber, but you're probably not too excited about removing the nut. Kuhnhausen's sketches don't quite give enough dimensions to make the calculations, but it could probably be done pretty well by measuring the dimension from the edge of the gas block to the front edge of the hole and then measuring or guessing at the angle of this hole.
You're just splitting hairs. Names. I know what the gas port does, or whatever you want to call it. I know how it's arranged in the construction of the barrel too. I was talking about the second hole's purpose and how it got there. The second part of you're post I agree with. I don't think it was factory done, which is what the OP's asking...Quote:
Originally Posted by firstflabn
i feel its the original park finish so have felt was factory done, feel was error or done on purpose as some kind of test
wtmr,
Here is what I am seeing...
1) the two holes do not line up at the same angle. The front (second) hole seems to be off-center of the cylinder.
2) the metal flow on the outside of the holes is different.
3) the cut angle of the front (second) hole is not consistant - it changes angles.
4) the two holes have different diameters and the front (second) hole has a changing diameter (like someone rotated/circled the drill bit while in the hole)
I am wondering if the "original finish" appearence is due to the years of carbon build up from gas coming through the hole. Based on all this, I doubt that it was done at the factory and that it got by manufacturer and ordnance inspectors.
As far as WHY? bunch of guesses come to mind... getting a stuck piston out of the cylinder??? .... Bubba trying to make it cycle faster?.... Trying to make it a single-action weapon?.... Who knows, Bubba and "I know what I am doing" military armorers do a alot of things.
Just my two cents...
Words have meanings. Technical terms have a purpose and "whatever you want to call it" does not compute. If it doesn't matter, let's call it a toaster from now on. Understanding the function of the components is fundamental to the timing of the sequence of events. That's why I asked which hole hole penetrated thru to the bore. That, along with the dimensional question, could raise an interesting question of when the piston cleared the hole vs. when the bullet exited the barrel. Not sure I have enough data on piston acceleration to draw a vaid conclusion, but would be fun to tackle the problem.Quote:
Originally Posted by browningautorifle
I tried to answer the OP's question, but I'm missing the point on how your level of understanding should influence my response to his question. Are you available to prescreen my future responses to others to make sure I don't risk offering anything you think you already know? Splitting hairs indeed.
It could just be a situation of a barrel that was miss drilled too close to the nut, put aside and when barrels became scarce, was taken out of the salvage bin, redrilled correctly and put on a carbine. If the nut threads cover the hole, no harm no foul, which would be what an inspector would think when he looked at it and passed to on to issue. But there is no data about this and therefore it is not even considered as anything beyond my worthless opinion.
here is pic showing the winch proof and the short or fat P that qhmc used https://www.milsurps.com/images/impo..._8085JPG-1.jpg
---------- Post added at 01:15 PM ---------- Previous post was at 01:11 PM ----------
the second hole which is clearly releasing the gas if was continued would have come out front of gas cylinder if it had continued at angle it was at. Someone clearly stopped. The normal hole just has a lot of carbon build up, they are same size.
'If the nut threads cover the hole, no harm no foul, which would be what an inspector would think when he looked at it and passed to on to issue.'
Guys; the hole on the piston end of the fitting where you can see the nut threads is the original, correct hole. You see the nut threads in all of them, which is why you have to remove the piston and nut to ream out the gas port using that hole. That's the only way to get to the gas port because of the angle as evidenced by the oblong shape of the hole. The other hole toward the muzzle end is the incorrect one and does indeed work as a 'gas vent' (unfortunately) and probably has turned that carbine into a straight-pull bolt action. I would have it wire-welded shut and push on towards Berlin!