The Ugly Truth
Got done a little early and am happy to report that "Officer's Model from Hell the Second" is now tickin' along happily. I think the sledge hammer and backin' over it with the truck probably did the trick.
On to the Norinco barrel...
Where to begin? This barrel was about as bad as I've ever seen and still allow the gun to function.
The damage to the locking lugs was due to the lower barrel lug being located too far to the rear by about .020 inch. This accomplished the same thing as the impact surface in the frame being set too far forward.
The barrel stopped against the frame before the barrel lugs had completely unlocked from the slide, and the result was the damage that was seen in the first pictures.
Additionally, the upper areas of the lugs were actually set back. The forward lug was affected for roughly half of its height...The center one by about a third, and the rear lug had been sheared off at an angle the took
.010 inch off the height.
Moving along to the headspace question...
I dropped a GO gauge into the chamber for starters. The rear face of the gauge stood above the hood by .008 inch...suggesting a slightly short chamber. Not an altogether bad thing if the gun is to be used for National
Match Bullseye competition...but not a good thing for feed reliability.
For the next part, I used a known good side as a control, and two stock
Norinco slides that checked within .003 inch of the specs on all critical dimension of the control.
The barrel was engaged into the control slide on the GO gauge, which it accepted easily. The NO NO gauge also locked into battery position easily, which would be cause for immediate rejection...but that's not the worst of it.
With the NO GO gauge in the barrel and in battery, I was able to slip a .023 feelergauge between the rear of the gauge and the breechface.
The aggregate dimensions added up to .045 inch of excessive headspace from the minumum...and .034 inch of excessive headspace
if the difference between GO and NO GO was split dead in the center.
To put it in simple terms...Dangerously excessive headspace. A .050 feeler gauge slipped between hood and breechface without drag, and
it stopped a .054 feeler gauge...putting the clearance at .052 plus/minus
.002 inch. Here was a classic example of "Headspacing on the Extractor".
On to the third problem...
The locking lugs were dimensioned well within spec from the barrel hood to the thrust faces of each lug, and there was a full .016 inch of fore and aft play in the barrel to slide lug engagement, which contributed to the lug setback because when the pistol fired. The barrel and slide lugs had a good running start at each other, and when the barrel was held firmly to the rear of its travel, there was a large gap between the hood and the slide. This wasn't measured, but was noted to be a substantial amount.
The fact that the locking lugs were dimensioned correctly from the barrel hood puts everything badly out of spec from the hood forward...and from the rear faces of the barrel lugs back. I don't see how the gun worked at all. Mr. Sample did a nice job of cleaning up the damaged areas, but it was in vain. This one was dead meat before the first round was fired.
Two conclusions were drawn from this:
The damage to the lugs...and probably the slide...was likely done within the first 500 rounds, and possibly the first 200. The previous owner probably noticed it and pawned the gun off on unsuspecting Dominic, who then proceeded to fire the gun and thus increased the damage to the point that he began to notice it. He very likely also noticed weak ejection and possibly a few short-cycle malfunctions due to the slide's recoil momentum being interrupted by its impact with the barrel. Based on my own experience, the two forward lugs would have sheared off within 500 rounds of the time that the pictures were taken.
It's also my opinion that both the previous owner and Dominic were extremely lucky that they have both eyes and all fingers intact. The
static headspace on this pistol was such that, by all rights, it should have
blown a case, with the possibility of sympathetic detonation of two or three rounds in the magazine.
A little knowledge of what to look for can go a long way to preventing us from being taken advantage of by unscrupulous "Horse Traders" who
have no qualms over passing on a defective gun to somebody else.
Your first clue that something is wrong is a large gap between hood and slide. Most production guns have a gap that can run from as little as .003 inch to as much as .012 or even a bit more. If this gap is larger, lay the gun down and walk away. A set of small feeler gauges carried in your pocket is all you need to guard against being taken.
Next...if the owner will allow you to field-strip the gun, push the barrel fully into the slide, hold it forward, and use the feeler gauges again to see what the gap is when the barrel is pushed firmly rearward. If the gap closes by as much as .005 inch, the gun is borderline. If pushing the barrel back allows the hood to touch the slide...walk away wth a smile on your face.
You've outsmarted the rascals.
If you're serious about buying only safe, serviceable pistols, invest in a
2 piece set of GO and NO GOf gauges. I keep an extra GO gauge that's .895 inch...or .003 inch shorter than the SAAMI minimum, strictly for the purpose of short-chambering a gun used strictly for target matches. Mine is home made, and not necessary for checking for safe headspace. If
you're truly serious, you can hire a machinist at a small job shop to make
a .910-.912 inch NO GO gauge to narrow it down a bit more. .920 NO GO is fine for an ordnance-spec gun, but slightly long for best accuracy
if the chamber is close to that maximum. Your red flag will be if the gun will almost go to battery on the .920 NO GO.
Now I gotta go rest my back...I blew it out again, and am now waddling like a
duck as I go about my routine. Time for the ol' crippled man to stretch out.
I shall return!
Cheers! (ouch)
