1911Tuner
Moderator Emeritus
Another 500 rounds seems to have settled things in pretty well, and the gun is a bit smoother as it rides into and out of battery. One little thing caught my attention about halfway into the session. The pistol started to vertically string the shots a bit out at 50 yards. When I got it back home, I found out why. The one thing that I didn't measure...The slidestop pinhole in the link. I was too busy checking the other, more critical specs, and didn't even give it a thought.
What's that they say about "ASS-U-ME?
My bad. No excuses
offered.
The unlock timing was inconsistent due to the pinhole being .213 in diameter. As the gun loosened up, the timing went haywire, and the accuracy along with it. The oversized hole in the link wasn't letting the pin use the link to unlock the barrel at the same place in the cycle, and the barrel's inconsistent unlock timing was throwing the shots in a vertical string.
I fished around in my parts box until I found a link that fit flush with the
lower lug, and didn't carry the barrel into vertical lock. The original link
had the slidestop pin slightly off the lower lug's forward radius, and was
contributing to a light stem bind as the barrel cammed up into the slide.
The correct link has solved the stem binding issue, and the pistol will hand-cycle SWCs as readily as hardball. I suspect that the vertical stringing will disappear too. I hope to re-test the gun sometime mid-week.
Don't know if this was a once-in-a-thousand fluke...or if it's something to watch for across the board with the Kart barrels...I can't imagine that a firm that produces barrels of the quality that this one has exhibited in every other aspect would do this as a matter of course, though.
Even with the stringing, I continue to be impressed with the accuracy of this barrel, and wouldn't hesitate to recommend it. Check the size of the hole in the link, though. .213 inch is way out of spec, and the slop could cause a late unlock/linkdown that has the potential to damage the locking lugs, depending on the individual gun.
What's that they say about "ASS-U-ME?
My bad. No excusesoffered.
The unlock timing was inconsistent due to the pinhole being .213 in diameter.
As the gun loosened up, the timing went haywire, and the accuracy along with it. The oversized hole in the link wasn't letting the pin use the link to unlock the barrel at the same place in the cycle, and the barrel's inconsistent unlock timing was throwing the shots in a vertical string.I fished around in my parts box until I found a link that fit flush with the
lower lug, and didn't carry the barrel into vertical lock. The original link
had the slidestop pin slightly off the lower lug's forward radius, and was
contributing to a light stem bind as the barrel cammed up into the slide.
The correct link has solved the stem binding issue, and the pistol will hand-cycle SWCs as readily as hardball. I suspect that the vertical stringing will disappear too. I hope to re-test the gun sometime mid-week.
Don't know if this was a once-in-a-thousand fluke...or if it's something to watch for across the board with the Kart barrels...I can't imagine that a firm that produces barrels of the quality that this one has exhibited in every other aspect would do this as a matter of course, though.
Even with the stringing, I continue to be impressed with the accuracy of this barrel, and wouldn't hesitate to recommend it. Check the size of the hole in the link, though. .213 inch is way out of spec, and the slop could cause a late unlock/linkdown that has the potential to damage the locking lugs, depending on the individual gun.
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