Colt/Kart-Monday

[1911Tuner]

Well...not bein' long on patience, I got my tired old patoot outta bed early and
made a short trek up to a little impromptu range not far from here to see if the relinking solved the problem. I've only got about 25 yards there, but
figured that if it strung at 50, it would string a little at 25.

The vertical stringing went away...as near as I can tell...and the groups are
nice and symmetrical. The point of impact is a little higher now...no doubt due to the barrel starting tounlock a little earlier...but no more than an inch-point-five.

The frame to slide fit is still tight, as is the vertical barrel lockup. Close examination of the locking lugs shows no linkdown timing damage, so everything is still good to go.

Curiously enough, the link that I replaced the original with was a Wilson #2,
which is .005 inch shorter than the "standard" .278 link...and about the
same amount that I lowered the rails. The #2 link was a near-perfect match for the lower lug dimensions...and the barrel neither rides the link, nor does it lock on the link...so everything worked out nicely.

Measuring the holes in the link a bit more carefully revealed that the hole is
.211X.214 inch...longer than it is wide. I was hurried last night, and just did a quick-check with the caliper without measuring twice at 90 degrees. I had relieved the hole with a drill rod and some 600-grit paper by about .001 inch to get the slidestop pin onto the lug...so this would account for that amount of the elongation. The material was just barely visible above the lug, and the clearancing that was done was mostly polishing to match things up and get the pin bearing evenly all the way across both sides of the lug and the link.
It would have likely worn in eventually anyway, and could have been done with a little J&B on the pin and a couple hundred rounds...but I wanted everything to lock up right from Jump Street.

The small hole is a little oversized too, coming in at .157 inch...measured three times, just to be sure my eyes weren't lyin' to me. Not a major issue,
but fairly sloppy with a .154 diameter pin. I may ream the hole and press in a
.156 pin later on...just to see what effect it has on the grouping and/or POI.

I'm still mightily impressed with the barrel, and these are minor issues. The system is very good and just the ticket for a hobby smith who wants a well-fitted and accurate barrel upgrade.

 

[Old Fuff]

Yup, I've seen a lot of interesting results when someone lowers the slide on the frame rails but doesn't pay any attention to what the link is doing. If the barrel/slide fit was loose in the first place, as with a stock service barrel, nothing may be amiss, but otherwise ...

I still don't see the (somewhat misnamed) E-Z fit barrel as a solution for the average owner/basement ?smith. Very few of them have headspace gauges, a chambering reamer, or even a set of calipers. A gunsmith who wants to install a match grade set-up without going to true hard-fit barrels would be another matter because they could afford to spend the money for required tooling.

While the increased accuracy is a plus, I wonder if it that much of one considering the way most individuals use their pistols, in particular those that are carried as a weapon. At say 25 yards is there a critical difference between a 1 ½ inch group and one running 2 ½ inches? A pistol being set up for competition would be another matter.

Anyway, I think the Springfield Barrel you experimented with before may still be the best option for anyone that isn?t set up to install any kind of a match-fit. When you have to ream the chamber for reliability you leave the average guy behind.

 

[1911Tuner]

Get Linked

Fuff said:


>Yup, I've seen a lot of interesting results when someone lowers the slide on the frame rails but doesn't pay any attention to what the link is doing. If the barrel/slide fit was loose in the first place, as with a stock service barrel, nothing may be amiss, but otherwise ...<
***************************

Yep...me too. I take full credit for droppin' my candy on that one. The only hint that anything was wrong was that the barrel was stopped a little too hard by the link when it went to bed. When I lowered the bridge a little, that part cleared up...but I still should have been more watchful. I mainly wanted to see if the average Joe would have a good chance of makin' one work. I still think so...IF...the pistol hasn't been refitted the way I did this one.
___________________

And:


>>I still don't see the (somewhat misnamed) E-Z fit barrel as a solution for the average owner/basement ?smith. Very few of them have headspace gauges, a chambering reamer, or even a set of calipers. A gunsmith who wants to install a match grade set-up without going to true hard-fit barrels would be another matter because they could afford to spend the money for required tooling.<<
********************

The gauges and the measurements were strictly my idea...in the interest of
satisfying my own curiosity. As I stated above, if the frame rails hadn't been
lowered, it probably would have been a cakewalk and not beyond the average
kitchen-table smith.

Now for the downside...

If the rails hadn't been lowered, the vertical lockup would have been limited to whatever it was when the pads had been cut enough to let the barrel lock into battery on the slidestop pin. The decreased engagement probably wouldn't have been an issue with standard-pressure .45 ACP ammo, but
if somebody had been inclined to set up a .45 Super...it well could have been,
since the instructions only allow for the first locking lug, and hope for equal or even light horizontal engagement on one of the others. In other words...
If I hadn't fit the hood to pick up the second lug too...and I hadn't dropped the frame rails...I would've had roughly 90% vertical engagement on one lug
instead of nearly 100% on two. At the present, I'm very close to picking up the #3 lug...at least particall...as the barrel settles in. I expect that headspace will go to about .901 total by the time that happens, but the lockup will be as strong as the design will allow.

That's why I like an oversized lower lug, and would like to see Kart offer a slightly different version of this otherwise excellent barrel...with about .010 inch more meat in the lower lug area. Just that much could mean all the difference. They should also provide slightly different instructions for fitting
the locking lugs for equal load bearing...as an option for the more experienced
installers. An extra .010 inch of material in the lower lug really wouldn't even require a lug cutter, and could be scraped and lapped in. If I can get Fred to
make a barrel for me to those specs, I'll try one more and report on it.

I may...as soon as I find time...have some welding done on the stock two-piece barrel that came in my GI Springfield, and hard-fit it to the old Colt...
just to compare. The custom-made EZ-Fit...if I can get it...will go into the Springer.