Sorting out the Rock Island

by Sarge, Saturday, January 07, 2012, 18:08 (4652 days ago)

In earlier posts I mentioned this gun’s propensity to fail to return fully into battery, and that the usual ‘forward assist’ push on the slide wouldn't rectify it. Even with a clean gun, it was evident in hand cycling ball rounds. I originally attributed this to excessive extractor tension. In this I was correct, but that wasn’t the entire problem.

I also noted that the chamber dimensions were tight, but even a tight-chambered 1911 will usually run for 100 rounds or so before it gets sluggish. My old ’45 Ithaca had a tight-chambered, 7-digit stainless National Match barrel, yet in four days I burned over 700 rounds of 200 LSWC reloads through it at NRA LE Instructor School (Topeka, 1991) in near 100 degree temps, with no malfs at all. That particular gun had the full AMTU treatment at some point in its life. I did a similar rebuild on a Colt Combat Commander in the late 70’s; fitted Bar-Sto barrel, tightened rails, the works. This was back when I still had eagle-eyes and that gun produced more than a few 5-shot, 2 ½”50 yard rested groups. It ran great, too. So I know that ‘tight’ guns can be reliable.

Something else was going on here and in an effort to identify ‘what’, I dug out an old Auto Ordnance barrel I’ve had laying around for years. It ran like a top, but had chatter marks in the rifling so I’ve never used it for serious shooting. Take a look at the front of the chambers on both barrels. The Rock Island barrel is on the right:

Frankly, I think A/O did a much better job with their ‘wadcutter throat’; but I digress. A closer look at the Rock Island chamber, here:

Some things became apparent when I took a close look and started taking measurements. There is next to NO leade into the rifling, which is bad ju-ju for the wadcutter loads I shoot by the bucket-fulls. I grabbed a few oddball rounds which include Winchester USA, Winchester SXT Federal FMJ and Wolf FMJ, all of which are 230 grain. I also added my 200 LSWC reload (1.250” OAL) and a reload using a 255 grain semi-wadcutter intended for the .45 Colt. The latter is loaded to 1.175” and all these loads have proven reliable in various 1911’s I’ve had.

I began by measuring the length of the barrel, including the hood. I then dropped each of aforementioned rounds lightly into the chamber, and measured the barrel again. A properly-cut chamber will admit in-spec .45 ACP ammo dropped into it and the case head will be flush with or at most, 2-3 thousandths below the hood. This barrel is short-chambered and various loads protruded 15 to 30 thousandths ABOVE the hood.

The final confirmation of this materialized when pushing the ‘high’ rounds on into the chamber, flush who the hood. Resistance was felt as they seated and it was necessary to pluck them from the barrel. This was particularly apparent with the 200 grain LSWC load and the leading shoulder of the bullet showed bright marks where in encountered the sharp edge of the chamber. These loads in particular have proved wonderfully reliable in other 1911’s I’ve owned.

This is a shame, folks. The factory Rock Island barrel is excellent in all other respects. It mikes a proper and perfectly-round 0.580” at the muzzle, reduces to 0.575” about a half-inch back; essentially ‘match’ barrel external dimensions. Excepting the wadcutter throat, the finish, lugs rifling etc. are excellent. I suspect it will shoot like a house afire, certainly within my 4” @ 50 yards requirement for carry guns.

So what to do? First, I have the old Auto Ord barrel plugged into the gun; so I’m not stuck with a pistol I can’t shoot. Second, the gun was sold through Davidsons and I’m told it can be exchanged through them without problems. Finally, Rock Island’s customer service is said to be good and I could probably return the gun to them for correction.

I’m choosing ‘none of the above’. I don’t buy guns to ship them all over the country. I’ll begin by contacting Rock Island and opening negotiations for a barrel exchange. We’ll see where it goes from there.

Lordy, I should open a lemonade stand. I certainly have a gift for finding raw material for one.