Sorting out the Rock Island

by Sarge, Saturday, January 07, 2012, 18:08 (4707 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:

[image]
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:

[image]
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.

Good diagonistics to finding the problems. RI should fix

by Cherokee @, Medina, Ohio, Saturday, January 07, 2012, 18:30 (4707 days ago) @ Sarge

you up. If it was me and they would not supply a properly chambered barrel, I'ed take it to my local gunsmith (that being Andy Horvath) and have him fix it. Then again, that AO barrel may work great.

Good diagonistics to finding the problems. RI should fix

by Sarge, Saturday, January 07, 2012, 21:22 (4707 days ago) @ Cherokee

The RI barrel appears near-perfect dimensionally & looks, at least, like it could be a good shooter. I don't expect any trouble getting it reamed or swapped out.

I have an STI Spartan

by cas, Saturday, January 07, 2012, 22:13 (4707 days ago) @ Sarge

Which IIRC the Rock Island comes from the same place, Armscorp. When I got it , it was constantly failing to lock up that last smidgen. When I started to read your post I thought you had the same issue.

My problem drove me nuts because it would only do it during matches, so I could never take the time to properly diagnose it. What I eventually found was that none of the loaded rounds were getting up and behind the extractor. The would all jump forward in front of it, being pushed into the chamber, then the extractor would snap over the rim when it locked up. Or I should say, most of the time.

I had some of that too, CAS...

by Sarge, Saturday, January 07, 2012, 23:46 (4706 days ago) @ cas

But reducing the extractor tension seems to have alleviated it. I need to yank mine out again and check it against this diagram...

[image]

It's good to have your OEM extractor to the above spec- but I have never regretted money spent an Ed Brown extractor.

I had some of that too, CAS...

by cas, Sunday, January 08, 2012, 17:22 (4706 days ago) @ Sarge

After playing, adjusting, fighting and fiddling with it a while I replaced it with an E.B. as well.

Then it started throwing most of the brass over my head. I tried making adjustments to correct that with no luck. Changed the ejector as well, same thing. Recoil springs.. same. About that time I said to myself, "you know.. I don't really care that they're going over my head." :-)

I had some of that too, CAS...

by Slow Hand ⌂ @, Indiana, Sunday, January 08, 2012, 17:28 (4706 days ago) @ cas

Over the head is fine but when they start bouncing off your forehead it gets bothersome!

It's just most of the time. lol

by cas, Sunday, January 08, 2012, 18:53 (4706 days ago) @ Slow Hand
edited by cas, Sunday, January 08, 2012, 19:03

Over my head I mean. The ones that hit me bounced off the overhead. And in slow-mo there's one shot that looks like two shells come out. Been trying to figure out what that was since day one. :-| (around the 50 second mark, that shot there are TWO shells in the air. It wasn't the shell from the previous shot, nor did the gun double. (???))

Is it posible the 2 shells are a reflection ?

by Cherokee @, Medina, Ohio, Sunday, January 08, 2012, 20:43 (4706 days ago) @ cas

nm

You can stop the video and clearly see two shells.

by cas, Sunday, January 08, 2012, 22:15 (4706 days ago) @ Cherokee
edited by cas, Sunday, January 08, 2012, 22:22

I wish I had the original video so I could slow it down even more. The "frame" speed and transfer aren't fast enough to really see what's going on. One frame you see a case coming out (going the wrong way) and the next you see it up above the same flight path, but now there's one closer to the camera on the right. One seems to pass to the right of the lens, one to the left.

Perhaps I was shooting so fast I caused a rift in the space tine continuum.;-)

[image]

Old trick

by JLF @, Sunday, January 08, 2012, 21:48 (4706 days ago) @ Sarge

This may be old news to everybody, including Ed Brown, but at the bottom of the notch on the extractor that the case feeds up into, it can help a lot to knock that sharp edge off with a file, and then polish it bright. This creates a bit of a "feed ramp" to help the case seat in the extractor as it rides up from the mag. Almost part two of the same operation is to polish the breech face as bright as you can make it, and deburr any ridges around the firing pin hole. The case makes a hard and fast ride under slide pressure to get where it needs to be, and can use all the help you can give it.

JLF

Amen Jack...

by Sarge, Monday, January 09, 2012, 06:45 (4705 days ago) @ JLF

Just got done beveling the extractor before I saw your post. The only thing I can add to it is a pic... once. That little bevel on the bottom of the hook itself, sure makes rounds feed up under the extractor slicker; you can really feel the difference when hand-cycling rounds slowly.

[image]

Thx JLF and Sarge. Very helpful.

by brionic @, Monday, January 09, 2012, 18:03 (4705 days ago) @ Sarge

.

Sorting out the Rock Island

by Sarge, The A/O barrel made it run..., Sunday, January 08, 2012, 15:11 (4706 days ago) @ Sarge

Just FWIW I shot three 8 round CMC mags of Federal ball through the Rock awhile ago, with the Auto Ordnance barrel installed. It is the first three magazines the pistol has cycled without failing to feed. At 50 yards they were all over an Osama target, but at least they were feeding and firing. I feel pretty confident that the bad chamber in the OEM barrel was 95% of its problems.

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