[Judah Ben-Hur]

Hi guys,

I bought a used Colt MKIV/Series 70 in 9mm awhile back but need a little advice on a problem that it has. With that said, I don't know the guns history or modifications that might have been done. I just got it out recently and thought I'd better get going on it because I'd like to shoot it when warmer weather comes around. Plus, 9mm is cheaper to shoot off the shelf when I don't feel like reloading 45's and 10mm's.

When you rack the slide back and slowly let it forward, it hangs up going into fully battery by about 1/8 inch. A little nudge and it goes. I've only put a few rounds through it when I bought it and had to push the slide closed on a few rounds. You feel a definitive "hitch" working the slide.

I looked it over yesterday and noticed that one of the barrel lugs has a slightly raised area that is obviously making it hang up trying to lock into the slide. The slide area seems nice and smooth so the barrel is the obvious culprit. I'm not a gunsmith but what would cause this initially to have happened and what is th best course of action to make it a reliable shooter again? Here are some pictures to better explain things.

What to do?

1) Sand it down myself? :what:
2) Take it to a gunsmith? Any recommended ones in Northeast PA? (I hate sending things like these away.
3) Find another barrel? Where on the net?

Thanks!

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[10X]

A lot of Series 70 guns hesitate just before going into battery because of the collet bushing putting pressure on the muzzle.

If you have to force the gun into battery when firing then you definitely have a fitting problem. The answer is to take some material off of the bottom lug of the barrel. If you have not done this before, it would be best to find a knowledgeable 1911 smith. Many say they know what they are doing, few do.

The fit at the rear of the barrel has a major affect on accuracy and reliability.

[harmonic]

When you rack the slide back and slowly let it forward

If that's the only time it does it, then why just "slowly let it forward?" Why not just pull the slide back and let it snap into place?


I've only put a few rounds through it when I bought it and had to push the slide closed on a few rounds.

So you're also saying that this happens while you're firing the gun?

From your pictures the gun may be used but it doesn't even look broken in. Has it been fired much?

But I would look at ammo. Are these reloads? I'd be checking the taper crimp, OD, etc. Does this happen with fmj factory ammo, too?

I'd also be looking at magazines.

There were a lot of quality control issues with the old Mk4/Series70 weapons. I'd break it in first with factory ammo. But no way would I whip out the old dremel and start zapping my gun. After I was sure it was sufficiently broken in, and if the problem persisted, I'd send it to somebody experienced in 1911s.

Unless you're definitely sure it's a defective barrel. Those can be replaced easily enough. But I'd hate for you to spend that money and then find the barrel wasn't the problem.

[Judah Ben-Hur]

It happens both ways so obviously it isn't right. I know because I also have 5 other 1911's, 6 if you want to include a New Agent and they are smooth as butter. It won't be a carry piece but I don't want to be using my thumb to be pushing the slide closed.

The gun didn't look like it had much through it but it only came with 1 magazine. I was using factory ammo. I dropped it off at a 1911 gunsmith just a few minutes ago. The phone just rang as I got home and he said the problem was the collet bushing. It was putting uneven pressure on the barrel during lockup. He put in a regular bushing and the problem went away. He is going to be ordering a bushing and match it to my barrel so the accuracy should be better.

I've read that the collet's could be substituted and they were a weak link.

I hope to have it going soon!

Thanks for replies and I'll keep you posted on how it shakes out.

[harmonic]

I had the collet bushing replaced on my series 70 govt model, also. Not because it was creating a problem but because there were a rumor that occasionally a "finger" would break off and jam the gun up solid. I think that threat was highly over rated even though I'll probably do the same with my gold cup.

[rcmodel]

I think that threat was highly over rated No, it wasn't.

I have had to drill out a slide stop and beat the slide off with a plastic hammer on more then one to get them apart.

rc

[Judah Ben-Hur]

I did read that you weren't supposed to take them all the way off the barrel. I didn't but it will not matter now anyways. Last night was the first time I took it down so I could take some pictures. There was also something about not pulling the slide back a bit to go and start field stripping it. I cannot find it anymore. I would like to try and find a manual for it to see what other surprises are out there.

I would not want to be drilling and pounding, that would make me angry.

[BBBBill]

I've never heard of any bushing causing flanging on a barrel lug. If the smith didn't remove the flanging, you've still got a problem. Flanging is usually indicative of inadequate link down clearance which can be caused by a link that's too long, an improperly dimensioned VIS/standing lug, etc. More diagnosis is in order.

[Judah Ben-Hur]

He was talking on the phone about something with the barrel link. I'll have to wait and see what comes about.

[navyretired 1]

Those collet bushings are a bit(h I spent almost a whole day geting a slide off when one of the fingers broke and wedged under another finger. I had to cut off slide stop and drive out slide stop pin, then force barrel forward enough to take pressure off collet fingers. If anyone needs some I've got a drawer full of those bushings.
That flanging on the barrel does indicate a minor long link problem, if not fixed it could ruin barrel and slide.
As to take down you push slide back about 1/2" to release collet finger pressure to make bushing easier to turn. If you don't releave that pressure you need a long bushing wrench because it is very locked up with slide forward.

[Oro]

As to take down you push slide back about 1/2" to release collet finger pressure to make bushing easier to turn.

If you do this each time, it prevents the fingers from stressing against their grain and possibly cracking. With proper use, these things are capable of great accuracy and long life.

If you have some extra I would sure take some for future use.

[navyretired 1]

Oro can you name one custom 45 smith who uses collet bushings?

[jdomin]

send the gun back to colt

[Judah Ben-Hur]

The last gun that I sent back to Colt was a painfully long experience. That option is off the table.

[Drail]

Collet bushings - because new and improved always sells. (and lowers manufacturing cost) Sure, maybe you've never seen one fail. They fail.