I have a series 70 Colt MKIV 45 ACP that has a soild barrel bushing with the original stock barrel. I bought this gun used so I dont know if the solid bushing came with the gun when new. My impression was that Series 70 guns (real Series 70 guns not the reintroduced models) all came from the factory with the collet bushing. I'd like to try a collet bushing to improve accuracy. The current solid bushing is loose and sloppy. My wife has a stock Series 80 which came with a collet bushing and its a tack driver. (Again, I thought all Series 80s had the solid bushing) Would it be harmful for me to try a collet bushing on my Series 70 Colt 1911 45?
I still have an original Colt MkIV Series 70 which I purchased new in the mid 70's. Mine came with a collet bushing and gives very good accuracy. I probably have 4-5,000 rounds through it with no problem.
I did get a solid bushing fitted, but it was so tight that it was a problem. I went back to the collet bushing since this is more of a sport gun then a SD gun.
I can't see that trying a collet bushing would hurt your firearm.
Properly adjusted, the collet bushing does work well. However, if the barrel links up too far and puts excess pressure on the bushing, the fingers will fatigue and break. Personally, I prefer a properly fitted solid bushing. Since your solid bushing has a sloppy fit, either it was not properly fitted or it was a GI style replacement. A properly fitted bushing can be turned by hand, but a bushing wrench makes it a whole lot easier.
Stans just made a good point. If you can even find an original Colt collet bushing, it may not fit your slide/barrel combination. Most smiths that I know of throw them away, but you may find one by asking around. I MIGHT have one here. If I do, you're welcome to it. Even if it does fit, it may not fit right. When the collets were right, they worked pretty well... when they didn't, the problems could range from bad functional reliability to breakage of one of the fingers. I've seen three that broke, and they locked the gun up solid. One was so bad, that I had to drill the slidestop off to get it apart. All three guns had damage to barrel, slide and frame, and on the one that I had to drill, the damage was bad. Colt stopped using those bushings for a reason.
Another point is that the collet bushing may or may not improve your accuracy, or improve it only a little. It depends on the vertical lock at the rear of the barrel... the lugs' fit in the slide, and the fit between the barrel hood and slide.
If you want to see if a tighter bushing will help without compromising reliability or risking damaging the gun, I'd give George Smith a call at EGW, (Evolution Gun Works) and give him your slide ID and barrel OD measurements. He can custom-turn one of their excellent angle-bored bushings that will fit your slide and barrel correctly. You'll need to let him know whether you want a wrench-turn fit or finger-tight fit in the slide. You can find EGW on the web by doing a search.
What 1911Tuner said... my MKIV Series 70 1911 originally had a collet bushing. I shot the gun for some thousands of rounds. One day at the range- clunk! A finger had broken off the collet, and locked up the gun. Fortunately, I had an idea about what might have happened, and so did not start yanking on the slide and make it worse. I shook the gun around until I heard something that sounded different. I was then able to retract the slide and remove the slide stop pin. I got a solid bushing from Irv Stone (Bar-Sto) that fits nice and tight -both in the slide and around the barrel- and have been just as happy with the gun's accuracy as I was before the breakage.
"I'd give George Smith a call at EGW, (Evolution Gun Works) and give him your slide ID and barrel OD measurements"
Can you send your slide and barrel (w/o frame) to them to get a custom fit?
FPrice asked:
Can you send your slide and barrel (w/0 frame) to them to get a custom
fit
Not sure, but I would imagine so. Never hurts to ask, and George is always happy to accommodate. You can raise him on the 1911Forum and ask him. Might be a 3-4 week turnaround though, and those boys can get it mighty close with just the dimensions. If you don't have a dial caliper, any machinist can measure the slide and barrel in about 30 seconds. Check with your local machine shops.
I will only use one bushing. Briley Spherical Drop In bushings are not only the easiest to instal, they're very accurate. They can be found at Brownells.
If you want to try a collet ("split") bushing, Gun Parts Corp. has them. Check at www.gunpartscorp.com.
The idea of the collect bushing seems good - eliminate all slop at the muzzle. They do break, however - I saw one on a early S80 Colt that split all the way out to the end.
I've never owned a gun with collet bushing myself, but I will pass along a tip from a spring guy(that would be me) since the collet bushing flexes and works sorta like a spring.
On all the fingers, I would carefully break the sharp corners inside and out all around. These sharp corners are a starting point for fatigue cracks, and life should improve with this simple mod. The same is true of any leaf spring in any gun, BTW.