Colt MKIV series 70 Question


August 7, 2012, 05:40 PM
I have a Colt MKIV series 70 Gov't model, vintage 1978. The gun has roughly 2700 rds fired through it. I can't seem to get a good group out of the gun, no matter who shoots it. I just recently bought a Gold Cup Trophy, and it shoots like a dream. My question is, if I were to replace the barrel and bushing with a match grade setup, will I have a drastic improvement in accuracy? My old Colt is in excellent condition, but I want to improve the accuracy.
Anyone have any tips that could improve the accuracy of this gun, without altering the original appearance. I don't want to mess with the frame or slide.

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August 7, 2012, 06:01 PM
A professionally fit barrel and bushing would probably go a long way in improving accuracy. You could keep the original barrel and collet bushing to preserve the originality of the pistol. You could also just have a new bushing fit to the original barrel and save more than a few dollars.

If your S70 is anything like mine, the trigger pull is really heavy and gritty.
A professional trigger job resulting in a 3.5# trigger with a clean break would also go a long way to improve shootability and therefore accuracy.

You could also install a 10-8NM rear sight (no slide mod required) and a stakes gold bead front sight, and that would also help and still preserve the pistols original appearance.

You're talking $400-$500 in mods, assuming quality parts, and professional work so the desire to improve performance has got to be pretty strong

Series 70
August 7, 2012, 06:10 PM
My Colt is one year newer than yours. The original barrel and bushing still give good service with at least 15,000 rounds fired. The mods I've made are a lowered ejection port, commander hammer, beavertail grip safety, trigger job, and long aluminum trigger. By far the most important for reliability was the ejection port, while the trigger job (just over 4 lbs, crisp) was critical for shootability. Oh, and sights. The factory sights are terrible, but that's a very individual choice.

I guess what I'm saying in an indirect way is that the base pistol is very solid. If you fix what's wrong, you'll get many years of fine service.

August 7, 2012, 06:24 PM
I had a trigger job done, and it has one the best triggers of any gun I own. I also replaced the original sights with the more modern Colt sights off of their newer 1911's. I saw new match barrels and bushing setup for about $240 or so. I don't know how much fitting they will require. This whole thing is an idea I have to improve on it. It's a great gun though, and I won't part with it

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