Dalpra--You're considering one of the finest handguns ever made. Minor cautions, having to do with the 1950s--60s vintage Colt National Match .45s--
These pistols were tuned especially for light target loads, usually something like a 185 to 200 gr. semi-wadcutter at maybe 750 fps— a typical load used something like 3.5 gr. of Bullseye powder.
One good result of this is that the barrels and ramps were throated nicely and I've never had any problem with any soft nose or hollow point load in my guns (I've had three of them.)
The down side is that things were set up so that the light loads could overcome slide inertia. Examine the underside of the slide, around the firing pin channel. Both sides of the slide are machined to remove metal at this point. You can see the extractor for most of its length. The other side is done similarly.
Also, the recoil spring is noticeably lighter than the standard government or "hardball" spring. The combination of these two factors with full power loads usually leads to some battering of the mechanism. On two of my pistols, I've had to have a gunsmith weld up a crack at the right rear of the slide, from extractor channel to the groove on the right-side bottom of the slide.
I recomend that anyone using on of these fine old guns with ball or ball-equivalent hand loads, take two precautions: Install a full weight government recoil spring. Don't go to a grossly overweight spring--this actually INCREASES felt recoil, changing the impulse and timing of the mechanism. Try a neoprene buffer behind the recoil spring, around the recoil spring guide rod. I've been using the Wilson Shock-Buff for many years, with perfect satisfaction. Thy are effective and cheap. Shun the spring buffer assembly in place of the standard guide rod. (1) They are not easy to tune to the exact degree of buffering you need, and, (2) When one goes to pieces while you're shooting, you have a mess on your hands.
These are WONDERFUL old pistols. Use the above precautions and keep some rear sight pins in your shooting box, with the proper size pin punch. Resist the temptation to use maximum hand loads. Guard the beveled NM bushing and recoil spring plug from anyone who might "trade out" their parts for ‘em. It is hard to find proper replacements.
The earlier NMs had a different rear sight--I think Accro brand. The Elliason came later. The undercut front sight is a little hard on some holsters. Please, don't do what I did and file or grind on it. If you must pack it in a holster, buy one with integral sight rails or neoprene sight channel. All in all, keep the piece in as near factory original configuration as you can. It is excellent just the way it is. If you want something different, there'll always be some nostalgic old dude (like me) who'd trade you for it.
Best regards,
RR
PS--I wrote the above off-line after reading the first few replies earlier in the day. I note that Steve Camp, Slabsides, and RickB have all commented on stuff I mentioned, except Steve mentioned the spring loaded sear gizmo. Dalpra, if you get the fine old piece, and I hope you can, make every effort to either find a proper manual telling how to handle the sear assembly, or get with someone who KNOWS the National Match to show you how to handle it. I make a slave pins from a round tooth pick, sand off the rough ends, and do a certain amount of cursing. A lot of people did what Steve did-- take out the factory sear, sear depressor part and the tiny little spring, and replace them with standard parts. (Save the parts carefully.) Then, of course, you need a trigger job. Your choice.
Terry M--Say hi to Shurf Jim next time you see him. He was present the night I got a bad scratch on the slide of my first NM .45, breaking open a plate glass door during a raid.
All the best - - -
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