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Gentlemen, Shane 45, some of what is written below is my small contribution to those of you in the quest for building your first accurate and reliable pistol. I hope this helps you’all keep things straight and solves some problems before you start.
When fitting a barrel, I use the center of the barrel, bore channel in the slide, for my center because this is what your barrel tracks in. The rear hood must be cut so it slides freely into the recess in the slide, without shifting the barrel in the channel.
IF the hood does not align the barrel in the center of the bolt face, it will bind the case rim upon going into battery.
Bolt Face: Some manufactures use the MINUMIN dimension of .476 for the width of the bolt face.
I just measured the rims of some new nickel-plated Federal Hyda-Shok, rims measure .4755, standard Federal ball brass case, 473.
Well, .4755 is a gauge fit in a .476 bolt face, if the barrel is a match grade fit and not perfectly centered in the bolt face the rim will BIND on one side and cause a jam going up the feed ramp.
Once your barrel is fit, put a case in the chamber with a .484 rim (or make a .484 gauge) and slip the barrel up into battery, hold it up to the light and make sure the rim is not binding in the bolt face. If it does bind you will have to open-up the bolt face on the side that is binding. To open the bolt face I made-up a piloted reamer and a makeshift broach to open-up the bolt face to .494.
If the slide measures below .484, I open it up to .494.
You can fudge cleaning-up the bolt face with a good hard, square file. I like the Brownells “1911 Barrel Locking Lug File” order # 080-751-000 to whittle this out. This is a good, hard, square file with safe sides. You will also need it to deepen the upper barrel lugs. Sometimes (but not often) the bolt face is broached on a diagonal, i.e. not square with the barrel channel. Some smiths teach to file the rear hood crooked to match the crooked bolt face. I DO NOT do this; I make sure the hood is squared with the chamber and true to the bolt face. If careful, it can be done with this file. Coat the hood and bolt face with ink and file & polish till square.
You don’t need a lot of fancy tooling and measuring instrument to do most of this fitting, a lot of times it faster and easier to use a file and a gauge than to set-up a machine.
I heard it said, “The true center of the slide is the firing pinhole”
Well, in my humble opinion, the firing pin hole is the LEAST most critical hole on the entire pistol, unless it’s so grossly off center and causes miss-fires.
Firing pinhole location: Some are not centered properly and for some reason they all seem to favor the port side. .010 is not that big of a deal but it would be nice to have a dead center hit on a custom gun. A center hit is best for and uniformed ignition.
What I would like to see is a after market manufacture like Caspian make a slide with the hole for the tip of the firing pin not drilled, so the smith can drill the hole in perfect location for the barrel.
To drill the pinhole; make a hardened gauge bushing the size of the chamber like a go-gauge with a pilot hole through the center for the firing pin drill, lock your fitted barrel into battery, put the drill on a extension through the muzzle and drill the hole with a hand drill. Walla, perfectly centered hole!
One 1911 manufacture said he CNC’s his parts and holds tolerances to .0005, that’s a ½ of thousandth. Well, I’m sure his machines are capable of holding these tolerances BUT him insinuating his frames and slides are all made to the .0005 is just plain BULL*%$#!
Or at least I haven’t measured one yet that did. I’m sure it can be done but you aren’t going to buy one for a $175.00. It would probably cost $1000 or more produce one within .0005 throughout.
You have to remember these parts are made in a production environment to keep the cost down. Mostly all the barrel channels, bolt faces pinhole are off by a little bit. It is tough to drill and ream a hole 6 inches deep without it running out a few thousandths or drill small pinholes without the drills walking and broaching square slots straight.
Good luck to all, Pete
[This message has been edited by Metal Smith (edited 12-03-2001).]
When fitting a barrel, I use the center of the barrel, bore channel in the slide, for my center because this is what your barrel tracks in. The rear hood must be cut so it slides freely into the recess in the slide, without shifting the barrel in the channel.
IF the hood does not align the barrel in the center of the bolt face, it will bind the case rim upon going into battery.
Bolt Face: Some manufactures use the MINUMIN dimension of .476 for the width of the bolt face.
I just measured the rims of some new nickel-plated Federal Hyda-Shok, rims measure .4755, standard Federal ball brass case, 473.
Well, .4755 is a gauge fit in a .476 bolt face, if the barrel is a match grade fit and not perfectly centered in the bolt face the rim will BIND on one side and cause a jam going up the feed ramp.
Once your barrel is fit, put a case in the chamber with a .484 rim (or make a .484 gauge) and slip the barrel up into battery, hold it up to the light and make sure the rim is not binding in the bolt face. If it does bind you will have to open-up the bolt face on the side that is binding. To open the bolt face I made-up a piloted reamer and a makeshift broach to open-up the bolt face to .494.
If the slide measures below .484, I open it up to .494.
You can fudge cleaning-up the bolt face with a good hard, square file. I like the Brownells “1911 Barrel Locking Lug File” order # 080-751-000 to whittle this out. This is a good, hard, square file with safe sides. You will also need it to deepen the upper barrel lugs. Sometimes (but not often) the bolt face is broached on a diagonal, i.e. not square with the barrel channel. Some smiths teach to file the rear hood crooked to match the crooked bolt face. I DO NOT do this; I make sure the hood is squared with the chamber and true to the bolt face. If careful, it can be done with this file. Coat the hood and bolt face with ink and file & polish till square.
You don’t need a lot of fancy tooling and measuring instrument to do most of this fitting, a lot of times it faster and easier to use a file and a gauge than to set-up a machine.
I heard it said, “The true center of the slide is the firing pinhole”
Well, in my humble opinion, the firing pin hole is the LEAST most critical hole on the entire pistol, unless it’s so grossly off center and causes miss-fires.
Firing pinhole location: Some are not centered properly and for some reason they all seem to favor the port side. .010 is not that big of a deal but it would be nice to have a dead center hit on a custom gun. A center hit is best for and uniformed ignition.
What I would like to see is a after market manufacture like Caspian make a slide with the hole for the tip of the firing pin not drilled, so the smith can drill the hole in perfect location for the barrel.
To drill the pinhole; make a hardened gauge bushing the size of the chamber like a go-gauge with a pilot hole through the center for the firing pin drill, lock your fitted barrel into battery, put the drill on a extension through the muzzle and drill the hole with a hand drill. Walla, perfectly centered hole!
One 1911 manufacture said he CNC’s his parts and holds tolerances to .0005, that’s a ½ of thousandth. Well, I’m sure his machines are capable of holding these tolerances BUT him insinuating his frames and slides are all made to the .0005 is just plain BULL*%$#!
Or at least I haven’t measured one yet that did. I’m sure it can be done but you aren’t going to buy one for a $175.00. It would probably cost $1000 or more produce one within .0005 throughout.
You have to remember these parts are made in a production environment to keep the cost down. Mostly all the barrel channels, bolt faces pinhole are off by a little bit. It is tough to drill and ream a hole 6 inches deep without it running out a few thousandths or drill small pinholes without the drills walking and broaching square slots straight.
Good luck to all, Pete
[This message has been edited by Metal Smith (edited 12-03-2001).]
