Friday, January 15, 2016

Gun Build, Slide Prep, Prior to Fitment

As you know, I am building another 1911.  I rebuilt one before, now this is from scratch.

So far, so good.

This gunsmith teaches what he knows.  And he learned his chops by first being a gunsmith, then joining the army to be a gunsmith.  For the Army Marksmanship Unit.  So we learn how to build a gun from parts the AMU way. 

There are lots of way to skin the cat of "let's make these parts into a 1911 pistol!"  We are learning the way they do it for the competitive pistol shooting team of the Army.

First thing...  Frame to slide fittage...

Inspect your parts.  The frame and slide.  You could be dead in the water here, at this stage.  Caspian is a good company, but they make mistakes.  It can happen. 

One of the advantages of doing pistolsmithing with the AMU?  If you have a defective part they have PILES more of that exact part to swap out.  You don't have to wait for replacements or return/replacements.

Then, you measure everything.  And the critical parts require more than calipers.  You need a micrometer.

Now you are measuring the slide rails, where they will fit into the frame rails, the Rail Height.  They have to be precise with a micrometer.  You get measurements like 0.118+/- inches.  Well there is blank space between 0.118 and 0.119, so you guesstimate the 10,000th place.  Now you have numbers you record like 0.1182, and 0.1180 and 0.1179.  The idea is find the lowest number.  Bring that number down to it's zero...  So in those three the lowest number is 0.1179.  So our target is now 0.1170.  Right on the line.  Not 0.11705.  0.1170!

See the green circles?  Measure at those spots.  Both sides.  Record on the worksheet

File the rails, clean, measure, record.  Is it 0.1170?  File some more, clean, measure, record...  You see? 

Then you get here.

"But what if I file too far T-Bolt?  What if I get 0.1169 on one side?"  Well, now you have a new target.  It's 0.1160 for the entire slide rail.  Careful.  You get to 0.1130 and you might as well get a new slide, you've gone too far, taken too much off.  There are places where you can fudge.  Closer to the muzzle where the frame doesn't contact the slide in lockup?  There is some wiggle room.  0.1165 can be acceptable, even desirable.  That little fragile nub in the frame where the thumb safety inlet is?  That too.  But lets get it right, for the whole length, shall we, so we don't worry about it. (In that picture above it even LOOKS .1169, but the camera is offset a bit.  Trust me, it is .1170)

Needless to say, you go slowly.  And your file technique gets better, fast with that pucker factor.

Oh, I'm not good with a file.   Maybe after 1000 hours of this...  Someone good with a file would go faster. Go slow.  Don't screw up.

Ok, you get that perfect 0.1170 for all 14 places you measure on the slide.  Maybe you bring the muzzle side to 0.1165 got a little relief up front.  You can now ease the corners. Make them less sharp.  Breathe easier. 

Next, pucker factor while you try to not ruin the Frame itself...


Comrade Misfit said...

I assume that a good gunsmith is going to charge roughly as much as a good mechanic. So, are we looking at, in essence, "how to build a $5,000 1911"?

New Jovian Thunderbolt said...

No... tuition is low low low $800 for 12 days of instruction. A great price.

And we get a slight deal on the parts price, but the markup margin is pretty thin between wholesale and retail.

So the cost is my time over 6 weekends, plus homework, plus parts is $2500.


Now if you are asking what the price is to you to buy one of his from scratch guns, then, yes, it'd set you back about $5000, out the door. But that way is quicker.

He said it takes him about 40 hours to make a gun like we are doing, except for the finish treatment. Which varies widely. Cold blue is less fancy than ION Bond coatings, but it's cheaper and faster, frex.

Or, say you want a rebuilt gun. There is a ARMSCOR Philippine $500 gun rebuilt with better barrel lockup and a trigger job, that is only $1300.

New Jovian Thunderbolt said...

"That way is quicker" If he happens to have what you want. There is a wait list if you want something made for you, special.