Friday, February 19, 2016

Eli Whitney

I realized what the thing is with 1911 pistols.  They are NOT made with interchangeable parts!

Interchangeable parts on firearms has been a goal for a long time, with lots of work toward that goal done at local Harper's Ferry Armory shy of 200 or so years ago.

I literally have to hand adjust every single serious part on this gun.  And if I ruin a part and need to swap it out?  I need to adjust that part, and the parts around it, and maybe the parts around THEM...

It's the beginning of the 21th Century!  Why can't America figure out mass production!

Seriously, this is actually a matter of tolerances.  We are fitting each part to each other with higher standards than 'bog' and very tight tolerance margins.   Or that is the idea, with various definitions of 'success'.

Now, if we loosen those tolerances and have a massive logistical tail, and I am the assemblyman on the circa 1912 Colt Factory floor... making the first M1911s, there are fewer fitting steps I'd need to accomplish.  If on part didn't fit, maybe swap it once or twice to get moving faster.  You get a slight looser gun.  A service grade gun.  Fine and reliable, but not a bulls-eye gun.  But the pistol wasn't intended to be.  It CAN be made accurate.  It is easier to make it accurate compared to an M9, but that, too, can be made very accurate.  There comes a cost to build a finer pistol, and not just in part material and quality.  Time and skill are a cost too.

It also means you can buy all the parts and they can be 'drop-in'.  I am at the stage where I could get a pistol put together without supervision from a big box sent by Brownells.  It would by necessity be not at good as this one I am taking my time with, and with the gunsmith supervision that whole time, but it'd be as good as any factory gun.  No lie.  Except...

There are a few sticking points I have...  Hammer and sear engagement of course.  Maybe the MOST important area.  I know noting about cosmetics.  Grip and thumb safety to sear and trigger bow are almost as important and my grok of them is only partial...  And there is all the "well, I've never seen THAT before" bit that I don't know how to cope with, so let's hope that doesn't come up.  The grip safety fitting and blending is a little iffy with me.  Even on a loose factory gun.  And I know very little about the cosmetic side of gun finishing, which is actually kinda important, if not for function, but for user confidence.

In other words, don't try to get me to make a pistol for you.

I told the gunsmith I'd be ready to do this on my own professionally in about 80 guns.  I could sell the 81st with confidence.  He thinks I might be able to do it sooner, but I am a slow head with poor attention to detail.  I'll stick with 80.  So after this I need to take the class 78 more time.  And at 1 class a year that mean I can retire from my day job and be a bona-fide smith in the year 2094.  Right around the corner.


Angus McThag said...

In 1943, at least, there was a requirement that parts interchange without fitting or the lot was rejected.

One test was taking several guns apart, tossing the parts in a box, shake vigorously, then reassemble. All guns needed to function for the lot to be accepted.

Remington-Rand lost nearly a years production to this testing, after making guns that worked, and interchanged with each other, but did not interchange with guns made by the other manufacturers... With a war on they still rejected them!

Today... Kimber has no incentive to interchange with Springfield. Springfield has no incentive to interchange with Colt. Colt has no incentive to interchange with Ruger. Ruger has no incentive to interchange with Smith and Wesson... and who else makes a 1911?

I grow to pity the people who make 1911 parts and have to account for all the OEM makers differences when making parts and it's no shock that there's lots of fitting involved now. Making it so it drops into one makers gun virtually insures that it's going to be impossible to fit to another!

azmountaintroll said...

So there's no MILSPEC for 1911s, or at least no one manufacturing to it?

Angus McThag said...

The M1911A1 never actually got a military specification!

There was a technical package and drawings given to any potential vendor.

D-P-355a is as close as it gets to a milspec for it. Like all such specs, it's more of a testing document than a making it document. It refers to all the other documents that you'd compile to start making them, of course.

The 1928 prints are out there online, you can compare a new 1911 to them if you've got the measuring tools.

staghounds said...

"Interchangeable" is as you know a variable term. I think Waltham pioneered the practice of having parts of known but differing values- jewels, springs, pivots etc. - at the assembly point. So if a .01 didn't fit, she'd grab a .02 and use that. I wonder if it's practical to gauge gun parts and use a similar process to make "tighter" ones.

Just My 2¢ said...

Here's the thing about current 1911's - They're based on the VP of Marketing's concept of how a 1911 should look and should be manufactured. Their target demographic is guys that want a 1911 that looks sharp and will maybe shoot a few thousand rounds through it. They won't be customized and they will probably never be shot enough to break one of the lesser-quality parts.

I think the article also explains the reason why a whole pile of very good 1911 gunsmiths refuse to accept anything but Colt and Springfield pistols. It is a hassle up with which they need not have to put.

Will said...

Look for a copy of Jerry Kuhnhausen's "The US M1911/M1911A1 Pistols...A shop Manual".

This is Volume2 of his .45 auto series.

Lots of drawings (over 600!) of parts and assemblies for the various 1911 types, with original specs.

I would consider it a bit odd if an expert on these guns didn't have Kuhnhausen's books in his reference library. About $40 each, and well worth it. (Amazon carries them)