Friday, November 28, 2008

Gunsmithery. Sorta.

So, the package from Brownell's arrived in my mailbox Wednesday, and I scurried downstairs to the gun cleaning area to install the stubby guide rod in my Para LTC 9 and relocate the full-length guide rod to my spare parts bin.

Now, what could be simpler than putting a new guide rod in the pistol, right? Right. Some of you might be aware of a manufacturing phenomenon called "tolerance stacking"; if you are, bear with me while I explain for the kids in the back...

See, all mass-produced parts are not really exactly the same size; there is an allowable range of size, ranging from a few hojillionths (in the case of hard disc read/write heads and mechanical artificial heart valves) to a couple tenths of an inch (really big nails or two-by-fours). These are called "manufacturing tolerances". The problem can arise when you have a situation like, oh, I don't know, say an Ed Brown 1911 guide rod with a head that is out near the maximum spec and a ParaUSA cast frame and slide that are way at the other end of the scale, vis a vis their interior dimensions.

Yeah.

So I'll be taking a stone to my guide rod head and mumbling imprecations about cast frames and slides under my breath while doing so...

Anyhow, this seems like a splendid time to bring up some handy dandy rules of gun mechanics, with a quick translation from catalogspeak into English:
  1. "Drop In" Installation: Some fitting required.
  2. Some Fitting Required: Better take it to a good gunsmith.
  3. Gunsmith Installation Recommended: ...and bring money.

The upside to the whole drama of messing with the gun is that you get to keep the old parts that come off it. It was some time ago that I realized I had a complete 1911 bottom end, less a hammer strut and the actual, you know, frame in my spare parts box. I've arranged to get my hands on those two missing parts, and soon my Ciener .22 conversion kit will have a permanent home and I'll have a dedicated .22LR training 1911.

10 comments:

Joe Allen said...

I always thought "Drop-in" meant: "Drop in to the gunsmith and as soon as they finished laughing at you, they'd do it while you wait instead of making you wait 6 months for it."

Must be a regional thing.

og said...

hey, do you have your conversion tables handy? i'm trying to remember how many hojillionths in a skosh.

keith said...

What ammo do you shoot thru your Ceiner topen to make it cycle? I tried about 10 brands before giving up and throwing it onto the shelf of my "expensive bad ideas" cabinet.

Keith

red said...

I look through Brownell's and find parts I want to order, then I think about my crazy Philipino 1911 and wonder how much work it will take!

Good luck with the filing and let me know about swapping bits. (It's metal by the way, no polymer on my gun)

Tony said...

"I've arranged to get my hands on those two missing parts, and soon my Ciener .22 conversion kit will have a permanent home and I'll have a dedicated .22LR training 1911."

I've been thinking about doing the same for years now. Only problem is, right now my conversion kit is legally a gun part, not a whole gun. If I were to add a dedicated lower (no permit requited in Finland) to it, I'd possibly have an illegal firearm in my hands (depending on how one would like to interpret the less than rational laws we have - the whole concept of a caliber conversion kit is strictly speaking unknown to the law, which makes permit issues weird) unless I applied for a new permit. And since this autumn, hand guns have been de facto banned here, so no way to get said permit even if I wanted to bother with the paper work...

I live in such a great country. :/

"What ammo do you shoot thru your Ceiner topen to make it cycle?"

Dunno about Tam, but I like shooting CCI Velocitor through mine.

McThag said...

The downside to saving the take-off parts is they tend to grow into complete guns and bloom when your wife is looking at the bank register.

BUSTED!

Even worse, the new R603 clone you've been carefully nurturing and feeding CLP to is her ideal rifle and she takes it as her own!

og said...

Ah, nevermind, I found it.

Cemetery's Gun Blob said...

lol....

I always thought '*drop in* installation' meant, *your better off having your factory parts altered, as opposed to purchasing our overpriced and not so slicked up aftermarket parts*.....

Anonymous said...

A few years ago, Industrial Archeologist [sic] Pat Malone won the Norton Prize by wheedling access to the vast cosmoline bunkers beneath the real Springfield Armory. Puzzled by the contrarian fact that the number of skilled smiths on the payroll had actually increased after the development of Armory Practise ("mass production" for those in the back), he put some Model of 1809 muskets 'under' an electron microscope. All those matching interchangeable parts were covered with hand file marks.

Tony, you live in a great country. You need to have a word with its current government.

og said...

What frame are you looking at, by the by? I have a nice longslide that I want to blue dark and put on an Essex stainless frame. Any thoughts on that choice? Or a better alternative in a similar cost zone?