PDA

View Full Version : Colt 6920 & MIM?


1911a1
03-04-12, 00:02
Bought my second Colt 6920 today to put back. I was checking out the hammer, sear etc. and I'd swear it was MIM. Maybe thery're forge marks but they look like the little circle identions from MIM. My older big pin 6920 has a different fire control of course but doesn't have the mold indentions. Anyone have the straight skinney on how Colt manufactures their fire control?
cptx123
03-04-12, 00:47
I thought that fcg's have always been made with the mim process.
MikeCLeonard
03-04-12, 03:02
Are you concerned that it matters one way or the other?
MarkG
03-04-12, 09:10
The hammer, trigger, bolt catch and selector on your Colt are cast. The only piece I have seen manufactured using metal injection molding is the magazine catch.
1911a1
03-04-12, 10:12
pic I lifted from another forum these fire control parts look like my new 6920. I know cast can show a lot of detail in the mold. I just know that the indented little round sprue marks can be indicaters of MIM. I just assumed wrong that at least the hammer would be a milled or forged/milled part.
silentmark
03-04-12, 11:24
There's been quite a debate about MIM, but i've never had any problem with the MIM gas keys that LMT uses on their BCG's. I wouldn't worry about it, just pull the trigger and go bang.
1911a1
03-04-12, 11:51
I realize there's a lot of hysteria concernig MIM and I suppose I'm adding to it.

I just feal that it is suspect incertain applications. Namely hammer that strike and extractors the are required to "spring" a little (1911s) or take impacts. Your gass key on your LMT takes a pretty good jolt of gas but it's still not much of a impact.

That said I've seen machined forgings. castings, billet break. I would imagine that a MIM part properly made may function fine.

I'm curious if the full auto military issue M4's have fire control parts made the same way?
RichDC2
03-04-12, 16:15
In the 1911 world replacing mim with forged is standard practice for a quality 1911 build. I don't here it brought up much in the AR world.
Kokopelli
03-04-12, 16:23
I suspect the custom aftermarket fire control parts are tool steel. Theycertainly should be for the price. Ron
.45fmjoe
03-04-12, 17:20
The Colt M15/AR-15 trigger and hammer have always been cast.
1911a1
03-04-12, 18:14
Thanks for the imput.

I traded off my old 6601 HBAR I bought in 1993. so the oldest Colt I have is an '08 model to compare it to.

I guess I just obsessing about a new gun purchase and want to insure they hadn't started cutting corners. I know the fire control group on a Colt has an enviable reputation for reliabilty.

Thanks to all again.
Colo.TJ
03-04-12, 20:25
MIM, just like any other manufacturing, can be bad, good, or great. Really depends on how much effort and money is spent on the process.

There may come a time when MIM is more desirable then cast or forged. Not in the foreseeable future but it's likely MIM will surpass those 'older' process' in manufacturing.

I still prefer cast or forged tool steel to MIM.:D
LPMan59
03-04-12, 20:43
In the 1911 world replacing mim with forged is standard practice for a quality 1911 build. I don't here it brought up much in the AR world.

i was wondering this as well. so often I read how cast and MIM parts make for a poor excuse for a 1911, but the same guys have never said anything about their ARs.

interesting for sure.
TedG
03-05-12, 07:48
Doesn't the hype about MIM parts sell a lot of after-market parts? I wonder who started the hype.
meganeura
03-06-12, 08:55
My understanding of MIM is that if done properly, with proper parts inspection done afterward, is perfectly fine. MIM parts are everywhere; cars, planes etc. It seems to me that Kimber started the bad reputation for MIM.
Sanpete
03-06-12, 09:09
Who says Colt even makes their FCG? I have a m4a1 at work and the markings are identical ti a couple FCG's in some of my personal AR's. MIM or not, I don't know, but they all have worked for me.
hotrodder636
03-06-12, 09:24
:haha:Took me a minute but I caught on...at first I was thinking you were talking Made in Mexico rather than metal injection molding
C4IGrant
03-06-12, 09:29
Who says Colt even makes their FCG? I have a m4a1 at work and the markings are identical ti a couple FCG's in some of my personal AR's. MIM or not, I don't know, but they all have worked for me.

Colt makes everything in house and also farms just about everything out as well. This way, if something happens to availability (in house) they have a back up source.

Interesting side not, the part that are NOT made by them get much higher QC than the parts made in house.


C4
Sanpete
03-06-12, 09:34
...

C4

Makes sense. Thanks.

This is one area that seems to have very little information available like steel type, manufacture process, hardening, etc. Hard to find good info. The only thing I've come up with from experience is 'DPMS kits suck' and all the other FCG's I've had have been indistinguishable from each other.
Doc Safari
03-06-12, 10:07
Interesting thread. One reason I shied away from the civilian legal AK's for so long was because of cast/MIM FCG parts, or just plain poorly made ones.

Since Colt follows the TDP, it's logical to assume that all AR FCG parts are cast even among top tier clones like BCM, Daniel Defense, LMT, and others....correct?
meganeura
03-06-12, 10:55
Nothing wrong with cast parts. Geissele trigger groups are all investment cast and they have a sterling reputation.