Viability of converting M4s to semi auto?

**okie** · 12-09-21, 11:38

A little backstory...

I installed an aftermarket trigger in my vintage LE, that resulted in reliability issues, to say the very least. I wasn't able to locate the original trigger (it's probably in a box in storage somewhere), so I just ordered a Colt milspec trigger. The new trigger did fix the issue, but now I find out yesterday (thanks to this forum!) that that very trigger is not only not the milspec Schmid triggers we've come to know, but that it's also part of a recall. How awesome is that, huh?

So anyways, the plan now is to simply buy a Colt full auto FCG and cut off the naughty bits. And this got me thinking, why not just have an SOT order a real M4, destroy the receiver, then give us the parts. Grind the naughty bits off the FCG, drop everything in a semi lower, and there you have it.

While this might sound extreme, it's the only way I can think of to get your hands on milspec parts anymore. I'm wondering how easy it is for SOTs to access M4s, and what the cost might be.

**TomMcC** · 12-09-21, 11:51

What???? I could be wrong, but, yeah, that seems extreme. If you're worried about getting quality FCG parts, since semi FCG parts aren't "milspec", wouldn't it be easier just to order them from another well known and respected company?

**okie** · 12-09-21, 11:59

Originally Posted by TomMcC

What???? I could be wrong, but, yeah, that seems extreme. If you're worried about getting quality FCG parts, since semi FCG parts aren't "milspec", wouldn't it be easier just to order them from another well known and respected company?

I tried, but I couldn't cut through all the smoke and mirrors. Specialized doesn't have any Schmid semi auto FCGs in stock, which kinda makes me think they're not making them anymore. So I just said screw it, I'll order the FA one and cut the little protrusions off. 10 minutes with a dremel and voila, guaranteed milspec semi auto FCG. The only downside is the safety will spin, but who really cares? I can't see that causing any problems. The only potential problem I see is if someone didn't know what they were doing and got it hot enough to anneal it. But if you cut slow and dunk it in water occasionally it's going to be fine.

**markm** · 12-09-21, 12:05

Originally Posted by okie

I tried, but I couldn't cut through all the smoke and mirrors. Specialized doesn't have any Schmid semi auto FCGs in stock, which kinda makes me think they're not making them anymore. So I just said screw it, I'll order the FA one and cut the little protrusions off. 10 minutes with a dremel and voila, guaranteed milspec semi auto FCG. The only downside is the safety will spin, but who really cares? I can't see that causing any problems. The only potential problem I see is if someone didn't know what they were doing and got it hot enough to anneal it. But if you cut slow and dunk it in water occasionally it's going to be fine.

Some Colt ARs came with 16 hammers installed. You don't have to do much modification. An AR safety and maybe modifying the tail on the trigger would do it. I'm still lost... I've never had issues with "GI" triggers that come in LMT, Colt, BCM, etc.

**Stickman** · 12-09-21, 12:11

Okie,

Its possible you are over thinking it. Buy a BCM FCG and be done with it.

**grizzman** · 12-09-21, 12:30

Originally Posted by Stickman

Okie,

Its possible you are over thinking it. Buy a BCM FCG and be done with it.

But that doesn’t meet the TDP!!! Ha ha ha

**okie** · 12-10-21, 00:35

Originally Posted by Stickman

Okie,

Its possible you are over thinking it. Buy a BCM FCG and be done with it.

It does appear they use Schmid FCGs, so that's good. But an FA FCG from Specialized is the same price, and sure is sure.

**okie** · 12-10-21, 00:25

Originally Posted by markm

Some Colt ARs came with 16 hammers installed. You don't have to do much modification. An AR safety and maybe modifying the tail on the trigger would do it. I'm still lost... I've never had issues with "GI" triggers that come in LMT, Colt, BCM, etc.

I've not any issues with it per se in the hundred or so rounds I've put on it, but it got recalled so I'm not going to find out either way. I was disappointed to see it's not Schmid, more disappointed to find out it was recalled, and yet more disappointed to read that it's likely MIM, which it sure looks like it.

All I know is the FA FCGs are the same price, are guaranteed to be milspec, and modifying them is quick, easy, and foolproof. To me, this is a no brainer. And now that the CR has replaced the LEs, it seems like just starting with an M4 parts kit is the easiest and maybe the cheapest option.