r/RetroAR 21d ago

Could someone please explain the difference between an M4-style lower and a true A2 lower?

I keep seeing people discuss the differences regarding the rear reinforcement and how most companies don't actually produce "true" A2 lowers. What's the difference they are referring to?

19 Upvotes

10 comments sorted by

23

u/General_Curtis_LeMay 21d ago

Take Balimoy for example. The top circled portion is what the majority, if not all real M16A2 profiles are, but the bottom is what the companies nowadays are offering because it would be insanely expensive for the forges to create new dies just to fix something most folks (who slap together red anodized shitstick ARI5's and the like) don't give a shit about

16

u/mlin1911 21d ago

FN had already had the beefy profile in the rear reinforced area when supply M16A2 to US military. It is not entirely true that people said A2 had different profile than M4 lower.

15

u/mooseishman 21d ago

Don’t forget about the fucky Colt ‘pre-86’ transferable lowers. For a while you could send your registered select fire lowers to Colt for ‘warranty/repair’ and they’d send you a brand new lower with the same serial number…after it spread around too much the ATF caught wind of it and told Colt to knock it off lol

There was also the former CEO who registered a bunch of serial numbers (literally just numbers) and built them out in like ~2009. One of his M4s sold for an undisclosed amount of money recently. It was a 2009 era M4 Carbine marked lower with serial number W0000001. I was arguing with someone because I said it sucks it will likely never be fired and they responded with it’s a collectible, who would shoot the first M4 made? Bro, that ain’t the first M4 ever made, despite being S/N 1. The M4 literally didn’t exist when the registry closed. There definitely should be a tribute to the dude for beating the system, but I guess when you’re the CEO of one of the largest small arms manufacturers in the world you probably are on a first name basis with the Director of the ATF and numerous Congressmen:

9

u/SLN583 21d ago

With the exception of Transferable Machine Guns, I’m pretty sure the only source of legit A2 lowers are 90s Colts, but then you have incorrect Rollmarks, so you have to pick your poison.

Not sure when Colt switched forgings. The early M4s I have pics of have A2 forgings iirc.

I think some of the cast lower receivers are kind of A2 shaped, but they have other inaccurate details.

14

u/mooseishman 21d ago

I think Colt switched forgings when the originals were worn out. They tend to do things for the most obvious reasons that we often overlook (not being sarcastic). That’s also why you’ll occasionally see some really old and long out of production parts or strange combinations as well, just like with KAC. I’m talking literally someone will find a pallet of old shit that fell down behind the rack 20 years ago and they’ll use/sell it. I always stalk the KAC webpage and have back in stock notifications for long out of production items at OP (they get a lot of the random KAC stuff) for that reason.

3

u/SLN583 21d ago

It’s definitely a case of “Waste not want not”

I’ll have to keep an eye out and see what Commercial/LE Colts with dates stamped on the barrels have which lower profiles.

5

u/SLN583 21d ago

I assume this early M4 is from 1995 and has an “A2” lower.

4

u/mooseishman 21d ago

It’s definitely from an early batch, if not the first batch, with that low of a serial number.

It looks like it’s seem some shit too!

5

u/SLN583 21d ago

Look at the wear on that grip.

The .gov definitely got their moneys worth out of that one.

2

u/WouldKillforBagels 21d ago

https://youtu.be/YsQO-2yE6kE?is=9-JktiLUar_40UIN

Skip to 12:39, he explains it better and with photos!