Crack in the M4

[brassburnz]

Check out this thread from rimfirecentral.com
I've heard rumors of cracked lowers, but never seen one.

http://rimfirecentral.com/forums/showthread.php?p=2541220#post2541220

[offrdmania]

On a normal lower the amount of force needed to make that kind of crack is enormous. This shows that the metallurgy of those lowers is that of pot metal most likely

[dchang0]

I call hoax. Bet the guy dropped it hard or smacked it really hard into something. I mean, I had a cheesy "toy-ish" Smith and Wesson .22LR pistol made entirely of cheapo aluminum and put thousands upon thousands of rounds through it with no frame cracks or stretching. That's got far less metal to absorb the recoil of the .22LR than any rifle.

[Q]

The housing looks thin. It looks like the bolt carrier did the damage. Unless it was from recoil harmonics. There probably are 20 or more like that.

[Noobert]

what the hell, are those full autos?!

[offrdmania]

No, its a messed up fire control on those things. Its called using existing parts and making them adapt to a new platform.

[thempopresense]

It's a 22lr colt according to the other thread. I wonder if they are slightly out of spec on purpose and someone tried to put a milspec upper on and hammered the pin in trying to make it fit.

Anyone own one that can verify lower specs?

[Cru Jones]

Maybe he tried to separate the upper and lower without loosening the flash hider???

[smittty]

Maybe he tried to separate the upper and lower without loosening the flash hider???

That's a good question. My friend has one of these and I don't think the upper is supposed to tilt off like a real AR. I'll have to ask him.

[Check Six]

Dang !

I wish I'd have seen the reports on that other website before I bought my Colt M-4 .22. After perusing the reports on rimfirecentral, I probably would have bought the S&W instead.

The only positive reports I've read is that Umarex for the most part is attempting to 'fix' many of the problems owners have had with their rifles.

[brassburnz]

On a normal lower the amount of force needed to make that kind of crack is enormous. This shows that the metallurgy of those lowers is that of pot metal most likely

The Umarex/Walther/Colt M4 is not an AR. The lower is just a shell. The trigger is not like an AR. The bolt stop doesn't work like an AR. The stock attachment is not like an AR. It just looks like an AR.

Forces from the blowback action and what little recoil there is, is absorbed by the trigger housing and bolt/barrel assembly.

The rear takedown pin doesn't touch the lower receiver. The takedown pin locks the bolt/barrel assembly into the trigger housing. Removing the rear takedown pin wouldn't make the lower shell crack.

[IMG][/IMG]

To me, it looks like someone whacked the right side of the stock really hard. i think that could cause the lower shell to crack. Even if it did crack, the rifle should still run just fine because the trigger housing would still be intact. The hammer and trigger pins are captured inside the two halves of the metal clamshells and are secured by four bolts and four nuts.

Unlike an AR, the Umarex doesn't need a stock assembly to run. The recoil spring is inside the upper. So even if the stock broke off, the Umarex would still run, but you'd probably be in violation of NFA rules for minimum overall length.

[dchang0]

Ah, excellent! A real Colt .22 owner steps in. Hey, Randy, just to make sure, you're saying that the trigger housing itself actually stops the bolt?

If that's true, then this dude definitely broke his Colt .22 some other way than by recoil.

All this makes me really glad I spent $1k building a Spike's dedicated AR.

[Arteel]

What recoil?

[brassburnz]

Ah, excellent! A real Colt .22 owner steps in. Hey, Randy, just to make sure, you're saying that the trigger housing itself actually stops the bolt?

If that's true, then this dude definitely broke his Colt .22 some other way than by recoil.

All this makes me really glad I spent $1k building a Spike's dedicated AR.

The square black piece on the top of the trigger housing is the buffer.

[IMG][/IMG]

I really like my little rifle, but then again, I also understand it's limitations. It's not an AR. If you think you're getting an AR, you'll be disappointed. If you want something that emulates a Colt M4 but shoots .22 rimfire, and it is very accurate with the right ammo, you'll be happy.

I will be building a dedicated .22 upper soon. I have a conversion I've been running, but accuracy just isn't that great. I hope the Spikes or TacSol dedicated upper has the accuracy to meet my needs.

[Dragon]

The housing looks thin. It looks like the bolt carrier did the damage. Unless it was from recoil harmonics. There probably are 20 or more like that.

Ah,that will rub out!