Broken Lower on new M4 .22

[bustamove]

A friend of mine recently purchased this rifle and has only put at best 100 rounds through it during two visits to the range. He noticed this crack when he was installing a scope on the rifle. Needless to say he wasn't very happy.

I'm wondering if anyone else has either had this problem, or has heard of this happening to someone else? Now Umarex has said they will repair this rifle, but they need to order a lower from Germany. Unfortunately this will take 90 days for them to complete (this is what they have said) I have kind of figured they need to stamp a new lower with his existing serial numbers so they can fix his rifle.

Any suggestions or answers, please feel free to comment. Any help woud be appreciated (anything along the lines of what may have caused this, or if you've heard about a failure like this one is what I mean by help).

Thanks, Bob

[bustamove]

If you notice in the photo, the pin that needs to be removed looks to me like the hole around the pin is much too large? My M4 has this pin in the same location, but the hole is only slightly larger than the pin itself.

This makes me wonder if there is a design change? If so, which is the older design? And again if there was a design change, why was it changed? Designs aren't changed for no reason.

[gunbroke]

If you notice in the photo, the pin that needs to be removed looks to me like the hole around the pin is much too large? My M4 has this pin in the same location, but the hole is only slightly larger than the pin itself.

This makes me wonder if there is a design change? If so, which is the older design? And again if there was a design change, why was it changed? Designs aren't changed for no reason.

I think you're on the right track with a design change. On my M4 the head of the pin sits on top of the side of the receiver. It looks like on your friend's M4 the hole was drilled larger in the housing so the pin head would sink into the side of the receiver, instead of sit on top of it. If you could, please ask your friend if this was indeed the case and get a partial serial number to see how earlier his rifle was made.

[bustamove]

I think you're on the right track with a design change. On my M4 the head of the pin sits on top of the side of the receiver. It looks like on your friend's M4 the hole was drilled larger in the housing so the pin head would sink into the side of the receiver, instead of sit on top of it. If you could, please ask your friend if this was indeed the case and get a partial serial number to see how earlier his rifle was made.

I asked him to get me that information, as soon as I get it from him I imagine we can figure out if it's an older design or a newer one? I seem to remember when the Colt M4's came out there were some big problems with ammo feeding, FTF's and FTE's. I believe if I'm not mistaken Umarex or Walther did some change to the gun to remedy this situation?

This kind of makes me wonder if this pin was redesigned at that time or not? But like you said, your's and mine are exactly the same where the head of the removeable pin sits directly on top of the Lower. The photo showing the cracked Lower looks like the hole is actually as big as the head of the pin itself.

One thing is for sure. It's going to be interesting to find out what happened.

[Malysh]

I might be able to help here. I only have a few modern Colt revolvers and my knowledge of old Colts consists of being able to identify basic models.
But I've collected and studied Colt M-16 and AR-15 variants for over 10 years, not that I'm the world's greatest expert. Just a student......

I am very sorry to see this person had such a drastic failure with their new carbine!

I cannot tell for sure from this picture, but the hole for the take down pin might not be bigger than it should. It might appear bigger because the lower receiver is cracked around the take down pin hole at 12:00 and 7:00 and is pulling the back portion of the lower receiver away and down and possibly exagerating the size of the pin hole as viewed after the fact. Considering that the buffer tube and spring are under tension via the back of an M-16 type lower receiver and lower receiver boss, that gap would be stretched even wider once the receiver around the hole cracked. See the separation at 7:00? It's pretty wide. A receiver failure of this type should definitely change not only the size, but the shape of the take down pin hole. It also appears to me that about half of that pin(on the right side of the circumference) is resting on top of the pin hole. It's only when you get near the cracked area where there is a lot of "daylight". It could be just material failure and not a dimensional flaw.
I do agree with you that if the take down pin hole is too big recoil forces of the bolt carrier impacting back and forth against the inside of the receiver would easily cause the receiver to crack.
Who knows, you're probably right. I am playing devil's advocate, I guess.

The problem with military M-4s reliably feeding ammo was caused by using a shorter barrel with an abreviated gas system. Colt had to spend many hours trying different gas port sizes before they came up with a gas port that was consistantly reliable. See "The Black Rifle II" by Chris Bertocci(spelling). This is a very comprehensive and well written book which contains a lot of information on the R&D and actual production of the Colt M-4 carbine. As a secondary issue to resolving the size of the gas port needed to reliably cycle the M-4 carbine with it's 14" barrel as opposed to the standard 20" barrel, Colt machined longer feed ramps in the barrel extension for all M-4 carbines that are different than the standard 20" rifle's feed ramps. Civilian or military, 20" barreled M-16s have classic feed ramps, well made M-4s all have the modified feed ramps. Another reason they changed the geometry of the feedramps was because the current military M-855 62 gr. projectile has a different shape and ogive than the M-193 ball 55 gr, ammo that was issued up until the A-2 and A-4 rifles and M-4 carbines came out.

I don't know if these 22lr Umarex "M-4s" are cast or forged aluminum receivers. I know the best M-16 variants including the military rifles are exclusively forged. There are civilian brands of M-16 variants that use cast receivers. Some folks have problems with them, most don't. I've built eight M-16 semi auto civilian variations and I only use Colt parts including upper and lower receivers, all of which are forged. I'm a snob about that, there are other good makers but I prefer Colts.
I would be surprised if these Umarex M-4 receivers are built to the tolerances and specs of a geniune Colt 5.56 M-4 or for that matter, a Noveske or Stag, Daniel Defense, HK, etc.

I am not very keen on Umarex products. It's stupid of me, but this company had a background in what, air guns and blank/starter pistols? All of a sudden they bought Walther and are producing grown up weapons. And taking licensing agreements with Colt. I hear of too many people with Walther P-22s pistols that don't function well and break easily. And the failure rate with the Walther PPS appears to be about 15%. I bet classic Walther pistols QC used to keep failure rates at about 1% or 2%. I have one of these pistols in 9mm that I've fired about 500 times with no issues, though.

As we all know a firearm failure can happen from any manufacturer.
Hopefully this is just one of those isolated freak cases. Since they are going to replace his lower receiver all he's lost is time.

HTH

[27 Beck]

A friend of mine recently purchased this rifle and has only put at best 100 rounds through it during two visits to the range. He noticed this crack when he was installing a scope on the rifle. Needless to say he wasn't very happy.

I'm wondering if anyone else has either had this problem, or has heard of this happening to someone else? Now Umarex has said they will repair this rifle, but they need to order a lower from Germany. Unfortunately this will take 90 days for them to complete (this is what they have said) I have kind of figured they need to stamp a new lower with his existing serial numbers so they can fix his rifle.

Any suggestions or answers, please feel free to comment. Any help woud be appreciated (anything along the lines of what may have caused this, or if you've heard about a failure like this one is what I mean by help).

Thanks, Bob

With damage that severe, Umarex should just man up and replace the rifle on the spot. Wait 90 days, the snow will be flying then.

[HerbG]

With damage that severe, Umarex should just man up and replace the rifle on the spot. Wait 90 days, the snow will be flying then.

I agree 100%. This isn't a Holland & Holland double rifle, it is a relatively inexpensive .22. Replace it, make the customer happy and get on with business!

This is the kind of problem that would make prospective purchasers of the rifle hesitate and see if this is an isolated incident. Having a "we'll fix it if and when we get the part from Germany" attitude does not do much to reassure that problems are going to be taken care if they do crop up.

[bustamove]

With damage that severe, Umarex should just man up and replace the rifle on the spot. Wait 90 days, the snow will be flying then.

I totally agree with you. About the only thing that gets in the way is the serial numbers on the gun are registered to him. This is the main reason it will take them that long to get the gun back to him. They have to get the part with his numbers stamped on it, and then repair his rifle.

Even with all of this I believe even though they can't deal with him directly as far as getting a gun to him. They could certainly use one of their suppliers to do an FFL exchange, change the registration numbers with the State of Maryland. And be done with it.

This way Umarex stepped up to the plate and hit a home run as the Customers would see it. You know? I just don't understand why some manufacturers pay a lot more money and piss away more time trying to get away from spending a little bit of money in the first place. If they just bit the so called bullet and did what was right for their Customer in a case like this, they would look more credible to any prospective customers. And show the customers they already had that they actually do care for and will take care of them if an unforseen situation like this if it happened to them.

I guess that's why I'd never make any money in business. So that is the main reason I never started one. I'd have great customer service and no money. But that's the way most of us feel........

[guy sajer]

I totally agree with you. About the only thing that gets in the way is the serial numbers on the gun are registered to him. This is the main reason it will take them that long to get the gun back to him. They have to get the part with his numbers stamped on it, and then repair his rifle.

We've never had to get a defective gun replaced through Umarex , but we've had many guns replaced from other gun companies in our 35yrs of business . Seldom do they replace using a new renumbered receiver . In almost all cases a new firearm with a new serial number is issued . They report the broken gun as destroyed to ATF and the customer will fill out a new 4473 and do the NICS check then take possession of the new firearm . More paperwork , but it's a quick fix .

In my opinion , waiting 90 days for a new receiver from Germany is unacceptable . We're I his dealer , I would be politely but firmly asking for a quicker solution . Either a new gun or refund .

[Mushinto]

... Any help woud be appreciated (anything along the lines of what may have caused this, or if you've heard about a failure like this one is what I mean by help). ...

You mean like this?







Umerex said they would send me a new rifle. I shipped the broke one out on Friday. They sounded very cooperative on the phone. I'll let you know.