CAV lowers are VERY strong.  They've been torture-tested by the AZ crew in ways that would make you cry, and still keep working.  They've been dropped, thrown, and even ran over.  And I'm pretty sure that Doug (ILove2Shoot) runs his Beowulf on a CAV lower, and I know he ran his Tromix .50AE upper on one.

Something else to remember: if your CAV lower breaks under normal use, they'll replace it for FREE.  If you break it through obvious abuse (which isn't going to be the case by just using a Beowulf upper), you can STILL have it replaced for only $30-35.

You just can't beat that.

-Troy

I think the new lowers are upgraded to be stronger, but I don't think AR recievers don't have much stress on them as it is. That's how they got away with using aluminum and making the rifle so light.

I get this question alot. so I am making a longer reply this time. I am also going to have this Takced up in our forum.

I have used my Tromix 50AE and Alexander Arms Beowolf uppers on a Cav15 MKI lower receiver.

I have fired quite a few hundred rounds of 50AE through my lower and then used it on my Beowolf upper once I got my Tromix Lower. I have put a few hundred Rounds through the upper and finally did have a minor failure on a weld point at the rear of the mag well. Was it a catastrophic failure, NO, the mag just dropped out when I fired it and so a new round would not get stripped out. I re-welded it, re mounted the upper, simple as that. I am still going. I don't think I had a 1,000 rounds through it though. Considering it was not designed for as heavy a recoil as this, I was not un-happy. For those that have the Beowolf, know that a few hundred rounds is a lot when firing this upper.

I would like to add that the lower I am using on it is a "Second", we tend to keep these for ourselves. So, I am not absolutely positive that the problem I had was exclusively caused by the Beowolf.

As far as a Cav Arms stand point, it has been a question of Normal use. The MKI receivers were designed for and around the 223 caliber. The idea of the larger heavy recoil calibers was never thought of or designed for in the original Cav 15 (for those that remember, the very first model of the MKI receivers was screwed together)

We have put alot of design time into the New MKII receivers. We are doing some new things with this Model that I am excited about. But will it work....We are planning on doing an extended endurance test to find out just how well it stands up to the large calibers.

Up till now, the official Cav Arms policy has been that we would repair the MKI receivers once, if you do use it on a Large Bore wild-cat upper. But, it has kinda been one of those things where we are still finding out how well the lowers hold up. We have lowers (Princes, Sunshine and The Judge) that have well over 20,000 rounds through 2 of them and Princes has even more then that, in 223 and 9mm. We are not saying to do it, but we are not saying "Please god, Don't do it", either.

I hope this answers all your questions.

Love2Shoot