[Shihan]

What would be pros and cons for going with a Polymer lower?

Anyone...Just to crazy and not worth it? Or maybe worth a shot and see?
The price isn't going to be a wallet killer and if it doesn't work out can always get a different one.

[JonM]

it might develop wear issues in the reciever pins or in the recoil tube area. but im taking a guess. there is little to no recoil stress on the lower itself. i would prolly stick to 5.56 or pistol calibers with one. im not a believer in polymer frames handgun or rifle. im not sure there are any pros. aluminum mil spec lowers i think might be lighter.

[stelliott80]

I recently shot an AR-15 that a friend bought with a Plum Crazy lower, which is composite (first time shooting composite; I own a few ARs, and all have DPMS lowers). The fit is very good between the upper and lower and between the pivot and takedown pins and lower. I read some online reviews from owners after I got home, and most are pretty positive. The cost of the Plum Crazy lower and conventional aluminum lowers is pretty similar. I've seen Plum Crazy lowers for around $100 or a bit more, and (in this case, DPMS) aluminum lowers for $125, just recently.

I guess I prefer the metal to the composite, but my one firsthand experience tells me that the composite isn't bad, and Plum Crazy claims it can take quite a bit of abuse.

[dog2000tj]

I have no experience with them but this thread caught my attention - http://www.firearmstalk.com/forums/f20/split-lower-26388/index2.html

Granted that issue may not pertain to all poly manufacturers. But i'll stick with the aluminum lowers, they seems to have a good track record

[spittinfire]

I personally can't see any issue with a polymer lower other then the threads. I personally wouldn't want one but I can't think of any reason why it wouldn't work. If there are concerns about the take down pins a sleeve could always be made which I guess could also apply to the threads.

[Dillinger]

The lower is little more than a housing to contain the operational parts.

However it also absorbs and transfers energy from the upper where the round is housed, to the recoil buffer which is attached to the lower by the very threads Spitty is talking about.

Of the "Polymer" type guns, we have seen about 6 or 8 that have had "explosive disassembly" caused issues resulting in cracks and atleast two outright breaks that I have seen personally.

My recommendation for a polymer lower would be heavily AGAINST, for what it's worth.

JD

[Shihan]

I could engrave it with a soldering iron. Making cool designs.

[Quentin]

I'd stay away from polymer lowers too. The lower is the firearm legally so you want something that will last a lifetime. They're not that much lighter than milspec and definitely not as strong. You see too many pictures of cracked plastic lowers so why chance it. Would you want to mortar one to clear a jam as is done when time is of the essense? Not me.

To be fair, my friend's Carbon-15 has held up well over two years but I still wouldn't buy one for myself.

Now in the future there will be better materials and the game can change.

[mjkeat]

Any opinions on the Cav Arms Mark II lower?

[Shihan]

Originally Posted by mjkeat

Any opinions on the Cav Arms Mark II lower?

Yes, The Yellow Lower with the a Black upper, GO Steelers.