View Full Version : Plum Crazy lower
smokinbarrels
05-15-11, 13:24
I posting this thread becuase I'm sure there are others out there that were like me and were wondering if these polymer lowers are any good. I have read hundreds of threads, posts, comments on these lowers but they almost all seemed to have the same underlying factor... none of the people posting their comments actually owned the lower. There's alot of "my friend has one", "I know a guy that worked with a guy who had one", "my next door neighbors cousin's husband ...." you get the idea. So a few months back I decided I will buy a complete Plum Crazy lower and put it to the test. This way I will now have first hand experience with it and I can pass my findings along to everyone else. My initial thoughts were, for $120, if I don't like the lower, I still get a 6 position stock and complete trigger group out of it.
When I got it, my first observation was how extremely light it was! There's no doubt about it, its light. The 6 position stock worked well. The saftey selector switch was a little tough at first but then worked fine after a few throws back and forth. Then I looked at the trigger group. Like the lower, the entire trigger group is also polymer. Trigger, hammer etc all polymer. It was then that I realized that the only metal parts on this lower was the buffer tube, recoil spring and the springs on the trigger group. HHmm, should be interesting. I know that Vulcan Armament has a polymer lower but I believe their trigger groups are still metal. I then read in the literature that the trigger group used is a proprietary trigger group and other companies after market / replacement parts will not work with this trigger group. The next thing I noticed right away was the serial number stamped on the side of the receiver. It looks like a sticker that some third grade art class student put on. Other than the serial number, the rest of the lower looks really good.
Plum Crazy states on their website and in the literature that comes with the lower, that it is intentionally tight fitting so there is no need for dropping in a buffer pad in the lower to ensure a snug fit. They weren't kidding. The lower is definitely a snug fit, no rattles at all. I've already used a DS Arms 20" upper, a Bushmaster 16" and a DPMS 16" with the lower and they all have a nice snug fit.
I have a little over 500 rds run through it already and I have not had any problems at all. I've been using Federal XM193 5.56 55gr, American Eagle .223 55gr, Cor Bon .223 DPX 62gr, Remington .223 PSP 55gr and BVAC .223 55gr.
So far I don't have any complaints about it. But then again, 500 rd is just breaking it in. I will continue to shoot it and I will post my findings here if anyone else is interested. If for some reason it does fail and breaks, I will be putting it in the dishwasher to see if you truly can clean a polymer gun that way. :D
Thanks for reading!
Smokinbarrels
SWATcop556
05-15-11, 13:44
I don't need to take a bite of a shit sandwich to know I don't want to eat it and $120 for a shit sandwich is expensive.
I don't need to take a bite of a shit sandwich to know I don't want to eat it and $120 for a shit sandwich is expensive.
OWNED....:laugh:Isn't the LPK plastic and only for the PC lower?Also,if you did search you'd see pics of broken lowers around.I can't see paying that much for something like that.
LowSpeed_HighDrag
05-15-11, 14:13
This has been discussed everywhere for far too long. Save up another hundred or so and buy a complete lower or build one from quality parts. A plastic FCG? Not for me. I wouldnt put this on a plinker. Glad yours works, but I wont take the chance.
An Undocumented Worker
05-15-11, 14:16
When these were first released, I saw a video of the inventor tapping the lower with the handle of a dinner knife to "prove" how tough they are. Along with the language used, I knew right then and there to not take that guy or his products seriously.
I don't have one of these and at this point have no plan to buy one.
however I do want to point out that the Steyr Aug has a polymer based trigger group.
So I think in the future as we look at improved systems polymer may be a way of reducing a soldiers combat load . ie Scar program
Again I am in now way endorsing this product but do see the benefits of polymers when done correctly in our weapon systems to reduce weight.
Remember not so long ago there were many who thought a weapon system made of alluminum compared to steel and wood was a horrible idea ;)
If the fact that its plastic didnt clue you in, mayber the price should have and if that didnt do it either the 3rd grader installed sticker serial number should have. There is a reason why every other manufacturer including the lower tier ones use 7075 forged aluminum for thier lowers why stray away from that.
ICANHITHIMMAN
05-15-11, 16:39
This has been discused at length here
https://www.m4carbine.net/showthread.php?t=29057
A picture is worth a thousand words. I think I will pass.
http://i804.photobucket.com/albums/yy324/recon013/DSCN0312.jpg
cthompson36
05-15-11, 18:22
Yeah I mean, Glocks are polymer, so if done right polymer isn't that bad of an idea... But honestly, 60$ more for a reputable brand alumninum mil-spec lower seems like a better idea to me.
variablebinary
05-15-11, 18:28
Yeah I mean, Glocks are polymer, so if done right polymer isn't that bad of an idea... But honestly, 60$ more for a reputable brand alumninum mil-spec lower seems like a better idea to me.
It's not just materials, it's also application
As long as the dimensions are to spec I don't see any issue with the material. There's plenty of weapons out there with polymer/non-aluminum construction. I'm not sold on polymer internals yet though.
The "broken gear" photos always leave me suspicious. Theres very little corroborating evidence you can get from internet forums that prove the blown up/broken gun was due to material or manufacturing issues vs. some hack doing something that would have snapped ANY gun in two.
OWNED....:laugh:Isn't the LPK plastic and only for the PC lower?Also,if you did search you'd see pics of broken lowers around.I can't see paying that much for something like that.
yes...a friend bought one...the only thing metal in it were the springs.....no thanks
also, PMAGS are FAR from dropping free in those
I don't need to take a bite of a shit sandwich to know I don't want to eat it and $120 for a shit sandwich is expensive.
Truth.
I think in theory it should work fine. If in this instance it's properly executed is questionable.
My biggest question though is why?
The Mil-spec lower is awful darn light. How much lighter is the polymer than a mil-spec? Or is it?
Glocks, M&Ps, etc are proven weapons. This lower is not. If you want to spend your $120 that's cool with me, but I don't like being a guinea pig, and certainly not with proprietary lower parts.
If Tango Down or Magpul or one of the other proven companies making polymer parts were to properly R&D and then T&E a lower I could see possibly giving it a try. Integral polymer trigger guard perhaps? Nicely flared mag well. Maybe an integral grip that accepts MIAD front and rear pieces? Molded in QD Swivel sockets (may need to be reinforced or something though). Maybe molded in aluminum reinforcement around the pin holes? A FDE lower?? I think that could sell well.
Like I said, I think the idea is viable if someone could show the benefit of it and then properly produce it. I don't think this is it though...
Good luck with yours.
RAM Engineer
05-15-11, 19:18
I don't need my structural engineering degree to know that you can't just take something designed and dimensioned around ONE set of materials and manufacturing processes and switch to a completely different set of materials and processes without putting a lot of engineering. This is NOT a form and function drop in change.
Forgive me for judging a book by it's cover, but them's the kinda engineering chops I do not expect from a company named "Plum Crazy".
It IS an ironic name though...
congrats,
please conti nue the tests
http://2.bp.blogspot.com/_VPuhohGQYfo/TEhaF9OVOcI/AAAAAAAAADU/T9g_LEI5Vew/s1600/Double+Face+Palm.jpg
Facejackets
05-15-11, 22:00
As long as the dimensions are to spec I don't see any issue with the material. There's plenty of weapons out there with polymer/non-aluminum construction. I'm not sold on polymer internals yet though.
The "broken gear" photos always leave me suspicious. Theres very little corroborating evidence you can get from internet forums that prove the blown up/broken gun was due to material or manufacturing issues vs. some hack doing something that would have snapped ANY gun in two.
Yeah...you want to know how that happened? The guy probably tried to loosen the castle nut. I almost snapped mine taking off the castle nut. Right now its on its way to Plum Crazy to get replaced. As soon as my replacement arrives, I am going to sell it.
**** that plastic piece of shit.
Thomas M-4
05-15-11, 22:24
I don't need my structural engineering degree to know that you can't just take something designed and dimensioned around ONE set of materials and manufacturing processes and switch to a completely different set of materials and processes without putting a lot of engineering. This is NOT a form and function drop in change.
Forgive me for judging a book by it's cover, but them's the kinda engineering chops I do not expect from a company named "Plum Crazy".
It IS an ironic name though...
This^^
You cant just swap out one material for another.
Yeah...you want to know how that happened? The guy probably tried to loosen the castle nut. I almost snapped mine taking off the castle nut. Right now its on its way to Plum Crazy to get replaced. As soon as my replacement arrives, I am going to sell it.
**** that plastic piece of shit.
The story behind the pic starts on post #45 on this link.
http://www.co-ar15.com/forums/showthread.php?t=29670&page=5
The guy was out shooting and the receiver snapped in half.
I can't believe we're even having a PLUM CRAPPY discussion on this site. :rolleyes:
Facejackets
05-16-11, 09:18
The story behind the pic starts on post #45 on this link.
http://www.co-ar15.com/forums/showthread.php?t=29670&page=5
The guy was out shooting and the receiver snapped in half.
ah. My bad. It looked like what almost happened to me! I also should have put "what probably happened".
I have had nothing but problems with mine, including the plastic FCG going full auto that my fiance is so sick of hearing about it, she is telling me to buy a Noveske (which isn't that bad of a problem I guess).
my fiance is so sick of hearing about it, she is telling me to buy a Noveske (which isn't that bad of a problem I guess)
Now THAT makes it all worthwhile!
The big factor is leverage. Polymer framed handguns have no stress points that are highly leveraged, so they are durable.
The polymer carbine lower has two points of extreme leverage. The first is the portion just ahead of the receiver extension, and the second is the hinge where it opens for take down.
If you are going to treat it gently, it should be OK. Otherwise it will be a problem.
Creepinbeetle
05-16-11, 10:21
Interesting.....
I agree on most comments already. Will add though, I could see a use for it, if it's going to used as a hunting rifle (lighten the load a bit while carring it over country).
Shouldn't see much of a round count....rounds to zero, store it, then maybe a handfull of rounds a year after that for hunting. That's strechin' it.
Though as anything else...I'd stick with the 7076 style lowers.
I agree on most comments already. Will add though, I could see a use for it, if it's going to used as a hunting rifle (lighten the load a bit while carring it over country).
The weight difference is about 7 ounces, I'd suck up those 7 ounces for the strength/reliability of a standard lower.
The issue isn't really polymer vs metal, but the fact that the AR lower was designed/dimensioned for 7000 ser Aluminum. There are lots of critical dimensions on it that can't be altered to allow the polymer to be thickened/reinforced to provide the needed strength.
Polymer works in glocks, and the SCAR/ACR/etc because those polymer parts were designed from the start to be polymer...
Failure2Stop
05-16-11, 10:37
The weight difference is about 7 ounces, I'd suck up those 7 ounces for the strength/reliability of a standard lower.
The issue isn't really polymer vs metal, but the fact that the AR lower was designed/dimensioned for 7000 ser Aluminum. There are lots of critical dimensions on it that can't be altered to allow the polymer to be thickened/reinforced to provide the needed strength.
Polymer works in glocks, and the SCAR/ACR/etc because those polymer parts were designed from the start to be polymer...
Yes!
And with that, this thread is done.
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