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-   -   Remember to check your parts, mine didn't fit (http://www.calguns.net/calgunforum/showthread.php?t=682321)

dingle_berry 01-18-2013 4:21 PM

Remember to check your parts, mine didn't fit
 
A friendly reminder that in these crazy times, check your parts! Don't just take your new LPK, grip, etc and throw it in your safe without at least a fit test.

Both my orders were from legitamet vendors; Riflegear (Magpul Kgrip) and Aimsurplus (CMMG LPK). I did a fit test using two different lowers and had problems with both orders.

The first problem isn't a big deal, just a pain...they sent me the wrong sized pistol grip screw. A buddy of mine thinks its a metric, who knows... I got a few 1/4X28 screws from work and they go in like butter. Whatever was in my CMMG LPK from Aimsurplus was not a 1/4X28. Doesn't instill a ton of confidence that the rest of their parts are right, but I'll find out this weekend.

The second problem is a bit ridiculous. The opening of the Magpul K grip that mates with the lower receiver is way undersized! I measured the thickness of two lowers and they are ~0.380". I then measured the Magpul grip opening and it was ~0.346". I went online and found a drawing that looks like the lower should be 0.375" nominal (http://www.firearmfiles.com/files/AR...%20Drawing.pdf), which would mean the Magpul is way off! I also measured the openings of the standard pistol grips that came with my CMMG and Spikes LPKs and they measured ~0.385"-0.405" at approximately the same location as the Magpul measured 0.346".

I've contacted both manufacturers, no word yet. Before this thread blows up with "I've gotten good parts from them", "mine work fine", etc I just want to reiterate that I am not saying CMMG or Magpul make crap parts. Unfortunately this is my first experience with both manufacturers, but I'm sure this is a very rare thing.

This post is just a reminder/warning to check your parts!

HK Dave 01-18-2013 4:26 PM

You tried spreading the part where the grip connects to the lower? I've had to use a whole lot of force in the past.

dingle_berry 01-18-2013 4:30 PM

I tried spreading the part using as much force as I was comfortable with (before I went to measuring), but I don't want a part that could be as much as 0.040" from where it should be.

I'm hoping this is some freak thing that happened with their mold, or during cooling of the part, or something, and they can send me a replacement that will actually fit.

MrPlink 01-18-2013 5:20 PM

I have a k grip. It was a lil tight but no Biggy. Its been on numerous lowers too.

tanakasan 01-18-2013 5:28 PM

My Magpul grips have all been (too) tight.

I use a heat gun to gently warm the grip and then it will go on and fit like a glove...even before the screw is installed. Easy.

Robert

Baconator 01-18-2013 5:36 PM

Yeah, magul have always been a super tight fight for me. Between that and the loctite on the screw you have to heat it up.

Fjold 01-18-2013 5:38 PM

I hammered a 3/8" round rod into the grip opening of one of mine because it was so tight. It's just plastic.

dingle_berry 01-18-2013 6:12 PM

Wow. To be honest these stories don't give me confidence. Sounds like I'll be asking for a refund instead of an exchange.

I've worked with plastics for a number of years and what you're describing sounds like really poor quality control and potentially poor design engineers.

GMG 01-18-2013 6:16 PM

Quote:

Originally Posted by dingle_berry (Post 10248844)
A friendly reminder that in these crazy times, check your parts! Don't just take your new LPK, grip, etc and throw it in your safe without at least a fit test.

Both my orders were from legitamet vendors; Riflegear (Magpul Kgrip) and Aimsurplus (CMMG LPK). I did a fit test using two different lowers and had problems with both orders.

The first problem isn't a big deal, just a pain...they sent me the wrong sized pistol grip screw. A buddy of mine thinks its a metric, who knows... I got a few 1/4X28 screws from work and they go in like butter. Whatever was in my CMMG LPK from Aimsurplus was not a 1/4X28. Doesn't instill a ton of confidence that the rest of their parts are right, but I'll find out this weekend.

The second problem is a bit ridiculous. The opening of the Magpul K grip that mates with the lower receiver is way undersized! I measured the thickness of two lowers and they are ~0.380". I then measured the Magpul grip opening and it was ~0.346". I went online and found a drawing that looks like the lower should be 0.375" nominal (http://www.firearmfiles.com/files/AR...%20Drawing.pdf), which would mean the Magpul is way off! I also measured the openings of the standard pistol grips that came with my CMMG and Spikes LPKs and they measured ~0.385"-0.405" at approximately the same location as the Magpul measured 0.346".

I've contacted both manufacturers, no word yet. Before this thread blows up with "I've gotten good parts from them", "mine work fine", etc I just want to reiterate that I am not saying CMMG or Magpul make crap parts. Unfortunately this is my first experience with both manufacturers, but I'm sure this is a very rare thing.

This post is just a reminder/warning to check your parts!

Sounds to me that this must be your first build, am I right?

dingle_berry 01-18-2013 6:19 PM

No it is not my first build. Based on your comments, I again repeat my concerns about using Magpul parts if they require such drastic measures just to have them fit. This assembly isn't complicated or tightly toleranced...I don't quite understand why they have such issues making good parts.

vliberatore 01-18-2013 6:30 PM

Quote:

Originally Posted by dingle_berry (Post 10250035)
No it is not my first build. Based on your comments, I again repeat my concerns about using Magpul parts if they require such drastic measures just to have them fit. This assembly isn't complicated or tightly toleranced...I don't quite understand why they have such issues making good parts.

Better too tight than too loose. If it's an issue, buy a Hogue grip.

dingle_berry 01-18-2013 6:36 PM

Its not "better too tight" if too tight means you can not assemble the grip on the lower, making the part is completely useless.
I do have an issue with poor quality/design, so I guess I'll be going elsewhere for my purchases from now on. I've got to admit, I'm a little disappointed that y'all (calguns) tolerate all of these issues...

Eargasm 01-18-2013 6:44 PM

What kind of lowers?

dingle_berry 01-18-2013 6:47 PM

If you think the lowers are the problem, please let me know what dimension I should be looking for. The drawing I found says the dimension should be 0.375" and my lowers measured to be ~0.380".

vliberatore 01-18-2013 6:59 PM

Quote:

Originally Posted by dingle_berry (Post 10250244)
Its not "better too tight" if too tight means you can not assemble the grip on the lower, making the part is completely useless.
I do have an issue with poor quality/design, so I guess I'll be going elsewhere for my purchases from now on. I've got to admit, I'm a little disappointed that y'all (calguns) tolerate all of these issues...

It's a plastic grip. How do you know it's Magpul's QC and not deformed from packing/shipping?

You're making a mountain out of a molehill. This is a non-issue. Seems like you just want something to complain about.

Eargasm 01-18-2013 7:00 PM

I ask what lower because I had a similar problem with the pistol grip screw & threads on my lower(s).

dingle_berry 01-18-2013 7:04 PM

Perhaps it is from shipping, although I'd be surprised, either way its a QC issue.

I don't think I'm making a mountain out of a molehill...sounds to me like you just want to argue with someone about something...so I'm done responding to your posts...

Again, the point of the post was to remind people to check the parts they receive...just like every other product you buy everyday of your life, just because you order it one way doesn't mean thats what you get when it arrives...

dingle_berry 01-18-2013 7:08 PM

I measured one Spikes Tactical lower receiver and two Tactical Machining 80s...I checked the spikes after my initial post...

What did you change on your pistol grip screw to get it to work? My 1/4X28s worked great...what lower did you buy? What company did you order your parts from where you had problems?

Obviously a Plant 01-18-2013 7:36 PM

For what people pay for plastic and aluminum parts for AR's, I think they should be damn near perfect. While I understand that most are made in the USA they are often priced as if they were one-of-a-kind pieces from a renowned artist, not one of a batch of a thousand made this month. If you charge $30 for a sling swivel, it should attach itself to your rifle for you. There should be no flash, no discoloration and it should fit like it was born there.
If your grip won't fit, have them send you one that will. $20 for an injection-molded piece of plastic that won't fit a standard lower is B.S.

sdsguy87 01-18-2013 7:47 PM

If it's too tight you can always sand down a bit but I get your concern. There shouldn't be a need to sand down for the price.

I just installed the MIAD grip and I screwed up the threads on my lower so I'll need to retap it but that grip was pretty tight to get on, which I liked because then I know once I put the screw that thing isn't going anywhere. I just had to slide it in the right way. (that's what she said)

supertrooper 01-19-2013 7:05 AM

i have never used anything from cmmg but the magpul grips i have bought came with their own grip screws that fit. all the magpul parts i own have fit perfectly. the moe and miad grips were snug fit but i would rather have i tight fitting grip so it doesnt wobble. the standard a2 grip on another ar was the biggest pita to install.

imo, your making a big deal over nothing.

GtRacerH 01-19-2013 7:48 AM

I put together my first lower recently. It's a Spike's and when I went to install the Magpul grip, it was definitely really tight. So much so, that I thought either the grip or lower were defective. I even considered sanding down the grip, but I didn't. Eventually I managed to angle it in just enough to were I could apply force to it and it went in fine after that. Now that it's on, I prefer that it went on tightly.

dingle_berry 01-19-2013 7:55 AM

So to be clear, I've made about 20 measurements on the grip, not a single location is large enough to accept the lower. In addition I have tried stretching the plastic and it can't be stretched to fit without serious concerns of breaking the part. I'm not *****ing because the part is a little out of spec, the damn thing can not fit!

Gotta be honest, disappointing experience with most of you calguns members. Seems like your brand loyalty is influencing your responses to someone who's having a legitimate problem.

The entire point of this post was to remind people, especially new buyers, to check what they bring home. Manufacturers make mistakes, parts get left out of assemblies, it happens. Either way I'm done with this thread.

GtRacerH 01-19-2013 8:13 AM

I agree, it shouldn't be that difficult but I still manage to put it on. Try getting an edge in on the highest rearmost point of the lower. Then just shimmy in with force. Or you can always return the thing and try another brand. Your money, your call.

vliberatore 01-19-2013 8:18 AM

Sanding plastic so it fits must be really difficult to do.

starsnuffer 01-19-2013 8:26 AM

I've always had to sand magpul parts. That goes for just about every part they make. Maybe I'm anal and don't like the molding seams, or maybe I'm old school and consider it the job of a gunsmith to use available tools to custom fit pieces together.

As much as the lego analogy gets passed around, they aren't legos. Plastic is much easier then metal to work on. Some sandpaper and a few needle files are all you need.

-W

MrPlink 01-19-2013 8:33 AM

This is getting funny.
A lil trollish though.

GtRacerH 01-19-2013 8:46 AM

Maybe he should sand then remeasure and recheck specs. What's trolling?? Lol

Justintoxicated 01-19-2013 9:24 AM

are you sure the threads were wrong on the screw? I had similar issues on with my CMMG 308 LPK. I happened to have a 1/4 28 die so I use it to clean up the threads in my JD Matched Set ($700) and that solved the issue for me. Even threads of the same size can have different tolerances.

Maybe this was my problem:
http://www.newmantools.com/taps/taptech.htm

I don't know... At least you didn't have to work the push pins in and out for hours with a punch just to make it so you could force them in by hand...

Nick5811 01-19-2013 9:28 AM

Quote:

Originally Posted by GtRacerH (Post 10254212)
I put together my first lower recently. It's a Spike's and when I went to install the Magpul grip, it was definitely really tight. So much so, that I thought either the grip or lower were defective. I even considered sanding down the grip, but I didn't. Eventually I managed to angle it in just enough to were I could apply force to it and it went in fine after that. Now that it's on, I prefer that it went on tightly.

Same thing happened to me. I bought a 'what was left' LPK from DPMS and had fitment issues on my new spike's lower. The MM grip was too tight to fit, and I had to shave a little away and then angle/pound to get it on. Then I ordered a buffer/tube/buttstock from amazon that was crap and didn't even allow my BCG to clear the bolt catch.

Quote:

Originally Posted by dingle_berry (Post 10254265)
So to be clear, I've made about 20 measurements on the grip, not a single location is large enough to accept the lower. In addition I have tried stretching the plastic and it can't be stretched to fit without serious concerns of breaking the part. I'm not *****ing because the part is a little out of spec, the damn thing can not fit!

Gotta be honest, disappointing experience with most of you calguns members. Seems like your brand loyalty is influencing your responses to someone who's having a legitimate problem.

The entire point of this post was to remind people, especially new buyers, to check what they bring home. Manufacturers make mistakes, parts get left out of assemblies, it happens. Either way I'm done with this thread.

Props to the OP for sharing his experience. I had the same concerns, and he gets a ration of crap from people for trying to help out someone else. Great job guys.

HK Dave 01-19-2013 9:50 AM

Use a little KY Jelly and force that sucker in there. :P

joeblowphony 01-19-2013 9:55 AM

I'd be really interested in what Magpul would have to say. Whether it was the intention to have things fit really tight to the point that a customer may have to rework the product or that they just have crap QC

zfields 01-19-2013 9:59 AM

I hope none of yall buy 1911s.

onegtalon 01-19-2013 10:53 AM

Quote:

Originally Posted by zfields (Post 10255194)
I hope none of yall buy 1911s.

+ 1000!


Sent from my iPhone
OneGtalon

jsipe007 01-19-2013 11:28 PM

I'm sorry for your troubles man but that is known as gunsmithing...

Parts are usually small so they can be fit the way the user wants. Granted in your case it seems a bit worse than usual but some heat or sand paper on the inside of the grip will make that a great shooter.

Parts that are tight are never a problem in my eyes. If the magpul grip was too big and had a lot of slop, the would be crappy QC IMHO

akjunkie 01-20-2013 1:07 AM

My ERGO & Tango Down Grips were tight too also. Had to install at an angle to spread the 'lips' open. If that don't help heat your grip up.


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