View Full Version : PWS 12" Keymod Rail.
SpankMonkey
10-14-13, 18:31
Picked up a 12" PWS keymod rail at the fun show Saturday. Its very lite and looks sharp. After purchasing I realized one of the key components of installing is using red loctite. I am not a fan of using loctite on rails to keep them secure.
Anyone out there been using one? Looking for feedback data before installing this.
Can you explain this better? Are you referring to Loc-tite on the barrel nut to hold it, or rail sections?
SpankMonkey
10-15-13, 00:38
Can you explain this better? Are you referring to Loc-tite on the barrel nut to hold it, or rail sections?
IG the locking system has two nuts. It works on the jam nut idea. Threading one nut behind another to lock the first nut.
The first piece (base Nut) has to be threaded on the reciever and you use red loctite to align the base nut to the receiver. The second nut threads into the base nut you glued which sticks out past the receiver threads. After the base nut dries you then insert your barrel and install the second nut. You torque and its done. The base nut is what you bolt the rail to.
Its confusing I will poct pics tomorrow after I get better light. It's a interesting idea and I can see its merits but not sure if I want to be the test case.
Leonidas24
10-15-13, 01:04
Can you explain this better? Are you referring to Loc-tite on the barrel nut to hold it, or rail sections?
I have one and finished installing it three nights ago. Jury's still out on it but the overall construction feels very good.
The process for affixing the handguard to the upper receiver is done with two pieces. A trunnion which is the piece that requires red loctite, is threaded onto the upper prior to installing the barrel and barrel nut and is squared up to the upper. I actually used rocksett (my prerogative) to do this and it feels sturdy thus far.
Once the loctite is set the barrel is then installed and the barrel nut threaded into the trunnion. I torqued my barrel nut just shy of 55 ft lbs during installation and it did not cause the trunnion to rotate.
One the barrel is secured to the upper the handguard is then installed to the trunnion's indexing points and secured with hex screws. There's a typo in the instructions however and the user is directed to torque the screws to 60 ft lbs. That's a ridiculous amount of torque for those and I ended up using around 49 inch pounds on top of blue loctite.
Overall it feels like it's going to be performer.
Interesting. I want to take a closer look at some point.
Sounds like its similar to the install of a JP Modular Hand Guard.
Hot Holster
10-15-13, 07:40
I believe this is what the OP is talking about. I'm not a big fan about the use of red loctite either.
SpankMonkey
10-15-13, 19:12
I have one and finished installing it three nights ago. Jury's still out on it but the overall construction feels very good.
The process for affixing the handguard to the upper receiver is done with two pieces. A trunnion which is the piece that requires red loctite, is threaded onto the upper prior to installing the barrel and barrel nut and is squared up to the upper. I actually used rocksett (my prerogative) to do this and it feels sturdy thus far.
Once the loctite is set the barrel is then installed and the barrel nut threaded into the trunnion. I torqued my barrel nut just shy of 55 ft lbs during installation and it did not cause the trunnion to rotate.
One the barrel is secured to the upper the handguard is then installed to the trunnion's indexing points and secured with hex screws. There's a typo in the instructions however and the user is directed to torque the screws to 60 ft lbs. That's a ridiculous amount of torque for those and I ended up using around 49 inch pounds on top of blue loctite.
Overall it feels like it's going to be performer.
Leonidas24 hit the nail on the head. Here is a pic from their website. I went ahead and glued it up last night. This afternoon I took MAP gas to the trunnion, it took over 2 mins and 30 seconds to break it loose using a large cresent wrench. It's solid and feels very strong.
I will let you guys know how it holds up in a few months. After today I feel it will be a winner. There is no way my chamber will ever get as hot as it took to break it loose unless running FA which I never run.
It looks good, very clean machining, I would like to see a thicker barrel nut. But I do not see a problem using the one supplied.
http://primaryweapons.com/store/pc/catalog/5KMR1151_L_6.jpg
Leonidas24 hit the nail on the head. Here is a pic from their website. I went ahead and glued it up last night. This afternoon I took MAP gas to the trunnion, it took over 2 mins and 30 seconds to break it loose using a large cresent wrench. It's solid and feels very strong.
I will let you guys know how it holds up in a few months. After today I feel it will be a winner. There is no way my chamber will ever get as hot as it took to break it loose unless running FA which I never run.
It looks good, very clean machining, I would like to see a thicker barrel nut. But I do not see a problem using the one supplied.
Hard to tell from the picture, but that doesn't look like any more than two or three threads on the barrel nut. Interested to hear how this holds up.
sounds like installation is similar to the Lancer hand guards. The Lancers are the only hand guards that I use locktite on. They seem to work fine and rotation doesn't seem to be an issue.
Is it me or is the barrel nut threaded on the wrong side of the trunnion....
Or maybe the rail is just too smart for me. :blink:
http://primaryweapons.com/store/pc/catalog/5KMR1151_L_4.jpg
Is it me or is the barrel nut threaded on the wrong side of the trunnion....
Or maybe the rail is just too smart for me. :blink:
http://primaryweapons.com/store/pc/catalog/5KMR1151_L_4.jpg
The picture is just confusing. It looks to me like after the trunion is aligned and the loctite dries, the barrel is inserted and the barrel nut is threaded from the opposite end you're looking at and torqued until it snugs the barrel extension against the upper. The barrel nut won't be nearly that far into the back of the trunion so the barrel nut will be exposed enough out of the front to torque the barrel nut using the holes.
You could look at it like a KAC URX rail except the trunion and the rail aren't one piece like the KAC. You locktite the KAC upper rail at the proper alignment, let the loctite dry then torque the barrel nut in place.
It's interesting they're requiring red loctite for the trunion when blue loctite should do fine. I had to put a great deal of heat on my KAC barrel nut and rail just to get the blue loctite to release.
I can't say for sure but I would suspect that PWS recommends red loctite just to be safe. I haven't run into any issues with the rail on my Mod1 so far. I know they fire their test and demo guns on FA quite a bit there in Southern Idaho to wring out issues. Im sure if you called them they could answer the question for you.
I can't say for sure but I would suspect that PWS recommends red loctite just to be safe. I haven't run into any issues with the rail on my Mod1 so far. I know they fire their test and demo guns on FA quite a bit there in Southern Idaho to wring out issues. Im sure if you called them they could answer the question for you.
It's not the fact that red would cause any issues but if you're going to remove the rail/trunion you'd better be ready to bring the heat if you don't want to damage the trunion or your upper receiver. I cannot remove my KAC rail without using a heat gun on high for nearly 5 minutes. That's with a liberal application of blue.
I'm pretty sure KAC has run their rails hard and still recommend blue. Red just seems like overkill to me.
This is not a bad rail especially for the price but with the practically bulletproof and sturdy design of the KAC URX 4 I'd prefer it. The solid threaded rail and shims act as the barrel nut so there's technically no barrel nut nor screws to loosen.
I completely agree that red loctite is overkill. In a roundabout way I have access to a contractor for PWS. I'll see if I can find an answer in the next day or so.
Just look at the installation instructions for the JP tube if PWS doesn't have any yet.
leadsender
12-26-13, 21:40
Just a heads up for anyone wanting to install this rail on a Vltor MUR upper receiver. You will have to shave the rails anti rotation tabs due to the thicker walls of the MUR.
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Just a heads up for anyone wanting to install this rail on a Vltor MUR upper receiver. You will have to shave the rails anti rotation tabs due to the thicker walls of the MUR.
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Are you sure? I am about to use this rail on a VLTR MUR upper (a MUR-1S which has the forward bolt assist if it matters). I dry fitted them and the rail's anti rotation tabs do not interfere with the upper at all. Everything fits fine with no issues.
Joe Mamma
im trying to get through my head how this thing is installed.
The inner nut does not appear to be threaded to thread onto the upper. Do you just pack it full of lock tite and slip it over the threads on the upper? If thats the case I dont know if I could trust it.
I also dont see how you torque the barrel on. If you put the inner nut on first, loc tite it in place, then the barrel installs and you put that larger outer nut on I dont see what the barrel extension sandwiches in between.
I tried searching for install instructions, but Google failed me
leadsender
12-28-13, 22:39
I installed it on a noveske marked vltor MUR with the thicker front. I had to file off about 1/8 of an inch off all 4 corners when is was all said and done to get it to seat all the way down on the upper
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leadsender
12-28-13, 22:45
im trying to get through my head how this thing is installed.
The inner nut does not appear to be threaded to thread onto the upper. Do you just pack it full of lock tite and slip it over the threads on the upper? If thats the case I dont know if I could trust it.
I also dont see how you torque the barrel on. If you put the inner nut on first, loc tite it in place, then the barrel installs and you put that larger outer nut on I dont see what the barrel extension sandwiches in between.
I tried searching for install instructions, but Google failed me.
You thread the trunnion (the part that the rail screws too on to the upper's threads that gets thread locked. You then install the barrel using the round nut and an included spanner wrench
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You thread the trunnion (the part that the rail screws too on to the upper's threads that gets thread locked. You then install the barrel using the round nut and an included spanner wrench
OK, that makes sense. The pictures are just weird. So the inner nut would NOT be that far back on the trunion like is shown on the pictures. The area where the spanner wrench goes would be sticking out the front. So a "reverse" barrel nut so to speak.
leadsender
12-28-13, 22:49
You got it right on now. The pictures are a little deceiving but once you get your hands on the parts you'll understand
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I like the way this one looks slightly better than the MI. I dont like that the barrel nut on the MI is exposed.
I just used a Noveske NSR for the first time and was very impressed with it, but I like built in QD attach points vs. having to use keymod QD on the Noveske.
Im very interested in checking out the new BCM keymod as well.
Im not a huge rail user so the Keymod stuff I like a lot because it shrinks the hand guard down quite a bit, even though I may never actually use the keymod points for much.
Like I need more excuses to build more uppers. Noveske, BCM, MI, PWS. SHIT.
I installed it on a noveske marked vltor MUR with the thicker front. I had to file off about 1/8 of an inch off all 4 corners when is was all said and done to get it to seat all the way down on the upper
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Now it makes sense. I have seen Noveske marked MUR uppers that are slightly different in that area (thicker) compared to VLTR MUR uppers (which are not Noveske marked). I don't know if all of the Noveske MUR uppers are the same.
Mine is just a regular stripped VLTR MUR upper, and the PWS rail fits flush with no fitting necessary.
Im not a huge rail user so the Keymod stuff I like a lot because it shrinks the hand guard down quite a bit, even though I may never actually use the keymod points for much.
That's one of the reasons I got this too.
Joe Mamma
Leonidas24
01-12-14, 01:11
Update:
The handguard trunnion broke free today while I was at work getting ready to leave for the day. I felt the handguard rotate maybe 1/32" to the left and right and noted the barrel also had about the same amount of movement up and down. I took everything to the back workbench and was amazed when I could disassemble the barrel from the upper by hand. The barrel nut rotated out with no force whatsoever, and at this point I've come to two conclusions.
1. Rocksett is not a good thread locker for this particular handguard. I realize now that while it is high heat resistant, rocksett isn't all that strong in the end. A local AK builder suggested red locktite and that's what I'm using now. He also said I could try black locktite but I'd never be able to get it off again.
2. I noted when I removed the barrel from the upper that the barrel extension was covered in slip 2000, as was the inside of the trunnion along with the gas tube, barrel nut, etc. It's possible that the prolonged exposure to the lubricant caused the rocksett to break down and lose its strength. With that said this rifle hasn't been fired in about a month and hasn't been subjected to any abuse in between.
I caution anybody using this handguard to keep an eye on the alignment of their upper/top rail and also physically try to rotate the rail from left to right to check for stability. I'll report how sturdy the red locktite is once it's set up.
leadsender
01-12-14, 01:40
As long as when you install the handguard flush with the receiver and engage the anti rotation tabs, there really shouldn't be any way for the handguard to rotate. I'm not saying the barrel can't work loose. But as long as the screws that hold the rail to the trunnion are torqued properly I really don't see the rail moving
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