[Fazorcat]

Hey Guys, just wondering if you ever had any of the screws come loose when shooting. I've had mine out a couple times so far and the screws directly above and below the mag release were loose...the bottom one was almost falling out! Didn't cause any problems, but wondering what those screws are even for, and if I should loc-tite them or something. I didn't want to over tighten them though as I don't know their purpose.

Also, where do I find the serial # for my gun? Does it have one?

Thanks

 

[jonnin]

all firearms in the usa are supposed to have a serial # (even home-made!). Its on some metal part somewhere, but I don't recall exactly where. It has to be on metal.

Yes, lock tite any loose screws. But use one of the weaker colors (blue?) that you can un-do if you need to. Shooting things loose is not uncommon on many firearms, often grip screws or front sights or other such things work loose.

 

[Liberty4Ever]

The PLR-16 serial number is located on the barrel nut, just in front of the receiver, and just behind the polymer forend if you have that accessory. It's laser etched into the metal finish. The serial number should start with "P".

The receiver screws were a bit loose on my PLR-16, at the lower rear of the magazine well. I'd normally recommend applying some blue Loctite thread locking compound and snugging them until they're tight, but the two halves of the glass fiber reinforced polymer receiver have some flex and the tension on these screws can determine the clearance when inserting or removing magazines. I'd still recommend blue Loctite, but test magazine insertion and the operation of the safety, trigger and bolt (a basic functional test with NO AMMO!) to make sure you aren't tightening the receiver screws so much that you cause a mechanical problem.

 

[Fazorcat]

Thanks Liberty. I do have blue Loctite. Would you do all the screws...even the 4 in the handgrip part? Or just the 2 by the magazine release?

About the serial number...is there a number when the chrome-lined barrels started? I'm curious as to what barrel I have. Since I bought this new a few months ago I'd think I have the new barrels, but just wondering. Hard to see what color my barrel is on the inside.

 

[haugrdr]

The chrome lined barrels started a few years ago...maybe 6-7. But we've now heard that they don't do chrome lined anymore. They use a salt bath nitriding process now...started this back in 2012.

Read this thread....KTWM is a long time poster here at KTOG, plus he's an engineer at Kel Tec...he should know.

http://www.thektog.org/forum/f88/sa...lacing-hard-chrome-lined-barrels-soon-249802/

Salt Bath Nitriding (SBN) is replacing hard-chrome lining of Kel-Tec rifle barrels soon. In fact some have probably allready shipped.

pretty much all the barrels that were hard chrome lined, will be SBN instead. All SU's, PLR's and RFB's. And even PMR-30's will get the treatment.

SBN is gaining favor in firearms and will increase the life of rifle barrels. Instead of 6k-10K rounds life with Hard chrome lining, you can get 8K-15K rounds life with SBN.

SBN will look differently, since the outside of the barrel is affected too. SBN barrels will look like they are simply blued, but you can feel the difference after de-greasing it, they are slicker and will not rust. This will be most noticable on parkerized guns, like the SU-16C, CA, or RFB.
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[Liberty4Ever]

haugrdr beat me to it on the nitrided barrel info. Kel-Tec usually phases in process changes (generally improvements but sometimes functionally similar cost reductions that are not necessarily improvements), so they typically don't have a hard cutoff for serial numbers where changes occur.

I'd probably use blue Loctite only on the receiver screws that were working loose, particularly those in the magazine well area, and just tighten the rest until they're snug. My reasoning for that is that on my PLR-16, if I snugged the receiver screws around the magazine well until they wouldn't back out, the magazine well was too tight around the magazine. If my memory is correct (it was many years ago), I think I didn't use any Loctite. I added thin shim washers to lengthen the spacers on the screws that were backing out so I could snug those screws properly without the magazine well binding on the magazine.

Blue Loctite isn't the trouble that red Loctite is when disassembling, but it can still be a pain. If the receiver ever needed to be disassembled and all the screws had blue Loctite, it could be inconvenient. Heat is usually used to loosen thread locking compounds, but that's problematic on a polymer receiver.

 

[Fazorcat]

Ok, found the serial number. It was a different format then I expected... 3 letters and 2 numbers.... P B H _ _ Thanks guys. Also put the loctite on. I'm gonna guess my barrel is the SBN type, but not 100% sure.

 

[haugrdr]

Ok, found the serial number. It was a different format then I expected... 3 letters and 2 numbers.... P B H _ _ Thanks guys. Also put the loctite on. I'm gonna guess my barrel is the SBN type, but not 100% sure.

You can call Kel Tec and ask them. They know what you have by the serial number.