So I got a PTR 9KT back in September that had to go back to PTR for a #28 locking piece/bolt fitment issue that ended up taking about 5 weeks to resolve, and ended up with me getting an entirely new firearm to replace the one I sent in because the smith found "an issue" with the trunion in addition to the locking piece having yuge bolt gap issues. The replacement still had the bolt gap issues, but I just threw in some HK -8 rollers, and that worked out. So here's some info on what I've done, and what I've changed/added. I put some stuff in here that others might find useful if they are considering looking at some of these items, info was scarce in some cases and so some were a roll of the dice when I bought them.



From the start my intention was to SBR this, and I've been waiting on a SiCo Omega 9K can that I bought in September. Thus, the need for the #28 locking piece. I went with the Choate/HK side folder PDW stock. I considered the B&T, but it looked like this one was a little shorter, which I wanted. The pushpin holes took a few hits from a round file to get them to line up with the holes in the receiver, but otherwise the stock was great from the start. With the stock folded, it just clears the rear of the SF light switch. There is just enough clearance to keep the stock from hitting the switch.



I decided on the MI MLOK rail. I tried out the HK K grip, and the HK handguard that just has the forward lip. The forward lip was handy while I waited on my F1 to clear, but after I got that back it came off. I tried the HK grip, and it worked just fine for what it is. However I wanted to mount a light, and I didn't really care for the idea of the short rail from HK Parts that replaces the push pin, and HK Parts was having their issues at the time as well. So I got the MI rail. It went on just fine (ETA: with process noted later), didn't interfere with the sling mount, and gave me the grip and light mount solutions that I was looking for. I used the Surefire X300 pistol light because it was compact, I didn't have to worry about a tape switch, and it wasn't difficult to install and remove as needed with no tools. Also, the positioning of the switch was perfect for activation with my thumb while holding the grip.



For the light mount I used the Magpul MLOK offset light mount. There wasn't any other way to fit the light onto the actual MLOK slots that would clear the sling, allow manipulation of the switch, or even allow the light to be mounted without interference, and the K grip was proving an issue. ETA: this is where the mounting of the grip and the light mount had to be worked out. Basically, I had to loosen up the K grip, install the Magpul mount, tighten it, and then tighten the K grip base back down. Otherwise the light mount was sitting at an angle on the grip base. Going in this order, there is room for everything.









ETA: if you're thinking about the MI unit, get it. The fit is perfect. There is the small hanger collar on the interior (the two small hex screws) that position and lock down the larger collar with the screw that replaces the push pin. once you get the small collar positioned correctly you tighten it down and then secure the large screw to hold it all in place. The rail sits flushed up to the receiver and is a much, much better fit than either of the two polymer grips that I tried out. Once you have it in place it's very firm.





I went with the A3 Tactical MLOK K Grip. I meant to order the polymer but ended up with the aluminum by mistake. The thing is solid, and I'm not worried about tearing it up at all. The grip is in two pieces: there is a common MLOK base and then you have the option of getting the standard or short grip length. The grip body is secured with a 1/2" nylon lock nut inside the grip. ETA: if I had it to do all over again, I'd probably go with the polymer and make sure that was the one in the shopping cart. I'm not displeased with the aluminum model, but I don't know that I wouldn't be just as well served with the polymer version.





I tried an RMR, and also an Aimpoint Micro on the rail. I just didn't like them. Might be ok with a lower Micro mount, but I really like the irons. The only thing I wanted to change was having the tritium sights, so I ordered a set. Install was easy, just knock the pin out of the front, and install the two piece front and then drift the pin back in. For the rear you remove the large sight locking screw and take it out, then install a spacer, the rear sight base, and then a longer locking screw and lock washer. ETA: the front sight is in two pieces; obviously you couldn't do a unitary piece with the tritium vial. The front sight blade itself is one piece, and has a large tail that the pin secures through. The other piece is the loop that fits in the space where the stock piece goes, and has a square cut-out that the tail from the sight blade fits into. You put the loop in the sight body first, then the sight blade, and then drift the pin back in. The stock front sight blade can be a little tricky to get out, however a small feeler gauge or very narrow driver can be used to get the stamping moving out of the cut. Once you break it free it comes out easily.





I discovered two things I didn't like with the rear sight. First, the locking screw head is HUGE. And the finish that is used on it is crap. So I ended up with a large, light-colored high contrast reflecting dome right in the field of view of the rear sight blades which sucked. So I decided to take some flat black enamel paint and try to knock down the glare. I removed the screw, degreased it, and hit it with the flat black. The second problem is that the large spacer that I mentioned kept the rear sight blades from sitting down low enough, and when I adjusted the rear drum all the way down I still had the ears of the sight that hold the tritium vials sitting up much higher than the rear drum aperture so at 25 yards my groups were sitting about 2.5" high. There was a gap between the rear sight base and the night sight base. I removed the large spacer, and now the rear sight base sits all the way down on the rear sight assembly and the tritium vials are in line with the rear sight aperture. Much better for both issues. I may try to reduce the profile of the spacer and return it to the sight, I don't know. I'll see if any problems show up.



For a sling, I went with the Vickers/BFG One Sling. I run their padded slings on a lot of other carbines and rifles, and I like the slider tab feature. However I was trying to keep the profile of the 9KT as minimal as possible, so the larger slings were going to be too much. The One Sling was perfect. Slimmer profile, no pad, and almost like it was made for the gun. When the stock is folded and the sling is draped across gun it doesn't have a huge amount of slack hanging all over and it is easy to put in the bag, pull out, and even move around the interior of a vehicle. I used an HK on the front, and adjust the body of the sling so that when adjusted to it's shortest length it stays close in to my chest, and at full extension I can shoulder the gun, but there is almost no slack and the gun is very stable. The rear double slider is run through the rear sling swivel on the stock and doubled back on itself. ETA: I do from time to time experience a problem with opening the stock up and locking it in place due to the rear sling swivel. The metal swivel can rotate around so that it interferes with the stock opening up and engaging the locking mechanism. Usually not a big deal and easily fixed. I've found that this doesn't happen when I am wearing the sling, but if I am not and I try to open the stock up then this can happen.







I wanted to SBR this so I could have a very compact PCC that could fit in a lowpro bag that would fit in with what I take to work or traveling. I found that I could fit the 9KT into a 5.11 messenger bag (ETA: this is the smallest of the series, the Mike version), and still have room for two 30 round mags, four 15 round mags, an Otis kit, some tools, and a few spare parts. I'm very happy with it. If I want to put some loose mags in, I can get probably another four 30 rounders inside and have no overt indications of a firearm. If I'm not worried about printing, I can fit three 30 round mags in each of the outside end pockets. The bag would be ridiculously heavy and bulky at that point however. ETA: I try to have copies of my stamp paperwork anywhere and everywhere that I might have the NFA items in. So I keep one for everything in all my vehicles, and then one in each case/bag. The messenger bag is ideal for this: plenty of pockets for the manual, NFA paperwork, small parts, an Otis 9mm circular kit pouch, battery carriers, and a ton of mags.





So after a few range sessions I've been very impressed. This thing is a blast to shoot. With the -8 rollers and the #28 locking piece I was a little concerned about recoil and bolt gap, but no problems. The first 500 rounds I had a few FTEs, including two impingements, but not more than what I was expecting from the reports of the initial break-in period for the 9KT. No sign of dimpling, and zero deformation or damage to the buffer. As with roller locks, it was filthy. ETA: with the stock and hotter (than US) loads, I was really expecting some kind of wear on the buffer. I was very happy to see that there was literally no wear at all. The buffer looks exactly like the spare buffer that I have that hasn't even been installed.

Looks awesome OP, enjoy it! Bummer you had all those bolt issues, seems like the K guns are a bit finicky. But it's all sorted now, which is great.

Thanks. Took a little work but at this point I’m happy with how it is going.

Great timing for the post. I just got back from the range with my new 9KT. Zero malfunctions and it's all sighted in.
It's a great companion to the 9CT which is only a couple weeks older. Lots of great info for me to go over.
Thanks for taking the time to create the thread.

Awesome, you're welcome. Even going through TOS and here there wasn't a lot of info on some of the specific things I was wanting to do. So I put this together to help out anybody else that was looking at the same stuff I was.
I was looking at the 9CT first, but the more I thought about it the more I wanted to go compact. I'm glad I got this first, but I still may go with the 9CT.

Attached File


I LOVE mine. I have the same A3 grip, but went with the Sig side folding and an SRO. I stoned my locking piece myself and added the -8 rollers. No gap issues now.

Did the "F" model firing pin spring come in the gun from PTR?

Both of my PTR-9CT and 9KT, bought last month, came with the "F" firing pin spring.

Can you post a pic showing where on the new 80 degree locking piece you stoned to get it to fit?

Updated original post with some ETAs on additional information.
As far as plans, I'm pretty happy with it right now.
I might look at the RMR or Micro again with different profile mount.
If Magpul actually releases their grip unit (they say late this year, we will see) and the price point is reasonable I do want to get that. I cannot stand the little dots on the side of the grip. The Magpul ambi selector -might- be on the list because my daughter is a lefty, but that would be the only reason I got one. With a little more time I will decide if I want to mess with a trigger pack that's been worked over to give me a smoother/faster trigger, but I am not displeased with the trigger at this point. It is easy to reset, but I haven't really been able to work on speed with it yet and the results from that will make that decision.
Obviously when my can gets broke out of NFA jail that dynamic might make some changes necessary. Ammo selection might change with that. I'm intending on going with a direct mount for the can, but I may go with the trip lug mount. Not even sure yet and I want to try the direct mount first.
I want to put a decent spares kit together. Right now it's looking like a few spare ejector springs, a spare extractor and spring, spare buffer and buffer screw. I think that will cover anything I would need in the field. Maybe an ejector lever in case that gets bent/deformed. Not sure I would need any other parts, but if anybody has experience that shows what else I may need I"m open to guidance.
For tools I typically just have the HK sight tool and then a Leatherman Surge with the bits kit. Might throw an HK go/no go gauge in, but I don't know that I will need it. My gap is right at the high end so if it changes it's likely to just get smaller and I expect it will be some time before I would get to the low end. The Surge was helpful with the few impingements I got. I will probably keep a SiCo spanner in the bag for any potential problems with the can. I'll also keep a silicon pad for handling the can in there.

Greatness.
I keep looking for an EO sight, but then I really like the irons. If I can find the right mount/sight combo I may put one on there I just haven't found it yet.
I thought about stoning mine, but I figured I'd let the warranty do the work on a NIB and never-fired gun, and now I"m glad I did since they found the vague "issue" with my barrel and trunion when they got it back. I still never found out exactly what that was, and I ended up with a new gun replacing another new gun. I also didn't get an inspection sheet with the replacement so I was a little concerned when I first shot it. All that said, I'm very happy with the replacement I got and even happier with what I've done to it. I cannot wait to get my can in.

I got the F spring, cocking tube, barrel, and other stuff as is from PTR.

I'm interested to see where you go on the RMR. I'd like to see a small compact option.

I've already hit my KT with the Dremel. My right side pimple bump on the grip is down 90% and feels so much better. Taking a coarse grinding stone wheel and using to scratch the surface closely matches the original surface of the grip. In the end both sides will not have anything resembling those pimples.

My mag well had some raised welds on the outside and a handful of sharp edges inside the mag well on the other side from PTR sanding them down. Now that I smoothied them down all I need to do is round over the back bottom corners of the SB Brace receiver mount. I've go a friend who can do park and paint the receiver after all said and done. The SB Brace mount is aluminum so just a blast and paint. Likely not bothering with anodizing for just a small piece.

Also, what size is that 5.11 Messenger Bag?

Yeah, something the size of the Micro is about as big as I would want to get. The RMR would be the size I would want to run. I tried an EOTech XPS3, but that was too big.

I've debated doing that, but I may just go with a Navy/FBI housing. I think I might want the straight grip.

Wow, mine didn't have anything like that. There were a few posts on TOS about some crappy welds/fitment when I was waiting on mine to come back and I was worried about that. I don't know if because mine was a replacement for a NIB gun or if their production just improved but mine was in very good condition from what I could tell and didn't appear to have any issues that others reported.

Mine is the Mike. It's a tight fit, the Lima might make for a better fit.

The Lima is a little longer, and slightly thicker which is where mine gets squeezed. Mine fits, but it is snug.
ETA:

Will do in a bit. Best way to do it is just to try to fit it in the bolt and see where it’s rubbing. Little by little, you’ll make it all the way in. Then, when it’s time to turn it, you’ll see where it’s hanging up.

Looks great! You could always consider removing the rear sight and using a m8 industries mount for your RMR. Positions the dot right above the front sight post.

Also franklin armory binary trigger is great. I just ordered a HK ambi navy housing for mine as I was tired of the way my SEF housing looked and felt.
The trigger pull and reset in single on the franklin binary is MUCH better than the stock trigger (at least in my Zenith Z-5P). It's much lighter and has a shorter reset IIRC

Thanks, shoots a lot better than I ever expected.
I looked at that, but I think on the PTRs the welded rail is going to interfere with that mount. It comes forward too far. I may just roll with the irons. They work great and this weekend when I was at the range the rounds were going almost exactly where I wanted them after I took the large spacer out, just needed a slight adjustment to the right.
I've started looking at that. The BFS could be a future purchase.
ETA: just saw that I can run that in my 91 clone as well. Saying no just got a little harder.