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Discussion Starter #1
I searched previous posts but most seem a little old. So forgive me if I didn't find what I was looking for.

I just purchased a PTR 9CT. I had previously watched a video of a guy having a bunch of failure to feed and failure to eject issues. Gun ended up getting damaged and the owner was told by PTR that is was because he ran is suppressed without the 80 degree locking piece. Nowhere in the manual or anywhere in presale does it stipulate this.

I reached out to PTR to verify and received this..."It is recommended that if you plan on running your 9CT suppressed, that you utilize an 80 degree locking piece. We currently do not have one on the market, and as of late, the aftermarket variants are having problems fitting our bolt head. We recommend that you seek the help of a professional gunsmith, to properly fit an 80 degree locking piece, if you choose to run the weapon suppressed".

Here is a note from RCM..."We are getting lots of emails from customers regarding the issue with our locking piece not fitting in a PTR Bolt Head. Its because the PTR Bolt Head is up to .007 undersized in the Locking Piece Pocket . RCM has no control of the quality standards of PTR. We suggest you grind or mill it to the dimensions of your bolt head".

So basically my understanding is that even a HK 80 degree locking piece wouldn't fit. I would imagine that a high percentage of people want to fire the PTR 9CT suppressed and I'm super disappointed that PTR doesn't offer any solution to this problem.

Does anyone have any other input they can offer? Has anyone purchase the RCM and had it milled down? What is the rough cost for a gunsmith to do this?

Thanks

Scott
 

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Just buy a RCM bolt or HK/Contract and sell the PTR one. Dont modify in spec parts to fit an out of spec one. You will be happier in the long run and by the time you had someone modify that locking peice you would be mostly there to buying an in spec part.
 

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Discussion Starter #3
Thanks for the info. I'm new to the platform. Is it only the bolt I'd need or the whole assembly?
 

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Discussion Starter #5
If that was truly the case for the PTR 9CT then why is PTR telling guys to run 80s? Apparently it becomes a warranty issue with them if you don't.
 

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If that was truly the case for the PTR 9CT then why is PTR telling guys to run 80s? Apparently it becomes a warranty issue with them if you don't.
He’s referring to German guns and other MP5’s that are in spec and built right. Not PTR’s, which are the bottom of the barrel in quality and consistency. PTR is the only manufacturer recommending 80 degree locking pieces on full size guns.

I’d also recommend just buying a bolt head instead of grinding a locking piece.
 

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Failure to feed and eject issues are typically related to other issues.

The locking peice sets the delay on when the rollers release. When you add a suppressor there is more backpressure/longer time before pressure drops so the locking peice adds longer delay so when the bolt is released it doesnt impact your buffer with too much energy. That impact will cause the bolt which still has rearward momentum to try to lock forcing the rollers out into the rails. This will start to show as dents appear to the rear of your rails. A gun running full auto will show the effects much quicker because of how quickly you are piling the abuse on the firearm. A semi will start showing it but it will take longer before the damage becomes evident depending on number of rounds and the ammo. Worse case scenario this abuse will damage the buffer assembly and could crack reciever at rear/start ovaling the stock pin hole on the reciever.

PTR is correct in not covering using the incorrect locking peice because you are abuaing the firearm if you do.
 

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If you are having an issue with the RCM 80* LP in a PTR bolt head, call the PTR CS and get an RMA / Pre-paid UPS shipping tag.

Box up the BCG and the RCM / HK 80* LP and ship it to PTR at no charge.

They will hone the carrier and (probably) give you a brand new in-spec bolt.

PTR will then ship the parts back to you.

Problem solved.

Since this has been an issue for at least 1 year, I'm surprised that any recently built PTR CT / KT have bolt heads / carriers that aren't "in-spec". Maybe they just kept using the smaller LP pocket ("out of spec") bolt heads and are playing the odds that its cheaper to use stock and do warranty work for a limited number of customers that use suppressors.

The PTR hate is strong among some in the community. I find their products excellent and their CS easy to work with and efficient. Only had to use it once. I own 3x PTR guns and they just run.

As far as I know, the "K" model is the only gun needing an 80* LP. I shoot my "CT" suppressed using the factory 100* LP without issue, as HK recommends.

YMMV.
 

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I have both PTR models and have not changed the locking pieces. Both have almost 2000 rounds each and I can't find any wear. Octavian is right on the money. I think PTR guns are outstanding. The downside of a 9KT is if you can afford the ammo now then you will exceed the cost of the gun very quickly....I left the locking pieces alone. I think the 100 works perfect in both models. I forgot to mention I run both almost exclusively suppressed. As a side note I have a PTR 32 and it is a sweet gun!
 

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Nice, tell someone their gun is garbage. You sir are an complete and utter assh0le, plain and simple. The OP is new to this forum and to this platform and thats how you welcome someone asking a question? ****
I said out of spec and bottom of the barrel quality wise. You and PTR both admit their guns are out of spec and I would say that amounts to low quality.
You introduced the word “garbage” into the conversation. As well as the personal attacks.
The fact remains that PTR isn’t compatible with in spec parts and is the only manufacturer that requires a change in the locking piece for full size guns. That’s an indication of a problem.
 

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He’s referring to German guns and other MP5’s that are in spec and built right. Not PTR’s, which are the bottom of the barrel in quality and consistency. PTR is the only manufacturer recommending 80 degree locking pieces on full size guns.

I’d also recommend just buying a bolt head instead of grinding a locking piece.
Haha, you are right, I sold my ptr 9kt recently and almost forgot how much I hated that thing, I got a zenith now and it's back to zenith for loose magwell and case deflector as well as the misaligned rear sight, I guess next time I'll have to go full HK or higher end builds. Clones just aren't the same.
 

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Octavian, you might be overreacting. But point of argument. 2 parts out of spec, locking peice and bolt head. If PTR didnt take such good care of their customers there would be a lot more people talking smack about them and it would cut into their business. But point of order. Their bolt heads have been out of spec for waaaaaaay too long. It is their achilles heel and it constantly rears up to bite them. It is a shame that they continue to let this go on. It is intentional at this point and inexcusable. They have made a choice to continue producing them this way and they even have had the brass ones to blame RCM and say its RCMs fault that the RCM locking peices do not fit in a PTR bolt. They are not making a lookalike in another caliber, they are making a copy that is excellent EXCEPT for bolt heads and locking peices. 2 of the most critical peices for correct function. I have helped A LOT of people get their PTRs running right and many were nearly new. 2 recently because PTR didnt bother disassembling their bolts before sandblasting and reparkerizing so both the recesses for their extractor were still filled with blast media, parkerizing remnants, and greasy sludge that wrecked their extractor springs. I do not want to turn this into a PTR Bash because I am happy they are making the 90 series roller locks, the more roller lock goodness the better, but it is a shame that so many people have to spend money to replace out of spec, dimensionally incorrect bolts and bolts too soft to hold up to get their nearly new gun to run the way it should have when it left PTR hands. This goes beyond the PTR9C. It stretches back through the 91 history. They are not Century but it is an continual embarrassment that it continues as a problem.

As for the 100 degree locking peice, the OP will still have to replace an expensive bolt to use the 100 degree because the PTR bolt is still out of spec. Especially since the expectation is that you can run these with silencers after making sure you have an appropriate locking peice installed and your bolt gap is good. Having to buy $143-197 bolt head to do what it should have from the factory is unacceptable.
 

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Does anyone have any other input they can offer? Has anyone purchase the RCM and had it milled down? What is the rough cost for a gunsmith to do this?

Thanks

Scott
i have a recent production PTR 9CT S/N: 9MC0068**.

It clearly has the in-house PTR bolt head.

It (oviously) came with a PTR 100* locing piece. I also have an HK 110*, and an RCM 80*.

All of them fit just fine, and bolt gap is within spec on each.

Now the magwell/mag catch, and crappy ETS mags? Well, that’s another issue entirely.
 

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I bought an RCM 80 degree locking piece for my PTR 9CT that I want to run suppressed, but haven't been able to yet. I bought the gun second hand, and it runs perfectly with the PTR bolt head and locking piece and no suppressor...it actually has a fake suppressor pinned/welded to it to make it legal to own in CT, but there's no added back pressure from that. I'll be having a gun smith replace that fake suppressor with a real one once the tax stamp is approved.

The RCM didn't fit the bolt head, and when I measured the thickness vs the PTR, it was a good deal thicker. I had a local gun smith grind the RCM until it matched the PTR for thickness.

Next thing I did was assemble it and measure the bolt gap...way too big. So I got the various - size rollers to see if I could get it in spec, and even with the -8 size the gap is still way over spec, not going to run the gun like that.. Gap is right in spec with the factory locking piece and factory rollers, so I can only assume there are other dimensions in the bolt head relative to the locking piece that aren't playing nicely together.

So anyways, I'd like to just start over. I want to leave the PTR bolt head alone with the original locking piece and rollers in a bag in the case the gun came in. I'll get a new bolt head to use with a new 80 degree locking piece. I don't really care about the money I spent on the one that the gun smith ground for me, I just want the gun to run right and not risk damage. Because of my stupid CT laws, once the suppressor is on, it'll always be on, so it'll always run suppressed. What would be the best stuff for me to buy, a new RCM 80 degree, and HK or RCM complete bolt head? Should I do a different locking piece and different recoil spring?

I'd love to have an actual HK or higher end clone, but it's very difficult making them CT legal (not impossible, but you need an FFL manufacturer to do it, and I'm not completely clear on how that works other than knowing I can't do it myself), and the PTR 9CT was already available in the right config.

For what it's worth, other than this, the quality seems great. The welds on the receiver are downright beautiful, the finish is great, I was able to install a Midwest Industries hand guard and it fit perfect, the sights are aligned really well (rear is almost exactly on center with the gun sighted in at 50 yards), other than ETS magazines, all others fit and run great...I just don't want to damage it running it suppressed once it's configured that way.
 

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Just buy a RCM bolt or HK/Contract and sell the PTR one. Dont modify in spec parts to fit an out of spec one. You will be happier in the long run and by the time you had someone modify that locking peice you would be mostly there to buying an in spec part.
I'm in a similar scenario as Scott, contemplating buying a PTR 9CT, will primarily run a DA Wolfman suppressor on it. Would the RCM bolt and 80 degree locking piece function properly if the weapon ran unsuppressed, on occasion? Sounds like other manufacturers don't recommend replacing a 100 degree locking piece for a full size MP5s. Is there a piece within the PTR that should be replaced to continue using a 100 degree piece, suppressed and unsuppressed, without damaging the weapon? Thanks in advance, new to roller delayed platforms.
 
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