Last year around December, I wound up picking up a PTR-91 from CDNN.  It came with the cheapest scope and rings made but it did come with the 10 extra magazines in the deal.  Not bad for under $900.00 but I wanted it better so I set out on the modifications.  Some mods were made that IMHO, are a "must have" modification in order to really make it a serviceable weapon.  Some mods were to make it a little easier to use and finally, some mods were "just because" or cosmetic in nature.
First, the "must have" mods.  The stock selector lever and magazine release are a joke.  The selector lever is far too short to manipulate without shifting your grip.  Also, the M-16 style magazine release is about on par with worthless.  Again, WAY too far forward for normal users to depress the button.  Not HK's or any clone manufacturer's fault as the original G3 design had to be changed omitting the paddle magazine release to a shelf design trigger group preventing a full auto trigger pack from being installed.  The solution was to get an extended selector lever form RTG guns to improve the ability to manipulate the selector lever without braking your grip every time.  While it's not as well located as an AR selector lever, it's an improvement I would put on par with the FN-FAL.  As for the magazine release, I sent my barreled receiver off to Bill Springfield in Colorado Springs to have a paddle magazine release installed,  This procedure is a delicate one in that drilling in the wrong spot can wreck a receiver and drilling just a hair too deep can leave you with a rifle that the ATF can construe as an attempt to convert your rifle to a Class III full auto weapon!  I was far more comfortable having this done by a professional and I am very happy with his work.



The extended selector lever.




Paddle magazine release.


Next is the "nice to have modifications I did.  First is the slim handguards don't turn back the heat all that well and leaves you with an exposed (and hot) trunion just waiting to contact skin.  The wide handguards protect your hand from barrel heat a bit better as well as solves the hot trunion issue as well.  Also, if you want a good bipod on an HK (which I passed on, just my tastes) you want to go with the wide handguard as well.  The down side is that the smaller stock cocking handle is now harder to manipulate.  In a weapon that by the nature of it's design doesn't allow for a bolt hold open device, easier manipulation of the cocking handle is a good thing.  My solution was to simply install a larger and better shaped HK21 machine gun cocking handle.  The installation was fairly straight forward and makes cocking a lot easier.



HK21 cocking handle and wide style handguards.


Finally we come to the "just because and cosmetic" modifications I made.  I already mentioned that having a trigger group that pivots on the front pin is a Class III no-no.  However, if you look at the first 2 pictures, it appears that's exactly what I have along with the S-E-F selector positions.  That's totally cosmetic.  I bought a "clipped and pinned" trigger housing from Bill Springfield when I had the paddle magazine release installed.  The paddle magazine release lever is welded in over the top of the drill hole and refinished.  I would have gotten by simply with that setup but wanted to go with a true G3 look and to disguise the face that the pivot pin has no hole on either side.  Finally, what's an old school battle rifle without a bayonet?  A replacement bayonet lug was put in place of the cocking tube cap and it is a serviceable piece.  I wouldn't really call that a cosmetic" modification, but more of a "just because" modification.  Why "just because"?  Because it tends to piss off liberal gun grabbers that I have a "scary bayonet" that can be mounted on my rifle for those drive by bayonetting opportunities life may throw our way.



Bayonet mount




Fix bayonets!!!

Looks great, I like it. A lot.

Very nice.

Nice work OP you did what i really want to do to mine i'm just too lazy/ working on too many other projects. I might drop you a pm with a bunch of questions soon

That looks really nice man. It sorta reminds me of the PTR91 (below) that I sold a few years back.

I usually ran the full stock at the range, but kept the collapsible stock on otherwise. I regret selling it and intend to buy another one, or maybe the new MKE Zenith version. The 91's are serious work-horse MBR's.

If you ask me, you totally missed the real "must have" modifications. Those being a heavy buffer and PWS muzzle brake. That combination does more to make the PTR shootable than anything else.  But to each his own.

Yeah, I did forget to mention the ejection port buffer for a higher percentage of reloadable brass and a heavy buffer to smooth out the sharper recoil impulses as compared to a gas gun. However, I wouldn't classify these parts as a "must have item" but a "nice to have modification" instead.  As far as muzzle brakes, I would not want to swap out a serviceable flash suppressor for a muzzle brake. Muzzle brakes have their place on range toys and gamer guns but their increase in muzzle blast and muzzle flash are too high of a price to pay when It comes to a fighting rifle.

That is a gorgeous rifle and what I plan to do eventually, except with a Navy lower. I still need to buy another PTR.. so many guns on the list, too little dinero