PDI makes one that is a slightly shorter than the stock barrel and has flutes. Although I am keeping the stock look of the PSG1. I like the stock look, reminds me of my friends mint RS HK PSG-1, which I am just in love with.
Very tricky to work on, just because if the gears are one notch off from there original position, the gearbox does not cycle correctly. Although after you are used to it, it is very reliable and easy to service.
The actual little plastic bolt is not what I was referring to not cycling correctly. Because the gearbox is a precock system and uses more of a mechanical auto shut off for the power to the motor, if the gears are one notch out of place the the piston will lock up when you precock the gearbox for the first shot. The lock up is similar to a regular gearbox with a half trigger pull on semi, although it happens before you even get your first shot off in the PSG1.
Once you got everything working though, it's a sweet system. I have only worked on a V.2 and V.3, the V.4 is by far my favorite now.
The SVD is my crawl in the mud gun. I use it in the water logged or messy fields that I know I will be crawling around in for hours. Dings or scratches on it only make it more Russian. xD I have to say, I wish I never sold my AtoZ. The A&K can certainly be nice after a little work inside, but the external quality just isn't near what my AtoZ was.
The PSG1 and WA2000 I use in urban environments. The PSG1 just has is far to much of a hassle to strip down and clean out if in the mud, and I would probably break down and cry if I found a ding or scratch on the metal or wood of the WA2000.
The M82....well... That thing is far to much of a hassle to mess around with in really any type of environment, and it just doesn't have the accuracy to make the hassle worth it.
The PSG1 is one of the two I had. I sold the first one because the trademarks were ground off and upgraded this one myself. Inside it is a 11.1 Lipo, Systema Mosfet, 300% Systema Full Tune Up Kit, PDI Chamber Block, Mabull bucking, concave spacer I just made myself, and a polished stock barrel. Probably so far the only AEG I have ever liked.
My favorite of the four has to be the WA2000 of course. The accuracy it puts out just completely overlooks it's weight, lack of sling possibility, and impossible to source mags. Once I finish up gunsmithing school, I may take on the challenge of making fiberglass furniture to replace the Walnut on it. That way I have no worries of dings in the wood and I can make it my full time skirmish piece.
What kind of internal work can be done on the dragunov because as far as I know there are not any replacement parts for it, sears especially. Actually if I really wanted to pony up the cash I could have my local machine shop cut me some invincible sears out of titanium.(sigh) A man can certainly dream can't he :.
Other than a polishing some stuff here and there, fun with some thread lock, better hop up bucking, and sealing a few spots, nothing else really needs to be done. I personally have not had any problems with my stock sear though.