Are they reliable?

Most are, some aren’t.

I have a 13thousand serial number DSA rpd and it runs like a top.

The earlier rpds had light primer strike issues. DSA takes care of their customers though, even if your not the original purchaser.

I am tempted to find a carbine version. The Rpd seems like it would be a lot of fun off of a tripod. I would like a more modern version though, not the classic.

I got the money for the carbine. I just don't want to drop the cash and be disappointed.

I picked up a used but unfired full-size one last year. So far I have 599 rounds through it; in that time it's had two or three light primer strikes, and last weekend I effed something up during the loading sequence so bad that I had to smack the top cover with a delrin hammer to get it to open back up. That said, for what it is to me (nothing more than a range toy), it's sufficiently reliable to have plenty of fun with. I wouldn't go to war with it but it's a hoot to shoot and always gets people's attention.

Are there any improvements to be made with the triggers on an rpd? Any way to insure less or no light primer strikes?

Lastly, any way to link more than two belts together? Say, maybe 4.

triggers aren't that great, its a striker fire conversion and has a pretty long pull. You can slightly re-shape the top of the trigger and thin down the dis-connector a bit then use a stone to polish the sear faces to smooth things up. A few guys have done modified hk trigger packs and made them a hammer fire setup that I'm sure has a great trigger feel but are one-off jobs and not production workable.

light primer strikes can be taken care of pretty completely. Remove the firing pin and use a counter sink to chamfer the back of the bolt where the firing pin goes into it for one. slightly re-shaping the firing pin at the front so it protrudes a bit more from the bolt (but not so much or so pointy that it pierces primers). be sure the striker isn't catching in the receiver anywhere that could be slowing it down. The striker will sometimes catch on the transfer bar or the sear which can cause it to occasionally not have enough energy to ignite the primer.  Be sure the transfer pin in the bolt carrier moves freely. There were a run of longer firing pins that helped with the issue as well. If all of the above is done there will be no light strike issues.

you can carefully bend the spiral pins between two links and physically splice the belts together but really there is no good way or reason to do it. when you get past a full belt (front and rear sections) it gets too big to store under the gun, plus its not rated for continuous fire for hundreds and hundreds of rounds. I saw a post sample with 7 belts spliced together that basically melted the gun down before it finished the belt. It broke permanently.  They need time to cool.

Most conversions have a variation of the striker design.
The problem with the striker design is it uses opposing spring forces, one that powers the striker and that opposes the main action spring.
If the striker spring is weak you get misfires if it's too strong you get short stroking or maybe burst fire.
When springs age or take a set the rates change again

Vector made custom longer stocks and I think added length that gives more room on spring rates but using the same trigger geometry it's still a long pull mushy trigger.

It's the reason above why I rolled my own.



https://www.ar15.com/forums/AK-47/RPD-semi-conversion-with-a-REAL-adjustable-trigger-system-/97-164563/