[BricksInAWall]

Hi Guys, I find myself in the position where I haven't upgraded a VSR-10 in about 8 years and don't really know what the go-to options are these days for the Cylinder, Piston, Spring Guide, Spring, Sears and Trigger? I assume an r-hopped EdGI steel is still the way to go for the barrel still? I tried searching through the forum and couldn't find a reliable guide made since 2014.
FWIW I'm working with a VFC M40A3 and everything I've read said the listed parts were compatible, but couldn't find any info saying a definitive yes/no for the hop up chamber, but from a brief glance at mine it doesn't seem to be.
Appreciate the info guys.

 

[Akami]

I am a bit co fused whether you're asking upgrade guide for VSR or VFC M40A3. If it's VSR, then,

So far from what I have read, AA chamber is very decent and you should go for that. As for trigger, I heard laylax trigger would last forever, but there's more option with pretty much the same durability (if not more) like Springer Custom Work and Bulltrigg, but for Bulltrigg you might need to shave some of your piston end since Bulltrigg has the sear moved backward pretty significant.

For the barrel, if you want and able to make yourself, @SiliconeSword guide to barrel lapping would helps you a lot. He also made a guide to DIY round nub/tensioner

 

[BricksInAWall]

Specifically, I'm talking about the VFC M40A3, but as I said in the original post, it's largely VSR-10 Compatible, so I guess a moderator decided it belonged in the VSR section. Are the PDI, Laylax, and AA options still the better choices for the Cylinder, Cylinder Head, Piston, and spring guide?

 

[Akami]

For the whole cylinder assembly, unless if I could make it myself, I would prefer to get a set of them since each company doesn't always make it the same as the original so there's bound to be some difference in the measurement when comparing them, leading to possible fitment problems if you mix match parts without knowing the dimension.

For spring guide I wouldn't go for laylax since their spring is 8mm and not 9mm, so I suppose their spring guide is also built to take 8mm springs.

In general, other than the piston's body, you would want them to be built from steel/stainless steel. I guess a PDI cylinder set could works, but I heard that it has bigger diameter so if you're going for it, make sure your receiver could take something like ~2mm bigger cylinder.