Upgrading an RPK

[Spike]

So I acquired an SRC RPK in a trade... i know that the internals are shitty, so I want to essentially rip everything out and use the obscenely long barrel to my advantage and make plastic laser beam spitter out of it.

I've been researching and seeing mixed reviews about when you need a bore up kit. The full inner barrel length is 640/650mm which some people say you need a bore up kit with, and others say it won't matter because it's too damn big anyway.

Would it be better to run a shorter inner barrel in it, like a 509 or something similar? I've never dealt with a set up this long before.

Also, for a snappy trigger response, high speed gears+high torque motor, yes?

Here's what I was thinking:

ARS Piston+cylinder head
Modify cylinder
Modify nozzle
SHS 15 teeth piston
Prommy 509mm (or 550?) 6.03 inner barrel
SHS neo magnet high torque motor

it already has a nice hop up unit in it...forget the brand

[Styrak]

A boreup kit is generally considered required when using a 650mm barrel yes. 550m it's not required (I had one in an AUG HBAR I used to run).

[lurkingknight]

I'd pick a lonex a1 or a2 over the shs motor... I heard the shs motors are nice, but are power hungry and inconsistent from one to the next.

A set of gears in the 13:1 or 16:1 would give you about 30-35 rounds per second with a 11.1v 25c lipo. Of course, you need to really set up the AOE and shimming properly for everything to survive.

[Spike]

I was actually going to use a set of modify high speeds... I had them in one of my CAs before and it shot like a dream. I don't want a ridiculous RoF, I just wanted to use the HS gears for trigger response.

I'll look into the lonex motors... haven't heard much about them.