I decided to get started on the Specna this evening while waiting for the motor I ordered for the M14. The Specna has been my primary for about a year now, ever since I installed a Gate Aster and Nova trigger. I know it's been a while since I last busted it open. The Aster said 10k rounds, so I need to do some general maintenance.
The gun is completely stock except for the Aster, Quantum, SHS piston, G&G piston head and Maxx Sport hopup unit. It currently gets ~30 RPS, 320 FPS and pretty good trigger response. The plan is to install a Tienly 40k, correct AOE, relube and reshim and maybe replace the gears with an SHS set. The main goal is longevity and quieting everything down. Here it is opened up:
Rather then correct AOE the way I normally do using sorbothane, I decided to try using silicone sealant and cutting it to size. I didn't have any aquarium sealant or similar, but I did have a cualk tube of 100% silicone. It came out white but silicone is silicone.
This is the first time I've ever done this and the first time I've seen it done (maybe for good reason, we shall see), so I figured I'd document it here.
I cleaned and "roughed" up the cylinder head (using a 60 grit Dremmel wheel) and stuck it in an old cylinder. Then I added about 1/4 inch of silicone and packed it down with my finger. That stuff is messy! And does not wash off with water. Now to let it dry and then (hopefully) pop it out of the cylinder and shave off enough for good AOE.
The tube doesn't tell me how long it takes to cure, but I'm going to wait until I get a new spring to land me as close to 400 FPS as possible. Any ideas? I'm thinking a PDI 170%.
While I'm here, here are a couple details about Specna Arms' Orion gearbox. Quality wise I believe it lands pretty close to the Cyma Platinum line, with features such as a full steel rack piston, quick change spring system (very well implemented too), pre-radiused and overall very clean. The sector gear has a delayer on it, and the Gate X-ASR (basically a 3034 mosfet) comes in the stock Edge gearbox. The Gate Aster comes in the Edge 2.0.
All these coupled with the excellent quality externals of the Edge series makes Specna Arms a good choice for beginner to mid level players. I'm really excited for their Edge AK line, but it is only available in Europe.
Anyway the gearbox is sitting on my desk with the new SHS gears (turns out the ones I had were actually 16:1s) shimmed and ready for the new spring and improved cylinder head.