A bit bored yesterday so I decided to pull apart my Specna and see why exactly it's so inaccurate (notably less accurate than my Lancer m4). Yes this is pissing in the wind somewhat trying to mod a crap rifle, but I might as well kill some time until TAC-41s are back in stock, and I might get a half decent shooter out of it, at least something I can lend a friend if they come skirmishing with me.
Think I've figured out what the issues are though. Firstly a crap loose o-ring for a piston seal. Easy fixed.
Then it looks like the 'buffer' at the end of the piston has loads of lost volume, and through the holes in the buffer I can see what look like holes in the piston itself.
Again should be a straightforward fix. Loctite and glue gun should do for that.
The third thing is a bit out of my wheelhouse and what I could do with some help with. Looking down the barrel, the hop rubber looks distorted and asymmetric on full or 3/4 hop, and I suspect it's that that's causing the windage innaccuracy.
Is there an aftermarket replacement for this? If there are a few types available, what are the relative benefits of different brands/hardnesses?
Is this rifle a copy of another gun?
Other than these issues everything else seems to be in reasonable order. Trigger is OK, barrel is clean. Bolt pull is already a little stiff so I'll stock with the stock spring.
I'm not going to throw good money after bad but I think I can stretch to a new hop rubber.
Any advice appreciated.