Looks like a B2. While not the best rifle in the world, they can be a fun plinker for knocking over tin cans.
You could dig out that leather breech seal and replace it with a nitrile rubber o-ring as that does look compressed. Loads of sizes available on ebay, so just need to measure the current leather one.
Looks like the barrel needs a good clean. You can make a cheap pullthrough with a length of thin wire. Just make a loop at one end using superglue, then stick a bit of cotton cloth through the loop with some 3-in 1 oil on it and pull it through the barrel a few times. Then replace it with another oil soaked bit of cloth. The pull a couple of dry cloths through.
The stock looks better than the one my mate had. His was painted with a brown paint and had brush marks and a bristle stuck in it lol.
I have re assembled my HW45 now and I'm amazed at the difference. I used the dry moly spray I bought, on the piston and sprayed some into the comp chamber. Added a very thin smear of moly paste on the rear of the piston and the spring guide and spring.
The ptfe piston sleeve I made should help keep any grease inside the piston.
Once I put it all back together it was a little grindy and dry to
**** so I put a smear more around the cocking slots and visible bit of the rear piston, which seems to have done the trick.
The power has dropped a bit as to be expected. 510-530 fps for Geco flat pellets and around 350 or so on the lower power setting. Very little smoke now, not like the thick cloud of smoke that was happening before. I got 3 shots ontop of each other at 7m, which I have never done before. Seems a lot more predictable and tamer now. It will need bedding in a bit as well.
Only thing I miss is the smell
.
