The $100 challenge.....

Last night I got stuck into the cylinder, drilled the transfer port out to 5.0mm and coned the entry using a couple of drills on the end of a long rod.  Next task was to clean up the inside edges of all of the various openings including the modified port so any new gland I fit won't be gouged during assembly.  For this I used a Noga de-burring tool where I could, some small round files (one curved for 2-stroke engine porting many years ago) and a chopstick with 400 wet & dry wrapped around it.

I Left work early today and spent some more time on THIS project again this afternoon and tonight. I'd earlier grabbed some .008 steel shim material from the engineer's (had previously worked out this was what I needed) and cut a washer for the breech pivot to take out the slop.  I'd also schemed a plan to improve the trigger by reducing its engagement.  I threaded a brass cable ferrule out to 3.0mm to take a cap screw and silver soldered this to the trigger with a shorter and lighter spring found for the trigger return.  Lastly, I cleaned up the piston, gland spring etc with brake clean and reassembled everything with moly grease on the sears and spring, Paslode oil on the gland and piston and my special oil on the breech components.

After a few adjustments to the trigger stop holding the barrel as I tested it I was very happy with its performance.  Did a few more tests holding the barrel and hitting the stock against the bench top and it held so on to the shooting!

Unfortunately, not a lot of good news from here.  The scope mount came loose, I knocked half a tin of JSB Exacts all over the floor and my chrony was giving me silly readings.  After I got my s*%t together, I managed some good groups at 6m, but nothing wonderful at 10m and on checking, neither was really any better than when I initially mounted the red dot to the barrel.  However, the trigger is super sweet to use and for Mercs - the 4.52 JSBs sit in the bore entry perfectly with no pressure required (those that didn't sustain skirt damage when I dropped them on the floor that is!).  The breech pivot without the original slop is also nice and closure a lot move positive now that it's all well lubricated with my 'special' oil!

Anyway, I'm going to call this Stage 1.  I'll do some more shooting with it tomorrow to see if I can produce any groups worth showing and then it's coming to bits again.  I have quite a bit more work planned with some Teflon sheet and rod having arrived today....

Paul I'm doing exactly the same as you, learning as I go - YouTube is such a great resource.

Started on Stage 2 tonight but didn't get very far.  I'd sourced some 0.5mm PTFE sheet from my friends at AliExpress but I failed to take account of the fact that the piston is swaged in at the centre so it's too snug a fit on the spring.  I can get it in without too much effort but it's not free to slide as it should so I packed it in early.  Went inside to the warmth of the fire and placed an order for some 0.3mm sheet and several short rods of various diameters.  I should clarify that whilst I'm buying this stuff for this project, it's also workshop stock for my multitude of other retirement projects (when I finally get to them).

I plan to make a new seal out of the same stuff but I'm thinking I need some other material in the centre of it to absorb the shock as I don't think the Teflon will handle it for long.  The factory seal is pretty bad so I definitely need to replace it with something.