bsa mercury

[royg52]

hi guys need some advice about my newly aquired .22 mercury mk2. in mint condition almost unmarked. took it to the club and fired a few shots through ,seemed powerful enough, mild recoil, but a bit graunchy when cocking. asked one of the lads about stripping the gun and he assured me it was very easy which it was. anyway it is all ready to go back together, after a good clean and polish to the compression chamber and piston. have decided to fit a new spring and breech seal from chambers. the piston seal o ring looks new. i had a job to remove the piston from the tube as it was very tight, and had to drift it out with metal bar and hammer, i was careful not to damage anything, i tried to put the piston back in but was still very tight, is this normal. finally need some advice on lubrication when putting back together, i have a big tub of moly grease, i know i should grease the mainspring and spring guide is any more lube required. final note, is it worth replacing any items, as chambers have alot of custom parts for the internals. many thanks guys. roy.

[baz]

Hi Roy good to see you on here

I usually put a bit of moly around rear of the piston where you will see pressure marks where it cocks

I also put a single drop of silicon oil around piston washer, although from memory I think the Mercury may run on O rings

I remember buying a new Mercury at "Whaleys" gunshop in North London, it was .177 and accounted for a good few Rabbits, and was considered hi-tech back then, I part exed it for a FWB Sport when they became available a few years later

The Mercury had more power than the Airsporter at the time and was about half the price, £35 I think

[ggggr]

Is the piston head plastic? These sometimes spread and need a rub down to fit.

[Silent Sniper]

i have a 177 mercury that i still use for hunting regularly if you give the inside of the cocking slot a polish and grease it up it smooths the cocking a bit i also think they benefit from a ptfe piston head if you dont want to make your own i think tr robb still sells them for about a tenner it does away with the washer and O ring and also takes a lot less running in than O ring plus you can increase the swept volume at the same time good luck

[red bob]

of all the rifles i refurbed ,this one came out the best giving great power at a tad over 11.5 ft lbs strong groupings consistant at 30 mtrs .the polishing of all the internals with a fine polishing wheel but with a minimum of the correct lube on the piston head and a bit more on the spring abbey gun grease lt30,with a full clean and relube of the barrel rifling.