Fitting the record unit to another make, I have done it to a Mk3 webley, Obtained an HW35 with a ruined cylinder, as i didnt have threading facility on my lathe at the time I bored the hole in the front of the HW rear block bigger cut the threaded portion of the block off & grafted it onto the front of the webley block that had been turned down. It worked. A better way would be to mill the slot in the webley block bigger to accept the trigger unit.
Or you could Use BSA Airsporter bits, The threaded portion on the Airsporter & Mercury is steel & is bolted onto the front of the alloy rear block with a big hollow bolt that facilitates adjustment of where it locks up when you screw the block into the cylinder.
So easiest way to convert a Prewar BSA without skilled lathe threading Is to take an HW 35 rear block cut off the threaded bit that goes into the cylinder & bolt an airsporter cylinder end plug onto it. It should be a relatively easy drilling & threading job. The HW block will need to be turned down on the outside.
BSA Airsporter & Mercury share the same cylinder threads as their prewar ancestors so breech blocks interchange. Think the Webley Mk3 is the same size.
Thanks for all the replies.
keith66, thank you for your reply, that's a big help & gives me a few ideas to contemplate that I hadn't considered, cheers
The Airsporter threads are definitely the same pitch but the plug is about 0.22 mm smaller in diameter than the pre War underlever threads.
The Airsporter back block wouldn't screw into the back block of my Webley MK3 cylinder as the threads didn't match --- the Webley threads being finer are probably some weird German thread form.
All the best Mick
I wonder how easy it would be to fit a CD/Rekord unit into a Mercury/Airsporter trigger block?
Pete
Far too many rifles to list now, all mainly British but the odd pesky foreigner has snuck in
I'm sure I've read of someone already doing that, Pete.
The biggest problem I can see is that the BSA latchrod is 5/16" in diameter and the Weihrauch's is @ 9.75mm.
The other problem (being serious) is does a Mercury or Airsporter warrant all the work to fit a decent trigger ?
All the best Mick
I totally agree with you Mick, I suppose if I had a well sorted highly customised Mercury, it might warrant such a conversion but I don't know what one would be like with nicely honed and fettled sears etc, I cleaned and polished up a Merc S trigger block once and done the same with the alloy trigger blade and it was surprising how nice and smooth just using the trigger was afterwards, I might have to experiment one day (when I get the time) and smooth out all the pivot points and polish up everything and see what that does.
Pete
Far too many rifles to list now, all mainly British but the odd pesky foreigner has snuck in
Hi Pete.
I took a long hard look at fitting a Rekord to a Mercury last night and came to the conclusion it was a none starter.
If you tried to fit the Rekord to the Mercury back block the top sear would have to poke out the top of the block and you'd also lose the ability to use the stock bolt.
If you tried to fit a Weihrauch back block you'd have to start with a 30mm bore one (35/77/80/97) build the block threads up with weld, and then turn it all down to the Mercury cylinder's OD.
Then you'd have to machine it to fit the Mercury cylinder plug, and you'd also lose the ability of using the stock bolt with this setup --- so it looks to be a bit of a none starter.
All the best Mick
I have successfully mounted a rekord trigger system on a diana 27.
Years ago i had a Mercury (new in 74) I stoned the trigger surfaces carefully & it was really good, simple but effective, I couldnt fault it & it was my go to hunting rifle for a few years.