A question for the airgun engineers on here.

[averageplinker]

Hi all,
I have a Mercury to refurbish an have been thinking of the simplest way to stop the breech jaws from spreading with use. It needs to be simple as I have only the usual diy tools (no lathes or milling machines I am afraid).
My thought is to drill and tap each end of the axis pin to take screws/bolts to hold the jaws in place. I intend to use Loctite on their threads.
Am I missing any engineering pitfalls? Is the axis pin hardened and likely to be difficult to drill for instance?
Thanks for any input you can offer.
Rich.

[Shed tuner]

Use a merc "S" bolt. Jaws just need a little machining on the outside (counterbore) so it sits flush.

[averageplinker]

Use a merc "S" bolt. Jaws just need a little machining on the outside (counterbore) so it sits flush.

Thanks Jon, that is an option. I have also considered using an HW breech bolt. But both require machining that I cannot do so myself would need me to source an engineer/gunsmith to do it for me.
Rich

[T 20]

Hi all,
I have a Mercury to refurbish an have been thinking of the simplest way to stop the breech jaws from spreading with use. It needs to be simple as I have only the usual diy tools (no lathes or milling machines I am afraid).
My thought is to drill and tap each end of the axis pin to take screws/bolts to hold the jaws in place. I intend to use picture on their threads.
Am I missing any engineering pitfalls? Is the axis pin hardened and likely to be difficult to drill for instance?
Thanks for any input you can offer.
Rich.

That method was described in SAR many years ago, but with countersunk screws being used coupled with the ends of the pin being countersunk.

The countersunk screws need to bottom out just as the jaws are nipped up.




All the best Mick

[averageplinker]

Just noticed spell check changed Loctite to picture in my original thread, bloomin' thing! :-)

[deejayuu]

Could a roll pin be used tapped for screws as you first thought?
Dim but willing.

[elanmac]

Rollpins are hardened and the hole down the centre is not usually very round.
Mac