Airsporter trigger block seperation problem

[sidelever]

My gunsmith has serviced my Airsporter Mk4.It was only pushing out 8ft/lb,but he was reluctant to take it apart again as the trigger block had a dodgy thread.I located a replacement trigger block and had it powder coated.
Despite his best efforts,the gunsmith cannot seperate the trigger block from the body tube,and doesn't want to try too hard just incase the tube is damaged.
The rifle has been returned to me.
Has anyone else had a similar problem.
Any advise gratefully received....
atb Sidelever

[Jenny Dipple]

It needs soaking in paraffin or diesel it might take a week, you could try a hot airgun on the cylinder, or get a strong person wearing rubber gloves for grip, then insert a steel bar through the hole in the trigger block; and give it a sharp tap with a hammer in clock wise then anti clock wise directions. do not put the cylinder in a vice. This problem is caused by the chemical reaction between aluminium and steel same as alloy wheels on your car, on reassembley use a smear of grease or copper anti sieze on the thread and it will come apart easy next time! Regards Jenny Dipple

[pennineway.fswo]

Hi sidelever

This is a common problem and many a good Airsporter has been damaged or ruined completely by impatient owners doing daft things like putting round bars, levers etc through the loading tap hole in order to restrain the cylinder while unscrewing the block

If the block is stuborn then you will need a workmate of something similar to hold the horizontal cylinder in when unscrewing the block.
make sure you remove the sights and loading tap and use leather around the cylinder to protect the finish

An electric paint stripper can be used to put heat on the steel cylinder adjacent to the thread but keep the heat off the trigger block.

A round bar through the hole in the trigger block casting may help you get sufficient purchase on the block to loosen the thing. If the cylinder is really tight then a shock may be necessary in way of a sharp tap on the alloy casting, but use a piece of wood against the alloy to prevent damage

I have stripped at least a couple of dozen Airsporters using the above procedure including Mk1&2's that had never been taken apart in 50 years, but you need to take care not to damage the rifle or its finish
Good luck
John

[Kingplinker]

Told you airsporters were a PITA

atvb

Dave

[Phil Russell]

I have had similar problems with a variety of rifles that have a screw out block.
To hold the action I use 3-4mm rubber sheet rather than leather as I find it holds better. Many times I can hold it in a 4" vice but if I need extra grip I use a much longer vice ... but if the action shows any sign of movement in the vice; stop.
It took a week of soaking in releasing fluid / heating and leverage to release one stubborn block on a Haenel. I had it soaking upright in a jar so that the fluid covered the whole block. Then it suddenly shifted.
Good luck .
Cheers, Phil

[Vic Thompson]

The way I use for this task is to clamp the flat part of the trigger block in a heavy vice using padding to prevent marking, then by wrapping non stretch small diameter lifting rope around a sheet of synthetic rubber on top of the body tube. I put say twenty turns of rope wrapped bifilar in two layers, then put a lever through the loop end and struggle, it never fails.

In my opinion the problem with these trigger blocks can be caused by the trigger block steel insert not being centrally aligned which then causes the alloy block to bind on the steel lip of the body tube on reassembly.

Lastly, if you bring it round to my place in Crawley I'll have a go at separating the parts in my workshop for you.

Vic T

[edbear2]

Same as above really, but it is often a help to get a heat gun on the cylinder in the thread area, and use plusgas.....the heat will draw in the lube better as it cools (capillary action).....as others have said, be patient....my record is 8 days with an old Militia soaking in plusgas, removing twice a day and heating the joint area then replacing....it will get in there in the end

[Airsporter1st]

With due respect to all those who have replied, this is not a block/cylinder that have become melded together due to corrosion over time - its just been reassembled by a gunsmith who knows there's something wrong, possibly cross threaded?

Therefore, prolonged soaking in solvents is unlikely to help. If you've tried all the above and still no joy, then a good machinest could machine the block out for you without damaging the tube/threads - especially as the block is knackered anyway!