Anyone re barrelled an Airsporter?

[DEAN C.]

I have a .177 mk 5 Airsporter (in amongst a collection of Airsporters and Mercury's) which has some pretty bad corrosion in the rifling, and was thinking about putting it in the lathe and cutting off and boring out the old barrel, and having a go at fitting another. My problem will be the fitting of the barrel up to the loading tap area and ensuring good alignment and seal and fit for the tap. Anyone got any thoughts or experience doing this?

My initial idea is to use an end mill to bore the old barrel out in the action, just short of the loading tap, and then align the new barrel bore to the action hole in front of the tap, before brazing.Hope this makes sense.

It is a spare action and not a complete gun so I dont have much to lose, and I am an engineer by trade so I dont find anything like this daunting, just interested to see if anyone has done anything similar or got any ideas. I know a few on here build the older BSA under-levers from parts, and heavily modify, so thought I would enquire.

[T 20]

Hi Dean

If you used a 10mm or 11mm OD barrel liner then this method would appear to be the most straight forward way of doing the job :-

https://m.youtube.com/watch?v=XZ7sQya7tyk

You could just profile the end of the barrel liner to fit the tap before glueing it in.




All the best Mick

[edbear2]

Hi Dean

If you used a 10mm or 11mm OD barrel liner then this method would appear to be the most straight forward way of doing the job :-

https://m.youtube.com/watch?v=XZ7sQya7tyk

You could just profile the end of the barrel liner to fit the tap before glueing it in.

All the best Mick

Parkers (Parker Hale) used to offer this service for the service rifle and small bores (parker rifling);

http://www.rifleman.org.uk/A.G._and_...rker-Hale.html

I have seen a 45" BSA Standard with a .25 barrel insert (in brass!) which I believe was done by the same guy who used to do HW80's in the past, but the problem is that quality gun drills (long series drills) are quite pricy (£25 or so for a 200mm dormer), but it would be an interesting project if you could source the sleeves (ideal project to make a .20 or .25 if you want to play with the tap as well!).

I would probably go about it the same way as the O.P. and prior to brazing mill the breech end of the barrel the same dia as the breech plug, and use an insert to locate the barrel onto prior to brazing. I personally think silver solder (silver brazing) would wick / flow better in this joint design so would probably use that (I would imagine it was a cost issue originally so they used bronze), unless you have access to a gas flux setup, in which case sifbronze is pretty good, but still not (IMHO) as sure as a prefluxed joint and Silver. I am not sure how far away the cylinder / beech joint is on these later guns, So obviously you will have to take precautions regarding that (coldfront or stand in water).

ATB, Ed

[junglie]

before you go to such drastic lenths have you tried polishing the bore with solvol autosol?

[thisisdonald]

is the barrel not silver soldered in place - I have a mk2 and there is a lump! yes a lump of silver solder right on the joint - at the top! - where the barrel meets the loading tap block. - oops, just reread this and seen the OP has a mk5.. have things changed since mk2?

[DEAN C.]

is the barrel not silver soldered in place - I have a mk2 and there is a lump! yes a lump of silver solder right on the joint - at the top! - where the barrel meets the loading tap block. - oops, just reread this and seen the OP has a mk5.. have things changed since mk2?

Hi, I have a couple of Mk2's and I think that the joint is done in a similar way, except the Mk2 has the barrel housing sliced away at the top. The problem I thought would be if you took the whole barrel out through to the loading tap, then you would have to try and ream the loading tap port without making it an oversize and losing the seal.
I think that the joint on a Mk5 is the same as a MK3/4/6/7, and simlar to the MK2. Mk1 and S models are totally different of course.
If I milled it out leaving a small depth of say 1mm, or tapered the last part of the hole into the loading port, then you would be able to leave the loading port original in size and finish.
Silver soldering would be the way to go as it is slightly lower temperature than brazing.

Thanks for the suggestions and thoughts everyone, keep them coming. T20's idea is very interesting, and Eds ideas are similar thinking to mine.

[DEAN C.]

before you go to such drastic lenths have you tried polishing the bore with solvol autosol?

When I say it has corrosion, I mean deep pitted areas that have no surface for about a third of the barrel. I put an abrasive felt down on a rod and it just looked worse, as it took all of the crud out of the pitting. It would shoot ok, but you would never get any accuracy. It is not just a few surface blemishes.
Thanks for the suggestion though.

[RichardH]

I have seen a 45" BSA Standard with a .25 barrel insert (in brass!) which I believe was done by the same guy who used to do HW80's in the past, but the problem is that quality gun drills (long series drills) are quite pricy (£25 or so for a 200mm dormer), but it would be an interesting project if you could source the sleeves (ideal project to make a .20 or .25 if you want to play with the tap as well!).

Steve Harper was the guy fitting the .25 liners, in between making air canes and replica pepperbox pistols for Brocock cartridges.

He also designed the valveing for Daystate.

Last time I spoke with him he had given up on making guns and was making expensive flutes for musicians

Truly a very talented man.

Eddie how feasible is setting up for relining, I am thinking more of rook rifles rather than airguns?

[edbear2]

Steve Harper was the guy fitting the .25 liners, in between making air canes and replica pepperbox pistols for Brocock cartridges.

He also designed the valveing for Daystate.

Last time I spoke with him he had given up on making guns and was making expensive flutes for musicians

Truly a very talented man.

Eddie how feasible is setting up for relining, I am thinking more of rook rifles rather than airguns?

Hi, Rich, I suppose the main expense would be a decent long bed lathe, or if you could find one, a boring rig.

Prices here seem fairly reasonable, but It might be worth investigating if you can get it done in the U.K., and at what cost, as if setting up to make money, the initial outlay will take some serious time to recoup if you can get it done already by an existing firm who are up and running. Maybe someone at Border or a similar firm could help more as something I am not really up on apart from tooling etc.

ATB, Ed