Anyone ever removed a barrel from a breech block??

[johnbaz]

Hi all

I have a HW95 that I was going to reduce the barrel length in my lathe (And recrown) but the barrel length in front of the breech block is 12.5" and the hollow headsock shaft is 14" long!

Has anyone ever used heat to expand the breech block to withdraw the barrel?

I know it can be done as I have a HW80 breech block that someone has already parted!! (They made a bit of a mess though!!)

The only other way I can think of to do the job is to make/harden some sort of a concaved cutting tool to fit in the chuck and use blocks on the bad to keep it central then push it with the tailstock with a centre in place!!

I wanted to reduce barrel length as when I fit an adapter and screwcut silencer it resembles a Brown Bess in length!!



John

[landymick]

The block has a pin in if its the older non star barrel.

[shabee]

What lathe do you have?
There are other ways, if you have a myford for example you can remove the chuck and use a collet in the mt2 spindle, should give you a couple of inches to play with.
Or can you cut the barrel off with a grinder leaving a bit to machine and spin the barrel in the chuck at one end and a fixed steady at the other? This will leave the shortened end free to machine,
clock it up with a dti.
eric

[edbear2]

Hi Mate, BTDT will be along shortly hopefully, as he has recently done a barrel swap on one..It's in AGW and possibly on here too if you search (335 barrel into HW block)

ATB, ED

[johnbaz]

The block has a pin in if its the older non star barrel.

Cheers Mick, It's a later one with no open sights and gilt trigger

What lathe do you have?
There are other ways, if you have a myford for example you can remove the chuck and use a collet in the mt2 spindle, should give you a couple of inches to play with.
Or can you cut the barrel off with a grinder leaving a bit to machine and spin the barrel in the chuck at one end and a fixed steady at the other? This will leave the shortened end free to machine,
clock it up with a dti.
eric

Hi Shabee

I have an old Faircut, I also have a Granville senior but I didn't measure that, Being a Vee pulley rather than the flat cone pulley on the Faircut, it could be shorter..

Probably easier to get a slip on silencer rather than the screw on HW jobbie and adapter!!

Thinking about it I may have one somewhere!!


Cheers, John

[johnbaz]

Just looked in my big bag of spares and found a slip on!!


Cheers, John

[Andy001]

I can't get access to the website at the moment as the security settings need changing on this stupid I pad

It's called another airgun blog, found a link that works

http://www.network54.com/Forum/79537...+barrel+change

[johnbaz]

Brilliant Andy

I had some bits and bats given by a mate, They'd been in his shed for years!

Among them was this HW80 breech block, It's had the same treatment to seperate it from the barrel!! (I never noticed!)

It's still knocking about 5the house somewhere!!

Ity looks as though he removed a BSA barrel from the block too then brazed it back on very roughly!!




Cheers, John

[ccdjg]

Removing the breech block seems a bit drastic just to crown a barrel, especially as IMO accurate crowning is nowhere near as critical in an airgun as in a firearm. I have crowned a cut-down barrel as you suggested , by holding the barrel in the cross slide and feeding it into the cutting tool rotated in the headstock chuck. The cutting tool was easily made from a common or garden spade bit, ground down to the desired profile with the cutting edge backed off a bit and then hardened. The resultant crowing was not as precise as doing it the other way round, but perfectly acceptable after finishing off with emery paper.

[johnbaz]

Removing the breech block seems a bit drastic just to crown a barrel, especially as IMO accurate crowning is nowhere near as critical in an airgun as in a firearm. I have crowned a cut-down barrel as you suggested , by holding the barrel in the cross slide and feeding it into the cutting tool rotated in the headstock chuck. The cutting tool was easily made from a common or garden spade bit, ground down to the desired profile with the cutting edge backed off a bit and then hardened. The resultant crowing was not as precise as doing it the other way round, but perfectly acceptable after finishing off with emery paper.

It was to remove around four inches from the end of the barrel as it seemed miles long with the HW screwcut silencer and adapter!

If I can't true it up in the lathe i'd rather not bother at all

I found a slip on type that doesn't make it look like a Punt gun any more!!



John

[shabee]

out of interest,
what length can you get to turn on your lathe? ie and still leave the saddle room to perform the OP.
and do you have a fixed steady to suit your lathe?
in my mind non of the other methods suggested will give an accurate crown , as to whether it matters, that's another discussion.
here is the idea that I am meaning https://www.youtube.com/watch?v=Fs0QuduNqQc
you can remove the tailstock to give extra length if you need to.
eric

[johnbaz]

out of interest,
what length can you get to turn on your lathe? ie and still leave the saddle room to perform the OP.
and do you have a fixed steady to suit your lathe?
in my mind non of the other methods suggested will give an accurate crown , as to whether it matters, that's another discussion.
here is the idea that I am meaning https://www.youtube.com/watch?v=Fs0QuduNqQc
you can remove the tailstock to give extra length if you need to.
eric

Hi Shabee

The Granville senior came with a four jaw chuck and a fixed steady but i've not got that one fixed up yet

The faircut didn't come with those bits unfortunately

I'll have to get the granville setup in placve of the old worn Faircut


John