Choking a .22 crosman barrel

[kkcomp]

Hi
Anyone know were i can get a choke put on a crosman .22 barrell it's fine at breech but
very loose at crown (5.52 pellet drops out) & shoots like a shotgun.

keith

[gedfinn 2]

Hi
Anyone know were i can get a choke put on a crosman .22 barrell it's fine at breech but
very loose at crown (5.52 pellet drops out) & shoots like a shotgun.

keith

Hi, I know how to do it !
After teaching Metallurgy for ( Just too long ) I,ll give you a clue ,
If you have a bar of metal ( Tube/Rod ) Etc , & want to put a bend in it or straighten it, Heat it dull red on the side only that you want to bend
It to

What happens is that the metal expands on the side that is heated ,
( Yes I know we all know that ) & in fact bends the wrong way !!!!!

But what really happens is that it bends because the heated area has expanded & the opposite side has " Give way " But it actually has deformed under " Elastic " Tension & on cooling will press back & Overcompensate for its Heated/Softer side !!
Not many people know that , Ha ha, Ged ( Therin lies the clue )

[delta1]

So which part of a circular barrel would the poster heat to make the hole through it shrink?

[oliver13]

Hi Keith,

From memory the barrel is near as dammit identical at both ends, would it not be easier to just reverse it?

Even if it does need a bit of work, I'm sure it would be minor compared to choking it?

Regards

[Jerry Cornelius]

He'd need to drill a new gas port, cut off the barrel behind the old one, and choke the new crown.

Have you considered DIY? I rechoked one with a hacksaw (!), engineer's square, set of files, round headed brass screw, polishing compound and a hand drill.

It worked fine.

[paul4be]

He'd need to drill a new gas port, cut off the barrel behind the old one, and choke the new crown.

Have you considered DIY? I rechoked one with a hacksaw (!), engineer's square, set of files, round headed brass screw, polishing compound and a hand drill.

It worked fine.

No you didn't, you recrowned one, not the same thing at all.

If it is that bad and there is no accuracy, it would be easier to just get another barrel.

[magicniner]

Hi, I know how to do it !
After teaching Metallurgy for ( Just too long ) I,ll give you a clue ,
If you have a bar of metal ( Tube/Rod ) Etc , & want to put a bend in it or straighten it, Heat it dull red on the side only that you want to bend
It to

What happens is that the metal expands on the side that is heated ,
( Yes I know we all know that ) & in fact bends the wrong way !!!!!

But what really happens is that it bends because the heated area has expanded & the opposite side has " Give way " But it actually has deformed under " Elastic " Tension & on cooling will press back & Overcompensate for its Heated/Softer side !!
Not many people know that , Ha ha, Ged ( Therin lies the clue )

Hillarious,
Ha Ha!
How about an answer rather than a clue?

Heating to red hot will cause surface oxidising and possibly damage to the profile of the rifling in the affected area, scrapping the barrel, unless carried out in a controlled atmosphere.

Choked barrels can be simply swaged after the rifling is cut, a process requiring a hydraulic press operating simultaneously from a minimum of 3 directions, preferably more,
Regards,
Nick

P.S You're still using commas where you need apostrophies

[Jerry Cornelius]

No you didn't, you recrowned one, not the same thing at all.


Oops :o

I mean, in search of a tighter bit of barrel, I cut off an inch, recrowned, and hey presto, I was in luck. But yes, you are right

[oliver13]

Hi,

Sorry, obviously a bit more to a Crosman barrel than I remember.

As a matter of interest, have you any idea how this barrel came to be in this condition?

Regards

PS. It's possible you don't need the full barrel length for optimum performance, simply removing the bad bit & recrowning might work, be warned though, this is something else I have remembered - so double check on that for sure...

[kkcomp]

Hi
Thanks for all the help looks like a new barrel then it was a 24" one i had shortened
it's never been good since.

keith

[sbd]

...can re-choke but I suspect it would be neither quick nor cheap :o

[air-tech]

So which part of a circular barrel would the poster heat to make the hole through it shrink?

The hole :D :D

[air-tech]

Aside, I don't remember the details, but "home choking" has been discussed methinks over at the Yellow forum.

[magicniner]

"home choking"

That sounds eminently suitable for cryptic clue merchants! :D

[magicniner]

This might be useful -

http://www.airgunhome.com/agforum/viewtopic.php?t=2114&highlight=choke

and this

http://www.airgunhome.com/agforum/viewtopic.php?p=19515

From an engineering point of view this looks like the way to go if you want to DIY choke a barrel, a Fly-Press might make consistant results easier but the posters in the linked threads used vices & hammers so folks without a serious metalworking workshop definitely stand a chance ;)
ATB,
Nick

[gedfinn 2]

Hillarious,
Ha Ha!
How about an answer rather than a clue?

Heating to red hot will cause surface oxidising and possibly damage to the profile of the rifling in the affected area, scrapping the barrel, unless carried out in a controlled atmosphere.

Choked barrels are simply swaged after the rifling is cut, a process requiring a hydraulic press operating simultaneously from a minimum of 3 directions, preferably more,
Regards,
Nick

I wasn,t going to reply ,Alas the Metallurgist above I thought was going to tell us ? ( Just what are your qualifications on this subject ? )
Mine I,ll just mention one, "King Fahd University of Petroleum & Minerals"Course Co-ordinator & Lecturer Metals 1984-1989, This & 20 years in the middle east, Same job suprisingly, Now show us yours ? You can google it !

The above barrel which started this thread is obviously worn , Probably by shooting Steel BB,s & Needs replacing ,
Barrels are indeed swaged to form a choke, However on his subject of metal oxidising when heated to dull red ( Just how do you think you Harden or case harden ) Tell us !

I know he doesn,t know, Or even how to ?
I,ll start with the barrel choking, As I said before, the above barrel is junk, I was trying to add a little " Material mechanics to the thread "
As you can see, It was a waste of time, I invited a conundrum thinking it might be intresting ( Got that wrong, Forgot about the spoon feeding )

I can see why many members don,t even post threads, !!! Why , They don,t need the hassle,

I,ll conclude on the barrel chocking,
First off, Heat the end of the barrel to a dull red ( 3-5 inches ) This will of course be all the way throughout its thickness, The key here is as I said in my thread, To cool the outside, This can be done in 2 way,s , I usually roll them in crushed ice, This in my opinion is the best way, Although water can be used, I prefer the above ,
The principal is exactly the same as I outlined, The cooled outer wall
Contracts on the " Softer because its hotter " Innner surface reducing the inner diameter of the tube/barrel IE Choked.

As regards his statement on the steel " Oxidizing " when heated to dull red, ( 910 c Upper critical point ) How does he think they Harden/Case harden steel,
I can,t leave any more Conundrums so I,ll tell him ! The steel to be hardened has to have a Carbon content of < 0.75 %
This is heated to just above 910 c Yes, Dull red & Quenched in water , It is now glass hard & would shatter if used, It has to be " Tempered " This means softened,
It is now heated up to a particular temperature ,These have colours for workshop use < IE Blue for a spring < Straw brown for a chisel etc & Quick quenched in water or brine to hold that particular state ! Industry uses carefully controlled temperatures & Time control.

I,m sorry for going on, Its that he keeps having a go, And as you can see, he know,s nothing on this subject <
You be the judge ? Ged.

[T 20]

Of course you could always have a word with someone who makes flexible Hydraulic pipes.

The machine my mate uses to swage the fittings on with looks the same as the machine Mr Taylor uses to impress the outside of his Smooth twist barrels with. ;)

Could this be the same type of machine as Theoben use ?


The only way I can see of using heat to produce a choke without damaging the rifling is to warm an undersize ring up until it expands just enough to fit onto the end of the barrel.
When it cools and contracts it should in theory shrink the barrel OD so a choke is produced ------ bit hit and miss though.





All the best Mick

[magicniner]

Just what are your qualifications on this subject ?.

I'm so, so glad you asked

1. I'm not a knobsock that can't tell the difference between an email and a PM, (or an apostrophy and a comma come to think of it) uses the two terms interchangeably and then accuses someone that can't work this out of being a liar - in public on the open forum.

2. I help where I can without giving cryptic little clues and being wrong when I finally admit what I know - choked barrels can be swaged.

3. If I piss on someone's bonfire and afterwards decide it was a mistake I'm man enough to make an apology, not make some piss-poor suggestion about olive branches.

That covers it :D
And you did ask ;)

[magicniner]

The above barrel which started this thread is obviously worn , Probably by shooting Steel BB,s & Needs replacing.

Brilliant,
You've found a currently available source of .22 Steel BBs that will fit down a rifled .22 Crosman barrel?
Or you're clutching at straws and spouting irrelevant rubbish,
You Decide :D
Ha Ha!

[magicniner]

( Just what are your qualifications on this subject ? )

I don't have a degree in English, neither, it would appear, do you :D

[magicniner]

I,ll conclude on the barrel chocking

Barrel chocking is easy, bung a couple of chocks under it :D
Choking is more complex, and the spelling of it, it seems, is too :cool:

[magicniner]

As regards his statement on the steel " Oxidizing " when heated to dull red, ( 910 c Upper critical point ) How does he think they Harden/Case harden steel

In a carefully controlled furnace with a neutral atmosphere, if you don't want to mess up the surface of the work.
Any metalurgist worth their salt would know that though :rolleyes:

[AD_K]

Hi
Anyone know were i can get a choke put on a crosman .22 barrell it's fine at breech but
very loose at crown (5.52 pellet drops out) & shoots like a shotgun.

keith

If its on a Rat Catcher, just throw the whole thing away and buy a new one.
Stop wasting your time. :cool:

[magicniner]

This is heated to just above 910 c Yes, Dull red & Quenched in water , It is now glass hard & would shatter if used, It has to be " Tempered " This means softened,
It is now heated up to a particular temperature ,These have colours for workshop use < IE Blue for a spring < Straw brown for a chisel etc & Quick quenched in water or brine to hold that particular state !

Conveniently missing out the only relevant info - the correct tempering colour for a barrel?
What trickery is this? :D

[oliver13]

'kinell.

[sol1821]

lol ;)

[AD_K]

Some things never change on this forum. Mainly the 'specialists'.

I know chaff all about metalurgy (sounds like a disease) but i can tell you if the OP tries to choke his barrell (oo er) using any of the previously mentioned techniques, he is going to royally cock it up.

Buy a new freaking barrel.

Give me your postcode and I'll even tell you who to order it from.

[Bulsaye]

with a note explaining the problem; and they'll give you another one. Their customer service is quite good. RB

[delta1]

Hi
Thanks for all the help looks like a new barrel then it was a 24" one i had shortened
it's never been good since.

keith



It appears that a couple of posters may have missed this post out.

As a mere Admin, I cannot help but wonder if, rather than wearing out due to the use of BB's; the part of the barrel removed toshorten it was actually the choke? :D

Rather than assume the length was reduced in the middle, or at the breech, I suspect that the easier route was taken, and the choke accidentlly removed by the 'Smith who shortened the barrel.

A replacement barrel seems the most realistic solution.
Shopping around may well reveal a source of shortened ones that function correctly with this gun,

:)