Crosman Air Pistol Owners Forum

Have you ever wanted to change the barrel on your shooter but dreaded the process? Quiet a bit of disassembling is involved, and the transfer port can be a "pill" to get right too.


I have an idea that may sound crazy but am willing to open up in hopes I won't be banished or pistol whipped for being "way out there" !!!


Requirements are: Would need a long breech other than plastic
Some machining skills and equipment to do precise machining.

Process: Measure from the pellet entry end of the barrel around 1 inch and cut off.
Chuck the short piece in a lathe and use an indicator to true with zero run out.
Face the end smooth and  remove all burrs.

Repeat for the other section of barrel.

Drill and tap the top of your breech in a location which will secure your 1 inch barrel section.  The piece that has the transfer port. You will never have to remove this again unless some other mod requires it. A barrel change will not require removing it.

If you order a new barrel from Charles, AC, or other vendors, request that it not be prepped other than a crown. Or, if it comes from Crosman cut the first inch off and square the remaining long piece.

Insert it into the breech and hold tight against the permanent section you have previously installed. Tighten your new set screws and go shoot your new barrel.



I have not factored in lining up the rifling, don't know if that is necessary. Looking for thoughts in this area.




Why would you think of something like this you ask????

As my present build nears completion I wonder if the 1600psi regulator will produce the results I seek. The recent post showing the Ninja Regs with 1800psi peaked my interest.
Without a riser breech, my build would need to be torn down to change out. The bottle will clear but the fill port and gauge won't.

With the set up I described the barrel could be removed with just a few turns of some setscrews and replaced, all within a few minutes and with no possible leaks.

Ok guys, start throwing stuff at me, I'm going to fire up a good cigar and get ready for your input.

i've seen this before  :P ;) .DAQ made a threaded breech and barrel assembly sometime ago iirc.barrels have been made smooth bore and than rifled in one assembly so that's a thought .two things right off are you would need to seal the barrel in the breech/receiver and the use of optics .beeman makes a springer that you can switch barrels(.177 /.22 ) .guess it could be done with some work .

Your not crazy your just nuts  ;D  ;D    Just kidding it sonds like a good idea and can me done easy.Now if you wanna get crazy you can thread the barrel into the breech.Just make your breech section of barrel longer about a inch from the end of the breech, this would lock up real good.
                           Mike

"Have you ever wanted to change the barrel on your shooter but dreaded the process? Quiet a bit of disassembling is involved, and the transfer port can be a "pill" to get right too."


Simple answer :  ME + Tools = TROUBLE!!

Longer answer :
When I had to take the 1740 apart, given that I'd put the 1377 carbine breeches on, I knew what I was in for, I was trying to be so careful not to lose anything.  Like the dummy I can be, I walked from one room to another with the lower in hand, you know with that cute like metal port in place.  It promptly got tipped and hit the floor rolling.  :-[

So, yea, I understand.   :-*

Sounds like a great idea.
I was thinking the same thing the other day. Having an inch or so of barrel with it in place in the breech with the port inserted and having the main barrel slot in. Butting up against the other piece and then a couple of grub screws to secure it through the top of the breech. Maybe little tiny craters in the barrel outer for lining up the grubs when slotting together and to add grip to the grubs contact point.

Or as before with the port bit and a slightly larger barrel. The larger barrel has a thread on it that screws up tight to the inner inch or so ported barrel piece.  A thread would need to be on the breech too.

Its of interest as I'm making a kind of take down rifle and this would be a great additional feature. But I don't have the tools to do it!

I'm rambling, its late, sorry!  ;)
Just thought it was cool that you had a similar idea!

Cheers  :-*

Another thought: This mod would maybe generate some business for Charles, Don, and A.C as they could stock up on the parts and offer them to those without the tools or skills to do it on their own.

Quote from: Crosshairs on February 26, 2011, 10:44:50 PM
Your not crazy your just nuts  ;D  ;D    Just kidding it sounds like a good idea and can me done easy.Now if you wanna get crazy you can thread the barrel into the breech.Just make your breech section of barrel longer about a inch from the end of the breech, this would lock up real good.
                           Mike

With the breech being .437' and the barrel being the same, I don't see threading working without changing one or the other to a different size.

would be a nice thing to have but i think the seal and the rifleing would be a big milestone to overcome. i got a 14" barrel this week with the intention to fit the polly mod so this struck my mind too as i realy dont want to strip it as its running fine.

An other way but a bit more expensive would be to have the barrel fitted in the breech just after the transfer port then extend the probe to compensate. so i guess you would need to machien the breech block again but with a smaller diameter at the loading area to take the lenght of the probe but allow the barrel to seat up against it.
the barrel would need to have a very good crown and butted up to a flat o-ring for air tightness. this way any barrel could be fitted without the need to take it appart. be cool for a takedown set up too.
Could be talking rubbish mind :)

Quote from: tatsumi on February 27, 2011, 01:33:55 AM
would be a nice thing to have but i think the seal and the rifleing would be a big milestone to overcome. i got a 14" barrel this week with the intention to fit the polly mod so this struck my mind too as i realy dont want to strip it as its running fine.

An other way but a bit more expensive would be to have the barrel fitted in the breech just after the transfer port then extend the probe to compensate. so i guess you would need to machien the breech block again but with a smaller diameter at the loading area to take the lenght of the probe but allow the barrel to seat up against it.
the barrel would need to have a very good crown and butted up to a flat o-ring for air tightness. this way any barrel could be fitted without the need to take it appart. be cool for a takedown set up too.
Could be talking rubbish mind :)

I'm thinking there is  a limited amount the probe can be extended, loading and cocking operation you know.

This is an interesting idea, actually the rifling doesn't start until just after the x-fer port. If you cut (and face) the barrel off just after that point, that piece could be soldered into the breech (once properly aligned) ... and a full diameter x-fer port nipple  as well, this would stop one potential point for leakage. Then perhaps an o-ring (and matching o-ring shoulder) could be machined on the barrel. You would install your new barrel , apply pressure to the barrel (against breech piece) and tighten the set screws. Hmmmm

I may have to mess with this idea sometime.

(http://i34.photobucket.com/albums/d136/darth2/Split_Barrel2.jpg)

if you set the barrel in place with set screws, would that not push the barrel down further than the rear section and would that not damage a pellet?

Sure it would, As I said in the post, "that piece could be soldered into the breech (once properly aligned)" As long a it was close (whatever that means) it should work. When we load a pellet, we push it past the x-fer port anyway into the other barrel section.

My drawing is off, so don't pay too much attention to that ... is was just a "seat of the pants" drawing.

Darth

If you bevel both ends at 45 degree angles (1) female and (1) male so the barrel slides over the stub and lap them together and leave the stub smooth bore until youââ,¬â,,¢re into the barrel I think that might work. You might lose a little pressure were the barrel meet the stub due to leaking but probably not too much.

Quote from: bdb12586 on February 28, 2011, 11:56:04 PM
If you bevel both ends at 45 degree angles (1) female and (1) male so the barrel slides over the stub and lap them together and leave the stub smooth bore until youââ,¬â,,¢re into the barrel I think that might work. You might lose a little pressure were the barrel meet the stub due to leaking but probably not too much.

I'm thinking no loss. An added step would be sure both ends are square and place a coat of RTV or blue LocTite on the end during assembly.
I have an unused short barrel that I will try this with when time permits. I will chrony before and after and post results.
Don't expect this any time soon. I have several other projects to complete first.

I read a post where a guy had the idea to o-ring the barrel something like this drawing. Then the barrel could be slid out by loosening some set screws. You would need to "locate" your barrels so that the ports would line up well.

(http://i34.photobucket.com/albums/d136/darth2/oringbarrel.jpg)

You would also need to find a way to seal the xfer port without touching the barrel.

Feasible idea.

There was an extra .177 barrel hanging around my place so I decided to go ahead and work on this quick change mod we been kicking around. The first 5/8" of the barrel was cut off, faced in the lathe, polished and made real purty(that's NC red neck for pretty). A grove for the #009 O-Ring was cut in the exit end  to help seal any leaks. The transfer port opening was machined to .157" x .187" for unrestricted air flow, hopefully The remaining long piece was faced off, polished and the crown improved. An extra 8-32 hole was tapped in the breech to secure the short piece of barrel. We had some SS tubing in .250x .209 that the TP was made from. After circle milling a .25 counter bore in the barrel .078 deep and one in the valve .100 deep the length of the SS tubing needed to be .295 long for a tight, leak free fit.

Below are some pics of the pieces mentioned in this post:

Nice work.  ;) Can you do a video of the piece in action?  :-*

Quote from: NorthStaR on March 04, 2011, 01:04:43 AM
Nice work.  ;) Can you do a video of the piece in action?  :-*

Sorry but don't have the means for a video.

Mr. 007s

Now here is a man after my own heart (Dark as it is). Take the bull by the horns and run with it.

Nice job !!  I'll be watching to see the accuracy results. My feeling is ... they will be just as it was before it was cut.

Darth

nicely done  :-*

Brains pure Brains you two put your brains together and look what you did.I just love teamwork.Great job.
                              Mike

Nice, all my sceptisism is slowly flowing away. looks promesing.

Hey darth, are all your stormtroopers equiped with crosman rogue's?

Yes ... they sound funny though ... must be the electronic valves.

Darth

Well done Mr.007s  :-*

  That quite a good machining job to nest the 0-ring. I would guess also that you will not lose any accuracy after this mod.

Maybe someday I can get one of the CNC mill guys to teach me how to run the machine and make some trick parts.

   -Gary

mr.007s
Thank you for this good idea. I have it built and it works perfectly.
Some pictures I have for you.

http://postimage.org/gallery/bg8w6vas/ (http://postimage.org/gallery/bg8w6vas/)


Michael


Edit: URL Picture update

Quote from: Michael_S. on March 12, 2011, 08:10:15 PM
mr.007s
Thank you for this good idea. I have it built and it works perfectly.
Some pictures I have for you.

http://postimage.org/my.php?gallery=d2sctvl4 (http://postimage.org/my.php?gallery=d2sctvl4)

Michael

That's great Michael! Was you doing a .177 or .22?
I haven't attempted a .22 cal yet. Still looking for an O-Ring that will work. The #010 has a too small ID and the #011 is too large on the OD.I might have to try a "tongue and groove" type seal for the .22.

I have a Crosman 2250 XT .22 caliber.
I use the O-ring from my Weihrauch HW 100 barrel.
The part number is 2679, the dimensions are 8 x1,5 mm. The material is NBR70.
I inserted the dimensions in the image.


Michael

"Edit" Picture update - O-Ring Diameter ""

This look's interesting.......

Quote from: Michael_S. on March 13, 2011, 08:33:49 AM
I have a Crosman 2250 XT .22 caliber.
I use the O-ring from my Weihrauch HW 100 barrel.
The part number is 2679, the dimensions are 8 x1,5 mm. The material is NBR70.
I inserted the dimensions in the image.


Michael

I don't think we have any metric rings at work but we do have the #011 which is .312ID x .437OD. I can work with that. Thank you for the info!