Easy Barrel Change-Maybe? Maybe Not?

mr007s · February 26, 2011, 05:40:25 PM

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.

eric · February 26, 2011, 07:03:30 PM

i've seen this before

.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 .

Crosshairs · February 26, 2011, 10:44:50 PM

Your not crazy your just nuts

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

T191032 · February 27, 2011, 12:31:23 AM

"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.

NorthStaR · February 27, 2011, 12:48:27 AM

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

mr007s · February 27, 2011, 01:17:27 AM

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 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.

tatsumi · 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

mr007s · February 27, 2011, 02:48:12 AM

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.

Darth · February 27, 2011, 03:51:50 AM

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.

Oane · February 27, 2011, 11:29:39 AM

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?

Darth · February 27, 2011, 07:08:10 PM

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

bdb12586 · 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 youÃ¢â,¬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.

mr007s · March 01, 2011, 12:03:31 AM

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 youÃ¢â,¬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.

Darth · March 01, 2011, 02:08:02 AM

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.

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

Feasible idea.

mr007s · March 04, 2011, 12:06:05 AM

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:

Here you can see the extra set screw in the breech

The pieces required for this mod

All pieces assembled

I test fired 4 ten shot strings thru the Chrony. Looks like around 30 shots the way it is set just now. Can't report on the accuracy factor yet, still waiting on PA to send a Weaver adaptor. Here are the results: