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All Springer/NP/PCP Air Gun Discussion General => "Bob and Lloyds Workshop" => Topic started by: ray1377 on June 11, 2024, 10:32:18 PM

Title: co2 transfer port size???
Post by: ray1377 on June 11, 2024, 10:32:18 PM
I know Crosman sells many different size transfer ports that will fit a 2240. My question is, with everything else staying the same, barrel length, pellet weight, hammer spring and hammer. What types of FPS or FPE changes can one expect to see from either going up in size or down in size? Does constricting co2 transfer ports have the same effect as when its done on a PCP?

Thanks
Ray
Title: Re: co2 transfer port size???
Post by: Rick67 on June 12, 2024, 09:45:42 AM
There was a gent here, or was it from the CAPOF (?), who told me that the OEM TP is just the right size for the C02 powered 22xx ‘cuz, at that time, I was thinking of using a Challenger TP. i should probably try it  ???

The Challenger TP (hole is really small; needle-like) is what I use for my 22xx PCP builds, and red, its equivalent, for 17xx guns.



Title: Re: co2 transfer port size???
Post by: Mzq284 on June 12, 2024, 08:39:55 PM
There was a gent here, or was it from the CAPOF (?), who told me that the OEM TP is just the right size for the C02 powered 22xx ‘cuz, at that time, I was thinking of using a Challenger TP. i should probably try it  ???

The Challenger TP (hole is really small; needle-like) is what I use for my 22xx PCP builds, and red, its equivalent, for 17xx guns.
Which Crosman guns do you use the transfer ports from? I have a PCP build coming up, I was thinking of using the one from the 3622 if available.
Also, does anyone here know of a chart with the sizes? I can make transfer ports if I have to, but I would rather buy a stainless factory one. I can always open it up
Title: Re: co2 transfer port size???
Post by: ray1377 on June 12, 2024, 11:20:17 PM
There was a gent here, or was it from the CAPOF (?), who told me that the OEM TP is just the right size for the C02 powered 22xx ‘cuz, at that time, I was thinking of using a Challenger TP. i should probably try it  ???

The Challenger TP (hole is really small; needle-like) is what I use for my 22xx PCP builds, and red, its equivalent, for 17xx guns.
Which Crosman guns do you use the transfer ports from? I have a PCP build coming up, I was thinking of using the one from the 3622 if available.
Also, does anyone here know of a chart with the sizes? I can make transfer ports if I have to, but I would rather buy a stainless factory one. I can always open it up

I do believe that any crosman "lego" style airgun that use the short or long steel breech can swap transfer ports. You could at one time order different ones for Marauder rifle and pistol to up the power. I read somewhere that a guy glued his transfer port hole with like JB weld and then re-drilled it back out at a different inside diameter. So there's that. I'm just curious if someone has changed out a bunch of different ones in a factory 2240 to see what kind of FPE and FPS they attained or lost with each swap.

Ray
Title: Re: co2 transfer port size???
Post by: Rick67 on June 13, 2024, 10:04:44 AM
There was a gent here, or was it from the CAPOF (?), who told me that the OEM TP is just the right size for the C02 powered 22xx ‘cuz, at that time, I was thinking of using a Challenger TP. i should probably try it  ???o

The Challenger TP (hole is really small; needle-like) is what I use for my 22xx PCP builds, and red, its equivalent, for 17xx guns.
Which Crosman guns do you use the transfer ports from? I have a PCP build coming up, I was thinking of using the one from the 3622 if available.
Also, does anyone here know of a chart with the sizes? I can make transfer ports if I have to, but I would rather buy a stainless factory one. I can always open it up

To reiterate, the Challenger TP; the obsolete model.

It’s just aluminum anodized in blue green, I think, although it says here it’s zinc plated, so it must be steel  ???

They’re cheap  :P

The ones for the PROD/17xx, which are taller, are $4+ and come in 3 port sizes: blue, silver, and red (smallest).
Title: Re: co2 transfer port size???
Post by: Mzq284 on June 14, 2024, 07:01:19 PM
There was a gent here, or was it from the CAPOF (?), who told me that the OEM TP is just the right size for the C02 powered 22xx ‘cuz, at that time, I was thinking of using a Challenger TP. i should probably try it  ???

The Challenger TP (hole is really small; needle-like) is what I use for my 22xx PCP builds, and red, its equivalent, for 17xx guns.
Which Crosman guns do you use the transfer ports from? I have a PCP build coming up, I was thinking of using the one from the 3622 if available.
Also, does anyone here know of a chart with the sizes? I can make transfer ports if I have to, but I would rather buy a stainless factory one. I can always open it up

I do believe that any crosman "lego" style airgun that use the short or long steel breech can swap transfer ports. You could at one time order different ones for Marauder rifle and pistol to up the power. I read somewhere that a guy glued his transfer port hole with like JB weld and then re-drilled it back out at a different inside diameter. So there's that. I'm just curious if someone has changed out a bunch of different ones in a factory 2240 to see what kind of FPE and FPS they attained or lost with each swap.

Ray
I would like to know that too
Title: Re: co2 transfer port size???
Post by: happymecanic on June 15, 2024, 06:21:09 AM
I know Crosman sells many different size transfer ports that will fit a 2240. My question is, with everything else staying the same, barrel length, pellet weight, hammer spring and hammer. What types of FPS or FPE changes can one expect to see from either going up in size or down in size? Does constricting co2 transfer ports have the same effect as when its done on a PCP?

Thanks
Ray

Hi Ray,

Yes constricting the TP will reduce velocity/power on a CO2 airgun, less gas = less energy.

I searched ''Crosman transfer port size chart'' and got a myriad of interesting results. Here's a link to a very interesting post on the CAPOF: https://www.crosman-air-pistol-owners-forum.com/board/index.php?topic=16637.0

If you're not a member and can't log in, here's the TP size chart posted by quickster47 (may you rest in peace Karl), hope that helps:
Title: Re: co2 transfer port size???
Post by: rsterne on June 16, 2024, 06:43:17 PM
That chart is based on the concept of "sonic choking", which does not apply in the way suggested....

Bob
Title: Re: co2 transfer port size???
Post by: ray1377 on June 17, 2024, 11:18:09 PM
I've been to the CAP quite a bit, never saw that chart before.
Interesting.

Ray
Title: Re: co2 transfer port size???
Post by: Walther on August 24, 2024, 04:32:16 PM
I know Crosman sells many different size transfer ports that will fit a 2240. My question is, with everything else staying the same, barrel length, pellet weight, hammer spring and hammer. What types of FPS or FPE changes can one expect to see from either going up in size or down in size? Does constricting co2 transfer ports have the same effect as when its done on a PCP?

Thanks
Ray

Small the port on a co2 the lower fps. visa versa.
maxium for .22 in a co2 22xx or chaser is about 4.5mm  after 4.5 the pellet could get stuck in the transfer port when loading. I find 3.8mm or 5/32  is a great compromise.
Title: Re: co2 transfer port size???
Post by: JPSAXNC on August 25, 2024, 08:24:40 AM
You can go bigger, but you would have to re-drill the hole in the barrel to the same size. .172 is a good choice.