Covverting from co2 to air info .

[melloairman]

Thinking of converting the 2240 to air . Not interested in more fps so I will keep the psi at 1000 -1100 as co2 is . Found the part in the UK from a reputable supplier that is inexpensive and should meet my needs . I plan on tethering any ways . It states not for HPA but I will be setting at the same psi as co2 . THE supplier gmac Here is video of it .
https://www.bing.com/videos/search?q...A8&FORM=VRDGAR
Also I bought a Dan Wesson air soft revolver for in the house shooting . If the land lord new I was shooting lead in the house he would evict me . So I found a unit that should work to tether it as well . It works on a lot of pellet pistols as well .Here is a video on it . It is called the ANT conversion .Marvin
https://www.bing.com/videos/search?q...79&FORM=VRDGAR

[Multigunner]

Even at the max CO2 pressure level of 900 PSI you will get a bit higher velocity when using air at that pressure instead of CO2. The O2 molecule and the Nitrogen molecule of atmospheric air pass through the exhaust valve faster and smoother than CO2 can.

[sixshootertexan]

I would still add more screws to the valve just in case. That one round head screw is not enough for me to feel safe.

[rsterne]

I have a big problem with the Video of the GMAC adapter, where they show the guy using a wrench to "align" the elbow to the side of the gun.... Threading the adapter into the gun with a wrench MAY put a lot of force against the valve, which in a 22XX is only retained by a single 6-40 screw.... That pressure could partially (or completely) shear the screw, leading to it failing.... The front cap on a 22XX should NEVER be tightened more than finger tight....

Both adapters seal against the end of the valve, so in theory the tube is never pressurized.... However, misuse, or improper installation could potentially lead to a problem, and it the tube ends up pressurized, you can pretty much guarantee that the stock 6-40 screw will shear off....

BE CAREFUL .....

Bob

[melloairman]

I ordered one today . Cost about 35 dollars including shipping . Marvin

[Multigunner]

"Both adapters seal against the end of the valve, so in theory the tube is never pressurized.... However, misuse, or improper installation could potentially lead to a problem, and it the tube ends up pressurized, you can pretty much guarantee that the stock 6-40 screw will shear off...."

Sounds like a relief port or two drilled into the tube is called for.

[rsterne]

In theory, the pressure can escape down along the sides of the valve and out the slots behind it, but a couple of holes can't hurt.... That won't solve the problem of overtightening the front cap with a wrench in an attempt to align the elbow, as shown in the video, damaging the small single valve retention screw....

Bob

[melloairman]

[QUOTE=Multigunner;4007070]"Both adapters seal against the end of the valve, so in theory the tube is never pressurized.... However, misuse, or improper installation could potentially lead to a problem, and it the tube ends up pressurized, you can pretty much guarantee that the stock 6-40 screw will shear off...."

Sounds like a relief port or two drilled into the tube is called for.[/QUOTE
If you would re read the post you should see that there is no more of a need to vent the tube than if I was still installing carts or bulk filling . Marvin

[Multigunner]

I was replying to this statement.

"However, misuse, or improper installation could potentially lead to a problem, and it the tube ends up pressurized, you can pretty much guarantee that the stock 6-40 screw will shear off...."

I understand that you don't intend to pressurize your gun any higher than the 900 PSI of a CO2 cartridge but the best laid plans of mice and men gang aft a glee.
The father of a school chum was killed while inflating a truck tire, his pressure gauge stuck so it inflated far past the 250 PSI called for to set the bead and sheared through the bolts holding the split rim together.

Others may intended to use higher pressures than you intend to so they might benefit from relief ports.

I don't see why one couldn't add more screws of a larger diameter spaced around the tube to secure the valve body better for use with HPA.

When dismantling a relic 760 rifle I found it had deep indentations in the tube that prevented the valve body from moving backwards.

Since seeing the video of the horrendous hole in the leg of the guy who's HPA conversion blew out I'm leery of such conversions.
Even 900 PSI can drive a heavy piece of metal at high velocities, the CO2 powered spearguns proved that well enough.

[rsterne]

there is no more of a need to vent the tube than if I was still installing carts or bulk filling

Actually, in order to BULK FILL a 22XX tube (which is NOT what the adapters do, they allow attachment of a larger CO2 tank directly to the valve, only the valve is under pressure).... then you MUST seal the valve into the tube with O-rings, the way a Disco valve is done.... This put the valve under the full end force of the gas inside the tube (880 lb.f. at 2000 psi).... Since CO2 on a hot day can reach 1900 psi, you therefore MUST mount the valve at least as well as a Disco valve, which means THREE 8-32 screws.... Proper engineering practices means having the valve screws able to withstand over 3000 lb.f. without failure, even for CO2....

There is a HUGE difference between using adapters as shown in the original post, and bulk-filling the tube.... They are NOT, REPEAT NOT, the same thing at all....

Bob

[melloairman]

Actually, in order to BULK FILL a 22XX tube (which is NOT what the adapters do, they allow attachment of a larger CO2 tank directly to the valve, only the valve is under pressure).... then you MUST seal the valve into the tube with O-rings, the way a Disco valve is done.... This put the valve under the full end force of the gas inside the tube (880 lb.f. at 2000 psi).... Since CO2 on a hot day can reach 1900 psi, you therefore MUST mount the valve at least as well as a Disco valve, which means THREE 8-32 screws.... Proper engineering practices means having the valve screws able to withstand over 3000 lb.f. without failure, even for CO2....

There is a HUGE difference between using adapters as shown in the original post, and bulk-filling the tube.... They are NOT, REPEAT NOT, the same thing at all....

Bob

Bob you as well need to re read this post as well as taking a look at GMAC web page . And remember that as shown in the video it is a adapter that lets you use a remote tank to what some consider bulk feed a 2240 . Now then since you want to tear apart my post as you normally do .I agree that one should not wrench on the adapter . But you need to be open minded . May be you are just to use to being a moderator at GTA and well .Marvin

[melloairman]

I ordered 2 of the ANT co2 to air kits today from Air Gun Depot . Then I went to JSD tank sight . He is having a sale on some of his tanks . I hit the button on a 62 ci 3000psi fill with a 1000 psi out let . With the correct fill adapter I need to feed the pistols . I was going to use one of my 80 cf tanks with a in line regulator I have . But I really did not want to have to move it out to the field all the time . I know every one is 4500psi and carbon fiber . But I got started in the BB before the 4500 psi days and have 3 80 cf 3000-3200 psi aluminum tanks that are know to out live the owners . Not A 10 year life cycle . Compressor will do 4500 . But I see no need in investing in the expensive 4500 tanks . And then again the cost factor of 3000 psi hose and connectors is much less than 4500 psi pieces as well . Marvin

[Multigunner]

I think you two are posting at cross purposes. Both are right but both seem to see the other as criticizing what they have posted due to both looking at different aspects of conversions.

Personally I figure that if only one very skinny screw holds the valve body in place that's a serious weak point even if not converted to either low pressure or high pressure air.


" Since CO2 on a hot day can reach 1900 psi,"

Last week I saw posts on another board about a Daisy Model 44 left out in the sun on the hood of a car. The valve body ruptured blasting chunks out of the top strap and breaking the rear sight base in half.

In the hot southern summer sunlight a black metal pistol frame can become too hot to hold in a very short time. A possible excuse for nickel plating the main tube of Crosman pump up and CO2 pistols. That or putting a lighter colored finish on the guns.
I'd been thinking of painting my converted 1377/.22 carbine, some tasteful contrasting color scheme.

[melloairman]

I think you two are posting at cross purposes. Both are right but both seem to see the other as criticizing what they have posted due to both looking at different aspects of conversions.

Personally I figure that if only one very skinny screw holds the valve body in place that's a serious weak point even if not converted to either low pressure or high pressure air.


" Since CO2 on a hot day can reach 1900 psi,"

Last week I saw posts on another board about a Daisy Model 44 left out in the sun on the hood of a car. The valve body ruptured blasting chunks out of the top strap and breaking the rear sight base in half.

In the hot southern summer sunlight a black metal pistol frame can become too hot to hold in a very short time. A possible excuse for nickel plating the main tube of Crosman pump up and CO2 pistols. That or putting a lighter colored finish on the guns.
I'd been thinking of painting my converted 1377/.22 carbine, some tasteful contrasting color scheme.

Some need to except the different terminology that is used in our language . And have a open mine . Crosman has been selling the pistols for years and I am sure some have been left in the sun. GMAC has been selling these adapters for years and some have been left in the sun . And there seems to be no reported problems . Unless maybe someone was really not using any judgment at all . If you have that much fear that your pistol is going to explode then do as you wish . I am open minded enough to except that point of view . I do not have that fear and as I stated I will be using air not co2 . Now then if some one that is going to use co2 and has that fear then don't do the conversion . One must at all times use good judgement with any type of gun . And leaving one on the hood of a car in the hot sun for any time is not in good judgement as far as I am concerned . But that is my opinion . Marvin

[jcwit]

I have an opinion also. If perchance it was safe Crosman would offer the items to make the conversion themselves.

But then I don't drive my auto 100 miles per hour just because it has the abillity to do so.

[jh45gun]

I agree if it was safe on that platform Crosman would be doing it.

[melloairman]

Went to the PO today . My 2 ANT kits were there .As well as my tank with the regulator and the .177 barrel for the 2240 . Marvin

[melloairman]

Installed 1 of the ANT conversions in the 4 inch barrel DW today . Hooked it up to my 80 cf tank filled to 3100 psi . Set the external tank regulator at 500 psi . and shoot 6 shoots . Grouping was wide . Set the regulator to 600 psi and it was accurate at 8 yards with 20 g balls . Shoot close to 200 balls through it . Nice not to have to worry about poi change due to pressure changes . And it is also nice not to have to buy co2 . I already have a compressor and 3 tanks . It bothered me to buy co2 with all this equipment here . Have to convert the 6 inch DW now . Also I tracked the piece to but the 2240 on air today and it states that it is at my PO box now . Marvin

[Multigunner]

Glad to hear you are having such good results. Being able to dial in the optimum pressure for best accuracy is quite a plus.

[melloairman]

Put the .177 barrel on the 2240 and installed the conversion to air from co2 this morning . Put 2500 psi in the 3000 psi 62 ci bottle that is regulated to 1000 psi . Shoot 100 pellets and used 500 psi of air out of the tank . Sure is nice to get away from the co2 .Marvin