This special Crosman 600 was modified to be bulk-filled with CO2. It caused today’s report to be written.
A revisit to bulk-fill airguns
This report covers:
- When to fill a bulk CO2 tank
- The big deal
- Huh?
- What happened?
- Empty or full
- CO2 gas
- What brought this up
- No gauge
- Refilling a bulk gun when it still has gas
- Summary
Today’s report was inspired by something I wanted to do and realized I couldn’t. Hopefully you will understand as you read.
When to fill a bulk CO2 tank
There is only one time to fill a bulk CO2 tank — when it’s empty! And you are probably saying, “Duh, BB. Of course that’s when you fill it. What’s so special about that?”
The big deal
What is so special about filling a bulk CO2 tank when it’s empty is that is the ONLY time you can fill it. Unlike the air tank on a pneumatic gun that can be topped off at any time, CO2 bulk tanks cannot be topped off unless a special step is taken.
Huh?
Many years ago I was shooting in a 10-meter air pistol match that could have propelled me to the Expert level in national competition. I was ranked a Sharpshooter with an average match score of 87 points per ten shots. I needed 88 points per ten shots to break into the Expert level. I was in the middle of the match when my pistol ran out of gas. Up to that point I had been shooting 9s and 10s and the hold for the next shot was a perfect 10, but I heard the pellet go out and knew that the gas pressure had dropped drastically. Instead of a 10 I shot a 6. It was directly below the 10. Let’s now look at a target.
A 10-meter pistol bull with the scoring rings numbered. I was holding for a perfect X (the center of the 10-ring) and my pellet went out so slow that it dropped down to the 6-ring, which is the first white scoring ring outside the bull. The pellet was in perfect alignment with the X ring (fractional scoring ring), but it didn’t matter.
That one shot unnerved me so much that I started throwing 8s and even a 7 or two. Had I concentrated after that shot I could still have shot Expert in that match but I was totally unnerved by that one shot. I guess it doesn’t take much to fluster me.
What happened?
My target pistol ran out of gas. Why hadn’t I filled it before the match started? Want to know why? Because I couldn’t! I was shooting my Chameleon target pistol in its bulk-fill mode and it didn’t allow for a top off until it was very close to empty. And that came in the middle of a 60-shot match.
The Chameleon was an inexpensive 10-meter CO2 pistol that ran on bulk gas or 12-gram cartridges.
Empty or full
Bulk CO2 tanks aren’t like the air reservoirs in precharged pneumatics (PCP). You can fill a PCP tank at any time and add as much or as little air as you like. CO2 tanks aren’t like that. They are either empty or full. And they are full until they go empty with no warning in-between. What I mean by that is the pressure in those tanks is always as high as it will go if there is still liquid CO2 inside.
CO2 gas
Bulk CO2 guns have reservoirs filled with liquid carbon dioxide. That liquid evaporates to a gas at a pressure of around 850 psi when the temperature is 70 degrees F/21.11 degrees C. As long as any liquid remains in the tank the gas pressure in that tank is 850 psi. The moment the last liquid evaporates the gas pressure drops like a stone — 400 psi, 250 psi, 150 psi, etc. That’s what happened to me in that match.
What brought this up
The reason I’m bringing this up today is I was going to shoot that special Crosman 600 pistol for velocity today, but I didn’t know the status of the fill. When Ian brought it back to me last month he said it had been filled, but I have dry-fired it 8-10 times since then just to see how it feels, so I didn’t know the status of the fill. I could shoot it and watch to see when the velocity dropped off, but I wondered how many of you know about the all-or-nothing status of bulk-fill airguns.
No gauge
Bulk CO2 guns don’t have pressure gauges unless they also operate on high-pressure air. And you can’t change the pressure in the reservoir. Temperature does that. Steyr once made a CO2 target pistol called the LP-1 that had a red button on the end of its cylinder. If the button was popped out the CO2 pressure was good. If it wasn’t popped out the pressure was bad. That pistol came with two cylinders and if you didn’t know the status in a match you either had to check that button after each shot or change cylinders.
The Chameleon I shot did not have a removable gas tank. It held gas in a tube inside the grip. That tube was small and held less gas than a standard cylinder so you were always in danger of running out.
It’s no problem for me to shoot the modified Crosman 600 pistol over the chronograph and watch for when the velocity drops off. I can then fill it and run the test. That’s easy. But how many of you were aware of this quirk? It’s probably one of the big things that killed CO2 for target shooting. The better target rifles and pistols come with two tanks and when one runs out you can switch. My Chameleon didn’t have a removable reservoir which is why I ran out of gas in the middle of a match.
Refilling a bulk gun when it still has gas
There is a way to fill a bulk CO2 gun or reservoir that still has some liquid in it. You chill the gun/reservoir below room temperature — far below if possible. Ian commented on this in his report about bulk filling. If you are in a place where that is possible to do then fine. But on the firing line in the middle of a national match is not the place. Chilling the tank to be filled is the special step mentioned at the beginning of this report.
Summary
I hope this little report has opened your eyes to the differences in filling with CO2 as opposed to filling with air. If you shoot a bulk-filled CO2 gun I would like to hear what you think.
B.B.,
Shootski has done Bulk Fill CO2 for a long time as well.
I am shocked that you weren’t clued in on weighing the cylinder or device when it was empty and when it was full.
The weight comparison is both a safety tool as well as a way of know when you are Running on EMPTY.
Questions?
shootski
Good morning BB. Looking at the Chameleon I realized it looks very much like the CZ I have. Which can be either bulk or cartridge filled also. So an “idea” came to my mind. Could it be modified to pcp? A foster valved tank cap could do the trick. As far as pressure concerned, 900 psi would work OK? Excuse my ignorance but I really love this CZ and I would like to use it on hpa along with the co2 cartridges since bulk filling is out of the question for me.
Thank you in advance for any help.
To clarify things by CZ I mean the Brno Tau 7.
Bill,
Yes, you can run your pistol on air and you can go up to about 1200 psi, but your shot count will decrease greatly. If you get 70 good shots now that will decrease to about 10-12.
BB
Thanks a lot Tom
Tom,
Bulk fill is the norm over here. The problem over here with chilling the tank before filling and our very warm climate is that it leads to valve locking the gun when exposed to sunlight. The increased temperature causes the CO2 to increase pressure causing the regular hammer blow to be ineffective in opening the valve. This is probably why the external hammer just like in the LD rifles are very popular over here. It allows the shooter to depressurize the gun to allow it to fire. Otherwise the shooter is forced to place ice bags over his CO2 tank to allow him to discharge normally.
Siraniko
Siraniko,
Are there any multi-stroke-pneumatic guns produced there currently (something akin to a Sheridan or a Crosman 362)? Or is all in-country production geared toward CO2? Thank you.
Blessings to you,
dave
thedavemyster,
There are still multi-stroke-pneumatic guns produced and marketed here. They have not progressed much in quality nor technology from the Benjamin 700 as featured here https://www.pyramydair.com/blog/2018/08/benjamin-700-multi-pump-repeater-part-3/
Still made of brass and in .22 caliber. The small improvement is the tube between the pump mechanism and the barrel acting as a reservoir allowing 7 shots after filling it from about 70 strokes making it a primitive self contained PCP.
CO2 guns are still produced but the boutique makers are gearing towards PCP production and some have ramped up their production enough to justify having the receivers be produced by CNC machinery. https://youtu.be/bxJD1pnpCT4?si=CRAuMmPfOg62fj4g
Siraniko
Here is an example of the current multi-stroke-pneumatic guns produced and marketed here. Even at that level of production it costs about $150 which is a princely sum especially when the average daily income here according Google is $10 per day.
Siraniko
“Still made of brass and in .22 caliber. The small improvement is the tube between the pump mechanism and the barrel acting as a reservoir allowing 7 shots after filling it from about 70 strokes making it a primitive self contained PCP.”
Siraniko, so this rifle you have here in your second picture matches the description above?
I think that’s awesome! A .22-caliber 7-shot self-contained PCP is one cool gun!!!
Perhaps not everyone’s cup of tea, but for an old duffer like me on a tiny farm, it’d be great.
Are these things for sale in the USA? Or are they strictly an in-country item?
Either way, thank you for sharing this interesting information! 🙂
Siraniko,
I tried searching for “multi-stroke-pneumatic guns produced in the Philippines for sale” but all I found was a couple of stores there that sold PCPs.
Are the multi-stroke-pneumatic guns made by small shops that don’t deal with exporting guns?
If so, that’d be a shame, as I think their wares are pretty neat. 🙂
Blessings to you,
dave
thedavemyster,
Unfortunately the rifle is rarely seen outside of our shores. Nobody thinks it will sell overseas so it is simply not sold.
Siraniko
“Nobody thinks it will sell overseas so it is simply not sold.”
Siraniko,
Sadly, they may have a point.
The only person I know who would buy one is…me! LOL! 🙂
Thank you for your response, and as always,
May God richly bless you,
dave
B.B.
How about a report on your Chameleon? Seems like a great little pistol!
Have a grreat weekend everybody!!
-Yogi
PS the Climatologists tell us that there is too much CO2 in the atmosphere. Lets ban CO2 guns!!! lol
Yogi,
Sorry but I got rid of my Chameleon years ago.
BB
Your old Chameleon is still working perfectly. I was shooting it last week. I don’t know what all the fuss is about–I can shoot sixes with it all day.
I’ve got ten or eleven bulk-fill guns. The ones with the larger cylinders are great in terms of shot count. You can hear the discharge sound change when the gun is running out of CO2 and needs a refill. But I’m not shooting a sanctioned match.
In my opinion, the biggest hurdle to bulk-fill NOW is the difficulty in getting a 10 or 20lb tank filled. When paintball guns all ran on CO2 it was really easy to find a place to fill. Now, my options are a couple dry ice suppliers for commercial blasting. There’s nothing easy or convenient when dealing with them.
But imagine sticking a paintball tank on your .22 cal rifle and getting 800+ shots…
Derrick,
Now I remember! You got my pistol.
I now can shoot sixes all day with no problem, too. 😉
BB
Got it and I love it. Your Chameleon is the fraternal twin to the Aeron B96 semi-auto that Frank Ballistreri sent me.
Derrick,
Bars and restaurants use dispensing machines that use CO2 Cylinders to operate there systems. They know places that will do bulk fill cylinder refills in your area.
hth,
shootski
Bulk-fill CO2 is one of those things that I take for granted until its gone. I only need the tank filled every few years, so I’m never dealing with the same person and the tank is inevitably out of hydro. The easiest place for me geographically isn’t at all far, but they close up around 3:30-4:00 weekdays and that entails leaving work early for the drop off and the pick up. And its just always a hassle. Maybe I should try the Airgas place down the street.
Do CO² tanks need hydrogen tested? They are only at 900 or so psi?
Roamin Greco,
Yes they require the HYDROstatic testing is required by DOT every 5 years in the USA. Depending on size and what service the pressure used for testing is between 3,000 an 10,000 PSI. The name is hydro because the cylinder is filled with incompressible water and pressurized which is much safer than air or other gases that are compressible and cause instant expansion explosions when the cylinder fails.
shootski
I picked up a mint Chameleon at the MidwestAirgunShow this year. It’s a neat little pistol, very well appointed, and shoots wonderfully. Unfortunately it didn’t come with the tool needed to loosen and tighten the Co2 cap . I’ll hopefully find one someday.
The vintage Crosman bulkfill pistols imho are some of the most accurate barrels I’ve used, especially with vintage Crosman pellets. Wish the industry could return to that kind of relationship with pellets/airguns from the same maker.
Take care BB
BB,
I have never done bulk filling of CO2 before but will likely be doing such in the near future. These new articles by Ian and you will be of much value to me as will your past writings concerning such. This will likely be a new experience for me and could be an opening of the flood gate.
Where are you taking me?! 😉
I’ll hitch a ride along with ya, pardner! Been considering bulk fill vs. an adapter to allow a CO² cartridge to be used to fill a bulk fill gun. I have a Crosman 111 and a 112 that I bought in a lot with a Smith & Wesson 79G to play with.
I like to have as many ways to fill the older Crosman guns as possible. When the Crosman 111 and 112 guns came out (in the late 50’s ?) they were very likely the most powerful air pistols around.
RG,
I could probably use one of those adapter thingies around here. I have a bulk fill CO2 airgun that needs filling. I am still playing with the idea of setting up a fill station. We shall see where all of this goes.
Ridge,
You’ll need a Crosman 112 and maybe the 118 multi shot rifle.
Derrick,
Give me a break dude. I just sent BB’s 150 back to him and just acquired a Benji 130, 132 and a 137 recently. I have not even had the opportunity to give them a serious look over, more or less rebuild and play with them yet. If they show up here, I will find a place for them to live and be comfortable as best I can, but as for me looking for them, I think I have enough on my plate for the moment.
Do not get me wrong. They are welcome to move into here if they so desire. I am just up to my eyeballs in antique airguns at the moment and need to get rid of a couple of the “young’uns” before I can deal with even more.
I saw your comment above about possibly getting into bulk fill and just had to run with it. Your foster care for wayward airguns is renowned.
I’ve got a 150, too. Its a hot shooter for its size, but it is LOUD.
I’m at the point where I’ve really got too many airguns. Lots of overlap and lots of guns I just wanted to try but haven’t moved out yet.
Derrick,
Like I said, I just have to find a home for some of these “young’uns”. Yes, it is not easy. That is why I sent that 150 back to BB. I have three more pistols to overhaul and test that just showed up here.
Now if I can just open the door and kick some of them out.
I understand. I’ve given some nice Crosman 22XX variations to friends, loaned out FWB 124 and a Gamo Compact to others. Neglect and rust always followed.
This is why I am very picky about where they go.
B.B. and readership: this is a difficult question to pose, but here goes. Could a system be devised to top off the CO² in a gun’s reservoir sort of like the way an air conditioning system’s refridgerant can be topped off?
Let’s say you were filling from an 88 gram tank with a valve. If the CO² is a liquid under pressure, then if the gun’s CO² reservoir and the 88 gram tank are connected and both under equal pressure, could the liquid CO² be lterally poured into the gun’s reservoir with the gaseous CO² bubbling back into the 88 gram tank?
The problem, with bulk fill, as I see it is there is only one path for the liquid to go in, but no path for the built up gas to exit and allow more gas to enter, so you need an empty or cold gun for the lower pressure in the empty gun to suck in the liquid CO² before the pressure equalizes. I hope I explained myself well enough.
RG, the normal way that A/C systems are topped off is via the suction side of the A/C unit’s compressor (when the compressor is running). The A/C unit’s compressor creates the necessary pressure differential as it runs. There are also other necessary devices such as an expansion valve (or a capillary tube or restrictor in some systems) that divides the high pressure side of the system from the low pressure side.
Roamin Greco,
The only way I could see such a thing could is if the gun had one small built in tank and a 2nd big tank that can be replaced. From the cumbersomeness of the system I don’t get what you are trying to achieve. Bulk filled CO2 rifles already have a good shot count.
Siraniko
Before I retired, I was working with a CO2 power generating system mostly design work with a lot of mathematical modeling. But basic problem can be solved with an infrared thermometer and a scale that can accurately weigh your gun / tank. If cooling the gun is difficult, then raising the temperature of the fill tank should be easier. If you have a hot water tap fill a container to set the fill tank. Wait a few minutes. The other method is to set the fill tank in the sunshine, usually readily available in the Philippines. Once a delta of about 10 F between the gun and the fill tank. You are good to go, even if both are greater than 88 F the delta temperature will result in a delta pressure. Just make sure to weigh the gun after fill, to check for over filling.
The final part to the puzzle is the use of a siphon tube on the fill tank, otherwise you have to hold the fill tank upside down and higher than your gun. Easy with a 20 oz fill tank, not so easy with a 20 lb tank.
If the fill tank is well above 88 F (> 94 F) a siphon tube is not necessary.
Do not allow temperature to get above 140 F that is the upper limit to most CO2 tanks.
Mike
bmwsmiley,
Thanks Mike! Totally agree with your explanation.
Readership Mike knows what he is talking about on this CO2 stuff.
shootski
PS: living in Spain we had a solar panel system that used a balanced CO2 system exposed to the Sunlight to drive the solar collector panels orientation to remain pointed directly toward the Sun in azimuth and elevation.
That solar panel positioning system sounds interesting. Does it self position based on pressure differentials due to the heat associated with the solar gain? Or is there more to it than that?
Elmer Fudd,
The collector aray was driven by two CO2 motors that were powered by the differential (Delta = ∆) in cylinder pressures.
The pressure ∆ caused by the two pair of CO2 cylinders being shaded by parts (adjustable Shades) of the aray from the sun’s rays as it followed the daily and yearly arc across the sky. The aray can be swivel pole or pantagraph frame mounted.
https://www.energysage.com/business-solutions/solar-trackers-everything-need-know/
The link above will iv you an idea of the why but as usual it is a fail because it fails to be K.I.S.S. (The last S. stands for Smarty according to Mark Devine retired Navy SEAL.) The system on our house in Spain was virtually maintenance free and didn’t need algorithms, processors, electricity or much more than the Sun. The return to morning position was a plunger that vented CO2 from the higher pressure cylinder to equalize the system and allowed a spring to return the aray to START; that spring was dual duty in that it dampened/eliminated any potential wind driven flutter of the aray.
Have not seen anything like it in the USA :^(
shootski
B.B.
Great info to know. I’ve never done bulk C02 but have considered it. I didn’t know you couldn’t fill a half full tank. I was thinking it was like filling propane tanks. They can be filled anytime. While the gas does boil at room temp, I do not know what psi the propane is.
Doc
That’s an interesting comparison, as might be LP (liquefied petroleum).
Doc,
Propane is around 113-115 psi at room temperature.
BB
Very low. I just read that it is the thing is airsoft “Green Gas”. That makes sense.
Doc
Doc, your reply got me to thinking about the propane trucks that deliver propane to tanks that folks use for heating their homes, etc. If I remember correctly, they use a pump to move the liquid propane from their trucks into the tanks being refilled. Am I remembering that correctly? Just off the top of my head, I think that that same principle might work for CO2. However, I think that the pressures involved, and the volumes of the tanks (in our guns), are both drastically different for CO2 versus propane. So this idea might not be very practical.
Elmer Fudd,
You are on to something!
Unfortunately, it kills off the K.I.S.S. benefit of CO2 propellent in airguns.
shootski
Elmer,
Correct, the propane truck that fills our tank does use a pump. When we fill a bottle from our tank, you “vent” the bottle and then we just what they call gravity feed it even though it’s not gravity doing it. The smaller bottle is low so the big tank is able to fill it. You can use a pump to fill the little bottles too (tanks on a forklift) but it’s not a must.
Doc
Doc Holiday,
Your statement “I didn’t know you couldn’t fill a half full tank.” Is false. Please carefully (re)read Mike’s reply above since he clearly covers how to do it.
It isn’t easy like refilling on most other gases but with the methods Mike describes it can IN FACT be done.
Shootski
B.B. and Readership,
If you need more information than Mike provided this Link is an excellent resource: https://www.rotasswhip.com/basic-knowledge-of-co2-gas-cylinder-filling#:~:text=You must fill carbon dioxide,standard of 0.6kg%2FL.
After you read you can decide if CO2 Bulk Fill is worth your while.
PCP in my opinion is the way to go and i own all the gear $$$ needed to do either.
shootski
I’m sitting on a case of Crosman CO² powerlets that I purchased on sale with free shipping for less than 50 cents per powerlet. So an adapter to let me bulk fill using those powerlets as the CO² source would be great, at least to be able to play around with the bulk fill guns I have. I know that there are a couple of folks that make them. Also there are adapters for the larger, disposable CO² tanks, like the 88 and 90 gram and also for paintball tanks.
Roamin,
I don’t think filling the little C02 carts would be worth it. I maybe wrong but seems like just not enough volume. Now as for filling 88-90gr tanks, that sounds you could be on to something there.
Doc
Doc Holiday,
There are/were adapters sold to do refills on the 88 gram “disposable” cylinders back two decades (last time i looked) ago to do just that. The cost of bulk fill CO2 (I think Tom recently pointed that fact out.) is VERY economic compared to cartridges or capsules.
Just like PCP costs early on for equipment IF all your airguns use bulk fill CO2 it is the way to go.
shootski
I’ve purchased most of the various 12g adapters off ebay. The one I use the most takes a 12g and turns it into an AirSource. The only problem– the adapter had a soft as butter piercing tip. Got about a half dozen punctures before it was too mashed over to pierce. I ended up remachining the piercing end to use the piercing mechanism and seals Crosman uses in the 38T, 1600, 357
Shootski,
Thanks for the link. The main thing I love about C02 is the shot count. Nothing like it (assuming you don’t need very high power shots). I’ve seen some reviews of Air Force PCP guns running on C02 bottles (was an option, not sure it still is). Very good shot counts and not bad velocity either. But if I had a compressor, maybe I wouldn’t fell so strong about it lol.
Doc
Doc Holiday,
IF you have a nearby fill source for air you can get two or more Carbon Fiber (the larger the more economical) cylinders and do a cascade to get nearly every PSI/cu. ft. out of your fill source. The life cycle cost is far cheaper than a compressor, not nearly as heavy/cumbersome, and it has way less maintenance required; also the air will be dry and clean! But you need to stick with PCP powerplants to get maximum ROI (Return On Investment) of your fill setup.
shootski
Saturday?! No wonder I cannot find a new subject. Sorry folks, but I am retired and I am having a hard time keeping track of the days. 🙂
“Saturday in the park
I think it was the Fourth of July
Saturday in the park
I think it was the Fourth of July
People dancing, people laughing
A man selling ice cream
Singing Italian songs.”
Off topic, but FM managed to get to the W Palm Beach FL gun show this Saturday and saw 3-4 tables stocked with airguns. One vendor had a Umarex Zelos for sale. One of these days we may get a proper airgun show around here.
FawltyManuel,
“One of these days we may get a proper airgun show around here.”
If you want it, really want it
Can you dig it? (Yes, I can)
And I’ve been waiting such a long time
For the day, yeah, woo
shootski
shootski,
You cannot sing either.
RidgeRunner,
Yup…flunked out of choir ;^)
But what i wrote is the last stanza of Chicago’s lyrics that FM used the first stanza of to start all of this exchange.
I do play a mean Bari Sax.
shootski
shootski,
Oh, I know where your part came from. I personally never liked that song in its entirety. Mrs. RR does not like Chicago period. With that song I must agree with her. As far as the city is concerned, I was not that impressed with it either, although it did have a pretty nice museum.
If you’re talking about the Museum of Science and Industry, indeed it is quite nice; you don’t get to see an authentic Type VII U-Boat or JU-87 dive bomber in many other places.
FM,
Nice museum. The rest of Chicago, eh.
FM,
You really should stick to the airgun show efforts.
I have never liked that song.
RidgeRunner,
How will you not miss airgun shows!
You better start making marks on the wall or bed post if you can find a nail in your retirement POW (Prisoner Of Wife) Camp.
shootski
shootski,
I seriously doubt I will be able to not attend any “local” airgun shows. Unless I am mistaken, I do believe Mrs. RR is actually encouraging me to attend the North Carolina show, not just Saturday, but also Friday. We shall see.
As far as the POW thing is concerned, it is my own doing.
RidgeRunner,
I hope you are NOT mistaken!
Internment is not a healthy situation.
shootski
shootski,
Number one, you should see my “prison”.
Number two, you should see the “warden”.
Number three, I do the foraging, so I am out frequently.
Number four, I am allowed on occasion to take the kids to airgun shows, etcetera due to good behavior.
In reality, it sure beats being interned in the “work world”. What a drudgery that was.
RidgeRunner,
I understand.
Would love to see your homestead one day and meet you and the family in person.
I do need to get to an airgun show my last one was a Roanoke show a long time ago.
“…“work world”. What a drudgery that was.”
I hear that from lots of other folks as well; guess i got lucky doing things that i really enjoyed in all three of my careers. I could have made more money flying for the airlines but that would have been very boring…now if it was PanAm Clipper flying boats that would have been a blast…just too late getting born!
shootski
shootski,
I do not want you spouting off any excuses. you are retired.
I am going to take my grandson to the NC Airgun Show on Saturday, November 2nd. We will be leaving from Roanoke/Salem that morning. You are invited. I will be driving from there. Be there or be square.
As of this moment I will have three air rifles and maybe one air pistol I will be wanting to sell/trade for something. There will still be at least one comfortable seat available in the Forester. You really should be filling it.
ROAD TRIP!
Cheers to your RT! May it happen.
“Prisoner Of Wife” – brilliant! Better be sure Mrs. FM is not peering over Worser Half’s shoulder…
FawltyManuel,
Hopefully you never pull a Terry Kath!
shootski
shootski…God forbid! Still have places to go, people to annoy, airgun targets to puncture.
FawltyManuel,
I have always wondered if it really was accidental!
shootski
Good Sunday evening everyone. I may be mistaken, but I saw this Diana Model 45 on a popular auction site and it seemed to be missing the characteristic screw / pin through the stock, just above the trigger guard. I am thinking this is an example of a Model 34 in Model 45 clothing. The trigger and the end cap are similar to the 34. Wish there were more pictures. But the T01 trigger was the two-screw adjustable one.
https://www.ebay.com/itm/256672761858?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=X9AXVjgcSJW&sssrc=4429486&ssuid=g1VQzXcdTNm&var=&widget_ver=artemis&media=COPY
Crosman 600 fans: check this out:
https://www.pyramydair.com/blog/2024/10/looking-at-an-unusual-crosman-600-pistol-part-1/#comment-521931