W. H. B. Smith & his argument for the superiority of CO2 rifles

[cinedux]

https://imgur.com/lBT9axq

The one pictured cost me $600NZ about ten years ago. It was offered as a prize in a sporting magazine.I got,the letter of congrats to the winner-from the Webley agent.Plus all the paperwork with a hardly used rifle.Looks a bit worn now!

[harry mac]

I've never read any of Smith's works, but how does he argue the superiority of CO2 over air?
Surely with the limitations of how CO2 works as a propellant, it can never offer the same levels of performance as compressed air? Hence there are no FAC rated CO2 rifles, but there's a profusion of air powered ones.

[45flint]

I've never read any of Smith's works, but how does he argue the superiority of CO2 over air?
Surely with the limitations of how CO2 works as a propellant, it can never offer the same levels of performance as compressed air? Hence there are no FAC rated CO2 rifles, but there's a profusion of air powered ones.

Sorry your missing the point, we are going back to the mid 1950’s when the book was written and comparing the vintage guns at that point in time. Or we could say rifles below the current UK 12 fpe limit? The Mark 3 is at 10 fpe and the 160 is at 11.4 fpe. This was before the power races. I could argue that for most purposes the power races have not given us a more pleasant rifle than the Mark 3?

[eyebull]

I've never read any of Smith's works, but how does he argue the superiority of CO2 over air?
Surely with the limitations of how CO2 works as a propellant, it can never offer the same levels of performance as compressed air? Hence there are no FAC rated CO2 rifles, but there's a profusion of air powered ones.

Though the invention of PCP predates CO2 by some margin, I don't think PCPs were commonly available at the time. Even if they were, the need for an expensive scuba tank as opposed to relatively commonplace CO2 tanks, and the relative expense of the powerplants (CO2 operates at a much lower pressure and is somewhat self-regulating, thus cheaper than PCP) would have bolstered his argument, not negated it.

[cringe]

Though the invention of PCP predates CO2 by some margin, I don't think PCPs were commonly available at the time. Even if they were, the need for an expensive scuba tank as opposed to relatively commonplace CO2 tanks, and the relative expense of the powerplants (CO2 operates at a much lower pressure and is somewhat self-regulating, thus cheaper than PCP) would have bolstered his argument, not negated it.

Hi, several years ago I experimented with building a 'sparklets' bulb powered gun. Not a rifle but a double barrelled .410 bore pistol, I was amazed at the power! and during my experiments I found that co2 works better in larger bores. I guess it's to do with expansion rates. I did not progress any further, as I don't like porridge! but it could have been even better if I had fitted some sort of heater device.
best regards Al

[Benelli B76]

Hi, several years ago I experimented with building a 'sparklets' bulb powered gun. Not a rifle but a double barrelled .410 bore pistol, I was amazed at the power! and during my experiments I found that co2 works better in larger bores. I guess it's to do with expansion rates. I did not progress any further, as I don't like porridge! but it could have been even better if I had fitted some sort of heater device.
best regards Al

Hence the latest .68 bore Umarex T4E HDS 68.


Baz

[cringe]

Hence the latest .68 bore Umarex T4E HDS 68.


Baz

To 45flint I apologise if I am interfering with your thread, and I am looking forward to your reviews [re spring verses co2].
this for attention of Baz, I googled that Umarex blar blar ! pistol and I am gob smacked! is that legal? it looks like a sawn of shotgun! they are promoting this as a weapon for self/home defence! I thought pistols were limited to 6ft/pounds in UK?
perhaps I spent too much of my time in the 1970's
kind regards Al

[45flint]

To 45flint I apologise if I am interfering with your thread, and I am looking forward to your reviews [re spring verses co2].
this for attention of Baz, I googled that Umarex blar blar ! pistol and I am gob smacked! is that legal? it looks like a sawn of shotgun! they are promoting this as a weapon for self/home defence! I thought pistols were limited to 6ft/pounds in UK?
perhaps I spent too much of my time in the 1970's
kind regards Al

I am fascinated by that sawn off shotgun. All good. Not sure my review will be much of one, lol. The biggest difference so far is the Mark 3 is almost silent and the 160 has such a crack that I really can’t risk shooting it much in the back yard. You can drum down the power on the 400 to back yard friendly but your plinking not hunting. But a 10 round mag makes it a lot of fun.

All three are more accurate than I am. Put the three on the table and have to choose which one to take home? I’m grabbing the Mark 3.

[Jerry Cornelius]

Hi, several years ago I experimented with building a 'sparklets' bulb powered gun. Not a rifle but a double barrelled .410 bore pistol, I was amazed at the power! and during my experiments I found that co2 works better in larger bores. I guess it's to do with expansion rates. I did not progress any further, as I don't like porridge! but it could have been even better if I had fitted some sort of heater device.
best regards Al

It’s probably nothing special about CO2, but simply F=PxA

A larger bore gives you a greater area, pressure is constant (particularly with CO2), so force increases. If I’ve done my sums correctly a 410 bore is 85mm2, and a .22 is 23.75, so you’ll be pushing the projectile with nearly four times the force

Velocity will probably be down (you may have more force but you’ve also got more mass), but as the limits are set on energy as you say it’s not really a project that can be safely conducted in the uk.

As for the springer vs co2 argument, a springer is in a sense more efficient as the transfer of energy to the pellet is adiabatic. However as the waste heat in a CO2 gun is created in the sparklet factory not the gun, it’s a theoretical point as far as the shooter is concerned. As for manners, I have a nicely set up FWB 127, and have just got an SFS Snipe, and tbh for both those guns (and also any good CO2 gun) the limiting factor on accuracy is me. So any slight benefit CO2 would have is moot

I would agree that for an average gun on an average day CO2 is likely to be more accurate though.

[cringe]

It’s probably nothing special about CO2, but simply F=PxA

A larger bore gives you a greater area, pressure is constant (particularly with CO2), so force increases. If I’ve done my sums correctly a 410 bore is 85mm2, and a .22 is 23.75, so you’ll be pushing the projectile with nearly four times the force

Velocity will probably be down (you may have more force but you’ve also got more mass), but as the limits are set on energy as you say it’s not really a project that can be safely conducted in the uk.

As for the springer vs co2 argument, a springer is in a sense more efficient as the transfer of energy to the pellet is adiabatic. However as the waste heat in a CO2 gun is created in the sparklet factory not the gun, it’s a theoretical point as far as the shooter is concerned. As for manners, I have a nicely set up FWB 127, and have just got an SFS Snipe, and tbh for both those guns (and also any good CO2 gun) the limiting factor on accuracy is me. So any slight benefit CO2 would have is moot

I would agree that for an average gun on an average day CO2 is likely to be more accurate though.

I like that, I don't understand it [yet!] shall have to look up 'adiabatic'? but as you say accuracy is down to the shooter.
kind regards Al.

[45flint]

I like that, I don't understand it [yet!] shall have to look up 'adiabatic'? but as you say accuracy is down to the shooter.
kind regards Al.

You would have to think that the average shooter will be more accurate with CO2 just because of the mechanics of the moving piston. But in real life in my backyard the Webley probably has the edge. It has far better sights and I would think a little edge on the trigger. But I’m used to spring guns and how to hold them.

[Jerry Cornelius]

I like that, I don't understand it [yet!] shall have to look up 'adiabatic'? but as you say accuracy is down to the shooter.
kind regards Al.

Sorry if you have already got it, but if not, you might be interested in the Cardew's book, Airguns from Trigger to Target. I don't think there is any question about how a spring powered airgun really works that they did not investigate.

Plus its in the finest British tradition of blokes in sheds, probably wearing cardigans, who really know their stuff.