Canadian Airgun Forum

Does anyone have any ideas or experience in getting a little more power out of air pistols?
I've got 2 UMAREX BB air pistols and an old Daisy pellet pistol that is like new. The 2 UMAREX pistols are very well built and realistic in appearance and operation but my old Daisy actually hits harder, probably partly due to being a pellet pistol. But the build quality and appearance doesn't come close to my UMAREX M&P 40 and my Beretta M92 A1.
I've read articles and seen a few videos where guys have done what's called "dieseling" but I don't really want to go that route. It seems like more of a hassle than anything else and it might do some damage to the firearm and seems like it can be inconsistent and unreliable.
I'd like to get a bit higher fps which should result is hitting a bit harder and being more accurate for longer distances.
I've seen where a few guys have attached barrels that were extended a few inches and you can get an increase in fps but also extending a barrel too much actually reduces performance. I haven't seen anywhere that extended barrels can be bought.
Understood there's only so much that can be done and still remain reliable and also some places have laws limiting airgun power but if it's possible to get a little closer to how my pellet pistol performs I'd like to give it a try.
Any suggestions?

I am assuming the BB pistols are CO2 powered. Can't help you with power increases, sorry. As well, a power increase is unlikely to increase accuracy.
Without the benefit of rifling to stabilize the 'round steel shot', increasing the speed is unlikely to improve accuracy. Different makes of BB's are slightly
different diameters. One might have to try different makes to find one that is more reliable, accuracy wise, in your pistols. If the barrels were rifled and
you could use lead round shot, then you could possibly fiddle with velocity trying to achieve better accuracy. The closer you can get a steel BB to fit the
bore, the better the potential accuracy will be and the "harder" it will shoot. BB's, being steel are all smaller than the bore. Different sizes will allow more or
less gas past the BB while it travels down the bore to the muzzle. This loss of gas pressure directly effects the velocity of the "shot".
In Canada, if a pistol produces over 500fps AND 4.2fpe, it then becomes a restricted firearm. If the barrel is less than about 4 1/4" in length, it also becomes
a prohibited firearm.

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Best Wishes
Daryl

I'm aware of everything you've noted and I already assumed the best way I might be able to get a bit more power might be to find a custom barrel a bit longer than stock, maybe even rifled, if that's possible. I believe it was on a video of the Airgun Detectives YouTube channel where he had mentioned he had experimented with longer barrel lengths to get a bit more power and fps and that it does work to a point until you go too long then it becomes counter-productive. He did say the barrels he tried were one-off experimental and he was doing the testing to find out what the optimum barrel length might be.
Attached is a screenshot from the Canada RCMP website defining the laws for BB guns and pellet guns, and you are correct in what you say. Airsoft laws are a bit different, but since I don't own any airsoft firearms I'm not mentioning those.
I'd like to get somewhere within the upper range between 400-500 fps and still be legal. I already do own handguns and I've gotten interested in BB and pellet pistols so I might be able to have a bit more freedom to enjoy this hobby in the great outdoors rather than be restricted to a firing range.

A rifled barrel will likely not help accuracy, due to the BB not being engrave by the rifling.
The only possibility it would help, is if the bore was smaller, thus less windage between the BB and the bore.
That might help accuracy but there is still air pressure loss due to the rifling grooves.

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Best Wishes
Daryl

I forget exactly which of the YT Airgun Detective's videos it was that he mentioned the testing with different barrel lengths because the main subject of that video was something else and he's got a lot of YT videos so a guy would have to try and find that specific video. It would probably be quite a mission to find it. I also don't recall if he mentioned he was doing his testing with a BB pistol or pellet pistol. Regardless, the logic of containing the propellant pressure a split second longer using a barrel with a longer length should result in better velocity, no matter what the clearance might be between the BB/pellet and the bore of the barrel. Closer tolerance should be obviously better you'd think.
Anyway, if anyone knows custom barrel lengths are available and do result in better performance, I'd be interested.

Have to say sorry first as you really couldn't expect too much on power and accuracy on a replica pistol, especially it's a BB gun.

You seems did the homework well and understood actually the round steel BB is uncontrollably rolling in the barrel after you pull the trigger... If in an airsoft replica, you can adjust the hopup setting to affect it a little bit, but for the steel 4.5mm BB, you couldn't do too much even if your pistol said has the top-up adjustment....

For an extended barrel replica, yes, there's a few in the market, for example, the famous CP88 competition. It surely give you some more fps and increase the accuracy. But that's (almost) the best they can offer... Because it's also limited by the co2 power plant...

And, that's not a after market tuning job for handy person like ' fit a barrel to the old gun in garage thing'...

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~Plinkers~
FX-M3-22 Compact#PP700-Carbine#Diana48-177#XS28M-25@26fpe#HW45 Beast#AW-Custom Z-Killer DE
~Competitors~
FWB300SU#Tau-7#IZH-46M#FWB-65#CP88-C
~Target~
HW 30s/35e/97k/40+Extender/P3+Scope/70#CZ200s Laminated@10fpe#AA ProSport-177@12fpe

You might lose accuracy with more power in a BB pistol. More speed might also mean more side spin on the BB.

If you are looking for more speed from a CO2 pistol you could add the longer barrel and tinker with the valve volume and hammer spring tension to increase flow. I'm not sure if it's even possible to get much more out of the clone pistols and I'm not aware of anyone who has tried. You would be better off making up a Crosman 1740 to the legal limit.

I'm not familiar with them. I'm guessing the 1740 is a .177caliber pellet and the 2240 is .22 caliber? And since you say "making up a Crosman 1740", both are able to be built to spec rather than bought of the shelf and ready for plug-and-play as the saying goes?

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We want a reduction to crime, violence and gun smuggling,
- they want a reduction in legal gun ownership.

Tracey Wilson, CCFR

Yes, the non blow back BB guns can give you a light more power and significant shot counts per co2, plus more accuracy... That's true but just not my cup of tea... Because buying a replica to me, the major purpose is not for power or accuracy, but for the real copy and collections...

If you really focus on power and accuracy, have to find something else...

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~Plinkers~
FX-M3-22 Compact#PP700-Carbine#Diana48-177#XS28M-25@26fpe#HW45 Beast#AW-Custom Z-Killer DE
~Competitors~
FWB300SU#Tau-7#IZH-46M#FWB-65#CP88-C
~Target~
HW 30s/35e/97k/40+Extender/P3+Scope/70#CZ200s Laminated@10fpe#AA ProSport-177@12fpe

You can get the .22cal Crosman 2240 in Canada (approx $80) but you can't get a detuned .177cal Crosman 1740 any more. You can buy parts to convert a 2240 to 1740 or better yet buy a Crosman 2300T or Snowpeak CP1-M.

https://canadashootingsupply.ca/product ... y-crosman/

https://canadashootingsupply.ca/product ... istol-177/

Here is a YouTube video I was shown today where this guy modified the firing valve, which is the valve at the top of the magazine. I'm not sure what model of air gun he did this modification to.
The valve in the video started as having 4 machined ports in which the outlets are 90 degrees to each other. The firing valve is modified so that instead of having 4 smaller ports it now has 2 large ports.
In the comments one guy says he did the modification and he got an increase from 268-276 fps on 0.25g bbs to 305-315 fps on 0.25g bbs. Interesting. I don't have a chronograph but if I could get a quality one that was accurate I might try this mod. I found a place that I can get the M&P40 firing valve for a little over $33 USD, which seems a bit pricey for this little small brass valve with a couple of seals.

https://www.youtube.com/watch?v=oQ0c1ew ... &index=124

Enlarging gas passages and piercing pin hole, giving the valve more volume, having more hammer strike and using a longer barrel are all good ways to get more velocity in a CO2 airgun. One may not necessarily be able to use all these mods, performance is in the details . I upped the velocity of my Daisy 74 BB rifle from 355 to 450 fps with a few simple mods.

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I've found a place where I can order seals and valves from for the UMAREX M&P40 and the M92 A1 so I might start with trying the magazine valve modification. But to evaluate this properly I guess I should do a before and after comparison using a chronograph. I see there's a wide variety and range of prices for chronos. Since I'd only use a chrono a few times a year I'd lie to find one that not expensive but accurate. And I think some chronos don't adapt easily to pistols. Compact would be good also cuz I see there's some that aren't. I see some guys have gotten chronos from AliExpress that were cheap but really, what can you expect from a $40 chronograph.....lol.

This Beretta A1 is beautiful
Too bad they never understood they HAD to make the Legendary 92FS instead ....

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