PCP Beeman Commodore Underlever Wild Velocity Spread

[Billm]

I decided to break out my regulated .177 Beeman underlever for the latest challenge. I started by cleaning the barrel. It’s shooting erratically. I tried two different types of pellets, with and without moderator. It doesn’t have an adjustable regulator and so the only adjustment is the hammer spring. I haven’t shot the rifle much and so I haven’t adjusted the hammer. It was shooting 7.4 gr H&N pellets at almost 1100fps. The deviation was wild , as in 40-100 fps. I adjusted the hammer spring down to around 890fps, meaning 790 - 930fps lol. It is not leaking at the breeches, at least not that I could tell. I really don’t know what would cause these velocity swings. I also tried H&N Barracuda 10.65gr pellets. Any ideas?

 

[FL22]

I don’t know anything about those Airguns, just a wild guess, but leaking O-ring on the regulator from the tank to the Plenum??

 

[Billm]

I don’t know anything about those Airguns, just a wild guess, but leaking O-ring on the regulator from the tank to the Plenum??

Yeah, I have a feeling that I may be taking it apart soon lol.

 

[FL22]

Yeah, I have a feeling that I may be taking it apart soon lol.

Tear it down, it’s good for you, it builds character and all that other b.s. lol.

 

[PasadenaMike]

Inconsistent velocities could be from inconsistent hammer strikes , It could be it’s out of tune. It could possibly be a bad regulator. It could be a bad batch of pellets try weighing them. Could be a busted breech seal, barrel seal…….

 

[Billm]

Inconsistent velocities could be from inconsistent hammer strikes , It could be it’s out of tune. It could possibly be a bad regulator. It could be a bad batch of pellets try weighing them. Could be a busted breech seal, barrel seal…….

The inconsistent hammer strikes is interesting. The hammer adjustment feels somewhat sloppy and has little resistance and at certain points you get that spring twang, like when a spring is catching on something as it s being compressed. Thanks

 

[Billm]

Tear it down, it’s good for you, it builds character and all that other b.s. lol.

I’m already having nightmares about it lol.

 

[PasadenaMike]

The inconsistent hammer strikes is interesting. The hammer adjustment feels somewhat sloppy and has little resistance and at certain points you get that spring twang, like when a spring is catching on something as it s being compressed. Thanks

You’re probably onto something

 

[FL22]

I’m already having nightmares abut it lol.

I promise to give you all the moral support that I can muster .

 

[JimT66]

I’m already having nightmares about it lol.

I have both the regulated version and the unregulated.one, both in .22. I not been able to shoot anything lately due to health issues, but my regulated version one sounds remarkably similar to yours. The unregulated one shoots great, hard and accurate. I have read that the regulators in the new Beemans are for crap. Non adjustable to boot. Fwiw anyway.

 

[Billm]

I have both the regulated version and the unregulated.one, both in .22. I not been able to shoot anything lately due to health issues, but my regulated version one sounds remarkably similar to yours. The unregulated one shoots great, hard and accurate. I have read that the regulators in the new Beemans are for crap. Non adjustable to boot. Fwiw anyway.

Yep. It was my first pcp and so I didn’t know any better lol. I just assumed the spread was normal. The first six months my model didn’t even show up in their catalog. Now it does with no info. When I bought it a year ago, I sent Beeman a few questions via their support request. I’ve never received a response. Two or three weeks ago I used their support request to ask about the extreme spread. I got an auto response telling me that they were swamped due to Covid- REALLY? Still no response.

 

[JimT66]

Yep. It was my first pcp and so I didn’t know any better lol. I just assumed the spread was normal. The first six months my model didn’t even show up in their catalog. Now it does with no info. When I bought it a year ago, I sent Beeman a few questions via their support request. I’ve never received a response. Two or three weeks ago I used their support request to ask about the extreme spread. I got an auto response telling me that they were swamped due to Covid- REALLY? Still no response.

That's a pitiful no response if I ever heard one. Mine has been crap since the day it arrived as well. I knew something had to wrong compared to my unregulated version. I didn't even bother calling them after I googled its reviews, and read up on them.
Sometimes a shot or three are as good as my unregulated, then, squat. Nowhere near my other pups. So I dressed it up with unused parts and hung it on the wall. Figure it's a hangar queen now. Strip as or when needed.

 

[Billm]

That's a pitiful no response if I ever heard one. Mine has been crap since the day it arrived as well. I knew something had to wrong compared to my unregulated version. I didn't even bother calling them after I googled its reviews, and read up on them.
Sometimes a shot or three are as good as my unregulated, then, squat. Nowhere near my other pups. So I dressed it up with unused parts and hung it on the wall. Figure it's a hangar queen now. Strip as or when needed.

lol, mines hanging on the wall too. Hangar queen, haven’t heard that in years.

 

[JimT66]

Some of us know about that little phrase. Younguns probably not so much.