After Market Valve For Beeman Chief?

[USAFANG6799]

Will any of the aftermarket valves fit the Beeman Chief without major modification? Possibility the QB valves?

Many thanks!

[Ribbonstone]

QB's would be way too small a diameter for the size of the Chief air tube...but if it's more power you are looking for (from that 2K tube),i';s look for betterair flow rather than a better valve (as it's a pretty "clean flowing" valve...as in not to obstructed) to start with.

[USAFANG6799]

Not necessarily looking for more power but better air efficiency use. I've noticed that from looking back at chrono data my shot count has been diminishing.
I recently replaced all the orings with little or no improvement. Holds air now much longer with no leaks for days on end. No air being vented past the probe using tissue test. This leads me to believe the valve is not using the air efficiently.

Many thanks for answering because you and Bob have done many reviews on your Chiefs.

Hope all is well is Cajun Country.

[Ribbonstone]

Not sure what to expect from the new ones...mine is one of the early ones that didn't come with a "power adjuster" (external striker spring adjuster),so it was a matter ofopeing it up and shortening or spacing the spring for adjustments.  Thought I would make an adjuster, but got pleased with the results for now and never have bothered.

With that said, do think they have potential....but like you, not real sure how well they are set up for efficient air use.

Avoided running efficiency numbers as I'm not sure what the actual volume of the air tube is...I've seen 135cc's, but my mreasure must be off as I kept coming up with 150-155cc's.  (Yeah...when it doubt, take the air tube off and fill it with water...then measure the water and dry out the wet tube.)

If 150cc's is right, can manage something like a ho-hum 1.25FPE/cuin (would be 27 shots inside 4% with 18gr. @ 770fps).   If 135 is the right volume, would be more like 1.4 FPE/cuin (which would be impressive considering all I did was fiddle with the striker spring).

So I gotta ask....how high do you have it cranked up?

Didn't find nearly as many shots  just a little faster (like 26-27 foot pounds) OR as many good shots cranked down much lower (like 19-20 foot pounds), for whatever reason it just liked that one area.

Guess it makes more sense with a page from the notebook.  Generally keep track of the total energy inside 4% as a guide to efficency.  So the total (from the top down) here runs from 502 foot pounds to 648 foot pounds.



Am sure there is more of either (energy/shot count)to be had if I want to go in there and fart around with the guts.

[USAFANG6799]

So I gotta ask....how high do you have it cranked up?

Well I had a nice worded explanation to your question but after I clicked on the "Post" link............POOF it did not post and lost it all 

Short answer is I have not been keeping track of it because the same turns don't always equal the same results according to my chrono.
I attribute that to being a sub $200 PCP.

[Ribbonstone]

Bob and I swapped photos in one post or another, the parts in mine are slightly different than the parts in his newer versions...are some small differences in strikers, the new ones have a "power adjuster",  evidently some change to the bolt probes, and very likely a few other things along with those.

It'skind of like the first Discoveries.  Folks were complaining about the firsts ones being not powerul enoughfrom the factory and runnin best at lower than max. pressure.  Today,it's much more common to see complaints about out-the-box rifles shooting fast and rapidly declining velocity (short shot count).


Basically, they change stuff and don't bother to tell us. Which is pretty much true of several other brands.



From what I can say from mine in .22, something like 25 shots at 25 foot pounds inside 4% velocity varation would be a "good" tune.    Could revise things so that 625 foot poundtotal could be something like 34 shots at 18 foot pounds or 30 foot pounds at 20 shots.

[USAFANG6799]

Bob and I swapped photos in one post or another, the parts in mine are slightly different than the parts in his newer versions...are some small differences in strikers, the new ones have a "power adjuster",  evidently some change to the bolt probes, and very likely a few other things along with those.

Yep I read Bobs in-dept review and found you two guys were the best when it came to getting to know the Chief.
Mine was like Bobs but still found some things on his that were different than mine in the hammer design.

It's kind of like the first Discoveries.  Folks were complaining about the firsts ones being not powerful enough from the factory and running best at lower than max. pressure.  Today,it's much more common to see complaints about out-the-box rifles shooting fast and rapidly declining velocity (short shot count).

I also have a Discovery that was less than satisfactory. But after some TLC which included a complete reseal with a power adjuster it's my go to rifle to take out a critter robbing the bird feeder.

From what I can say from mine in .22, something like 25 shots at 25 foot pounds inside 4% velocity varation would be a "good" tune.    Could revise things so that 625 foot pound total could be something like 34 shots at 18 foot pounds or 30 foot pounds at 20 shots.

Basically, they change stuff and don't bother to tell us. Which is pretty much true of several other brands.

It's called treating people like mushrooms. Keep them in the dark and feed them BS 

From what I can say from mine in .22, something like 25 shots at 25 foot pounds inside 4% velocity varation would be a "good" tune.

That's what I use for a benchmark to tune both the Chief and the Discovery. The Discovery is like my Marauder for dependability and reliability.
I'm hoping the Fortitude will be the three out of two for Crosman/Benjamin when I decide to buy one.

[USAFANG6799]

So I gotta ask....how high do you have it cranked up?

Rib, this is with the power adjuster turned in all the way. Looks like I could have gotten a few more shots but got tired of shooting :-)
Your thoughts please.

Created: 09/25/18 06:58 PM
Description: Beeman Chief - after all orings replaced
Notes 1: Crosman Hollow Point 14.3
Notes 2: 2000-1600 psi
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 14.30
Temp: 58 °F
BP: 30.32 inHg
Altitude: 0.00
#          FPS  FT-LBS      PF
26    806      20.63    11.53
25    809      20.78    11.57
24    820      21.35    11.73
23    827      21.72    11.83
22    831      21.93    11.88
21    831      21.93    11.88
20    839      22.36    12.00
19    845      22.68    12.08
18    851      23.00    12.17
17    854      23.16    12.21
16    859      23.43    12.28
15    865      23.76    12.37
14    865      23.76    12.37
13    872      24.15    12.47
12    868      23.93    12.41
11    872      24.15    12.47
10    874      24.26    12.50
9    866      23.82    12.38
8    857      23.32    12.26
7    850      22.95    12.15
6    839      22.36    12.00
5    830      21.88    11.87
4    819      21.30    11.71
3    812      20.94    11.61
2    809      20.78    11.57
1    796      20.12    11.38
Average: 841.0 FPS
SD: 23.7 FPS
Min: 796 FPS
Max: 874 FPS
Spread: 78 FPS
Shot/sec: 0.0
True MV: 841 FPS
Group Size (in): 0.00

[Ribbonstone]

The odd thing about your numbers is that it runs only over 400psi (2000-1600), which is a really tight pressure spread.

From your numbers, you managed to get26 shots....agree, only 15 of them were strictly inside of 4% (which might be 17 shots next time up). 

So estimating, you got 15 good 23 foot pound shots with about  300PSi (1900-1700psi).


So the real "clues" to this are:

1. It's running over a very short pressure range (but for that range, actually running quite well).
2. Striker spring adjusted to the max. and still started slow at max. rated (2K) pressure.

On a personal note....mineBy strict defination, more like ahots #6-#20 would be inside 4%...might get a different results  loves heavier pellets....15.9/16gr. - 21grains. I occasionly check it out with the lighter weights, but it's never done as well as it has with the moderately heavy weights.

One other "clue" is how much more energy a heavy weight pellets gets over a lite weight/standard weightr pellet.  It'spretty much a "given" that it will earn more energy, but if it is drasticaly more, then you can assume that there is a good bit of "extra" air being released e each shot.


Lets try to clear that up.

14.3gr. @ 850fps / 23 foot pounds might become  775fps/24 foot pounds when uing 18gr. pellets, but if the 18gr. numbers become something like 790fps/ 25 foot pounds...the valve is releasing a good bit more air per shot than the light weights can convert to energy.

So far, without doing any valve mods, the trend has been that lighter weight strikers/lighter force strikers have resulted in the narrow pressure ranges.  Stronger striker spring tensions.heavier strikers have resulted in a wider pressure range (but usually higher energy for about the same shot count.

[USAFANG6799]

I'll try it with 18 and 21 grains to check the results.

Many thanks for your insight!