Tuning How to maximize consistent power shot count on Benjamin Akela .22

I just bought a Benjamin Akela .22 to use for target shooting only in my 10 meter Olympic target range. I do not need high power but consistent velocity and maximum shot count per fill. I would prefer not to install a Lane regulator just now since I do not wish to void the 5 year warranty. I can shorten hammer spring and other mods as others have done but I do not need high velocity for target work. Any ideas welcome since I am new at this.
 
Without a regulator...

1. Choke down on the transfer port
2. Apply some form of hammer debounce device. Either an SSG or bstaley O-ring buffer would be my choice*
3. Experiment with the hammer strike to get a useful bell curve starting at 3000psi or less.
4. If the energy is more than you want, choke down on the transfer port some more. If it’s less than you want, open up the transfer port. 

* An SSG requires some DIY fabrication. A bstaley requires none...all you need are O-rings but it can sometimes require several iterations of trial and error to get the results you want.
 
Yes, from what I’m seeing online, the Akela’s power wheel influences the transfer port.

I’m sure someone has curated a nice introduction on both the SSG and bstaley techniques but I don’t have them at my fingertips. I expect you’ll find plenty of examples of each with a search, some with detailed tuning steps, and fewer still that go into the theory of operation. I suggest you at least sift through a few threads to get the gist of it, and I’ll be glad to field specific questions from there. Later when I get some time I’ll search my notes and links for suitable tutorials.
 
Here's a little something to help familiarize you with a bstaley O-ring buffer. I'll explain about the SSG in a follow up.

In its simplest form, it is just a stack of O-rings placed between the hammer and valve:


When you pull the trigger and the hammer flies forward and smacks the valve stem, it also hits the O-rings. The result is less lift and dwell which reduces the amount of air released by the valve, whereby giving you more shots at lower power.

Refer to this example:


See the blue curve at the top? The marking "3)70D" means qty 3 70 durometer O-rings and "0T" means zero turns on the hammer spring adjuster (minimum hammer spring tension). The velocity peaked at over 1000fps which is no good for pellets and the shot count was abysmal.

So I swapped out one of the 70 durometer O-rings for a harder 90 durometer, making the stack a little more firm overall, and also added a flat washer to make the stack a little taller. Then I plotted a couple more curves with differing amounts of hammer spring preload (3.5 turns and 1.5 turns as you see labeled).

The results were much closer to what I was looking for. I settled on the red curve in the middle. That took the power down from 18fpe to 14fpe and the number of useful shots (inside of a 4% extreme spread) more than doubled from 12 to 29. The total energy on a fill also increased by 66% (from 273fpe up to 454fpe).
 
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That seems to be a very useful and easy to do mod. The Akela has a trimming power port that can be turned down as well limiting the amount of air into the valve. I am wondering if having this turned to minimum or maximum would make a significant difference with the tuning above. Next would be where to source proper sized and durometer O rings for my specific rifle. All this seemed to be done with out shortening the hammer spring. Thanks for sharing, the visual really helps me grasp who this is done.
 
If this is of any use to you I used my new chronograph to measure my FPS using the CPHP 14.3 gr. pellets. Full power yielded 950-970 FPS. Yes, you're reading that correctly :). Lowering it 2 notches brought me to about the 860-870 range. I now have it set in the middle which is where I'll keep it for this pellet which is now shooting at 840-850 fps. This will improve my shot count and significantly reduce the noise level. And it's still shooting a pretty decent fps.
 
FYI, I ran across this thread on GTA showing an example of an SSG for the Akela:

https://www.gatewaytoairguns.org/GTA/index.php?topic=176720.0

And in it, Troy indicates the tube ID is 30mm. That detail may inform the O-ring size you would need for a bstaley buffer, but it wasn't sufficiently clear to me that hammer rides in the same 30mm space. 

It looks like he has a related thread here on AGN so you may want to try reaching out by private message to see if he can advise on it.

https://www.airgunnation.com/topic/benjamin-akela-22/
 
I now have it set in the middle which is where I'll keep it for this pellet which is now shooting at 840-850 fps.

The OP would probably benefit from a more significant detune since he's interested in 10m duty. A popular velocity range is more like 500 - 600fps, sometimes less. It makes for super quiet shooting in long-barreled rifle and long, long shot strings on a fill so that's more along the lines of what I was thinking. However if the 800s suits your needs, by all means keep it simple and enjoy it. The most important thing is to have fun!
 
Nervoustrig is right. I would like to detune this to around 500 fps for target only work at 10 Meters. I have no need for higher velocities for punching paper, so maximizing my shot count with a lower velocity would be ideal for my particular situation I do no hunting and am limited in my back yard to a 10 Meter setup. I am in a power chair, on oxygen, and have only one eye so my needs differ significantly from most of the advanced shooters here. Been there done that with my fully tricked out Air Force Talon with 24" Lothar Walter target barrel and custom LDC. Too powerful to shoot in my location anymore since I like to keep all my pellets on the property. Thanks to all you guys with suggestions. We are going in the right direction just need to go a little further for my needs. I could put a regulator in this Akela but don't want to void my warranty, so any mods done need to be reversible just in case I need the warranty.
 
I now have it set in the middle which is where I'll keep it for this pellet which is now shooting at 840-850 fps.

The OP would probably benefit from a more significant detune since he's interested in 10m duty. A popular velocity range is more like 500 - 600fps, sometimes less. It makes for super quiet shooting in long-barreled rifle and long, long shot strings on a fill so that's more along the lines of what I was thinking. However if the 800s suits your needs, by all means keep it simple and enjoy it. The most important thing is to have fun!

..I'm open to any and all suggestions. Dropping it down further is a simple twist of the TP so I will certainly give it a try at a lower setting to see what my results are.
 
The O-ring buffer is one of my favorite tuning methods on the Prod. :) It may work well with the stock over-sprung hammer on the Akela.

FWIW: On, the Akela, there will be some implementation problems/issues to work out.

The hammer has a "big nose" on it. A different bumper, narrow/tall O-ring stack, or turning down the nose are possible solves.

IMG_5520.1639049073.jpg


It uses a heavy cocking lug, that is locktited to the hammer, and needs to be removed to exit receiver. It uses a narrow screwdriver slot for removal, vs the stronger hex key. Plan on using some heat to remove it. Access from the top is good, with rail removed.

I'd leave the TP restrictor on full open. I like to open the ports when using the buffer, but these Craftsman guns have some restrictions that make that limited. The power wheel has little room for enlarging, and valve exhaust is near an O-ring groove.

Parts are available from crosman. Spring was $3.50 and hammer was $10.

If you try the buffer, definitely like to see your results.


 
I am by no means mechanically inclined however a friend of mine had converted his Maximus to a euro sub 10 foot pound rifle by swapping his factory high power Maximus parts with factory parts specific to the England sub 12 foot pound model variant. He ordered all the factory parts from a Crosman parts dealer somewhere in Europe.

He had planned on going even lower by adding a regulator I think it was 600 or 700 pounds psi. Still planned on filling the gun to 2000 pounds psi. Not sure if he went for it. I was curious since I own a Maximus too.

I would think regardless of what you do Crosman may suspect you opened up your gun even if you swap back the original parts especially if they have a record of you ordering extra Akela factory parts from them. That is if you ever send your gun back for warranty and if not extra careful with the screws.

I have seen simple power reduction done by the 3 oring hammer to valve pin buffer mod and transfer port reduction using skinny pen ink insert tubing shoved inside the factory transfer port to epoxy plugging and drilling out a smaller hole. Plus same diameter thinner wire hammer spring matched from the local hardware store then shortened if needed.

Was going to have mine done at that time too but changed my mind and rather have the normal power in case I needed to kill pests at 50 yards and only did the oring buffer mod which did lower the power a little.

I would order a replacement barrel and alot of extra baffles to take up the slack space and have a machinist shorten it from the breach end by possibly half the length. Should be instant slower shooting and really quiet too. Probably order a replacement shroud too to chop and threaded to the same length as the end of the air reservoir shortening the overall length maybe by a few inches.

Or just buy another Akela for $350 that someone mentioned on this forum which I recall reading recently as well as the Cayden selling for the same price.

Run the second one low power. Chop it add a regulator and mod it go for it.

If it were me I would opt for something in 177 since the ammo is cheaper if low power close target shooting is to be done especially in a 10 meter match shooting environment.

You could sell your Akela to someone who doesn't know they can be bought for $350 especially to someone who did not read this reply and go and buy a BSA Ultra in 177 or the BSA mini that is half the power specific to 10 meter and youth shooting. The one that cost around same as the retail selling price of the Akela.

Or a T200 something like that. It is a CZ Air Arms 177 single shot target rifle. I think that is $500 or $550 if you shop around.

If you are shooting at a 10 meter match scoring on 10 meter targets I would think you would be at a disadvantage shooting 22 caliber versus everyone else shooting 177. Less wiggle room in the center bull with the larger diameter pellet?

If there is a return policy for your Akela especially knowing they can be had for $350 if you paid more than $350 and you really are into low power 10 meter shooting then I would return it and buy a more purpose built 177 for obvious reasons including more accuracy advantage scoring on 10 meter target bulls higher shot count use less air quieter shooting cheaper ammo better trigger and so fourth. That's just me though.






 
Here's a little something to help familiarize you with a bstaley O-ring buffer. I'll explain about the SSG in a follow up.

In its simplest form, it is just a stack of O-rings placed between the hammer and valve:


When you pull the trigger and the hammer flies forward and smacks the valve stem, it also hits the O-rings. The result is less lift and dwell which reduces the amount of air released by the valve, whereby giving you more shots at lower power.

Refer to this example:


See the blue curve at the top? The marking "3)70D" means qty 3 70 durometer O-rings and "0T" means zero turns on the hammer spring adjuster (minimum hammer spring tension). The velocity peaked at over 1000fps which is no good for pellets and the shot count was abysmal.

So I swapped out one of the 70 durometer O-rings for a harder 90 durometer, making the stack a little more firm overall, and also added a flat washer to make the stack a little taller. Then I plotted a couple more curves with differing amounts of hammer spring preload (3.5 turns and 1.5 turns as you see labeled).

The results were much closer to what I was looking for. I settled on the red curve in the middle. That took the power down from 18fpe to 14fpe and the number of useful shots (inside of a 4% extreme spread) more than doubled from 12 to 29. The total energy on a fill also increased by 66% (from 273fpe up to 454fpe).
what is the gun on that tune nt?
 
Cmon guys. Cut the hammer spring to 2.8” (for .22) get a nice flat curve, and then he can use transfer port adjuster knob to tune to 500fps. This is a five minute job. If it’s a .177 caliber, cut hammer spring to 2.57”.

The Craftsman series guns are oversprung from the factory. I would start with this simple spring adjustment (via shortening it) before trying any of those complex mods. If you want to go back to the stock 3.5” spring, they $3.50 from Crosman.

Hope this helps

Ed

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Cmon guys. Cut the hammer spring to 2.8” (for .22) get a nice flat curve, and then he can use transfer port adjuster knob to tune to 500fps. This is a five minute job. If it’s a .177 caliber, cut hammer spring to 2.57”.

The Craftsman series guns are oversprung from the factory. I would start with this simple spring adjustment (via shortening it) before trying any of those complex mods. If you want to go back to the stock 3.5” spring, they $3.50 from Crosman.

Hope this helps

Ed

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cutting the spring yeah but tp restriction is wasteful