Akela .177 Shot String

[EPG]

I posted on this forum in the past regarding the amazing improvement in shot string with my .177 Akela and .22 Cayden by shortening the hammer springs from the stock 3.5” length to 2.57” for my Akela and 2.7” for my Cayden.

The Akela had a steadily declining (“cliff”) shot string when new. It was shooting even heavy pellets - 10.3g - way too fast (950fps) - and the hammer spring adjustment screw was backed all the way out (useless for tuning). The only way to get to a reasonable 860-910fps velocity was by closing down the “power adjuster” (transfer port restrictor) knob. I’d get about 25-28 shots before there was significant POI shift due to velocity fall off.

I’ve run 100 shot strings (a lot of effort) about 5 times since shortening the Akela’s hammer spring to 2.57”. Every time it showed that I now had 100+ usable shots. But I never got around to doing a “full” shot string - i.e. where the ending velocity matched the beginning velocity.

Over the past few days I did so. Results show that my Akela now gets 140 usable shots from a 3000psi fill (!!). The freakin thing is the 2nd cheapest airgun I own - and it shoots dime sized 5-shot 40 yard groups over and over again. The best group in this shot string measured .09” - yep - no kidding - .09” at 40 yards (40.38 measured with a green laser). And I’m not trying that hard when you are just firing off group after group.

I have done nothing else to the rifle other than adjusting the trigger to 11 ounce pull weight. So, if you have one of these Akela/Cayden/Kratos rifles with a steadily declining shot string (I’m certain that every .177 and .22 does) - then try shortening your hammer spring down to the lengths discussed above.

 

[dizzums]

why is 950 too fast for a 177? ..i like them about 1050 and id probably be shooting 7.9s ..

 

[EPG]

why is 950 too fast for a 177? ..i like them about 1050 and id probably be shooting 7.9s ..

Generally, diabolo shaped pellets are most stable under 900fps. The sweet spot for maximum stability/ accuracy while still retaining as much velocity (for flatter trajectory) as possible is 850-880fps.

Above 920fps, pellet speed enters the “trans sonic” zone, which creates some instability and therefore accuracy suffers.

There are always exceptions. For example, I own an RTI Prophet Performance.22 that has a very slow twist rate rifling (32-1). This slower spin rate allows higher velocities (up to 1050fps) while still maintaining good pellet stability.

 

[tcarlson777]

Great job presenting the data on your Akela, EPG. That is a very accurate rifle and what a great shot count! That is one of the reasons I’m thinking about buying a .177, the high shot count, and cheaper ammo. 

 

[biohazardman]

Shot 46 to shot 121 are within 20fps of each other. So, seems to me that would be a good fill pressure to use to stay within 20fps with your Extreme Spread and have the best accuracy for close to 80 shots.

Good job on the testing and good post.

 

[EPG]

Shot 46 to shot 121 are within 20fps of each other. So, seems to me that would be a good fill pressure to use to stay within 20fps with your Extreme Spread and have the best accuracy for close to 80 shots.

Good job on the testing and good post.

Agreed, I could fill to about 2600 and get a 20fps extreme spread.

However, at normal pellet gun distances of 25 to 50 yards, my experience target shooting has shown a minimal noticeable POI shift with even a 40fps spread. This is especially true with .177 (flat trajectory) being shot 870-910fps. The difference in POI due to a 40fps spread at 40 yards is likely less than the POI shift due to pellet to pellet variances if just shooting unsorted JSBs from the tin.

Thats why I think a lot of shooters should really test this and consider their use case before purchasing a pellet gun with dual regulators and 40+ o-rings (I’ve been there, done that). If you are typically shooting 50 yards and in, you don’t need a 3fps spread to achieve consistent accuracy. It’s crazy overkill IMO. I started with regulated PCPs and now own 3 unregulated PCPs. They all seem as accurate (Daystate Huntsman is crazy accurate) as my regulated guns.

Besides shortening the hammer spring, I also stripped my Akela to bare wood and refinished the stock with Tru-Oil.

 

[ToddGeddes63]

nice looking results on the stock. Thanks for the information on your adjustments. I have the cayden and it shoots good, I'm happy with it. I've thought about the Akela but the cocking lever being so far back, and on the right side, (I'm a lefty) would be a challenge. I still like to see results from owners and what they are doing with them.

TODD

 

[Hammer]

Are these springs readily available for experimentation? From Crosman?

 

[rdpjr6504]

They are but I have had 8 on order for over a month. They are said to be in stock by 1st of the month.

 

[Mhoad3544]

I posted on this forum in the past regarding the amazing improvement in shot string with my .177 Akela and .22 Cayden by shortening the hammer springs from the stock 3.5” length to 2.57” for my Akela and 2.7” for my Cayden.

The Akela had a steadily declining (“cliff”) shot string when new. It was shooting even heavy pellets - 10.3g - way too fast (950fps) - and the hammer spring adjustment screw was backed all the way out (useless for tuning). The only way to get to a reasonable 860-910fps velocity was by closing down the “power adjuster” (transfer port restrictor) knob. I’d get about 25-28 shots before there was significant POI shift due to velocity fall off.

I’ve run 100 shot strings (a lot of effort) about 5 times since shortening the Akela’s hammer spring to 2.57”. Every time it showed that I now had 100+ usable shots. But I never got around to doing a “full” shot string - i.e. where the ending velocity matched the beginning velocity.

Over the past few days I did so. Results show that my Akela now gets 140 usable shots from a 3000psi fill (!!). The freakin thing is the 2nd cheapest airgun I own - and it shoots dime sized 5-shot 40 yard groups over and over again. The best group in this shot string measured .09” - yep - no kidding - .09” at 40 yards (40.38 measured with a green laser). And I’m not trying that hard when you are just firing off group after group.

I have done nothing else to the rifle other than adjusting the trigger to 11 ounce pull weight. So, if you have one of these Akela/Cayden/Kratos rifles with a steadily declining shot string (I’m certain that every .177 and .22 does) - then try shortening your hammer spring down to the lengths discussed above.View attachment 207237View attachment 207243View attachment 207248

That was a great post. Did wonders for my 177 Akela and saved me many hours of time and energy. Thank you for your diligent research on this!

 

[Raysfan]

I did the same, cut down hammer spring snd finished the stock with tru oil on my .22 Akela. I really like mine good trigger and very accurate. Also very backyard friendly. Nice work

 

[douger]

LOOKS GREAT

 

[cyknife]

Utah had akelas for 299. Couldnt pass....

Came with both mags cracked on the loading plate. UA sent two more one of which was cracked. Hope they hold up.

Gun arrived with 3k in the tank. I shot three mags testing noise level down to 2.5k. Did the felt and hair curler in the shroud trick. It needs no extra moderation which is nice. Then I cut the spring down to 2.57" and shot two mags worth while manipulating the TP knob for a low of 599fps and a high of 1015fps using 7.9 gr cphp's and the hammer spring aduster at zero turns. Stopped at 2k ...so 70 shots with 1000 psi ---thats pretty efficient.

Haven't mounted optics yet so have no idea as to what it will do accuracy wise. Am waiting for cp domes 10.5 gr to shoot for effect.

 

[Pfddi]

I couldn't pass it up either! My son is trying to shoot rabbits in his yard with a BB gun and I have convinced him that is not a good idea. So I got the .177 Akela. I added a scope and noticed that it seemed to move around and my shots were not centering very well. So I went and bought the Buck Rail scope ring support and the tri rail that also supports the barrel to see if I could reduce any barrel movement. Not here yet, but if anyone else has done this, please chime in.
I will add the Tru-Oil to the stock and then add the mods at @EPG has so graciously outlined above! It really shows that you don't need a 2nd regulator to get a great shot string and decent performance out of an unregulated gun.

 

[Raysfan]

I couldn't pass it up either! My son is trying to shoot rabbits in his yard with a BB gun and I have convinced him that is not a good idea. So I got the .177 Akela. I added a scope and noticed that it seemed to move around and my shots were not centering very well. So I went and bought the Buck Rail scope ring support and the tri rail that also supports the barrel to see if I could reduce any barrel movement. Not here yet, but if anyone else has done this, please chime in.
I will add the Tru-Oil to the stock and then add the mods at @EPG has so graciously outlined above! It really shows that you don't need a 2nd regulator to get a great shot string and decent performance out of an unregulated gun.

The Buck Rail barrel band is outstanding. Solidified the barrel nicely. I was have an inch POI change when I put on a moderator. Gone now. You will enjoy the cheap upgrades.

 

[Tomygun1]

E,
Your input and work with hammer springs on Caydens and Akela’s was spot on, and after trimming mine I was also able to increase my shot count while keeping my velocity above 900fps by adjusting the venturi with both 177 and 22cal. That was important to me as I shoot 75yds so I need the velocity. I call that success.

So I also experimented with my Diana’s and Crosmans by trimming the hammer springs. That didn’t work at all. All that accomplished was a loss of velocity with a shot count gain that pretty much didn’t matter. With these I am in the process of going back the other direction by adding at least a full factory hammer spring. My next experiment will be with duplex hammer springs. I see many possibilities of screwing two light weight springs together for a progressive response. So far it looks promising and if it works out I will try this in the future on the Cayden and Akela’s to see what happens. Anyone already tried this?

Tom

 

[MileHighAirGunner]

I couldn't pass it up either! My son is trying to shoot rabbits in his yard with a BB gun and I have convinced him that is not a good idea. So I got the .177 Akela. I added a scope and noticed that it seemed to move around and my shots were not centering very well. So I went and bought the Buck Rail scope ring support and the tri rail that also supports the barrel to see if I could reduce any barrel movement. Not here yet, but if anyone else has done this, please chime in.
I will add the Tru-Oil to the stock and then add the mods at @EPG has so graciously outlined above! It really shows that you don't need a 2nd regulator to get a great shot string and decent performance out of an unregulated gun.

Yes there have been some that have experimented with twin spring set ups. https://www.gatewaytoairguns.org/GTA/index.php?topic=194057.0

 

[MileHighAirGunner]

The Buckrail tri rail barrel band and scope rail support are nice add ons. The quality was surprisingly quite good I thought, especially for a 3D printed part and they fit perfectly.
The Turkish walnut stocks come rather dry but a few coats of True Oil really brings out their beauty. I like glossy wood stocks though. Mine can use a few more coats and a little more polishing I think.
Overall I’ve been quite happy with my three Akela’s.

 

[DARKHORSE1967]

Airgun Revisions sells tuning spring kits for the Craftsman Series.

 

[maxtrouble]

There is a gentleman on here called @thammer that does a lot of tuning with these rifles with great success. Send him a PM about your rifle and see what he can recommend.