Brocock/BRK BRK Ghost Wheel only lowering FPS by 10

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Triggs75

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Oct 9, 2023
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Pleasant hill, California
Ok so I went for the FX pocket chrony instead of buying a new microphone for my lab radar since it looks so easy to set up compared to the Lab Radar.

I have my regulator set at 120 BAR and am shooting the JSB 18.3gr pellets with the wheel set to minimum. In my other thread I was stating that I was not getting that many shots before I have to refill the tank so I lowered the reg to 120 and set the wheel to minimum.

Wheel set to minimum is am still getting 916 FPS and then set the wheel to max and am getting 923 FPS. It appears the wheel is not working - thoughts?

I will try to call AOA tomorrow but I can only imagine how busy they are with the holiday shopping going on right now.

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Any help appreciated.

Thank you, Chad
 
From your other thread....."
Gun is BRK Ghost .22 plus. Reg is set to 150 and had the turn wheel on the back set to max. Shooting JSB 18.3gr and was getting about 50 shots with the gun filled to about 3300 psi. After the 50 shots the shots were really dropping. I only got about another 20 shots before the reg was in the yellow and the gun was only shooting about 100 psi."

I think that was before you had a chronograph? You didn't mention a speed with the reg @ 150bar, but to only get 50 shots means you were shooting those 18.1s pretty dang fast. I think 140bar might also be too fast for 18.1s....but it's hard to say without knowing which of the hammer springs your gun has in it.

To get 650-750fps with 18.1s I think you're going to need a really low reg pressure, like 80-100bar. You also won't get much fps change from min to max at that lower reg. But again, it's hard to know for sure without Knowing which hammer spring you have.

There may even be a possibility of needing a lighter hammer spring for your desired speed of 650-750fps, and a heavier hammer spring for when you want to push those same 18.1s to the typical 890-920fps where they really shine.

The Ghost has three primary means of adjusting the power output, not counting the weight of the chosen projectile. Those three are the strength of the hammer spring itself, the preload you put on the hammer spring (via the power wheel), and the regulator pressure. Finding the balance between all three of those adjustments takes some documentation. And you also may need to accept that your low power desires and high power desires might need two different hammer springs.
 
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Thank you for your reply. You are correct I didn’t have the chrono at the 150 bar time.

I will increase it back to 140-150 and see if it will adjust the 100 or so fps.

And will adjust to the 80-100 on the reg to see what that does. I assume it is ok for the gun and I lower that much?

Also I will look at the lighter spring to possibly swap in and out depending on my needs.

If I get the .177 barrel conversion kit, I assume those will hit lighter for plinking in my home? If so looks like I got to drop some more money 😬.

Thank you chad
 
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Triggs75 said:
Thank you for your reply. You are correct I didn’t have the chrono at the 150 bar time.

I will increase it back to 140-150 and see if it will adjust the 100 or so fps.

And will adjust to the 80-100 on the reg to see what that does. I assume it is ok for the gun and I lower that much?

Also I will look at the lighter spring to possibly swap in and out depending on my needs.

If I get the .177 barrel conversion kit, I assume those will hit lighter for plinking in my home? If so looks like I got to drop some more money 😬.

Thank you chad
Click to expand...

Yes, 80-100bar should be well within reason for your regulator. One of the valves in my Ghost would leak if the regulator was set down around 60-65bar. But I haven't had any trouble with reg pressures above that.

Yes, the .177 would be one option for lower energy indoor shooting. A cheaper option (won't have to buy another barrel kit) might even be a lighter weight of .22 pellet, something in the 14 grain territory. Get those down around the 650fps that you mention and youre in plinker paradise, it'll be quiet, just barely sip air, and be safer. But I can almost promise that you'll need a lighter hammer spring than what you have to get 650 with 14grain pellets.
 
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This is the spring (on left) that I've swapped with the OEM spring (right) that was on my .22 Ghost Carbine (US version). I've powered down my Ghost to shoot at 650 FPS with 14.3 grain pellets. Although it's shorter, it's a little stiffer. My Ghost's regulator set point is 60 BAR and power wheel is on setting 17 to produce 650 FPS. I got the spring at Ace Hardware. I have a spare--if you can't find one at your hardware store, let me know and I can send you mine.
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spinj said:
This is the spring (on left) that I've swapped with the OEM spring (right) that was on my .22 Ghost Carbine (US version). I've powered down my Ghost to shoot at 650 FPS with 14.3 grain pellets. Although it's shorter, it's a little stiffer. My Ghost's regulator set point is 60 BAR and power wheel is on setting 17 to produce 650 FPS. I got the spring at Ace Hardware.
Click to expand...

I also experimented with a shorter/stiffer spring like that, also from ACE. Ghost valve is very receptive to changes in the rate of the hammer spring and opens alot of opportunities to get exactly what you want. I noticed a very different "feel" to the cocking with the short/stuff spring. Hardly any effort to cock until the cocking lever is through most of its travel, and then you feel the spring start to compress. There seemed to be some potentially positive effects in the shot cycle/air conservation by making the already free flight hammer even more free flight via use of a much shorter spring.
 
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Franklink said:
I also experimented with a shorter/stiffer spring like that, also from ACE. Ghost valve is very receptive to changes in the rate of the hammer spring and opens alot of opportunities to get exactly what you want. I noticed a very different "feel" to the cocking with the short/stuff spring. Hardly any effort to cock until the cocking lever is through most of its travel, and then you feel the spring start to compress. There seemed to be some potentially positive effects in the shot cycle/air conservation by making the already free flight hammer even more free flight via use of a much shorter spring.
Click to expand...
Yes, the lighter cocking effort as a result of the short-stroke spring pays dividends in terms of air efficiency, less stress on the valve, and a lighter trigger-pull break.
 
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You just have to remove the drop down portion of the rear assembly.

One bolt to remove the plastic buttpad first, don't lose the square nut.

You won't need to disassemble as far as this photo but it's the best I have to illustrate. Yours will look like the one on the right. Remove the three bolts that are at the top in the triangular pattern. And also the lower bolt that is in the top portion of the groove for the plastic butt plate.
Screenshot_20231125-102819.png

That aluminum drop piece that the plastic buttplate bolts to will now fall off.

The hammer tension wheel looks like one of these...cone shaped end fits into the back of the hammer spring.
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Hammer tension wheel has nothing holding it at this point. It'll fall right off the gun, hammer spring is in that hole, tip the gun up and it'll fall out. Don't lose the ball bearing in the hammer wheel.

When you're putting it back together, be careful of the pattern in which you tighten those four bolts back down. You can inadvertently create a bit of a bind in the cocking. It'll still cock with the bind, but not smoothly. If you end up with a binding side lever, revisit how you tightened the four bolts that hold this rear part to the rest of the gun.
 
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I spoke with Chris, I believe was his name, from AOA regarding the minimal change in fps when changing the wheel and he thinks there might be a HP spring in my rifle. He is sending me a lighter hammer spring to place in my rifle to see if that does the trick.

Hope to get it by end of this week but with the holiday madness all businesses get it might be a little longer.

Will update post once received and tested.

Thank you all

Chad
 
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Quick update and will update more tomorrow.

I received the new spring from AOA today and swapped it out with the one in my rifle and there is a noticeable difference. The new spring is one coil less and much easier to squeeze together in your fingers vs the one in the rifle. The one in the rifle seems to be the HP spring in a plus rifle.

Will do some test shots tomorrow. So for anyone whose wheel does not adjust the fps you prob have the HP spring in your rifle.

Thanks for the help

Chad
 
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The spring did the trick. Set reg to 125 bar and with the wheel set to min was get in the high 680s and set to max was about 905 fps.

That is just amazing being able to change your fps by 220 fps on the fly by just spinning the wheel.

Below is half a mag on min and half on max on the wheel

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I feel a bit like a broken record but yes, getting the balance between spring rate and reg pressure opens up the magic of the Ghost.

In a perfect world I'd love to see the barrel kits include the option of various hammer springs. Ie somebody buying a .22 HP barrel should get the 0.047 and 0.052 wire hammer spring with it, or at least be advised that they're likely to need those springs also.

Glad to hear youre getting the fps swing you were hoping for, really does open up the possibilities.
 
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