Brocock/BRK BRK Ghost Wheel only lowering FPS by 10

Jump to latest Follow Reply
cavedweller said:
My experience in both the 17” and 23” barrel in .177, using the lowest power spring, regardless of pellet weight, is using more than 115/120 reg pressure will net negligible difference utilizing the power wheel and may actually result in some slower speeds. Don’t know why but it is a thing. Remembering that we don’t really want or need Diablo pellets moving faster than 915/920 fps. But I’d definitely check the hammer spring shoe as it may be loose.
Click to expand...

His gun is exhibiting behavior of only being able to reach plateau based on the pressure...which is indicative of balance valve issues or being over-sprung.
Experiencing no changes based on pre-load while he can attest to the cocking effort increasing means the adjuster is working as intended but is not performing as intended...

-Matt
 
Upvote 0
What sticks out to me is many people claiming this effect occurring, so I must assume all of their .177's come from the factory in such a state, either over-sprung or under-vented, and with no posted solution I wanna lean towards it being more complicated, such as the balance vent/chamber volume.

I could be way off base, but if it walks like a duck, and quacks like a duck, or in this instance, behaves like a Don Cothran valve, then the culprit very well may be the vent/balance chamber volume in the worse case, and best case the valve is over-sprung.

-Matt
 
  • Like
Reactions: msg1979
Upvote 0
My hp ft ghost is set at 100 bar pw 7 lightest kit hammer spring shooting 13.4 to 807 fps. My other ghost was originally a 25 now sporting a 28” 177 barrel shooting 13 gr hsb slugs to 1024fps with the spring that came in 25 and 140 bar. You should be able to set this gun up for most anything without much trouble so long as you pay attention to what its telling you. By the way in 25 cal 140 bar 33.9 pellets went 940
 
Upvote 0
cavedweller said:
Barrel length?
You will need to reduce reg pressure back to around 115/120 as for that weight pellet using the white FAC spring your PWR wheel won’t do much better for your speed.
To increase efficiency and effectiveness of power wheel you need to decrease or increase spring type but which spring is installed?
Also your hammer may have slipped a bit and require adjustment / retightening.
Click to expand...
Its the 23"
No the KO 13.43 slug normally needs 970fps.
 
Upvote 0
Solo1 said:
My hp ft ghost is set at 100 bar pw 7 lightest kit hammer spring shooting 13.4 to 807 fps. My other ghost was originally a 25 now sporting a 28” 177 barrel shooting 13 gr hsb slugs to 1024fps with the spring that came in 25 and 140 bar. You should be able to set this gun up for most anything without much trouble so long as you pay attention to what its telling you. By the way in 25 cal 140 bar 33.9 pellets went 940
Click to expand...
Due to Soren Drost (a Danish BRK / Daystate tester) The 28" have a bigger port and therefor able to reach more power than the 23" with smaller port
 
Upvote 0
Stubbers said:
What sticks out to me is many people claiming this effect occurring, so I must assume all of their .177's come from the factory in such a state, either over-sprung or under-vented, and with no posted solution I wanna lean towards it being more complicated, such as the balance vent/chamber volume.

I could be way off base, but if it walks like a duck, and quacks like a duck, or in this instance, behaves like a Don Cothran valve, then the culprit very well may be the vent/balance chamber volume in the worse case, and best case the valve is over-sprung.

-Matt
Click to expand...
Ill have the spring ratio within some hours when I dissamble the Ghost

I havent heard anything on different valves / updated valves - So I hope the problem is only at an overpowered spring.
 
Upvote 0
The transfer porting situation is interesting.
This is a .177 Carbine barrel and a .22 HP barrel...
Screenshot_20240914-222207.png

The 28" .177 mentioned above must be ovaled like the .22 HP in the photo I just shared.

Often see 75-80% of bore size mentioned as the max size of transfer port before loading issues (pellet/slug tipping into the transfer port).

A 0.125" to on a .177 would make it about 70-71%. So there's a smidge more to be had there for a round TP. Or the ovalized would increase the effective even further.

It's all about desired use though. If wanting to push s slug fast.....versus a nice air conservative 19fpe pellet tune...too big of a port can be worse than too small of a port, again, depending on desired use.
 
Upvote 0
Franklink said:
The transfer porting situation is interesting.
This is a .177 Carbine barrel and a .22 HP barrel...
View attachment 496205

The 28" .177 mentioned above must be ovaled like the .22 HP in the photo I just shared.

Often see 75-80% of bore size mentioned as the max size of transfer port before loading issues (pellet/slug tipping into the transfer port).

A 0.125" to on a .177 would make it about 70-71%. So there's a smidge more to be had there for a round TP. Or the ovalized would increase the effective even further.

It's all about desired use though. If wanting to push s slug fast.....versus a nice air conservative 19fpe pellet tune...too big of a port can be worse than too small of a port, again, depending on desired use.
Click to expand...
The upcoming performance version of the Delta Wolf and later Ghost comes with a 28" barrel with bigger port

I have access to a guy who mods barrels. Maybe I should have a bigger Transfer port done later in the process
 
Upvote 0
Problem found!
Why did they put the ekstra heavy spring in - that makes no sense.

"BRK labeled "light" had a wire size of 0.046inches. "Heavy" was 0.051. "Extra Heavy" was 0.057."

I've just made a claim to Krale that my powerwheel isnt working as intended. They must send me the right spring so my powerwheel starts working. There are no dealers in EU which have accesories to the Ghost. They only have the Ghost. So buying a spring set my self from UK will be +£90 with tax and fee :(

IMG20240915091924.jpg
 
Last edited:
  • Like
  • Love
Reactions: Stubbers and Franklink
Upvote 0
Success!

The 0.051" wire spring will push a .22 to 58fpe. I think you'd be up into the 20grain slugs before such a heavy spring would be necessary in a .177.

I use the 0.051 for 35fpe slugs in .20 and 58fpe pellets in .22. The 0.046-0.047" hammer spring works better for everything under about 35fpe. ("Better" being less cocking force, more air conservation, less harsh shot cycle).
 
Upvote 0
Franklink said:
Success!

The 0.051" wire spring will push a .22 to 58fpe. I think you'd be up into the 20grain slugs before such a heavy spring would be necessary in a .177.

I use the 0.051 for 35fpe slugs in .20 and 58fpe pellets in .22. The 0.046-0.047" hammer spring works better for everything under about 35fpe. ("Better" being less cocking force, more air conservation, less harsh shot cycle).
Click to expand...
Yes. Thank you to you guys that where spot on. I often see 100x options when asking for solutions inhere. Your councelling was right on spot. Thx!

Which spring would you recommend me if I want the powerwheel to finetune and not make big steps to the FPS.
 
  • Love
Reactions: Stubbers
Upvote 0
If there is no TP adjuster (something that chokes the transfer port), you would heavily rely on regulator pressure to tame the gun shooting light pellets vs tuned for shooting heavier slugs in the most optimal conditions (tuned 97% away from plateau for both light pellet and heavy slug).

Hopefully with the right spring, you can still create enough lift/dwell at a higher pressure for slugs, and then be able to lower the power wheel settings enough for lighter pellets to shoot 900~ fps.

There is a HUGE difference between .046" wire and .057" wire. Glad you're getting to the bottom of this.

-Matt
 
  • Like
Reactions: msg1979
Upvote 0
MartinT said:
Where did you get them, I’m interested too!
Click to expand...

Mcmaster is a great source.

Here is a link to their selection of 2" springs.

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
www.mcmaster.com www.mcmaster.com
 
  • Like
Reactions: MartinT
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu