Brocock/BRK Commander XR hammer bounce

Hello fellow airgunners, hope all is well!

So I bought a brocock commander off the classifieds last week, I’ve wanted a brocock for a while now and pulled the trigger. Great rifle, almost no complaints! I noticed first shot that it sounded like it was waisting a ton of air and it seemed like it wasn’t getting as many shots as I’d expect.

Well I went to tuning on it today to see if I couldn’t help these issues. Played with hammer spring and raised the reg pressure up a tad. Still sounded like it’s dumping a lot of air, even with the HS backed way off. It really sounded like it had a bad case of hammer bounce but the gun seems to have a slingshot hammer setup which is how I cured my Kral guns of hammer bounce so I somewhat dismissed the hammer bounce problem. After playing with the tune and no difference in sound I decided to slo mo record the hammer and sure enough it’s got bad hammer bounce. My cure to this before is the short stiff spring/slingshot hammer but with this one coming from the factory setup this way I’m not sure what to do.

Any and all help is greatly appreciated!

Beau
 
Ok so I figured out the issue. The spring in the gun does work as a slingshot, however the spring is too soft to keep from loading back up when the hammer rebounds. Since I bought the gun used I don’t know if this is the factory spring or not, I assume it is though.
Digging through my spring box I was able to come up with a contraption that worked. Much shorter and stiffer spring, I haven’t completely eliminated the bounce but greatly reduced it. I’ll order proper springs for it tonight and that should take care of the issue completely. A captured spring would be ideal, maybe I’ll get to it one of these day!

Hope this helps someone else out as I haven’t found much info on tuning the brocock rifles. If anyone else has something to add I’d love to hear it.

Also this is an extremely easy rifle to work on. Build quality, fit and finish and handling are all excellent as well!

Beau
 
Ok so I figured out the issue. The spring in the gun does work as a slingshot, however the spring is too soft to keep from loading back up when the hammer rebounds. Since I bought the gun used I don’t know if this is the factory spring or not, I assume it is though.
Digging through my spring box I was able to come up with a contraption that worked. Much shorter and stiffer spring, I haven’t completely eliminated the bounce but greatly reduced it. I’ll order proper springs for it tonight and that should take care of the issue completely. A captured spring would be ideal, maybe I’ll get to it one of these day!

Hope this helps someone else out as I haven’t found much info on tuning the brocock rifles. If anyone else has something to add I’d love to hear it.

Also this is an extremely easy rifle to work on. Build quality, fit and finish and handling are all excellent as well!

Beau
@zx10wall is a great tuner esp with these platforms
 
Ok so I figured out the issue. The spring in the gun does work as a slingshot, however the spring is too soft to keep from loading back up when the hammer rebounds. Since I bought the gun used I don’t know if this is the factory spring or not, I assume it is though.
Digging through my spring box I was able to come up with a contraption that worked. Much shorter and stiffer spring, I haven’t completely eliminated the bounce but greatly reduced it. I’ll order proper springs for it tonight and that should take care of the issue completely. A captured spring would be ideal, maybe I’ll get to it one of these day!

Hope this helps someone else out as I haven’t found much info on tuning the brocock rifles. If anyone else has something to add I’d love to hear it.

Also this is an extremely easy rifle to work on. Build quality, fit and finish and handling are all excellent as well!

Beau
@zx10wall is a great tuner esp with these platforms
also how old is the gun? Last update / refresh of all the orings?
 
Yeah I’m hoping he will chime in on this. Not sure the date of manufacture, it’s an xr model so it can’t be real old. I assume it has the o-rings from the factory still in it. Nothing noticeable as far as o rings go, a reseal isn’t a bad idea but she does seem to be doing good as far as that goes. The hammer bounce was awful though, again not sure if it was the factory spring or not. If I can get my slow mo video to upload I’ll put it up.

Thank you
 
Is there any air blowing out of that port? Any chance air blowing past the valve stem could be forcing the hammer back enough to preload? Just a thought, never seen one of these rifles.

I just checked the forum and it sure seems like a lot of hammer bounce videos on the brocock rifles. None mention any sort of fix though.
 
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How big are these hammer springs? I have a XR Magnum .22cal and it sounds like it dumps a lot of air also. I have the spring kit for the Ghost and am wondering if they're a similar size.
I can’t locate my dial calipers at the moment so this ain’t exact. My factory spring is about 1/4” ID 3/8” OD 2” long
The spring setup that I cobbled together from stuff I have laying around is nothing like the factory spring, but will work until I get the correct springs.

Id guess you’re experiencing hammer bounce as well. Just slow mo video the cutout in the stock that shows your hammer or take the stock off and video it. It will tell you for sure.
 
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I have a brocock commander HR (previous model to the xr) It has no issues with hammer bounce, and I think it is the quietest gun I have ever shot, and with the smoothest shot cycle. (Least hammer slap etc.) It is also very accurat. I guess not every “improved” gun is always better in real life.
Man I’ve almost pulled the trigger on one of the older brococks multiple times. Wish I would have so I could compare.

Again this gun is very nice in every way possible, I really have no complaints. However the is not what I’d call a quiet gun or real smooth shot cycle. My FX Streamline in 22 is much quieter and smoother. I think getting the valve running right will make it a really sweet shooter though, and I have no idea if all of the valve is factory or not. I bought the gun used and It’s pretty easy to swap hammer springs. But it also sounds like plenty of people have the same issue so I assume it came from brocock like that.
 
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Nope I just know it’s part of the hammer, I don’t know exactly how the valve in this gun works. I do know if the way I got the gun is it working in its optimal state than that’s a shame. It’s louder than my Aea hp varmint making twice the power. Also with the spring changes I made the hammer stopped bouncing as much and the report got much crisper. Also you can get hammer bounce with a spring that has no preload on it.

I assume you’re saying it’s got a dead blow style hammer?
 
Nope I just know it’s part of the hammer, I don’t know exactly how the valve in this gun works. I do know if the way I got the gun is it working in its optimal state than that’s a shame. It’s louder than my Aea hp varmint making twice the power. Also with the spring changes I made the hammer stopped bouncing as much and the report got much crisper. Also you can get hammer bounce with a spring that has no preload on it.

I assume you’re saying it’s got a dead blow style hammer?
No, as the hammer has the main spring for the outer part of the hammer which supplies the firing force and then the free floating inner part that hits the valve which also has a soft spring which should play no part in the firing it's simply there to reset the inner part of the hammer.

Have a look here for the explanation.

 
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Not to try to derail this thread. Is it okay to dry fire this hammer system with no air in the rifle? I accidentally did it once when I was degassing the rifle to lower the reg pressure. Insert moron smiley here.
Cant see any problem with that in fact there is less stress with no air in the system it will just open the valve a bit further and unless there is some kind of positive stop to the valve which I don't think there is it will be fine.
 
No, as the hammer has the main spring for the outer part of the hammer which supplies the firing force and then the free floating inner part that hits the valve which also has a soft spring which should play no part in the firing it's simply there to reset the inner part of the hammer.

Have a look here for the explanation.

Thank you very much for the video I will watch it when I get time. I wonder why they’re running the way they do. The way I got it it’s obviously dumping way more air than it should. Seems like something is out of whack.
 
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