Tuning BSA R-10, New Huma regulator, hammer spring adjustment not affecting power

Title says a lot of it. Everything is back together, old faulty reg is out, new Huma reg is in. Gun holds air and fires just fine but is only slinging the lighter 15 grain JSB's between 765 and 770 fps. I've watched what I can find of video's on YouTube and I have made it this far but the last step was supposed to be turning the hammer spring in to increase power. The video's say turn 1/4 turn at a time and check over chronograph. I've turned the hammer spring in at least 5 or 6 full 360 degree rotations and I don't have a single bit of increase in power out of the gun. 

Does anyone have any advise or info they can help me with please?

Thank you in advance!!

Cliff
 
You might be maxed out at your regulator setting. Do you know what it’s set at ? I’m not familiar with the R10 internals . Is it possible that you’re not actually making any adjustment and the tensioner is spinning free ?

Well, the reg is from Huma and they have some instruction in their own support videos specific to the FAC american BSA R-10. They say the regulator is set where it should be from the factory per the gun it is ordered for and not to change it, only to change the setting of the hammer spring, which they also give instruction on.

That being said, I also just found another video by them saying that when you adjust the hammer spring, to either put the cap back on or cover the opening tightly with your thumb before testing it again so I'm going to start with that tomorrow.



Back the hammer spring out to minimum start from there see if it helps if not then adjust the reg pressure higher.

Odoyle, I think you are right. I have actually already backed the hammer spring out to minimum tonight in anticipation of starting from scratch tomorrow. Also going to try to put the cap back on after adjustment, before testing new settings. 

Thank you for the help guys! Anyone else that wants to chime in with help / suggestions, I'm all ears! 
 
Hi Cliff, welcome back. I have done quite a bit of testing and tuning with my R10 (MK2 .22). I still have the original reg in mine as it has performed well so far and everything but the shroud and moderator is stock. I have not found any noticable difference in velocity readings with the hammer spring cover on or off. The sweet spot for accuracy + power + shot count on mine was at 876fps with 15.89 JSB's. I believe the reg was set near 140 bar but I do not have a reg tester to confirm an exact setting (and the fill gauge is anything but precise. Lol)

It does sound like your reg needs to be turned up just a tiny bit. Just for an FYI in case your are interested- I just upped my reg about 15 to 20 bar and am getting good results with NSA 17.5 x .2165 slugs @ 890fps. I have NSA .216 and .2155 slugs on the way for more testing. A lighthearted look at some of my testing: https://www.airgunnation.com/topic/the-tale-of-the-wererabbit/?referrer=1.
 
That's low, mine is sending 18g JSBs at just under 900fps and the reg set at 140bar. 

What was it shooting before? If it was low from the factory it might be one of the following.

Transfer Port

You didn't happen to measure the TP? R-10s have 4.7mm or 5.00mm TPs I believe. The non FACs are much smaller 2.7mm I think.

Knock off valve restrictor 

While not likely you may have the knock off valve restrictor installed on the valve stem. I don't think my R10 had one but my Scorpions did. You'll need to remove it if it's installed. Xtx air on youtube has a video that shows how.

If it was shooting faster b4 the HUMA the reg probably needs to be adjusted. Its possnle they mislabeled the regulator.
 
That's low, mine is sending 18g JSBs at just under 900fps and the reg set at 140bar. 

What was it shooting before? If it was low from the factory it might be one of the following.

Transfer Port

You didn't happen to measure the TP? R-10s have 4.7mm or 5.00mm TPs I believe. The non FACs are much smaller 2.7mm I think.

Knock off valve restrictor 

While not likely you may have the knock off valve restrictor installed on the valve stem. I don't think my R10 had one but my Scorpions did. You'll need to remove it if it's installed. Xtx air on youtube has a video that shows how.

If it was shooting faster b4 the HUMA the reg probably needs to be adjusted. Its possnle they mislabeled the regulator.

here is how it was shooting with the OEM reg. Any idea on how to adjust the Huma reg? 

https://www.airgunnation.com/topic/50-shots-with-the-bsa-r-10-mkii-22-pics-mini-review/
 
The Huma has a brass screw on the end with marks for pressure on the side, simple.

Good point. I'm just noticing Humas website says you can adjust the regs. They should update their videos online, they say not to adjust them. Glad I tore the sticker off the end indicating what power level I'd be adjusting to. Oh well, my fault. I'll just try to get the hammer spring back to where it was and adjust the reg incrementally to get it right. At least there's a pic of the reg with the sticker on it so I can at least see how much to turn it for 10 bar or however I end up doing it. 

Thank you for the heads up, you greatly simplified this for me, just going to take a little trial and error 
 
Back the hammer spring out to minimum start from there see if it helps if not then adjust the reg pressure higher.

OK, now I'm super confused. I backed the hammer spring all the way out as far as it would go and still be able to screw the cap on, it literally made no difference what so ever to the power of the gun. 765 to 770 fps backed all the way out and 765 to 770 fps turned in 8 or ten full turns. What am I missing?

I know I can just pull the regulator out and adjust it to get the power up, but now I'm worried there might be something wrong with the hammer spring. Would it be prudent to spray some lube down there in case whatever the hammer spring is pushing against is stuck?

I put an entire mag through it with no change in FPS after quite a bit of unscrewing of the spring so........anyone have any ideas?
 
Take it apart and turn the reg up. You’re getting the max velocity for your regs set point with your hammer spring backed all the way off. Your reg is set too low. Next you need to decide what pellet you want to shoot and set your reg so your max speed is a little higher than where you want to shoot them. I have two .22 guns that I like to shoot 15.89’s and 18.1’s. I set the reg for the lighter pellets to be 900fps then back the hammer spring down to 880fps. Then I just live with the 18’s going a little slower. It’s a balance tune in which both will be accurate.
 
I just looked at your old topic that you provided a link to. Yep, you were shooting 18.1’s at 835fps. That’s the tune that will let you shoot 15.89’s good too because they won’t be going warp speed. I’m guessing you’re going to have to turn that reg up close to 20b to get you where you need to be. Remember I said guessing. All guns react a little different.
 
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Take it apart and turn the reg up. You’re getting the max velocity for your regs set point with your hammer spring backed all the way off. Your reg is set too low. Next you need to decide what pellet you want to shoot and set your reg so your max speed is a little higher than where you want to shoot them. I have two .22 guns that I like to shoot 15.89’s and 18.1’s. I set the reg for the lighter pellets to be 900fps then back the hammer spring down to 880fps. Then I just live with the 18’s going a little slower. It’s a balance tune in which both will be accurate.

Thank you for the help, I'm pretty sure I understand what you are saying, the reg pressure is too low for the hammer spring to be affecting the power yet? I took the reg out, adjusted it almost a half turn counter clockwise and then back again a little bit, as per Huma instructions for increasing power. I was not able to test it today though as I ran out of sunlight and could not get the chronograph to work under my indoor lights so will try again tomorrow. 

Thanks again for the help it is greatly appreciated! +accuracy
 
A half turn is a little extreme on a Huma. I would have turned it from 12:00 to 9:00. Hope you went the right direction.

Yes, went counter clockwise. The only reason I went that far is because the directions say when increasing the power, go past where you want to be and then turn it back some so I didn't end up going the full half turn. After turning it back it was maybe 1/3 of a turn total. I've put a few rounds through it and while I can't chrony it yet, it seemed to shoot fine. Didn't feel like it was coming out too hot or anything. I'm really interested to see where it's at when I have daylight tomorrow, will definitely report back
 
Take it apart and turn the reg up. You’re getting the max velocity for your regs set point with your hammer spring backed all the way off. Your reg is set too low. Next you need to decide what pellet you want to shoot and set your reg so your max speed is a little higher than where you want to shoot them. I have two .22 guns that I like to shoot 15.89’s and 18.1’s. I set the reg for the lighter pellets to be 900fps then back the hammer spring down to 880fps. Then I just live with the 18’s going a little slower. It’s a balance tune in which both will be accurate.

Thank you for the help, I'm pretty sure I understand what you are saying, the reg pressure is too low for the hammer spring to be affecting the power yet? I took the reg out, adjusted it almost a half turn counter clockwise and then back again a little bit, as per Huma instructions for increasing power. I was not able to test it today though as I ran out of sunlight and could not get the chronograph to work under my indoor lights so will try again tomorrow. 

Thanks again for the help it is greatly appreciated! +accuracy

MARK your BEFORE and AFTER dial indicators with a sharpie on the regulator itself so you ain't doing all of this blindly in case you gotta go back.
 
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Take it apart and turn the reg up. You’re getting the max velocity for your regs set point with your hammer spring backed all the way off. Your reg is set too low. Next you need to decide what pellet you want to shoot and set your reg so your max speed is a little higher than where you want to shoot them. I have two .22 guns that I like to shoot 15.89’s and 18.1’s. I set the reg for the lighter pellets to be 900fps then back the hammer spring down to 880fps. Then I just live with the 18’s going a little slower. It’s a balance tune in which both will be accurate.

Thank you for the help, I'm pretty sure I understand what you are saying, the reg pressure is too low for the hammer spring to be affecting the power yet? I took the reg out, adjusted it almost a half turn counter clockwise and then back again a little bit, as per Huma instructions for increasing power. I was not able to test it today though as I ran out of sunlight and could not get the chronograph to work under my indoor lights so will try again tomorrow. 

Thanks again for the help it is greatly appreciated! +accuracy

MARK your BEFORE and AFTER dial indicators with a sharpie on the regulator itself so you ain't doing all of this blindly in case you gotta go back.

Great tip, there is an indent on the reg from the factory, I used it as a guide so I could get back to my starting point if needed 👍
 
Ok, progress is being made. I have been able to chrony the results of my first reg adjustment. It put the 15 grains at almost exactly 850 fps and the 18 grains at about 805 fps. I'm going to move the reg a little more to try to get the 15 grains up to about 890 or so. Depending on how close I get I will maybe try to move the hammer spring to adjust a bit and test for accuracy afterwards so I can make sure it is tuned properly for both calibers. 

Interestingly, I have always previously filled my gun to one notch below 250 bar on the manometer. When empty, the gun would read zero at the zero line. Now it reads zero one notch above the zero line and I have to fill the gun all the way to the 250 bar max reading to get the same number of shots. Not a big deal, but thought it was worth noting in case anyone had any idea what would cause this phenomenon. 

Will report back shortly with results of second reg adjustment