B50 Detune

[GarthThomas]

Thankyou very much for that explanation, I will work to that end. I am not looking for a cannon, it was money that dictated me buying this gun and I like the looks. Having come into this hobby by getting a QB57 I guess now I don't know when to run away.

[Ribbonstone]

Even with good advice, nothing like fiddling around with an open mind to find out first hand what works. 

You didn't care for the 12 foot pound goal, but you got there...just make a new goal and work towards that. Have had some where the goal was "as many shots as possible at 12 foot pounds", others that I'd accept "however many shots I can get at 30 foot pounds", but most often its something like "X foot pounds and Y good shots per fill".

Just for argument, when you had it tuned to 12 foot pounds, what did you find to be wrong?  Just lack of power, or did the gun shoot crappy? I mention this becasue some times, the best way to spot a problem is by chronograph.

Consider this:


Realized something was wrong here.  Did take me a little time, but it turned out to be a little burr on the striker locating screw (that little screw on the top that runs in a slot and keeps the striker from rotating). Must have dinged it the last time I assembled the gun, and that burr would sometimes drag. 

Agree with Tim, the valve return spring itself doesn't supply much of the closing force and I'd not change that in isolation (if at all).

[GarthThomas]

I was getting good consistent shots at 12lbs and plenty of them but I have a springer thats near there already. I had previously shot the B50 at 50 yds before the tune with good results, the difference 6lbs makes is more than I expected, I enjoyed the extra range and I think the velocity will help in windy conditions,
So maybe when I need to get in the reservoir for the inevitable repairs I can try an altered firing valve. Thats as soon as I can figure out the internal parts that Tim described. Thanks for your help and encouragement.

[Ribbonstone]

Don't go looking for trouble.

At the fill pressures you are using and with the lighter striker, are likely to have a long service life with the standard parts.  I'd use them until I had a problem, then get inside the valve. 

PCp's do bring out the power hunger, being able to make one shoot to high energy has a certain appeal. But there is nothing in this world for free, and the cost of that increased energy is a lot more filling effort and a bit more stress on the system.



So what do you ant it to shoot? 18 foot pounds? 22 foot pounds? 32 foot pounds?

[GarthThomas]

I think 17ftlbs is good for now, I have never owned or shot an airgun this powerful before so this level should keep me occupied for a while.
I have limited access to places to shoot and I think if I bumped it up I might have less.
One thing I did do was bore out the end cap so the spring wasn't so tight, I think it has dropped the spring pressure down.
I have to get out and shoot more often because if it's just sitting there I have this incredible urge to take it apart and start tinkering.

[Ribbonstone]

Sounds like a pretty reasonable compromise to me.

Leave the insides alone for a bit and shoot it for a bit.  Rather than just tinker with it, find out how it shoots...if you'd want it quieter...if the trigger needs a little adjusting (at least it has screws for that)....how it shoots with heavy weight pellets...etc.

Lot of things to learn besides changing power.

[arbab]

Great thread I have a B51, Ive downloaded and read the book by chris over a year ago, only few tinkerings has been done on mine.  is there any updates on that book or newly discovered tweaks for this gun?