B&A Disco Max Valve Question

[amidemon]

Who's got one and what kind of shot string can I expect? Mainly want to know how its going to
affect my number of shots per fill. Any input is appreciated.

[rsterne]

I've never used the B&A valve but I can tell you what to expect when you make any PCP "breathe better" by increasing port size and flow.... The velocity will usually increase and the peak of the curve will move to a lower pressure.... In addition, the shot string will become more curved.... and hence the number of shots within a given velocity window will decrease.... In a nutshell, you can expect fewer shots at a higher velocity assuming the valve breathes better.... Depending on how well the valve breathes, you may need to either DECREASE the fill and refill pressures.... or fit a power adjuster and increase the hammer spring tension.... If you do the latter, you should get even more power.... and once again, fewer shots....

Bob

[amidemon]

Thanks Bob,

  That pretty well goes along with my expectations. I was also hoping someone with a B&A valve would
give me some numbers from their experience. I am currently modding my Disco. Last night I shot it for
the first time with the B&A valve, just for fun, because I haven't had time to shoot for a few days.
I have the slightest puff of air coming from between the breech and the air tube when it fires, so I wasn't
trying to be very scientific in my observations. After around 10 shots I noticed a difference in the report, I looked
at the gauge and saw the needle on the yellow. I started at the topside of the green (2000psi). This much
decrease in shot number was a little more than I had expected. sinc it was easily giving me 25 or so "good" shots
in stock form.

The sad part of all this is that I own a chronograph and have never used it on my Disco. I was always happy
with the performance, so just didn't worry about it much. Now that I got the itch to mod it, I don't have any
hard/documented numbers to compare it to....

I guess I'll have to save my allowance and buy another Disco.   Just don't tell my wife.

[rsterne]

There is a LOT of data on the Disco.... they don't vary that much, so you could probably just use my numbers, for instance.... Here is what my stock .22 cal did with a variety of pellets....



Bob

[amidemon]

Thanks Bob,
 I'll save that image. By the way, what program do you use for those shot string graphs?

[rsterne]

I store my data in MS Excel and then use their charting feature.... To turn them in to a JPEG file you save the chart to MS Paint and then save as a JPEG.... Then you can crop and resize with any photo editor and upload to Photobucket for internet display....

Bob