LOW FILL PSI

[melloroadman]

What rifle other than the Discovery has a low fill of about 2000 -2200 in .22 cal. and what is the shot count .Marvin

[daved]

Only ones that come to mind would be a Mac1 USFT, a Big Ed tuned B 50/51, and some Talons.  Found out after I traded it off that one of my Talons had been shooting very nicely at only 2300 psi fill level.  I believe any of the above will get 40 shots or more.  That said, most any PCP can be tuned to shoot at lower fill levels, you just have to be willing to give up some power.  Later.

Dave

[melloroadman]

Yes but I want to keep the fps up for 50 - 75 yard shoots .Marvin

[preez]

My HPA 850 will give about 30-40 shots of 750 fps from 2200 to 1250 psi

A well dialed-in talon with 18" or 24" barrel would easily do the same

Chris

[melloroadman]

I would like to stay away from the talons .Marvin

[preez]

melloroadman - 10/14/2008  9:06 PM

I would like to stay away from the talons .Marvin

But Why?????? ;)

[melloroadman]

Not my cup of tea .Marvin

[preez]

Hehehe, that's what I thought, until I shot one....

I resisted for 3 months and then gave in.

There is no cure for this

Chris

[spysir]

Buy tuned from Ed or tune it yourself in minutes, do look at :
http://www.klickcue.com/air_rifle/%3Cspan%20class='highlight'%3Eb50%3C/span%3E_51/technical_details_for_adjusting_the_bam_%3Cspan%20class='highlight'%3Eb50%3C/span%3E_51.pdf
 Our numbers wont be exactly like a stock one as our hammer is milled 2mm shorter giving more run at the striker and it has a 25" barrel otherwise stock except for the lighter hammer spring. 2000psi fill yields 30fpe - 915fps w/JSB 15.9g for right at 30 shots.

   John

[scottinharwood]

I would go with the B50/51.  I tuned my B51 ala 'The Book' and put in a lighter McMaster-Carr hammer spring with a screw power adjuster (adjusts hammer spring tension).  I get 40-shots in 0.177 ranging in a smooth velocity per shot curve from 855fps to 915fps with a starting fill pressure of 1850# shooting Crosman Premiers at 10.5gn.  They have a good ballistic coefficient so retain the most velocity at 50 yards.  You can get a BigEd tuned version in either 0.177 or 0.22 with a Lothar Walther barrel for the best accuracy.

Any better shot to shot velocity consistency would require a higher priced PCP with a regulator or a regulator conversion for an existing PCP - the BSA Super Ten for instance but these also require the dreaded 210 BAR fill prssures.  I gen'd up a possible design for a regulator for the Benjamin Discovery but I do not have machine shop capability.  The design would allow you to  pump the Discovery up to a higher pressure, say 2500#,  and regulate the shot pressure to about 1450# (the sweet spot pressure for my Disco 0.22 which I also tuned up).

Ultimately though, it comes down to getting pellets that are both accurate and have the highest ballistic coefficient possible - hence my use of Premier's.

Hope this helps

Scott

[melloroadman]

Scott whats the trigger like compared to your Discovery .Marvin

[scottinharwood]

Marvin:

As you probably know, I did the lower link mod on the discovery and it lets go nicely at about a third of the original pull weight.

As part of the B-51 tune, I did polish all trigger wear surfaces and the part of the hammer weight that contacts the trigger with 600-grit oiled sand paper and lubed with white lithium grease.  The trigger was never that bad to begin with and the tune helped it along a bit.

In comparison, the B-51 wins hands down; its trigger is lighter and smoother than the Discovery (after the lower link mod) and adjustable (which I have never tried), but after tuning the Discovery its trigger lighter and  smoother than before, but still a harder pull with a bit less predictability.  If you do not do the lower link mod on the Discovery, there is no comparison; the B-51 wins all around in any case.

The Discover trigger lower link mod lets it approach a GRT III trigger on a Crosman Quest or Storm XT - smooth but still with some weight to it.

Compared to the AA S400, again, no comparison, the S400 is truly smooth and light.

My lightest trigger comes on my Baikal IZH 46 - light as a feather and the shot always takes me by surprise.

Hope this helps.  If I had a pull weight measuring gauge I would get some numbers to you - sorry its all subjective

[melloroadman]

N/T

[preez]

Now I want a B-51 again...

[melloroadman]

I thought about one when I bought my Discovery which I am happy with but . Marvin