What fps can I expect with a .177 Discovery with the power adjuster mounted on it ? On the lower side especially ?
Mulling on getting an all in one Disco for 10mtr Air Rifle open sight competition and filed target.
Also can I put a 1377 type trigger frame on it if I remove the Disco trigger group ?

Many thanks

Point177

about the number you would get on a Disco with the power adjuster installed and set for the lower side. But I am 99.99% sure you can use a 1377 trigger frame on the Disco.

Carl

...amount of spacing (preload) into the hammerspring, and thus increase the energy of the hammer stroke and consequently the power of the shot. So the only way to lower velocity when adding an adjuster is to simultaneously substitute a softer or shorter hammer spring. If you keep the stock spring, then an adjuster always means more velocity - never less.

If you do change out the spring, then there's no limit to how low you can go in velocity - all the way to zero if you (perversly) chose. But there is a (minor) complication - whenever you reduce the power of the hammerspring, you'll also need to reduce the fill pressure to maintain a reasonably symmetrical and consistent shot-count velocity curve.

Steve

Stock spring works fine as will many after market springs.
You can achieve from 0 fps to 900 fps and above with the stock spring

Steve

This is one of the external power adjusters I make and use

And I will tell you without a doubt with the stock spring I get the FPS down to 0 and up to 968.2 with the stock spring.

There is no need to change out the stock spring.

I do make internal adjusters for a local club that teaches a safety shooting class to the youth, they require a set fps as there young inside shooters.

In order to change the FPS on the internal adjusters there is a need to change out the spring but that is by design. The only reason the internal power adjusters are adjustable is to maximize the installed spring.not to set the FPS.

I adopted the BMW spring color scheme as I do love my BMW and found the study of spring characteristics quite fascinating, yellow, blue & green for the BMW.

I could say yes you are correct on the internal powers adjusters a spring change is needed but only because it is design that way.

I could make and sell the internal powers adjusters for the open market then offer a whole line of springs to set the FPS at $5.00 bucks a pop but what a waist of hard earned cash.

It's better to have an external adjuster that utilizes one spring for many different settings.

With a true understanding of how springs work you can have it both ways and not as you would advise.

When the stock Disco endcap is already just a thumbscrew, locknut, and guide away from being a perfectly serviceable adjuster, why would anyone go to so much bulk and expense just to avoid a simple and far more cost-effective replacement spring?



If - that is - he had even a basic understanding of how "power adjusters" work in the first place?

Steve

fit function and appearance

...aftermarket part.

Steve