FX Drs .25 tuning

[Gambler]

Hi.
Just got my inlet, probe and shp, so I could transformer my .177 -> .25.

Was a little dissapointed that the inlet came without the 2 orings it needed but I had some spare inlets from m3 so that worked out.

I tought I could but a manometer in the bottom of the plenum instead of the angled bracket, but that was not possible to I have still no idea of my plenum preassure. But what would be a ok place to start out 100-110bar?

My m3 had 90bar and shot 910 with king heavy, but it has bigger plenum and 100mm longer barrel.

I think I have to stay with pellets to get highest possible shotcount with this 600mm air cylinder. Im going to make it 700mm as soon as I find a place that sells the longer tube (I have liner and liner housing from 700mm m3)

Edit: with the same settings i used on .177 13gr KO @ 940fps i now only have around 600fps with bigger plenum 33gr K.heavy

 

[Jman4183]

I don’t know if this helps you, but when I bought my drs .25 cal the dealership (the pellet shop) told me to assume around a 150 bar reg pressure. That feels about right. I have an M3 and a drs .25 cal just like you sounds like. Def pellets for shot count. I don’t get through a whole mag firing 36 grain javelins before needing to refill. This is ok for my uses right now. I mainly use the drs as a quick grab gun if I see game out back or I feel like I need to defend our pup.

 

[Gambler]

Yeah, but I guess the 36 jav need more air to get to dessired speeds. I have no idea where I am with preassure right now, I read someplace that the .177 comes with around 100bar, and I have adjusted half a turn up from there to get the 13gr to 940 ish.
So maybe im around 120 and just need more hammer, but again, its starting to get harder too.

 

[msg1979]

My drs 700 .177 was set up to a 20g slug. ~150bar.
I shoot 16g at 120bar and hammer 99% of max to 120bar.

Dunno if that can belp

 

[Impact701]

I don't shoot pellets from my DRS 22 700 or my DRS 25 700, but I have found the DRS likes 5 to 10 bar more reg pressure than my M3. The extra reg pressure closes the valve quicker giving you a higher shot count, than on a lower reg pressure trying to shoot the same velocity.
My M3 25 700 @150bar shoots 40gr H&N Heavy slug 980fps.
My DRS 25 700 @ 155bar shoots the same 40gr 980fps.
I get 18 shots on a fill.

You definitely need a angled manometer bracket and gauge to set the reg correctly.

 

[Gambler]

Thanks, I was hoping to not reach 150bar to get the king heavys to around 900fps

 

[Gambler]

Found out today that my speed may have been off from the start, the chrono is faulty and I had a few shots today over 2300fps so have to get a new one to see where im actualy at.