Adding one of these to a Veteran is probably about the most simple diy pcp project there is.
First gotta remove action from stock.
Here's some pics of the steps. I measured the distance between the scope tower and the breech because trigger feel and function is so dependent on that distance in these guns. I usually have pencil marks on the tube but the tube will be in a different place after the plenum addition.
Loosen up all the tower screws.
I degassed by cracking the gauge open just a bit but you can also use the trigger cover screw inside the hammer tension adjust. I didn't want to go that route because I wanted to see results with the exact same hammer tension.
At this point just unthread the tube
Apply some silicone grease to the oring seen here and to the one on the plenum. I also grease up the threads lightly. Silicone on the threads may not do much, but I've always figured it might help from them seizing up.
Screw it all back together.
Duplicate the distance between tower and breech as the 12 tower screws are tightened back up.
As for the outcome.....
Same hammer tension, fps with the 18.13s went from 940-960.
Maxed out hammer tension will now throw the NSAs 17.5/0.2165 @ 1020-1030 vs 990 before.
Maxed out hammer tension will now produce 920-930fps with the 25.4gr Monster RDs vs 900 before.
It also did a full 9 mags at 960fps (JSB 18.13gr) before dropping off the reg and it'd only do 8 full mags at 940fps prior to the plenum.
So, it seems to give about 20-25fps more than it did pre-plenum and maybe 10-15% more shots-nothing earth shattering but any increase in energy or efficiency is welcome.
Also, it might be a bit more consistent now?
These 40 shots had a high of 949.5fps, low of 943.6, an ES of 9.53, and an SD of 2.23.
53 yards.
I don't remember it being quite so consistent prior ( although this is still a relatively new gun so we could be seeing regulator break-in here.
First gotta remove action from stock.
Here's some pics of the steps. I measured the distance between the scope tower and the breech because trigger feel and function is so dependent on that distance in these guns. I usually have pencil marks on the tube but the tube will be in a different place after the plenum addition.
Loosen up all the tower screws.
I degassed by cracking the gauge open just a bit but you can also use the trigger cover screw inside the hammer tension adjust. I didn't want to go that route because I wanted to see results with the exact same hammer tension.
At this point just unthread the tube
Apply some silicone grease to the oring seen here and to the one on the plenum. I also grease up the threads lightly. Silicone on the threads may not do much, but I've always figured it might help from them seizing up.
Screw it all back together.
Duplicate the distance between tower and breech as the 12 tower screws are tightened back up.
As for the outcome.....
Same hammer tension, fps with the 18.13s went from 940-960.
Maxed out hammer tension will now throw the NSAs 17.5/0.2165 @ 1020-1030 vs 990 before.
Maxed out hammer tension will now produce 920-930fps with the 25.4gr Monster RDs vs 900 before.
It also did a full 9 mags at 960fps (JSB 18.13gr) before dropping off the reg and it'd only do 8 full mags at 940fps prior to the plenum.
So, it seems to give about 20-25fps more than it did pre-plenum and maybe 10-15% more shots-nothing earth shattering but any increase in energy or efficiency is welcome.
Also, it might be a bit more consistent now?
These 40 shots had a high of 949.5fps, low of 943.6, an ES of 9.53, and an SD of 2.23.
53 yards.
I don't remember it being quite so consistent prior ( although this is still a relatively new gun so we could be seeing regulator break-in here.
