Okay first of all the .22 cal 250z will do 60fpe out of the box, no plenum mod.
A 40gr Ace slug doing 900fps is 72fpe… the Z is probably not gonna hit that. For one you need a slug power kit to open the valve properly above 2800psi.
I don’t know what the rules are for your completion but if you’re allowed to add a plenum mod then your plan is viable. After adding the plenum my Z loved shooting 35gr slugs at 950fps for 70fpe. Granted mine was in .25 cal but these guns are made the exact same way, the block is exactly the same it’s just the barrel, breach and pellet probe that are .25 cal. Yes a .22gr slug will be longer than .25gr in the same weight but considering we’re looking at a diameter difference of .03” there’s not gonna be a lot of difference.
The biggest issue I see is the QC on the .22 cal barrels. The problems are well documented on this forum. It sucks too because the .25 barrels are f***ing solid AF.
I’m actually working on machining a .22cal Skout barrel to fit into a 250z for a fellow forum member. I cannot report back yet, because the master machinist who owns the equipment had surgery a month ago and is still out. He’s in his 80s and while I could go elsewhere he’s graciously agreed to teach me how he machines barrels. Considering he did the barrel for my EQ, which has been an unqualified success, I’m not willing to seek other options yet.
That being said, I’ll keep y’all posted.
Overall I really like your idea because the best aspect of the Z, is the one people don’t talk about. Barrel harmonics! The air-over-barrel design gives the gun incredibly stable barrel harmonics. The regulator is also really freaking good so you add those together and you have a recipe for exceptional REPEATABLE accuracy.
BUT!
My recommendation is to get the 270 which is supposed to be out this month or June. Digging deep into the shot show videos I picked up a snippet where the barra guy said “we added a much bigger plenum and it makes 20% more power than the 250z.” That’s 70fpe out of the box y’all!!!
Personally I’m dying for the 350z… haha my shooting has evolved a lot in the last 18 months and I’m definitely in my “long range” era… lol I was “plinking” at 300y last weekend!
Finally,
Welcome to the forum fellow shooter. I hope you end up in the Barra family because these dudes are the coolest people on the whole forum. A lot of the guys commenting here have been in this little community since the 250z came out. They really know the in’s and outs of this gun. Others are newer but have taken that tribal knowledge and pushed the gun even further
@PestPlasteringPlinker is a great example of this… I’m not as active on here as I was, work is brutally busy these days. But I used to be on here a lot more and frankly I love to piss people off sometimes. *The Daystate fanboys nod emphatically*
But the 250z crew is by far my favorite. I step in here to say to my bros and see that everyone is still killing it. This is where you wanna be I promise.