A friend of mine has an Evol 22 with a 15” barrel. He is shooting 25.4 MRDs and recently crono’d it for the first time. He is shooting about 750 FPS which seems rather slow to me. Can anyone tell me what a OEM tune would be using MRDs?
You mention the 22 JTS @895-920. Is that with the stock reg at 1900?OEM tune would put the reg right around 1900 psi and power right about 30ish fpe so his gun seems to be shooting well.
You are not going to get the 25.4 MRDs much faster than 900 fps before the gun starts getting a not so enjoyable shot cycle. That will be with reg at around 2250 psi.
Mine actually did very well with the JTS 22grain pellets and that's a more mild tune and enjoyable shot cycle. Speed around 895-920. The JTS and AEA pellets really seem to like around 900 fps.
That's around 39 fpe so you will need to bump up the reg a bit. Prob around 2100 psi will get you there. If you think about it that's really not that bad. That's about a 145 bar reg setting with a 15" barrel which is pretty good.You mention the 22 JTS @895-920. Is that with the stock reg at 1900?
@Buckeye68 That is a large and unusual extreme spread for an Evol. Because you seem proficient at working on it, I'd suggest removing the hammer, spring, and poppet and especially the valve assembly and clean and polish everything. Reasom being, some of the blue colored springs will chip and those chips collect on the valve stem and then lodge in between the stem and the valve body's hole causing erratic shot cycles. An accumulated amount of dirt/debris on the valve stem will gall the aluminum onto the stainless stem and cause drag also.Took the gun apart after I got home from work tonight. The HS adjustment back way out. I screwed it in all the way and the it maxed out at 875 fps.
After reading your comment, I decided to pull the trigger and HS to check to see how dirty they were. Wow, dirty was an understatement. The spring had zero paint on it. I cleaned everything including the trigger and reassembled everything back together. I did order a complete o ring kit on Friday from AoA. Also, I checked the seal on the pellet pusher stem when I fired off a shot with a little piece of TP. When I fired off the shot, the TP blew off the stem. I ordered an extra o ring for it just to get me up and running for next Sunday’s indoor match. Tuning is a pain in the a$$ with all the adjustments inside the stock, but I ended up clamping the receiver down in my drill press vice so I can make HS adjustments without putting it in the stock. Thanks for all help from everyone!@Buckeye68 That is a large and unusual extreme spread for an Evol. Because you seem proficient at working on it, I'd suggest removing the hammer, spring, and poppet and especially the valve assembly and clean and polish everything. Reasom being, some of the blue colored springs will chip and those chips collect on the valve stem and then lodge in between the stem and the valve body's hole causing erratic shot cycles. An accumulated amount of dirt/debris on the valve stem will gall the aluminum onto the stainless stem and cause drag also.
On my Evol Magnon I bought used it had an erratic spread that was due to age and an accumulation of debris on the valve stem. After a complete disassembly I stripped all the paint from the spring, polished it, the hammer, the valve stem, and the valve body hole where the stem rides in, then installed fresh o-rings on the valve body and no lube on the valve stem or valve body hole so it will not collect dust or debris in the future. My extreme spread is usually within a couple fps.