Diana Trail Scout/Mrod Air Max Plinkster/SPA CR600W

I have the Mrodair version in .177 and like most CO2 guns its factory setup is wasteful of gas, thus it is unnecessarily loud. I added a Bstaley O-ring buffer tall enough to just knock off the top 5% of velocity and shot count doubled and it sounds more like a click than a pop.

I checked my old writeup and I used -113 size O-rings. The nose of the hammer was slightly too large (it would have wedged into the O-rings and gotten stuck) so I chucked it into my drill press and abraded it down with an emery wheel in the Dremel.

You could instead use a smaller cross section but I'm not sure how well they'd stay put. That would be a -016 size.

Here's the writeup if you're interested:
https://www.gatewaytoairguns.org/GTA/index.php?topic=143793

However there's more detail about the bstaley approach in an older CP1-M thread, including pictures of how I handled reducing the hammer's nose:
https://www.gatewaytoairguns.org/GTA/index.php?topic=124266.msg1221255#msg1221255


Regarding loudness, it’s been a while so I’m hesitant to compare it to a rimfire but it was definitely not what I would have considered backyard friendly. Now it is, and would even be fine for shooting in a basement range without disturbing others in the house. 

Mine is a .22 and very quiet...Other than the trigger which is a little wobbly from side to side this is a great and accurate little gun.

No: I have the standard version purchased from Mrodair.

The Diana version will pierce all three 12g's. the Mrodair Plinkster will only pierce one at a time if that makes any difference in your choice.

As far as quiet, Mike @ TKO can probably supply you with something a lot better than the OEM/s

Do yourself a favor and buy the XISICO XS-60C from flying dragon air rifles for 130 and have Mike melick tune it for you. I swear that guy does magic to those Chinese airguns. I think he charges like 100 bucks for the full insane tune where he recrowns and laps everything but if you just want a power tune or something it should be much less. I think the gun itself is a bit more accurate than the plinkster but that's just from reading reports online. I can't verify that however I've dealt with Mike a few times and he's a really great guy. He sent me new seals for my old springer for free and talked me through a difficult rebuild. Definitely a good guy to deal with. 

did you end up getting the XS-60c or the CR600w? I picked up the later only because mike didn't have any 22 calibers in stock right now. But I'm interested in how the two guns compare accuracy/power/trigger/noise wise.

You don't want to have Mike do the full power tune if you want it quiet tho. Probably should have mentioned that. If you tell him I want it quiet he will do a great job.

I’d be super interested in knowing what kind of FPS/FPE you’re getting out of the cr600w (that is, if you have a chrony or know someone who does). Looking for something capable of taking squirrels and narrowed it down to the xs60 full power tune (about 730 FPS with cp 14.3 pellets) or a crosman 2400kt w/24” barrel and power valve (620 FPS with 14.3 gr cp). Those stats are just what I’ve pulled from various online reviews conducted under ideal temperature conditions.



The Crosman 2400 KT in 24 inch barrel looks to be at the minimum power range of what I would be interested in, so just wondering if the CR 600 is up in the power range or not….or can it be economically tuned to get there.

Hadn’t Heard of the cr600 before today, but but like you, can’t find the others available online… I’ve been checking on FlyingDragon for a month or two and even emailed Xisico as well but apparently they still can’t get the .22 xs60 in stock and the crosman custom shop is still closed while they wait on supply back orders.

so interested to hear about what kind of power or tunes could be done to a cr600.

I've only shot it once since getting the cr600w but I was pretty pleased with the accuracy, <0.5" group at 15 yards. The magazine's not the best, I'm going to order some 3d printed ones that are supposed to be better.

I haven't modded it yet, and I need to get a chrony (any recs?) but I have done research on the mods.

My plan is to swap the valve spring for something lighter (leaves the valve open longer), and drill out the ports (4 of them) to 4.5mm.

The other two popular mods are swapping the hammer spring for something stronger (I'm going to pass on this one at first bc I heard it makes cocking harder), and drilling out the valve chamber to give it more volume (I'm still confused how this one helps, but maybe once I get the gun open it will make more sense and I'll do it too).

There's a guy on youtube who did these mods and he's (allegedly) getting 15-16 fpe in .22.

You might also want to checkout the Artemis CP2, I ordered one from Krale and it got here in 3 days. I've only been shooting it in pistol form, but I bet in rifle form it would be similar to the cr600w. The same mods apply since they are the same internals.

The wood stock on the cr600w is nice though. I bought it from Wes (https://airgunarcheryfun.ca/) who was very helpful, but if you order from Krale I'm pretty sure you get the suppressor included (which works great on my cp2) and it arrives faster.

Please be advised the CR600W is like most CO2 guns, it comes from the factory with an excess of hammer strike. It wastes CO2. Using a heavier hammer spring or weaker valve spring will only make it waste more CO2. It will do nothing to increase the velocity. What it will do is make it louder and magnify the self-cooling effect from the blast of expanding CO2 vapor. That will cause the temperature of the CO2 cartridge to fall which reduces the operating pressure and can lead to a loss in velocity.

For more power, the name of the game is porting. Barrel port as big you can get it...though no bigger than 80% of the caliber for a simple round port or pellets may get damaged when passing over it. Transfer port the same size or a smidge larger. Same thing for the valve exhaust and valve throat...a bit larger to account for the area occupied by the stem. Check the bolt probe when it is fully forward, making sure it isn't restricting flow at the barrel port. Might need to shape it or thin out the nose.

When the porting is all done, then try manipulating the hammer spring tension (HST). You may find that it is already producing max velocity (adding tension does not increase velocity), and instead will need to be reduced somewhat to keep from wasting CO2. Whatever the case, adjust the HST for somewhere in the vicinity of 95 - 97% of the max velocity. That will improve the extreme spread, especially when using it at varying temperatures. That's a big deal for a CO2 guns used for pest control. Just a minor annoyance for punching holes in paper but vastly more important when pulling the trigger on a living thing.

My .22 MrodAir Plinkster is noticeably quieter than comparable-power .22 Co2 Rifles, but not as quiet as a click or “pfffft”.