Joe, congrats on your new rifle.I don't have a daisy, so I can't answer those questions, but 30 weight oil is generally used in small engines like lawn mowers.
I don't think you'll lose any power per pump by not slamming the lever all the way closed. For that matter, I and a few others remove the retainer spring altogether to make pumping smoother and quieter. Adding a piece of felt to cushion the lever makes it even quieter. The lever will stay in place without the retainer as long as the gun is working as it should.Like James suggested, less stroke would lower the potential power. So would a dished piston if the dish were big enough to prevent additional pumps from building "too much" pressure in the valve. Even a longer air intake slot in the compression tube could limit max power and would be very easy and cheap for the company to do. It would also be easily converted to normal power by swapping out the tube- if that's what they did. Big if.A book could be written on lubes! Personally, I use Mobil 1 5w-20 motor oil. And as mentioned there are quite a few people who use ATF. "Secret Sauce" is another popular lube, it's a type of hydraulic fluid. I don't know why Daisy still would recommend non detergent motor oil in this day and age. Back in the olden days, detergents/additives could be just about anything so it makes sense to have not to used them, but todays modern engines all use synthetic/rubber type products and the detergent oils don't hurt them. For that matter, Pellgunoil is a nickel's worth of detergent motor oil repackaged into 1/4 ounce tubes. The main thing is to not use WD40 or penetrating fluids. Silicone oil has its place but it's not for metal to metal wear points. I don't know all the O-ring sizes, hopefully someone will post them. I believe -113 O-rings are used on the piston and compression tube. You can buy an O-ring / Wiper Seal Kit from Daisy for $1.00, p/n 169909-000. Chamber Seal Kit is p/n 169910-000, $1.00. Diagram and contact info below.For a lead dust collector that hushes the sound level significantly, I and others here have had excellent results using units made by Geo Schoonmaker. They're 3-D printed, fit like a glove, look good and work even better. Very affordable to boot. You'll need to ask about shipping.
You're welcome, glad to offer what I can.Hard to say positively, but it does sound like it's shooting as well as any 880 here in the US. Have you checked out the uber affordable chrony that member Jimmy posted about? https://www.gatewaytoairguns.org/GTA/index.php?topic=151661.0I've filled the pistons but haven't tried adding preload to the 'hammer' spring. It would be interesting to know what the change in MV was with only that done with no other changes. The cast metal pump lever doesn't flex anything like the plastic ones do but the joints do develop slop over time and that costs efficiency for sure. I have had to replace the metal levers on two of my 880s with the current production plastic lever to get rid of the sloppy linkage and I picked up MV in the process. All levers will eventually get loose with enough use so I just keep them lubricated and watch for any slop developing. FWIW, the current plastic lever flexes but it's nowhere near as bad as the plastic version that was used before it!I believe folks often overthink the whole oil thing- I know I did!The O-rings are common sizes, the times I've needed to replace them I didn't look at the size I used is all. Hopefully someone paid attention and can give you some sizes to work with. I mentioned the Daisy part numbers as an alternative, not that they have to be sourced from Daisy.The whole LDC thing is a touchy subject over here and that's about all I can say on the subject, I'm sure you understand.Daisy has great customer support, for sure! I hope their always able to sell us parts at affordable prices but with Gamo having bought Daisy, what may come next is anyone's guess.
The whole LDC thing is a touchy subject over here and that's about all I can say on the subject, I'm sure you understand.
I have been using #113 and #012 size "O" rings and they have been working fine.
Joe- lots of great advice from others with way more expertise than me. One of my (3) 880s gives me 12.5 fpe at 20 pumps (though I typically shoot it at 8.1 fpe with 8 pumps, using 10.5gr Piranhas). It is stock except for removing the lawyer spring, polishing up the sear and trigger contact area, credit card mod on the trigger and filling in the piston head and BB hole with Plasti-Steel, and a Geo moderator on the front. Did nothing to the pump arm nor did I shim the valve or pumphead. One thing you can do to quiet the pumping sound in addition to removing the catch spring (which I learned on this forum) is put a piece of velcro on the pump arm where it contacts the bottom of the gun - makes a big difference on the "clacking" sound.
If memory serves me right, I believe, in a heavy duty air compressor used at the semi truck repair shop I used to work at (for 24 years), we used to use a 30 weight non detergent oil in it. Maybe check with some auto and truck repair shops to see if that's what they use, and see where they get it. I but 30 weight non detergent oil at any Ace Hardware stores here in Hawaii.
Last, I just wanted to point out a few really useful videos on youtube by a person called "Daisy880Fanatic" - if you search him out, you'll find them easily enough. Also, here's a curve of fps/fpe vs # pumps for one of my 880s. Have fun!