MrTea

Standard 30-round style stanags that only take 30 BBs? Nuprol make em. Can select 30 or 140 BBs with a small switch.

If memory serves, there was nothing done to the RIF unless it had been reversed prior to being sold. I don't think i've got the guys discord anymore either annoyingly so I can't ask. Edit: I do have it and have shot them a message.

@ak2m4 Measured at 480mm. This doesn't mean the person who owned it before me changed anything but why would they go for a shorter brass inner barrel?

Funnily enough, it's a full/non-ported cylinder. I 100% sure of this as I kept all the parts/spares from this build in it's own box so I didn't get them crossed with anything else.

I'll take the current setup and use the stock barrel and see what happens to the FPS. Should give an idea as to whether the barrel is causing significant FPS drops. If this turns out to not be causing large FPS drops, i'll test the airseal afterwards. Sound good?

6.12mm yes, 360-ish long IIRC and a full/non-ported cylinder.

That's annoying. The air seal was perfect when I originally changed out the stock compression parts but I can definitely go back and check again when I get the time.

That was what I was going to do initially however it appears his XT springs don't go past M150. Up until this point, it's exactly what I was using. Not yet. Now i'm closer to the limit, and have it chrono-ing consistently, i'm going to give it a test on 0.36g BBs to see how it's performing.

Actual progress this time around but additional confusion. I tried sanding down the Maple Leaf MR hop rubber feed lips. No matter how little I took each time, I could never get a rubber that resulted in consistent FPS readings - at one point I got an FPS reading of ~800 so IDK 😅 I've been messing with different hop rubbers trying to find one that consistently works especially when the stock hop rubber ended up splitting when changing it over. I was going to try the a ML Macaron 60 degree as i've never had an issue with them before and they just worked. During the process of installing it I noticed that the hop unit wasn't applying hop evenly, it was applying too much pressure on the right side resulting in uneven hop. I think this is simply due to the way the hop unit is designed that makes the hop arm slightly off center. Happily I managed to remedy this quite quickly by using a small o-ring that I had lying around which I think is for a MOSCART fill valve? All I did was just put this between the body of the hop unit and the hop arm. Before anyone mentions it, yes the screw is in the wrong side of the hop unit and no, this isn't what was causing the issue with the misaligned hop arm Now that I had sorted that I moved onto changing the hop rubber. I have a prommy purple I was going to try out but for some reason I just wanted to try a Maple Leaf Macaron yellow/60 degree just because they've worked flawlessly on everything I've put them on. I also installed the bucking with the Gearparts Omega 70 nub from AK2M4 and it worked. I am so mad. I am confused as to why this works. Before I tested this, i'd bought and installed a SHS M160 spring to creep up the FPS. The spring is very twangy (if that makes sense) and it's pretty annoying. Since starting this build, i've changed which outdoors site I go to and they allow 450fps for DMRs so i've still got a bit of headroom that i'd have to buy an M170 equivalent to get to. Is a SP160 the same as a M170? Could it be the MR hop bucking didn't work as the hop window on the inner barrel is too small causing inconsistent contact? I am at a loss as to why this suddenly works... I want to buy another ML MR hop rubber and try it but I feel like if I disturb the hop rubber in the slightest it's gonna throw a fit and not work anymore.