B40

some of you have allready my lube thread this is kinda of a follow up

trigger is sort of sirted….it could be better…the AA410 feelig went away once trigger got under real pressure, but its till miles ahead of the stock trigger….

i wont do a review of the rifle…plenty of those around, but i will tell what i have done to it to make it just a little better

heres the rifle

heres the temperature in the garage with port open….when it was time to assemble i had to close ports to stop prying neighbour eyes from thinking im building weapons….and thernometer reached 109f arghhh that is freaking hot….and i was drenched in sweat after 20-30 test shots….

ok so heres what the rifle went through
to remove stock 4 screws must go..piece of cake…remember loctiting them when assembling…they will rattle loose otherwise

the trigger group is held by one single screw in front of the trigger assembly….theres very little pressure on the piston spring…so its easy to just hold a hand over the trigger goup and let it extend…nothing violent here

heres the spring is fully streched…only couple of inches, and when assembling an be pressed back in place with one and and screw put back in with the other…unless your an 8 year old kid with no muscles.

out comes trigger group

main spring with quides

closer look at front and rear guide….front guide is a tad loose might machine a tighter fitting unit for it…rear guide is fitting nicely no play really a loose pressfit if i can call it that

to get the compression chamber out some suggest removing the c clips, but i find it easer to just knock out the crosspin, its allready soo loose i had to give it dab of loctite to keep it in place…so a little knock with a rubber mallet and a screwdriver and it came right out

now the compression tube can be removed…

heres the piston after it was pullet from the compression tube, not how it has a delrin/teflon guide riding inside the compression tube as well as one riding outside it

some mixed pictures of the piston seal and guide

everything filled with this brown gunk…didnt feel greasy…felt more like glue residue, evaporated machining fluid, burnt oil ….

the endcap of the compression tube had to come off

they had obviosly used some threadlock, but there some rubber in those threads too !!!????

this was the sight the greeted me when it finally came off

looks like pulverized oring and glue residue….plus some threadlock gunk

compression tube was pretty rough…looked like a galvanized tube…with more of this brown gunk burt to the sides

ok i only got a few more pictures…as this is the time things get messy with polishing compounds, and grease…and i dont wanna get that stuff on my camera

to polish the inside of the tube i tightly wrapped some fleece around an aluminum rod i had, and taped it in place….filled it up with crome prolish which is a mild sanding compound….and the polishing commenced…it was enough to get the brown crap out of there…so the felt got a layer of 2000 grit sand paper and i honed it carefully, in the lathe…spinning at low rpm…moving the compression tube back and fourth making sure not to sand one place more than the other…that helped…then the crome polish came into action again…and tube was very shiny and clean after that, allthough some spots that looked liked it was galvanized was still in there, but nothing i could do about them without increasing the ID of the tube…

outside of the compression tube which is visible got polished up too just for the looks of it.

inside of the rifle body there was clear scratch marks from where the compression tube glides when it gets cocked…so that got honed as well

everything got lubed with the honda moly the inside of the compression tube got a layer that was then dried away with paper towel…this i think will leave just a tiny coating there, side of seal got a thin layer, the quides both got a healthy dose of the stuff.

the iside of the rifle qot a layer of it…meybe a tad too much, but compression tube now moves silky smooth.

spring, and quides got a thick layer of it….not sure that was smart, since the grease is not very sticky….doone is done i will replace next time, when i get a some real tar for it.

everything put pack together including the new trigger job, and the rifles firing cycle was vastly different…no twang…trigger was so much better…but not like the AA410 trigger was while i had it out, it works differently under pressure, but still 100 times better than stock form.

over the chrony it was up from 14.5 to 16.1 fpe …right around 675 with jsb 16 grainers…..it did a couple of shots going up from 675 to 685 to 699 which must have been a bit of diesling and the settled back for a shot string ranging from 673 to 678 fps over 20-30 shots

i found i was able to follow though much easier now i will redo the trigger once more just to see if i can make it a super trigger….

the groups where 1″ at 16 yards…horrible to say the least…but the times i really tried the groups where 1cmx1.5cm edge to edge so ctc it would have been a very small group…i just need to learn the trigger and what kind of hold this rifle likes….they say 2000 shots and the chinaspring is done…at that time i might go for the full maccari tuneup granted i get the trigger perfect….but for now….im quite happy, i would like to be able to get the shroud off and take a look at that crown in there, and maybe do a little shroud work…carbonfiber maybe ?

over and out….