In this video I'll be making a valve and a connector for a manometer and a fill nipple for a stainless PCP tank, the maximum pressure is 4000 PSI, but to ensure safety I recommend 3500 PSI. Keep following this series of videos and you'll see the finished version soon, it will be really powerful in just 4,5mm. I am expecting around 1100-1200 fps minimum using a 15.4 grain slug. Fund my projects: LATHE used in the video: MINI Lathe 7x16 800W (Europe and USA link): Asia link: Parts, tools & materials: 25mm brass rod: 27x2mm 304 tube: pressure gauge: fill nipple: O-ring: HSS mills: drill bits: drill bit: center drills: m10x1 tap: m6x1 tap: POM rod: teflon rod: 4mm steel rod: grub screws: countersunk screw: sanding tool: brass tube: silicone oil: 10mm thick spring: o ring