HK MSG90A1.The base for this one is a VFC PSG1.I wanted an MSG90A1 for my collection,and already have PSG1'S.These,the G3's,and Gen2 MP5's are seriously good shooting guns.IMO probably the best ones VFC has made so far.The secret to them is the rotary chamber they all use,and in the case of the PSG and G3 the npas loading nozzle.The VFC PSG1 really requires no upgrades at all,and absolutely demands heavyweight ammo.Mine on testing chronoed at 2.8j's and overhopped .36's at 80m's.With .43's or .45's shoots extremely nicely out over 90m's easily.To pull this off I first removed the STANAG scope mounts.I then bought a Midwest Firearms G3 extended scope mount base,and removed the mounting bracket closest to the ejection port for silent decocker clearance.After that I removed the lower third of a G3 front sight triple frame,reamed the cocking tube section a bit,and installed it on the end of the cocking tube.After that it was a simple matter of notching either side of the very front of the handguard cocking tube channel for front sight clearance.The uppers on these have no rear iron sight base like G3's and other old pattern HK's have.I ordered said iron sight base,and 1200M diopter.After centering and clamping,I TIG welded the sight base to the upper,and installed the diopter.MSG's use essentially the same trigger pack as the PSG.MSG's use their very own trigger housing.The VFC PSG doesnt use a trigger pack like the MSG/PSG, but rather a semi only pack using the same trigger pack frame as the G3.Fearing fitment and clearance issues,I opted for a SEF navy lower.Trigger pack installation was easy and straightforward.While I was at it I removed the plastic cover for the magazine paddle release,and installed a paddle release also.To pull off a convincing build of one of these IMO absolutely requires the MSG90 stock.Its a key element.After a solid two weeks of searching here,there,and all points inbetween I finally tracked down an HK MSG90 stock.Factory stocks are all MSG90's.I wanted mine to be the A1 variant,so I also ordered an HK21 stock buttpad.after both arrived,I removed the stock from its back plate,and installed it onto the PSG backplate.Next I removed the spring clips from the backing plate on the buttpad.The backing plate is aluminum, and the buttpad itself is simply glued on.I used a jewlers on the backing plate to soften the glue,and remove the rubber pad.I then measured the thickness of the backing plate,and applied that measurement to the butt end of the MSG90 stock.The stock is all polymer except the adjustment bolts,so a hacksaw made short work of removing the end of the stocks butt.Some epoxy,and creative clamping affixed the rubber buttpad to the end of the MSG90 stock.Adding the Harris clone bipod finished it for now.I do need to revisit it,and make the barrel stabilizer with Rotex muzzle brake mount along with repainting.Maybe this spring.