Here's a couple of my long range piece:
Hey, look, it's the rifle with the same name as my screen name....a PSG-1
No, it isn't a 'real' PSG-1, those cost about $10-15K. Mine still cost about $5K, though.
This rifle began life as an HK-91. The entire receiver was taken apart, trued up and re-welded, reinforcing rails welded in place, and a scope rail welded to the top of the receiver.
Next, a 30" Hart 416 stainless steel .30 caliber barrel with a 1 in 12 twist was fitted to the rifle, and chambered with a '95 JGS Palma Match chamber.
Then, of course, being an H&K with delayed roller locked action, the chamber had to be fluted by EDM process.
Also, the locking piece was changed out for a 23 degree angle PSG-1 locking piece, due to the different recoil impulse from the 30" barrel, as opposed to the stock 18" barrel that was initially on the rifle.
Then, the rifle was fitted with a PSG-1 fully adjustable buttstock (and they're proud of these things, last time I checked, they were about 800 dollars)
Also, the stock HK-91 trigger was sent to Williams trigger systems for the set trigger modification. On normal mode, the pull weight is 4.25 lbs, with no creep. On 'set' mode, the pull weight is reduced to 2.5 lbs. A PSG-1 walnut handgrip with adjustable shelf was installed.
Instead of using a PSG-1 forearm and the adapter, a special trunnion extension was fabricated and machined, then, a free floated forearm was made from 1/8" aluminum plate, radius bent, and slotted.
This rifle is capable of shooting 1/2 MOA at 1/2 a mile. (That's a 4 inch clay pigeon on a berm 880 yards downrange) At 100 yards, it will shoot 1/2" groups. I did the welding, but as far as the actual gunsmithing, barrel work, etc, that was done by a gunsmith in Charleston, SC, John Geiges. He built rifles for competition shooters, the military, and law enforcement. His rifles placed in national, and international events.