Wish you luck, young jedi. Remember anything over .50 caliber requires ATF approval, destructive weapons license and $200 tax per round. Do some research on recoil and how to counter it. The more a weapon weighs the more it will absorb the recoil, higher velocity of the cartridge the more recoil. Your task will be to find the balance of portability and the limit a human can tolerate. Reseach big bore elephant guns or anti tank rifle of early WWII. The British Boys .55 is at the upper limit.mostly just because Black lagoon is one of my favorite TV shows. I plan on having this and eventually if I ever have the money, get a gunsmith to make karkonen from Hellsing for me..... now, that is going to be the hard/impossible one to get as it would require me to design the thing from the ground up. Good thing I'm going into weapons engineering after college though.
and yes that's a 30mm sniper rifle.
I won't even attempt alucards guns, though. Converting a 92fs to close enough is simple, and designing the rifle will take a lot less time than two different extended slide .50 cal handguns.
I didn't know anything over 20mm actually existed.... and I thought the rtw-20 and the nt-20 were bad ***.I remember the XM109! I went down to Murfessboro, TN from Fort Campbell, Ky in 1998 to work on this project. The upper can be swapped with a .50 BMG upper (like a AR15 conversion). The 25mm round is actually a rifled grenade like the 40mm round for the Mk19. Not a high velocity round like the 25mm Bushmaster on the M2/M3 Bradleys. The cartridge uses a warhead (ie HE, yellow rounds or the blue Training Practice). The challenge was getting recoil under controll. The impluse with the 25mm (1") was the same as with a M82 in .50 BMG. The other project that I got to work on was the SPR which became the Mk12 5.56mm Special Purpose Rifle.
Have met and worked with Ronnie Barrett on a few occasions. I always called this rifle a "Man Portable Light Cannon" which a cannon is classified over 17mm or 3/4"(.750"). The problem with a 12/7x99 or .50 BMG cartridge is that is a kynetic energy round. Further the target, the less it has energy to defeat the target (same with a 30-06). With a warhead, range is inmaterial as the explosive charge isn't reliant on velocity. Damage is the same wheter 50m or 2000m.