338 Lapua & 375 cheytac competitor

[Chriznak]

Anyone aware of a 338 Lapua base-size cartridge that has been made as long as a Cheytac case and necked up to 375? I'm thinking it would:
1.be a good ballistic mini-me to the 50 BMG running a 700 grain bullet at bc~.80 or so.
2.be more efficient than the 375 Cheytac in regards to barrel-life & powder-consumption for kinetic energy.
3.function better out of a browning m2 style or General Dynamics LWMMG style gun than the 338 norma mag.
4.have better brass flow & reload-ability than the 375 Allen express.

I like the relationship the mk262 223 Rem. round has to the cold-war era m80 308 Win. round. Attributes that result in less cost to shoot, train with & practice:
*equal bc
*equal muzzle velocity
*half the bullet-weight
*half the powder

*the same kind of powder (ie varget, IMR 4166, etc)
*less muzzle blast
*smaller primer.
*suppressors that are dual-use for 308 win & 223 rem
*gun "platforms" (AR, DT MDR, etc) that have same interface for both 308 win & 223 rem

I would like to find or wildcat a cartridge that has the same relationship the mk262 has to the m80 cartridge but in regard to the 50 bmg running 700 grain solid/fmj/raufoss(with COAL sized to run in an m107). I would also think the cartridge would function in a scaled down browning m2, barret m107, or cheytac-size bolt-actions(with smaller bolt-face), or scaled-up General Dynamics LWMMG.

I'm thinking a .375 bullet made lock-base fmj style (for hard-targets) and an Accubond LR style( for hunting) can both be made to have the same bc & weight as the .375 350 grain SMK. All 3 bullet types would have a lower minimum-velocity than the .375 350 grain solids in case a user wants to run the cartridge out of a barrel shorter than 29".

I'm thinking other shooters would appreciate a Mini-Me to the 50 bmg also.

The closest thing I have found is the 375 allen express. I suspect the 375 Allen Express has insufficient body-taper & excessive shoulder angle to function in a select-fire gun.

I look forward to conversing with whoever wants to respond here.

Edited February 5, 2016 by Chriznak