Reloading .303 British : Mk 7z vs my Match Loads

I had 190 rounds of Winchester made1943 MkVIIz. I tore down two of the cartridges and weighed the (WC846?) Ball powder and both weighed out @ 44.6grns. Unfortunately I discovered that the two MkVIIz bullets had two different weights, with one weighing 171.9 and the other weighing 175.2. I took the remaining 46 rounds from the original 48 round cardboard box and chronographed those rounds with the chronograph set up exactly 8 feet from the end of the muzzle. The averaged FPS was recorded @2398.6 with only four of those reaching the Golden MkVIIz 2440 FPS. At 100 yards my first two ten shot groups averaged 1.47" MOA. At 200 yards the following two sets of ten shot groups averaged 2.94" MOA.  The remaining 6 rounds were sent down range towards an 8" metal circular plate @ 300 yards. All six rounds hit their mark and staying at just under a 6" spread. 

I wanted to compare that to some modern handloads I had worked on. Using the 174grn FMJ-BT PPU projectiles and 39.0grns of IMR4064, IMR4895, Norma 202, and Varget with Federal GM215M primers for ignition, I loaded 4 sets of 20 rounds of each powder and recorded a averaged FPS of 2382 for the IMR4064, a FPS of 2387 for the IMR4895,  2442 FPS for the Norma 202 and 2414 FPS for the Varget. The accuracy for each was recorded at, from best to average to below par @ 100 yards was as such.

Norma 202/39.0grns = 1.28" 

IMR4064/39.0grns = 1.55"

IMR4895/39.0grns = 1.67"

Varget/39.0grns 1.74"

The Varget numbers had me perplexed because Hodgdons load data shows a minimum 37.0grns and a maximum of 41.1grns so I assumed that using the middle ground charge of 39.0grns would have produced tighter groupings. I was dismayed to learn that almost all other sources of information showed that 39.1grns of Varget was at maximum charge weight. I reduced the charge weight to match my IMR3031 load of 36.0grns and gained a significant amount of accuracy back albeit at a loss of FPS. The chronographed averaged FPS was recorded at 2364 while the averaged ten shot group measured in at 1.497" @ 100 yards.

(I have noticed in the past that pushing the 174grn SP/BTHP/FMJ-BT projectiles over 2450 to 2500 plus FPS has a tendency to cause erratic flight patterns if not causing some of those bullets to lose complete stability and go divergent on all three axis.)

My accuracy load using 36.3grns of IMR3031, Federal GM215M primers,.311 174grn FMJ-BT projectiles and a C.O.L. 3.110" as well as my load using 39.7grns of VihtaVuori N540,  Federal GM215M primers, .311 174grn FMJ-BT projectiles with a C.O.L.  of 3.110" outperform the Winchester MkVIIz Ball Ammunition by more than .55" under MOA for both loads as well as having the FPS down to 2144 for the IMR3031 and 2368 for the VVN540.

For hunting using the 180grn SP I have found that 36.0grns to 38.0grns of IMR3031 will also outperform the MkVIIz ammunition out to 200+ yards with a mean spread of 2.2 MOA @ 200 yards.