Newcastle what distance are we talking regarding plinking? I,ve used all weights with Unique, but the heavy ones seem to work the best, I use 14grns for the .303 and .308. normally for 100yds/mtrs
The .308 with 110grn RN bullets are excellent, proof is in the pudding as they say see link below, I use this round with every .308/7.62mm rifle, very good in the Ishapore 2A1.
The .303 produces similar results, should be able to do a comparison next time at the 100 yrd range, as I,ll have a scope on it. (eyesight not that good in a dark tunnel)
L42 repro at the range