Reason I ask is I bought some 405 gr casts and my groups have been terrible, some going through side ways at 100 yds. This gun shoots 1 1/2 " groups at 100yds with jacketed bullets and 6-8" groups with casts. Need gas checks?
My 1895G shoots far beter with plain base bullets (no gas checks) than with gas checeked lead. The load you use can affect accuracy a lot too. Groupc could easily vary by a few inches at 100 yards depending on how many grains of powder you are using and which powder you choose....
