With its flat meplat, it looks like that bullet is somewhere between a round nose and a truncated cone. It will seat short with that shape. The only bullets with noses long enough for 1.275" are the elliptical round nose profiles. The hemispherical round noses and flat meplat noses are too short in shape for that, meaning the distance from the tip down to the bullet shoulder where the meplat starts is too short to allow full cartridge overall length. Instead, that shoulder runs into the lands and stops the case mouth from getting all the way to its chamber shoulder.
If you want to know if this can affect pressure, then look for a difference in seating depth from that of the longer round nose shapes.
For example, the military's round nose projectile is 0.680" long. Typically you find their cartridges are about 1.265" long, giving them a little wiggle room for cartridge-to-cartridge seating variation. The seating depth is:
Case Length + Bullet Length - COL = Seating Depth
so we have:
0.898' + 0.680' - 1.265" = 0.313"
So if you seat your bullet that same amount using the same powder charge you are likely to be fine. You said you had to go to 1.190". So, rearranging the above, if your bullets are:
Seating Depth + COL - Case Length = Bullet Length
0.313 + 1.190" -0.898" = 0.605"
So if your bullet is 0.605" long or less, you are at or have less than the same seating depth as military ball ammo and should be fine up to their load level or to commercial ball load levels (about 350 ft-lbs using Bullseye or Unique or something in that burn rate range).
