The D166 bullet is .310" diameter. The ogive is different resulting in a longer bearing surface.
Rifles with the 'D' throat modification have had the lands removed further forward of the typical Russian specification so they will accept the D166 ammunition.
28/30s are another matter. Here is a quote from Doug Bowser on the subject from http://www.mosinnagant.net/finland/Bowser.asp
The "S" type ( 180 gr flat based ) and the D46 type ( step boatailed) ammo the Finns produced at SAKO and Valtion Patrunnas Tehdas ( State Cartridge Factory ) was manufactured with .309" bullets. The D100 ( 200 gr step boatail) ammo was also .309". I believe the Finns were concerned with oversized bullets in the M28/30 or they would have manufactured their ammo with .310" bullets. I do not believe the practice of firing .310" surplus ammo in the M28/30 is dangerous, IF the barrel shank is marked with the "D". The real problem with oversized bullets is the possibility of the bullet being squeezed to tightly by the neck of the cartridge by the neck of the chamber. This may cause higher pressures to develop by increasing the amount of force required to push the bullet from the case when fired. I also think the steel cored bullets of some milsurp ammo may cause higher pressures in the .3082" bore. Bullets are very hot when traveling in the bore and if the core is filled with lead it becomes soft. A slightly oversized lead cored bullet will not usually cause any serious problems. I personally WOULD NOT use STEEL CORED .310" milsurp ammo in a M28/30.
and
The reloaded ammo usually performs better than the milsurp variety, and allows you to load soft point or match grade ammo for hunting and target shooting. I recommend that shooters of the M28/30 use handloads to bring out the potential of their rifle. I would also suggest the shooter wanting to use milsurp 7.62X54 ammo use it in a Model 39 Finn. I am enclosing the test fire that I did on reloads and milsurp ammo. I believe the M39 is potentially as accurate as the M28/30 with the proper bullet diameter.
Since MOST of the misurp ammo available these days has magnetic bullets, I would shy away from using it in a 28/30.
Rifles with the 'D' throat modification have had the lands removed further forward of the typical Russian specification so they will accept the D166 ammunition.
28/30s are another matter. Here is a quote from Doug Bowser on the subject from http://www.mosinnagant.net/finland/Bowser.asp
The "S" type ( 180 gr flat based ) and the D46 type ( step boatailed) ammo the Finns produced at SAKO and Valtion Patrunnas Tehdas ( State Cartridge Factory ) was manufactured with .309" bullets. The D100 ( 200 gr step boatail) ammo was also .309". I believe the Finns were concerned with oversized bullets in the M28/30 or they would have manufactured their ammo with .310" bullets. I do not believe the practice of firing .310" surplus ammo in the M28/30 is dangerous, IF the barrel shank is marked with the "D". The real problem with oversized bullets is the possibility of the bullet being squeezed to tightly by the neck of the cartridge by the neck of the chamber. This may cause higher pressures to develop by increasing the amount of force required to push the bullet from the case when fired. I also think the steel cored bullets of some milsurp ammo may cause higher pressures in the .3082" bore. Bullets are very hot when traveling in the bore and if the core is filled with lead it becomes soft. A slightly oversized lead cored bullet will not usually cause any serious problems. I personally WOULD NOT use STEEL CORED .310" milsurp ammo in a M28/30.
and
The reloaded ammo usually performs better than the milsurp variety, and allows you to load soft point or match grade ammo for hunting and target shooting. I recommend that shooters of the M28/30 use handloads to bring out the potential of their rifle. I would also suggest the shooter wanting to use milsurp 7.62X54 ammo use it in a Model 39 Finn. I am enclosing the test fire that I did on reloads and milsurp ammo. I believe the M39 is potentially as accurate as the M28/30 with the proper bullet diameter.
Since MOST of the misurp ammo available these days has magnetic bullets, I would shy away from using it in a 28/30.
