Remington model 12 date of mfg

[John Gyde]

According to Rem records your M/12 was made in 1912. In my opinion the Pre-M/12 ended in late 1910 when Rem started using the M/12 designation in their advertising. Some M/12s did not have the model designation on them as late as 1917 while existing barrels were used up.

[John Gyde]

Yup, use standard velocity ammo only. Hi-vel will work but puts too much strain on the breechblock. The end result is a sloppy action.