Almost sounds like you're taking the data as an absolute measurement of velocity. It can vary as much as 150'ps from rifle to rifle. The only way to tell how your barrel performs is to put the ammunition thru chronograph screens. You might find out your barrel is pushing bullets far beyond the printed data. One reason for the variation- roughness of the cut of the barrel. Assuming it is a military rifle, they weren't all that interested in a super accurate barrel for a military rifle. Most soldiers had to fire over 50 rounds just to get one hit. The soldiers were not expert marksmen so there was no need to make an extremely accurate rifle. Your barrel may be extremely smooth and let the bullets fly. More commonly, the barrels will be rough and cause drag on the bullets as they go down the barrel which reduces velocity. They didn't change out the cutting tool that cut the rifling near as often as any current non-military rifle barrel. Put your ammo thru a chronograph. You might just surprise yerself.
I know you are right! I slugged it, came out 311. I do not own a chrono, would likely spend my money on something else.
I am just making a guess at the velocity loss
I could have any rifle I wanted but am intrigued with this old turd.
I like the idea of being an oddball too.
The cartridge is very old and I like to reload it with just a Lee hand tool loader. I used to reload on a 1050 for our Dept. and had tons of reloading equipment, owned a 450 and a single stage press for years and one day just decided to sell everything and shoot one rifle.
I may buy a 223 down the road? I had three AR-15's and 8 1911's, sold them all but love a good shotgun.
I am running a 20 gauge 3 inch and #4 shot for yotes. Have to have close for it too be clean takedown.
Sorry to drift from the subject but it is relative to my choices.