To start NEVER shoot a low serial number 1903 before it has been thoroughly checked by a professional gunsmith.
When researching receiver failures I found an example that the rail was fractured with a mallet by Army testing in the 1920's. That receiver was only 89 digits from mine which really hit home. In the receivers defense however, it was fine until whacked with a mallet so...
The head used is a Nosler Partition 150gr Spitzer. Pricey yes but it happens to be one of the very few bare lead semi-skirted base bullets available. Brass is LC Match therefore the load is reduced a half grain. It also received a light kiss of a crimp from the Lee factory crimp die. I didn't setup the chronograph for a true reading but will next time out. As outlined in range reports this is the resulting initial 5 shot group.
150gr Nosler Partition
47.4gr W760
Federal 210 LR Primer
COL 3.260
COL is based on OAL gauge measurement of this bullet in the throat of my rifle. Measurement was 3.270, I gave .010 breathing room.
I take no responsibility for this load or your reloading practices. What happens on your reloading bench and the results thereof is strictly your responsibility.