[NWPilgrim]

The M1 Garand is a special case when considering going beyond max charge weights in a manual. You don't want to beat up the op rod and receiver. It is not designed to handle the full range of loads for which the SAAMI .30-06 cartridge is rated.

You don't want to rely on other loading data, no matter how ubiquitous, if you don't have all the info for it (OAL, tuned gas ports, primers used, etc.).

The Garand is the last rifle I would venture beyond the manual with. Look around at other manuals or load data that gives more complete info on the other factors.

I will say the Hornady data for the M1 Carbine is misleadingly low. I followed the manual and using a starting or in-between charge of W296 would not cycle the action properly. I even bought a new spring, re-cleaned and lubed it very carefully. Finally I found like you did, lots of recommendations from other handloaders; for exactly 15.0 gr of W296 as being the original military load. Hornady listed I think 14.9 gr as max. Checking with other manuals, I worked up test loads and sure enough right at 15.0 gr everything worked perfectly. 14.8 did not cut it at all and 14.9 was almost there. I've never experienced such a sensitive action before.