Daryl,

You are correct. The 256 Newton is a 30/06 necked down to take a 6.5mm bullet and is slightly shorten (2mm). Newton first imported 6.5mm barreled Mausers and chambered them for his 256 Newton cartridge that he designed. When the war in Europe broke out, he could not get Mauser rifles so he developed his own rifle. While he was developing his rifle (1st model or 1916 Newton), he rebarreled/restocked a few Springfields in 256 Newton. (I had &sold a 256 Newton Springfield marked NAC).

However, as the European war progressed, he could not get ammunition and that was what killed the Newton Arms Co (NAC). He made about 4000 rifles.

At the same time, Newton also developed the 30 Newton and 35 Newton These are the same basic case, just different bullets. That is the same case that Ruger used for its 375 Ruger. Ruger won't admit it but a 375 Ruger can be necked doiwn to either 30 Newton or 35 Newton. The 30 Newton has semilar ballastics to the later 30 Win Mag.

The Newton has a neat takedown system in that the magazine can drop down and then unscrew the bold retaining the action from the stock. ll have double set triggers. and some have a bolt tang sight.
Barrels look worn because the rifling is semi-eliptical.

I have collected and sold a number of 256 and 30 Newtons. They are great guns that were impcted by WWI. Jamison mad a run of 256 and 30 Newton brass and I was able to get some then.