Drew;
I actually see the "Guaranteed for" & "Bored For" as speaking of two different things. The Guaranteed For I see as they are saying their guns are amply strong to handle the increased pressure of the New Smokeless shells.
The Bored For I see best exemplified by this quote;
"All guns bored true to gauge to use wads same size of gauge of gun."
Also the Colt statement;
"Barrels specially bored for nitro powder when so ordered."
It just seems one has to read the Ads very carefully to fully understand what they are saying. It just seems to me that, assuming barrels of similar weight, thus like wall thicknesses that varying the bore size by some .020'-.030" would have little impact on the actual strength of the barrel or its ability to handle any given type of powder.
Those barrels with intentionally oversized bores for using the brass cases with over sized wads would likely not perform well with the smokeless loads in paper cases with wads "Same size as gauge of Gun".
In an 1892 LAC catalog slightly contradictory statements are made on different pages.
On one page in a discussion of guns for Nitro Powder they state, " These guns we are boring smaller or for the use of wads same size as bore.
On another page under instructions for loads the state when using brass cases to use wads 2 sizes larger than borte of gun & for paper cases to use wads 1 size larger than bore.
This raises another question. I measured some left over 12ga card & filler wads purchased the late 1950's. Actual measurement was about .750" or 11 ga. 11 gauge wads from the same era for all brass cases measured around .770" or just shy of 10 ga. I do not have any wads from the 1890's to measure. Were 12 ga wads then considered to be more like .730" or had they already taken on the larger .750" size? This could have a definite bearing on Lefever's recommended wad sizing.
