He also neglects to mention MANY Savage MLIIs and the MDMs also had large bores but somehow tons of people figured out how to shoot them. Lets not forget TB was a huge Savage supporter for many years and should be very well of this fact. He also had a MDM and even mentions the large bore in an article.
Pretty common for a 45cal to run .451-.452. Probably more common than a true .450.
Obviously he is not very good at simple math either. He claims 121fps difference twice.
Back when i was working to establish some "pluses" and "minuses" of the .52 rifles ... I found that the stemmed plug did give me a 121 f.p.s. higher velocity.
My chronographing with the same rifle and load averaged 1,924 f.p.s. (with around 3,075 f.p.e.). With the standard "non-stemmed" DISC Extreme breech plug installed in the same rifle, the load was good for 1,903 f.p.s. - 121 f.p.s. slower than with the stemmed plug.
My best advice to TB is quit advocating HUGE loads of BH209. This isnt the first time ive seen him post potentially dangerous load data that exceeds Western's, CVA's and Tradition's limits.
This same load out of a 30-inch barreled break-open .50 caliber in-line, like the Traditions LDR models or the CVA Accura V2 LR, in cool weather is good for 2,082 f.p.s. - and 2,886 foot-pounds of energy at the muzzle. (Yes, cooler temperatures tend to equate to slightly faster velocities with saboted bullets.) A 130-grain charge of Blackhorn 209 out of these longer barreled in-line rifles pushes velocity to around 2,110 f.p.s., with around 2,970 f.p.e. - and 140-grains of the powder takes velocity to around 2,135 f.p.s. - and energy to 3,036 f.p.e.