Saxtonyoung,
You are correct, the "Varminter" rifles used by the White Shooting Team to win the 2006 Manufactures Match were .367 caliber. They had the customary .0035" deep rifling that White is known for. So in center fire world, these would have been .374-.375ish caliber, not .38 like someone is trying to get you to believe. You had it right all along.
What some of the experts that are trying to correct you still don't realize is, muzzleloader calibers are measured off the land diameter, while center fire calibers are measured on the groove diameter. I told them this a couple years back, but they must keep forgetting?
"The ‘Varminter’ is in .367 caliber with 1-15 twist, throwing a tight multi-channelured lubricated almost slip-fit bullet weighing 305 grains. Barrel is 28 inches long, standard 1.10′ at the breech tapering to quarter sized at the muzzle, which is turned to fit the straight-line starter pictured below."
"The nose of the straight-line starter is turned to fit the bullet. The barrel has a slight choke, which makes it a mite difficult to load with ramrod alone. Since shooting this rifle at varmints and target is meant to be deliberate, I don’t mind the starter. Once the bullet is past the muzzle, it slides easily down to the powder."
"The Varminter rifle is fitted with a Morgan adjustable recoil pad. It will adjust up or down to fit the shooter’s face and shoulder geometry. The trigger is a Bold and pull weight is adjusted to 2 lbs which means the safety won’t work- use the secondary pullcock safety. The rifle is shot from a freshly cleaned and brushed barrel, powder is loaded down a long tube so it won’t pick up any residual moisture from the barrel walls and also so it stacks in the barrel pretty much the same for each shot. A bullet is then placed in the starter, then a poly wad is placed under the bullet in the starter, the starter is up-ended on the fitted muzzle and the bullet and wad are smacked down with the palm. The ramrod is then used to gently push the bullet down on the powder, being careful to use the same pressure for each loading. Groups of less than 1 MOA are average from a double rest."
"WHITE RIFLES TEAM WINS THE 2006 MANUFACTURER’S MATCH"
"That’s me, Doc White, on the left, then Rusty Cottrell, Lowell Crane, Merle Crane, David Jones and Steven Dick. The four with the rifles were the shooters, I got to cheer, while Steve managed the spotting scope and was handy in case we needed him as an alternate shooter. David Jones was the #1 individual shooter, Rusty was #2. The Crane brothers were # 6 & 7. Obviously, all are fine shots. The White team established a new record for the match, shooting 1132- 14X, eclipsing the old record of 1101-8X set in 2005 by the Knight team. David Jones also shot a new individual record for the match, shooting a 291-3X. He missed 9 points out of 300. WOW! It is hard for me to express how proud I am of this team of shooters. Their dedication to the task was exemplary. No one will ever know how many hours of practice it took to do this, let alone the mind control and discipline. They have my hearty thanks, little reward for their mighty accomplishment. The match was discontinued after White cleaned everyone’s clock. I guess we get to keep the trophy."
Here's is the whole story. And yes to the OP, Doc White also had some .330 cal and .350 cal "Squirrel" rifles over the years as well. The .451 caliber rifles were affectionately called the "Squirrel Rifles" by the guys that preferred the .504 caliber and .540 caliber rifles. This was all in fun. Doc does have a few typos in there as to rifling depth, he incorrectly lists it as .035" instead of the correct .0035". Enjoy!
http://whitemuzzleloading.com/designing-for-accuracy/