Can anyone tell me if there is a different way to check the head spacing on a Thompson? I have a 375 H&H that the casing fell apart after I shot. It was reload and it was the 3rd reload. It was the mildest load and it was seated .010. Mr. Brown at E.Authur said that checking the head spacin on a thompson was different than checking it on a normal rifle. PLEASE somebody confirm this for me so I don't have to send my barrel back and make myself look foolish.

The best way is to chamber a go gage and a no-go gage. If your rifle will not go into battery with a go gage, then the chamber is too short. If it will go into batter with a no-go gage, the chamber is too long. If it will go into battery with a go gage, but not a no-go gage, then it is within tolerance.

Strick,
First welcome, drag up a stump, kick back and grab a cold brew, join in.
I have shot Contenders for 37 years and I work on Encore pistols. I have also known Eben Brown since he bought the BF Company, about 20 years.

What phil says is true. Also what Eben says is true. However, it makes no real difference.

Here is why. It actually does not matter in a TC single shot handgun or rifle, with a bottleneck cartridge. You want to set your own headspacing from the first shot on. Best accuracy with a contender or Encore is obtained when the cartridge headspaces on the shoulder, not the rim or belt. Your 375 headspaces on the belt but has a long chamber.

Try this with UNFIRED brass: load the ammo, take a lube pad with you to the range. As you chamber each round, lube the brass first. Fire the round, the lube will allow the brass to slip and not grab the chamber wall. This is like fireforming a wildcat cartridge. Now size the brass leaving about 1/8 inch of the neck, above the shoulder, untouched. Your case streatching will stop and your accuracy will improve. Remember you are loading one cartridge for one gun.

Additional hint, use the extractor as an indicator and load every cartridge with the same letter or number in the headstamp pointing to the left corner of the extractor. Your cartridges will return to the chamber just like they came out, every time.
Ed