45 Colt/410 Contender barrel question.

[45&30-30]

I have a 10" T/C Contender barrel marked 45 Colt with adjustable rear sight and post front sight I purchased about 10 years ago from ebay. I use 2 1/2" and 3" shells. I have taken several grouse a year with it. I was just noticing the chamber looks like it was first bored for 45 Colt then 410. I can see the step between the two chamberings. They are not perfectly concentric to one another. The choke is about 2" long and has rifling grooves that are straight, no helix and a key that fits in to them to install/remove it. My question/curiosity is do all 45/410 factory barrels have markings to denote both chamberings or is this a conversion someone did?

[JimB..]

It seems unlikely that someone would have modified a 45lc barrel when the 45/410 barrels are cheap and readily available, but I don’t know the answer to your question.

[M-Tecs]

That was a common modification to the 45 Colt when the first came out and the BATF was playing games with the 45/410 barrels. I had one and like yours it is not marked. The factory 45/410's common now but it was not always the case.

[falmike]

it is set up for “hot shot” rounds. The “choke” would shatter the casing and straighten out the shot stream so it would not spread out as rapidly from the spin of the rifling.

[M-Tecs]

it is set up for “hot shot” rounds. The “choke” would shatter the casing and straighten out the shot stream so it would not spread out as rapidly from the spin of the rifling.

I don't remember TC making "hot shots" in 45 Colt but now I am wondering if I owned one?

They did make them in 357 and 44 Mag. I have shot both and owned a 44 Mag for a short time. My 45 Colt had an external chokes like the early hot shots. Later 357/44 Hot Shots had internal chokes. I replaced my 45 Colt external choke with an internal choke 45/410 with a rib and flip sights. It would not surprise me if TC made 45 Colt hot shot barrel full well knowing they would be after market chambered in 410. It's very possible that's what I had. TC was pushing the BATF hard for awhile. I am more sure TC never made 45 Colt Hot Shot Ammo. I remember reading something to that effect at the time but I don't fully recall the details. Hopefully someone can fill in the details.

http://castboolits.gunloads.com/showthread.php?162989-TC-Hot-Shot-barrels-questions

[panhed65]

Your barrel sounds exactly like mine, I can't imagine someone would have gone to the trouble of the straight rifled choke being installed, even if tc would sell one separate as a part, be kind of expensive compared to just buying the barrel.
Barry

[MT Gianni]

Rumor was that many of the early TC bbls were chambered with a bench vise and a drill. It would not be a huge surprise to find they were done in two operations with the second one not having much for a pilot to be centered in. There is a reason people who want a hard hitting 45 Colt seek for a specific chamber rather than the 410/45.

[nhithaca]

Lot of good info over on Grey Beard's site about the issues with T/C's chambers.
Surprising how well their barrels shoot considering how much trouble they had with this operation. As I understand it the worse factory chambers were the 357 mag/max and the 45/410.

And T/C only made the Hot Shots in 357 and 44. Being in NH I see them from time to time at local gun shows here. They are now collectable if all original. This was when they were fighting with the Feds over the 45/410 (which went to the Supreme Court) and ultimately they did win.

[45&30-30]

Good information and history provided. It prompted me to spend a little more time web surfing. This threads author https://www.firearmstalk.com/threads/t-c-contender-45lc-410.17138/ says he inherited a barrel marked 45 Colt that has a screw in choke yet won't accept even a 2.5" 410 shell. Hmm...

[M-Tecs]

Good information and history provided. It prompted me to spend a little more time web surfing. This threads author https://www.firearmstalk.com/threads/t-c-contender-45lc-410.17138/ says he inherited a barrel marked 45 Colt that has a screw in choke yet won't accept even a 2.5" 410 shell. Hmm...

I been pocking around also and it does appear that TC did make 45 Colt Hot Shot barrels, however, it also appears that they never made ammo for it. Anyway reaming the chamber for 410 was common before the BATF issue was settled.

https://www.go2gbo.com/forums/36-thompson-center-handguns-sponsored-ed-s-tcs/254889-hot-shot-barrels-vs-regular-barrels-octagonal-round.html