TC White Mountain Carbine

[mdshann]

I recently picked up my first muzzle loader, a Thompson Center White Mountain Carbine in 50 cal. I am curious if anyone can help me identify the twist rate of the barrel. Is there some way to measure it? The rifle is so clean I'm not sure it's even been fired, if it has it was only a few times. Thanks!

 

[Are. M.]

It's a hoss of a little gun and a lot of fun to shoot. The .45s and .50s with a 21" barrel have a 1/20 twist rate. Good for conicals/sabots at higher velocities. Dial back your powder charge to ~50grs if you want to shoot patched round ball.

 

[bubba.50]

Some had 1 in 20 twist and some had 1 in either 28 or 38 twist.

 

[Are. M.]

I know the .54s had a 1/48 twist. They also had a 1" barrel vs the 15/16ths" in the .45s and .50s. I think I remember someone on here saying some of the older models had slower twist.

RM

 

[Loyalist Dave]

I recently picked up my first muzzle loader, a Thompson Center White Mountain Carbine in 50 cal. I am curious if anyone can help me identify the twist rate of the barrel. Is there some way to measure it? The rifle is so clean I'm not sure it's even been fired, if it has it was only a few times. Thanks!

I'm pretty certain that, the Thompson Center company Catalog #20 lists the White Mountain Carbine twist rates thus:

45 caliber 1:48
50 caliber 1:20
54 caliber 1:48

and Thompson Center Catalog #22 lists the White Mountain Carbine twist rates thus:

50 caliber 1:38
54 caliber 1:48

I believe that TC issued a catalog each year, so the above twist rates were in 1985, and the latter twist rates were in 1987.

LD

 

[mdshann]

Hmmm... So it seems that it's either 1:20 or 1:38. I don't have the rifle with me to verify, but if I recall correctly the serial number is around 32200-ish.

Does anyone know of a way to measure it?

Does it really even matter?

I have some round ball I want to shoot out of it for practice, but I can't find any damn powder locally. I'd like to use it hunting this season, so at some point I also want to consider trying some other type of projectile. From my understanding the twist rate matters when choosing a projectile, so it's good to know what it is.

Thanks for your help!

 

[Zonie]

Hmmm... So it seems that it's either 1:20 or 1:38. I don't have the rifle with me to verify, but if I recall correctly the serial number is around 32200-ish.

Does anyone know of a way to measure it?

Does it really even matter?

I have some round ball I want to shoot out of it for practice, but I can't find any damn powder locally. I'd like to use it hunting this season, so at some point I also want to consider trying some other type of projectile. From my understanding the twist rate matters when choosing a projectile, so it's good to know what it is.

Thanks for your help!

To measure the twist get tape measure, a cleaning rod with the proper cleaning jag on it, a cleaning patch, a little oil, a piece of masking tape and a pen or felt tip marker.

Lightly oil the patch, place it on the jag and run the rod/jag down the barrel until it stops at the breech.
Place the masking tape around the rod so that it's lower edge is in line with or flush to the muzzle.
Use the pen or marker to mark the tape in line with the front sight.

Slowly, very carefully, pull the cleaning rod/jag back out of the barrel allowing it to rotate with the twist.
When the mark has rotated half way around from the front sight (180°) stop.
Now, measure the distance from the muzzle to the lower edge of the masking tape.
Multiply this distance by 2 and you will have the answer to the riflings rate of twist.

If the patched jag comes out of the barrel before the rod has rotated 180°, then stop when the mark has rotated 1/4 of a full revolution (90°) and multiply the distance from the muzzle to the bottom of the tape by 4.

Do this several times to check the distance. Often, the cleaning patch will lose it's grip on the rifling and skip to the next groove. Especially if you weren't careful in letting the rod rotate freely.
After getting several readings, use the one that repeated most often.

As for the rate of twist and what the barrel will shoot the best, the faster rate is good for elongated bullets. It can work with patched balls too if the rifling grooves are deep enough but often the fast twist barrels have very shallow rifling grooves. Shallow rifling grooves do not work well with cloth patches.

 

[Old Hawkeye]

Track of the Wolf has one in 50 caliber for sale with a 28" barrel and a 1 in 48" twist. So the one for sale in "real life" doesn't match any of the quoted specs from the previous posts. Did they change a lot from year to year??? Did the different barrel lengths have different twists? Why all the variances in barrel lengths & twist rates people have given? Thinking of buying the one on TOTW so, just curious!

 

[Cattywompuss]

If I remember right, most T/Cs actually have the twist rate engraved on the barrel don't they? Maybe not the older guns from 70s,80s, but I thought every more recent one I've seen actually had it on the barrel.

 

[deermanok]

I don't think it's a carbine if it has a 28 inch barrel?

 

[SmokepoleSam]

Cattywompus, you are right the older guns didn't have the twist rate on the barrels. Sorry I don't know when they started doing that. Maybe someone with more knowledge will chime in.

 

[bubba.50]

Track of the Wolf has one in 50 caliber for sale with a 28" barrel and a 1 in 48" twist. So the one for sale in "real life" doesn't match any of the quoted specs from the previous posts. Did they change a lot from year to year??? Did the different barrel lengths have different twists? Why all the variances in barrel lengths & twist rates people have given? Thinking of buying the one on TOTW so, just curious!

White Mountain Carbines never had 28in barrels. If Track has such an animal it's most likely a White Mountain stock with a Hawken barrel on it.

 

[bubba.50]

If I remember right, most T/Cs actually have the twist rate engraved on the barrel don't they? Maybe not the older guns from 70s,80s, but I thought every more recent one I've seen actually had it on the barrel.

the only ones I'm aware of that had the twist stamped on the barrel were the roundball twist barrels from the Fox Ridge custom shop and maybe the Pennsylvania Hunter/Match rifles and perhaps the Clelland and the Hawken Classic which also had roundball barrels.

 

[user 48679]

White Mountain Carbines never had 28in barrels.

If Track has such an animal it's most likely a White Mountain stock with a Hawken barrel on it.

Ding -ding - ding... we have a winner ! !

From Track:


Thompson Center White Mountain Carbine,

.50 caliber, 28" T/C Hawken barrel,
walnut, blued, rubber recoil pad, sling studs, fiber optic sights, used

 

[Old Hawkeye]

White Mountain Carbines never had 28in barrels. If Track has such an animal it's most likely a White Mountain stock with a Hawken barrel on it.

Yes! I went back & looked again & it is a White Mountain Carbine retro fitted with a 28" TC Hawken barrel. Still would make a nice hunting rifle for those wanting sling swivels, a recoil pad, & modern sights.

 

[mdshann]

To measure the twist get tape measure, a cleaning rod with the proper cleaning jag on it, a cleaning patch, a little oil, a piece of masking tape and a pen or felt tip marker.

Lightly oil the patch, place it on the jag and run the rod/jag down the barrel until it stops at the breech.
Place the masking tape around the rod so that it's lower edge is in line with or flush to the muzzle.
Use the pen or marker to mark the tape in line with the front sight.

Slowly, very carefully, pull the cleaning rod/jag back out of the barrel allowing it to rotate with the twist.
When the mark has rotated half way around from the front sight (180°) stop.
Now, measure the distance from the muzzle to the lower edge of the masking tape.
Multiply this distance by 2 and you will have the answer to the riflings rate of twist.

If the patched jag comes out of the barrel before the rod has rotated 180°, then stop when the mark has rotated 1/4 of a full revolution (90°) and multiply the distance from the muzzle to the bottom of the tape by 4.

Do this several times to check the distance. Often, the cleaning patch will lose it's grip on the rifling and skip to the next groove. Especially if you weren't careful in letting the rod rotate freely.
After getting several readings, use the one that repeated most often.

As for the rate of twist and what the barrel will shoot the best, the faster rate is good for elongated bullets. It can work with patched balls too if the rifling grooves are deep enough but often the fast twist barrels have very shallow rifling grooves. Shallow rifling grooves do not work well with cloth patches.

Thanks! I'll give this a try and let you guys know what I find out.

 

[mdshann]

If I remember right, most T/Cs actually have the twist rate engraved on the barrel don't they? Maybe not the older guns from 70s,80s, but I thought every more recent one I've seen actually had it on the barrel.

Nope, it's not marked on the barrel. I wish it were so easy lol!

 

[bubba.50]

Nope, it's not marked on the barrel. I wish it were so easy lol!

The Hawken barrel on that White Mountain Carbine stock is 1 in 48 twist as were they all. Exceptions to this are the roundball twist barrels from the custom shop and these are always marked ‘roundball twist 1 in 60’

 

[mdshann]

To measure the twist get tape measure, a cleaning rod with the proper cleaning jag on it, a cleaning patch, a little oil, a piece of masking tape and a pen or felt tip marker.

Lightly oil the patch, place it on the jag and run the rod/jag down the barrel until it stops at the breech.
Place the masking tape around the rod so that it's lower edge is in line with or flush to the muzzle.
Use the pen or marker to mark the tape in line with the front sight.

Slowly, very carefully, pull the cleaning rod/jag back out of the barrel allowing it to rotate with the twist.
When the mark has rotated half way around from the front sight (180°) stop.
Now, measure the distance from the muzzle to the lower edge of the masking tape.
Multiply this distance by 2 and you will have the answer to the riflings rate of twist.

If the patched jag comes out of the barrel before the rod has rotated 180°, then stop when the mark has rotated 1/4 of a full revolution (90°) and multiply the distance from the muzzle to the bottom of the tape by 4.

Do this several times to check the distance. Often, the cleaning patch will lose it's grip on the rifling and skip to the next groove. Especially if you weren't careful in letting the rod rotate freely.
After getting several readings, use the one that repeated most often.

As for the rate of twist and what the barrel will shoot the best, the faster rate is good for elongated bullets. It can work with patched balls too if the rifling grooves are deep enough but often the fast twist barrels have very shallow rifling grooves. Shallow rifling grooves do not work well with cloth patches.

I think it's a 1:20. I keep getting either 7" to 180 deg or about 9 1/2" to 10" depending on how well it grabs the patch when I start pulling.

Darn, I bought a box of round balls!

 

[bubba.50]

My confusion as to which gun we talkin' about with two different ones bein' bandied about. Definitely sounds like your gun is 1 in 20 twist because TC never made a 1 in 14 twist. LOL.

My earlier comment pertained to the White Mountain/Hawken hybrid at Track of the Wolf.