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How to "slug the bore"

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Can anyone here help me ? I want to slug my muzzleloader bore. I have a 50cal T/C Wht. Mtn. Carbine, and a .54 Renegade that I want to shoot slugs from. I was told to slug the bore to get the proper slug size.
I have not been able to find out how, everything I see on the internet is for slugging rifles and pistols with an open breech. So how would I slug a closed breech muzzleloader? Any help would be appreciated.
 
Look up "pin gauge". We use them all the time in the NSSA to determine barrel dia.

You don't need an entire set. Use a dial caliper to get an idea of where you are. Example gun- 1863 Springfield repop, unknown actual bore size. Get dial caliper and check. Caliper says 578ish. Order .575, .577, .579 pin gauges off Amazon, like about $6ea. First, 575 drops all the way to the bottom. Barrel is larger than .575. Next .577 goes in but with less play. Barrel is larger than .577. Next .579 doesn't go. Barrel is .578.

Easy to do, you'll likely only need 3-4 sizes. The gauges don't wear out and are handy if you have to ever check a similar caliber gun again.

Alternatively, take the barrels to a machine shop. Most have a complete set of the gauges. Get them to check for you.
 
Probably not the best way to get bore size but when I found a Tingle and didn't know the bore size I took a larger soft lead ball and lightly tapped it into the bore at the muzzle about 1/3 to 1/2 way. I pried it back out with a knife trying not to distort it. Then I measured the lands and grooves with calipers. I'm sure it wasn't exact but close enough to get close.
 
Can anyone here help me ? I want to slug my muzzleloader bore. I have a 50cal T/C Wht. Mtn. Carbine, and a .54 Renegade that I want to shoot slugs from. I was told to slug the bore to get the proper slug size.
I have not been able to find out how, everything I see on the internet is for slugging rifles and pistols with an open breech. So how would I slug a closed breech muzzleloader? Any help would be appreciated.
Unless you plan on using a slip fit bullet that is bore size, such as a .451 in a Volunteer rifle Then you should slug the bore. Be aware that you're probably going to have to invest in a mould, sizing die, wads and lead to get the rifles to shoot decently. On the other hand, if you plan on using a Maxi type bullet from T/C, Hornady or Lee, they are self engraving into the grooves when loaded and there's really no need to slug the bore. My humble opinion.
 
What gemmer said. Since its a T/C, I would just order Lee "real" mini ball moulds and your good to go. Just order 050 and 054.
 
I drilled a hole in an oversized soft lead ball and put a bolt or nail through the ball. I used a deep walled socket to drive the ball into the barrel with the ed of the bolt up. I pulled the bolt and ball from the barrel and I had a measurable slug.
 
An easy way to slug a bore in a muzzle loader is to put a solid brass rod of about 3/8" dia and about 4" long in the barrel. Then take a lead ball that is over caliber size and tap it down the bore about 4-6". Now take the barrel and invert it and shake the brass rod up and down until the ball comes out. Now measure the ball for your land to land and groove to groove measurements.
 
Can anyone here help me ? I want to slug my muzzleloader bore. I have a 50cal T/C Wht. Mtn. Carbine, and a .54 Renegade that I want to shoot slugs from. I was told to slug the bore to get the proper slug size.
I have not been able to find out how, everything I see on the internet is for slugging rifles and pistols with an open breech. So how would I slug a closed breech muzzleloader? Any help would be appreciated.
With both the TC White Mountain and the Renegade, IMO, you don't really need to slug the barrel to figure out what the actual bore size is.
If the barrel hasn't been rebored, it will be within .001 of the size shown for its' caliber.

The guns that really need to have a slug forced into the bore are some of the Italian and Spanish (and definitely the Indian) made guns.
Also, all of the original antique barrels that you might want to use for shooting lead bullets need to have it done because back in the day, the actual bore size varied a lot from gun to gun.

The TC barrels use an even number of rifling grooves so as long as the barrel doesn't have the "Quick Load Accurizor" muzzle on it, you can measure the bore using a digital or dial caliper. Just be sure you are measuring the bore size and not the rifling groove diameter.

These Digital calipers are quiet inexpensive and even though they are made in China, they are very accurate.
They can measure inside measurements like you would use for a bore, outside measurements like you would use for a bullet and depth measurements that you want to measure to an accuracy of 1/2 of a thousandth of an inch.
My only gripe with the Digital calipers is, the battery usually is dead when I want to measure something. That's why I own 1 Digital caliper and 3 Dial calipers. :)

If your measuring a bore with an odd number of rifling grooves like 3,5,7 or 9, you will have a real hard time trying to measure the bore because when one probe is on a land, the other one will be in a rifling groove. The best way to measure bores with these odd numbers of grooves is with a precision plug gage. Usually any really good machine shop in your area will have a set of these so if you bring the removed barrel to them they can do the job in just a few minutes and it usually won't cost much to have them do it.
 
An easy way to slug a bore in a muzzle loader is to put a solid brass rod of about 3/8" dia and about 4" long in the barrel. Then take a lead ball that is over caliber size and tap it down the bore about 4-6". Now take the barrel and invert it and shake the brass rod up and down until the ball comes out. Now measure the ball for your land to land and groove to groove measurements.
It's handy to have a 7/16" and 1/2'' diameter brass rod a foot long for just such work
 
Unless you have an odd number of lands and grooves, or the bore is choked or the muzzle badly worn or even coned. Then you have the problem of the progressive rifling in barrels. (The grooves are deeper at the breech than at the muzzle.) A standard TC with factory rifling is no problem, but there are guns out there that are difficult at best to slug. Many of the old H&H barrels had rifling that was deeper near the lands than at the center of the groove. (Similar to Pope rifling.) Alex Henry rifles were also very different with an odd spiral groove, IIRC with 7 grooves.
 
I drilled a hole in an oversized soft lead ball and put a bolt or nail through the ball. I used a deep walled socket to drive the ball into the barrel with the ed of the bolt up. I pulled the bolt and ball from the barrel and I had a measurable slug.
Do this with a nut a couple of washers that are just a hair undersized and a couple of tight fitting wads with a washer and nut to hold them on the end of the bolt. Insert into bore-pour some cerrosafe in and let it set for @ 30 minutes. Measure after another 30 minutes.
 
Bottom line is that the gentleman is taking about two T/C barrels, not ones with exotic twists or groove depths. No need here to reinvent the wheel. A maxi type conical will do just fine, if that's what he wants to shoot.
 
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