Help on calculating twist.

[Nitsudttesrod]

I'm trying to figure out the rate of twist on a barrel which is in a new to me 54 cal rifle I just bought. The barrel has no markings at all so I can't tell who manufactured it. I attached a 12 gauge copper brush to my ram rod and put a .018 patch over it and inserted this down the barrel. Upon reaching the breach I did the old tape the ram rod/ tape the barrel at the front sight thing lining the tape up. I then proceeded to pull out the ram rod slowly watching for when I got to the 1/4 turn mark. When I got to a quarter turn I measured the distance from the tape to the muzzle and got a measurement of 25". I did this several times and got the same measurement. That would make the barrel a 1:100 twist. Did I do something wrong? That seems abnormal to me but what do I know I'm a newbie. Anyone ever heard of a twist rate like that?

 

[Zonie]

You done good with your method and if 25 inches is what you got for 1/4 of a full turn then you do have a 1:100 twist in that barrel.

That does seem a bit slow but you said it was in a rifled (I assume), 12 guage barrel.

A roundball for that size bore would be in the neighborhood of .690 in diameter for a patched ball and big patched balls don't need a fast twist to fly straight.

You didn't say but, what kind of rifle do you have ?

 

[don hepler]

That don't sound right for a 54 cal rifle. Instead of using the shotgun brush, try a jag with fairly snug patch. I think something slipped, on that other deal. I would guess something more like 1 turn in 70 inches or 1/2 turn in 35 inches.

 

[Zonie]

OH. :redface:

My frinkle up.

I saw the 12 guage brush and didn't see the .54 caliber.

Yes, a 1:100 twist in a .54 does sound slow but IMO, a patched roundball for one could shoot very nicely with that twist.

When it comes to roundballs, they do not need to be "stabilized" like a bullet does.

Their "short length" doesn't require a fast twist to keep them from tumbling.
All their rotation needs to do is to cancel out any deflections caused by the high speed air as they fly downrange.

 

[Nitsudttesrod]

My rifle is a .54 cal plains style rifle. I just bought it and have yet to fire her. The seller said it was custom and it has no markings. I used the 12 gauge brush because I don't have a jag or cleaning kit yet and I wanted to get her cleaned up right away. The bore looks great with no rust or pitting. Any idea where I can get a jag or cleaning kit for a .54 cal besides online? I'm considering making my own range rod as well.

 

[Nitsudttesrod]

Here's what she looks like:

http://i347.photobucket.com/albums/p474/nitsudragde/20170313_175640_zps9avtql6f.jpg http://i347.photobucket.com/albums/p474/nitsudragde/20170313_175830_zpsetwcgfzs.jpg http://i347.photobucket.com/albums/p474/nitsudragde/20170313_205423_zpsnffshbon.jpg

 

[nkbj]

Nitsud,
My method, masking tape can be wrapped around the rod to make tight fit for a greased patch to measure the twist.

Congrats on a nice looking rifle.

 

[Nitsudttesrod]

Thanks, I'll give that a try to see if I get a different result.

 

[Toomuch51]

I'm trying to figure out the rate of twist on a barrel which is in a new to me 54 cal rifle I just bought. The barrel has no markings at all so I can't tell who manufactured it. I attached a 12 gauge copper brush to my ram rod and put a .018 patch over it and inserted this down the barrel. Upon reaching the breach I did the old tape the ram rod/ tape the barrel at the front sight thing lining the tape up. I then proceeded to pull out the ram rod slowly watching for when I got to the 1/4 turn mark. When I got to a quarter turn I measured the distance from the tape to the muzzle and got a measurement of 25". I did this several times and got the same measurement. That would make the barrel a 1:100 twist. Did I do something wrong? That seems abnormal to me but what do I know I'm a newbie.

( Anyone ever heard of a twist rate like that?)

The English Baker rifle .72 cal. used a 1:120 twist

 

[azmntman]

Beautiful gun! Awesome wood :thumbsup:

 

[Rifleman1776]

Very nice looking rifle.
A 1:100 twist is not impossible. Not common but possible. However, to stabilize your ball and get the best groups you will need very hefty charges. My .54 Jaeger, with 1:72" twist, needs charges north of 100 gr. It is not a light rifle and those loads make for very uncomfortable recoil. :shocked2: Be prepared.