1:48 Twist throwing curve balls


March 20, 2011, 11:14 AM
Or maybe screw balls.

I spent 3 hours at the range working with my Lyman Trade Rifle. I had ran out of BP earlier this year, and got 3 more pounds of GOEX FF. I wanted to check my zero, just in case this lot was different from the batch I had bought 2 years before.

I started at 25 yards, and adjusted to dead on (I have the Lyman 57 SML receiver sight). At 50 yards, POI was about 1 inch left so I moved the sights to be 2" high at 50 yards, dead center otherwise.

Then, at 100 yards, POI was 8" left.

I rechecked at 50, still 2" high.

I rechecked at 25, .5" high and 1" RIGHT.

It looks like helical yaw anomaly you might see in overstabilized conical rifle/pistol bullets.

I am using .535" 54 round ball, .018 pillow ticking, spit over dried Moose milk lube, 110 grains of FF.

Any ideas.

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45-70 Ranger
March 20, 2011, 11:30 AM
Man you got me on this one. I can presume that you are using the same components that you used last year and have changed nothing but the powder? I don't have a 54, but a 50 T/C hawken, but with a 1:48 twist. Out to 150 yds or so, RB's shoot well. In over 45 years of shooting BP weapons, I've never encountered such an odd event. I'm stumped! Maybe another member can shed some light on the subject that will help out. I hope you get this fixed. It can be real frustrating when your weapon goes off the mark and you cannot find the cause....


March 20, 2011, 11:51 AM
Sounds like a stiff wind blowing right to left.

March 20, 2011, 11:59 AM
1:48 is about right for conical bullets, but a little fast for round balls.

March 20, 2011, 12:05 PM
You do know that you only sight your rifle in between 11:00am-1:00pm
don't you. And you shoot toward the North.

March 20, 2011, 03:33 PM
110 grains for a round ball in a 1:48 28" barrel seems too much to me. You imply that's a round and load that you've already zeroed the gun for, but I wouldn't expect that combination to work very well. Are those numbers group centers or single rounds? How big are the groups?

March 20, 2011, 05:56 PM
I built a short barrel CVA 50 cal rifle to shoot patched balls. It has a 1-48 barrel which I was told would be good for either RB or conicals. I about wore myself and the gun out trying different powder charge and powder granulation, patching material and balls. Nothing would stay on an 8.5 x 11 sheet of paper at 30 yards.
Just before I wrapped it around a tree I saw a box of TC 285? gr maxihunters in Walmart. The first 3 rounds cut a pretty clover leaf at 30 yds. I could not find a powder charge both FFFg and FFg that would not shoot very well.
I finally settled on 85 grs of FFg because it was dead on at 75yds with my sight settings.

March 20, 2011, 05:56 PM
I originally sighted in 2 years ago using 3F and a .535 ball and 0.18 patch. Shot 2.5-3" at 100 yards.

All my local dealer had in his magazine was 2F, so I went with the same load, 110g.

I am sure the interior ballistics (what is happening in the barrel) is slightly different going from 3F to 2F. Maybe the ball is obturating less with the 2F?

I know in Lyman's first edition black powder manual, round balls slightly flattened in hotter loads in some of their stop action photographs.

March 20, 2011, 11:36 PM
I would suggest that your use of 2F is the first thing to correct - from an experimental standpoint, that was your change. Go back to 3F and see what you get.

110gr does seem kind of hot for the 1:48 barrel. Not so much because of the twist, but also because normally barrels in that twist expect bullets, and are more shallowly rifled. With a hot load, you may well be "stripping" out of the rifling.

I saw the same thing with my TC Hawken in 50 cal. Up to 80gr of 3F, it shot like a dream. Above that, my accuracy suffered severely. Generally, the lower the charge the better it shot - if I was in a match shooting 25 yard paper, I used 50 gr. In contrast, my custom made Hawkin has a long twist, roundball barrel with deep rifling, and is 35" long, and wants 120gr of 3F to shoot well. Glad I have a 1" barrel on it....

I would venture that the ball obturating is not that influential - remember, you have a patch that prevents the ball from really engaging the rifling. The patch does the sealing and the engaging of the rifling. Any obturation would help a bit, but you probably have un-rounded the ball quite a bit with the tight ball and thick patch you are using.

My method would be this:

Go back to 3F
Sight in at 25 yards, varying powder to get the tightest group
Leaving the sights alone, repeat at 50 and then 100
Compare results, THEN make your powder decision
After making the charge decision, adjust the sights for 100

Because my eyes aren't that good for 100, I zero at 25. If I am right on at 25, I find I am there at 100. Also, since I just use one charge for all ranges, I have a feel for elevation - just a bit more blade if out far, dead on for less than 100.

This has worked for me, but your mileage may vary.

Loyalist Dave
March 21, 2011, 10:58 AM
Tis' sound, sage advice. My .54 with 70 grains of 3Fg goes through deer broadside at 100 yards, so I'd back off the loading a bit. Check your patches and be sure you're not having problems there. You changed the powder size, it may be acting different on your patches.


March 21, 2011, 02:45 PM
how do, new here, try dropping your powder charge to 90, then in cress it at 5 g ie 95 then 100 then 105. see if it still does it, to see what it does could be barrel thump, do to loose wedge pin(s). just a thought

March 23, 2011, 12:35 AM
Hmmmmmmmmm.....I cut my teeth on T-C Hawkens and Renegades, all 1:48, and I've never seen that behavior, so I'm stumped. Have you checked your patches for cutting or burning? Or (and here's a really ugly thought), is your barrel warped? I sent a new barrel back to T-C once because it had a 1/8" warp in it. I checked it with a fishing pole-I just looped some of the line around the handle and tied the other end to the tip guide so I had a nice string line that I could lay along the flats of the barrel. It wouldn't take much of a warp to send your ball into the next ZIP code.

March 23, 2011, 04:43 PM
I put a diode bore light down the bore. No pitting, rust or muzzle damage, but two rifling grooves about 8" down from the muzzle had scratches straight across the groove, as if the cutting broach had stopped and reversed. Hard to say what it is, and what effect it would have. You cannot feel it with a cleaning patch, but you can certainly see it.

Any, I ordered 40 Hornady Plains bullets, the hollow base type.

I will start at 60 grains and work up with these. I will report back after a range trip.

Thanks for all the feedback :D

March 23, 2011, 05:16 PM
Looks a little like this?

March 23, 2011, 05:19 PM
In my built from kit T/C Hawken, I shoot 45 grains of FFG and a .013" thick patch for very good accuracy with home cast round balls.
My hunting load is 90 grains of FFG behind a home cast 370 grain Maxi-Ball.

March 23, 2011, 06:01 PM
I have read several posts in the past that pushing a PRB too fast in a fast twist rifle (1:48) as compared with a 1:60 is a loser for accuracy. 110 Gr. is for cutting down small trees, and going through telephone books. I have a Traditions Frontier that will chew the center out of a 3" circle at 50 Yds with a load of 60 Gr of 2f 777, or 70 Gr of 2f Goex. Slow it down. Besides - 70 gr will give you 100 shots from a 1 Lb. can.

March 23, 2011, 08:48 PM
Looks a little like this?
Very similar, except it only covers 2 adjacent grooves then stops.
In my built from kit T/C Hawken, I shoot 45 grains of FFG and a .013" thick patch for very good accuracy with home cast round balls.
My hunting load is 90 grains of FFG behind a home cast 370 grain Maxi-Ball.I love Maxi-Balls but was unable to locate any in stock at the moment. I originally shot this gun with home cast REAL bullets.
Slow it down. Besides - 70 gr will give you 100 shots from a 1 Lb. can.I will try that as part of the Plains Bullet range trip.

Thanks again all.

March 23, 2011, 08:52 PM
I have 2 boxes of 20 each of Thompson Center 370 gr Maxi-Balls. These
were made by T/C. Any offers?

March 23, 2011, 11:16 PM
370 gr is 50 cal? I need 54 cal.

March 24, 2011, 01:31 AM
Hornady .54 Great Plains is on sale at Cabela's:



Hornady Great Plains Bullets

Outstanding bullet! Great lube very accurate out of my .54 cal Hawkens with 100 grains of Pyrodex RS powder.

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