Question Concerning Tumbling Lead bullets on Paper Target

[okdee]

Hello all,

I am looking for some thoughts and maybes and what-to-look for's!

I have a Winchester 1876 lever-action rifle in 45-75 caliber, with a 28" barrel. I am loading it with a
350 gr ( .459 dia ) Lead bullet.
38 gr of IMR3031, average velocity is 1411 f/s.

There was a cross wind of about 15-30 mph, cloudy and about 70 degrees.

Out of 7 shots, 6 bullets hit the paper target tumbling or keyholeing.

I looked at the crown and does not appear to my naive eye, to be any burrs. I looked the best I could down the barrel and there is rifling, although it is scant. I also noticed some pitting on the north side of the chamber. I slugged the barrel and as near as I can tell, .454 to .456.

Any thoughts, directions or offers of advice would be helpful in helping me figure this one out!

Cheers, Oklahoma Dee

[Griff]

With "scant" rifling, how hard are yer bullets?

Although you don't find any burrs, is the rifling @ the muzzle equal in depth?

Have you tried loads around 1200fps? Hard bullet, scant rifling & hi-speed in combination could cause unstable flight. Change one factor and you might regain stable flight.

[okdee]

Thanks Griff!

The rifle was born in 1883 and so there may be bit a worn-ness about the barrel!

I am not sure how hard the lead bullets are, I wil inquire.

I closely inspected the muzzle with a magnifier and there does seem to be some unevenness on the crown and some slight pitting and the rifling, as far as I can see, does NOT extend up to the muzzle.

I kinda wondered if a slower velocity might help.

It may very well be a worn out barrel.

I may have to have a qualified gunsmith, review the gun with me. Then look at my options.

Cheers,
Oklahoma Dee

[w30wcf]

okdee,
Bullet size and hardness have a lot to do with tumbling bullets.
Here's a forum dedicated to 1876 shooters. They will be able to help.
http://www.cascity.com/forumhall/index.php?board=89.0

Good luck,
w30wcf

[Old Time Hunter]

If it is worn, consider having Bob Hoyt in Fairfield, Pa. re-line it, he does an awesome job with a chrome-moly sleeve and from the outside you will not even know it has been improved. He is also very reasonable...i.e. almost cheap compared to most.

[flatnose]

You may have poor quality bullets.
If you slugged the complete barrel length, the measurement you have will be for the tightest spot in the barrel, .454 or .456. You need to slug just the muzzle end of the barrel for the last 3" or so. If the diameter is larger than the tightest spot on your bore, it may contribute to your problems.
I would clean the barrel first, very lightly oil it, and try pushing a tightly fitting patch through the bore. You will be able to fell where there are tight spots, if any.
Depending on how good or bad the barrel is, I would replace it. before that, I would try slowing the bullet down to 1200fps or thereabouts.

[Lefty Dude]

Lower the speed, and they will stop the tumble.
With that big cartridge you my have trouble, shooting a reduced load that will get you too 1000fps or 1100.

A full case of Black Powder, 2F and I'll bet it won't tumble.

I would try a different powder, 3031 my not be the powder you need.

[El Chivo]

I had a good accurate load, then in hot weather the bullets went wild and many started tumbling.

I just shot up the rest of those in mild weather and they were fine. So pressure must have been a little high due to the hot temps.

Anyway, back off on the load and see if they settle down.

[okdee]

Thanks to Everyone that replied!

I will be knocking down the velocity and maybe even take the old girl over to a local gunsmith and see what they think about the bore. A 28 inch barrel is kinda hard to really get a good look at. Maybe it is time for buying a bore scope?

Cheers to everyone!
Oklahoma Dee

[Tycer]

I have a 32-20 that scatters lead hardcast bullets, but shoots gas checked ones quite well.

[SFRanger7GP]

I bought some bullets from a guy that I had been buying from for years. He changed his casting recipe and starting casting really hard. My plinking loads would not stabilize a bullet in 44 special, 45 colt, 45-70, 44-40, 38-55 and 32-20. The bullets tumbled in all of my normal loads and leaded pretty bad. If I loaded the bullets up to high velocity I had no problems. I ended up loading the 44 bullets in magnum loads and the 45 bullets in my casull. That stopped the tumbling and leading but it wasn't what I wanted. Needless to say I don't order from him anymore.

[the telegraphist]

Hello all,

I am looking for some thoughts and maybes and what-to-look for's!

I have a Winchester 1876 lever-action rifle in 45-75 caliber, with a 28" barrel. I am loading it with a
350 gr ( .459 dia ) Lead bullet.
38 gr of IMR3031, average velocity is 1411 f/s.

There was a cross wind of about 15-30 mph, cloudy and about 70 degrees.

Out of 7 shots, 6 bullets hit the paper target tumbling or keyholeing.

I looked at the crown and does not appear to my naive eye, to be any burrs. I looked the best I could down the barrel and there is rifling, although it is scant. I also noticed some pitting on the north side of the chamber. I slugged the barrel and as near as I can tell, .454 to .456.

Any thoughts, directions or offers of advice would be helpful in helping me figure this one out!

Cheers, Oklahoma Dee

Gday fellah
Come down to around 1250fps, sounds like they are too hard cast. But as others have mentioned check rifling. Rifles at best can be finicky regarding bullet hardness. If they are too hard the rifling cannot get a good grip. Gasses start bypassing the projectile and a whole host of interesting things start happening, none of them enhacing accuracy. Gas check may help in certain circumstances. Loading lead to "top" velocity. Lymans cast bullet handbook has a wealth of info, worth the money.

[KirkD]

Oklahoma Dee, I've got acceptable accuracy (5-shot groups at 100 yards of 4" or less) out of some pretty sorry looking sewer pipes, but there are a few tricks in my bag. Here are few suggestions:

1. Don't use slow powders like IMR 3031 in a worn bore ..... its burn rate is too slow, giving a pressure peak much lower than BP for the same velocity, failing to bump up the bullet to fill the bore.

2. Try a smokeless powder that more closely matches FFg in its burn rate and relative quickness. A good example would be 2400, SR4759 or even 5744. These are all slightly slower than BP, so will be safe in your old rifle for original ballistics, but may bump up the bullet.

3. One sheet of single ply toilet paper, loosely fold and rolled, with the butt ends stuffed in first, can work wonders with an old bore. It will raise the velocity by about 100 fps, so reduce your powder charge if you use it.

4. Gas checks

5. I always like to use wheel weight lead (BHN 12 or therebouts) so that it can bump up more readily. Hard cast bullets don't bump up very easily.

6. Keep ballistics (bullet weight, hardness and velocity) to original black powder ballistics

[cowboykell]

Smokeless powder will NOT bump up a bullet.

[KirkD]

Smokeless powder will NOT bump up a bullet.

It certainly will if it has the same peak pressure as black powder. I do it all the time in making smokeless loads that match bp pressures. Use powders in the blue dot/ 2400 range. You can go with faster powders ... Unique and Bullseye will bump up a bullet much better than black powder, but at a peak pressure that significantly exceeds BP. I never use faster powders like Unique in an original BP gun.

There has been some work done on pressure curves of BP vs smokeless. Sherman Bell has published some interesting stuff. Bottom line: smokeless powders with the same peak pressures as BP will bump of a bullet exactly as well as BP .... every time ..... no exceptions. The trick is to be familiar enough with burn rates and relative quickness of smokeless powders so that one can match BP ballistics.

[okdee]

Great Thoughts all around!

What is the definition of "bump up a bullet" ??

Is this when the force of the expanding gases, while pushing the lead bullet down and out the bore, actually cause a lead bullet to become deformed or misshapen from the original casting?

Greatly appreciate the ideas and "tricks" !

Cheers,
Oklahoma Dee

[Old Time Hunter]

What is the definition of "bump up a bullet" ??

Is this when the force of the expanding gases, while pushing the lead bullet down and out the bore, actually cause a lead bullet to become deformed or misshapen from the original casting?

Yep.

I actually have used Unique with success on hard to straighten out "tumbling" bullets, just have to be ultra careful(12.5 to 13.5 to start out with max). The 2400 works well too. My guess is that the bullets are too hard and .454 sounds awful tight, .459 to .460 would be more like it. The .454 does sound correct for the lands though.

[KirkD]

One more thing to add to the bag of tricks, although it's not really a trick, but one of those things that just doesn't make any sense ..... I've had a few .458 caliber old BP Winchesters that shot perfectly fine with a .457 or a .458 cast bullet (i.e., 5-shot groups at 100 in the 2" category), but start throwing 24" 'patterns' at 25 yards with a .460 bullet tumbling head over heels, just .002" over groove diameter. Don't ask why, because I don't understand it. Same bullet, just sized larger. Moral of the story .... try groove diameter, then try .001" over groove diameter, then try .002 over groove diameter. See which shoots best. bullet that are tumbling that are sized for one diameter may shoot very well sized to another. My general preference is .001" over groove diameter, but even that has to be adjusted up or down depending upon the condition of the bore and throat.

[O.S.O.K.]

I read through this rather quickly but did anyone suggest slugging the barrel to determine actual groove diameter? Rifles of that production date had some variences to say the least - I'd guess that you're looking at a specimine with .460+ bore diameter.

One thing you can do is to use hollow based bullets of 1-30 tin to lead alloy. Especially since you're wanting standard velocity loads. These tend to be very accurate even with the larger bore diameters becuase the thin "skirt" expands easily to grab the rifling.

I like Mike Venturino's favorite smokeless bp-approximation propellant - XMP-5744 or I think it's Western Powder now?

Around 28 grains of 5744 with a 400 grain bullet will give 1350fps or so.

My 2.

[cowboykell]

Smokeless powder will NOT bump up a bullet. Black powder has the "explosiveness" to bump up a bullet that smokeless doesn't. It is one of the main differences between the two powders. I have shot many .403 bullets through a .406 bore using several different smokeless powders and recovered the bullets from a snowbank....still .403 !

[KirkD]

Smokeless powder will NOT bump up a bullet. Black powder has the "explosiveness" to bump up a bullet that smokeless doesn't. It is one of the main differences between the two powders. I have shot many .403 bullets through a .406 bore using several different smokeless powders and recovered the bullets from a snowbank....still .403 !

It depends upon what smokeless powder you were using. Smokeless powder has a large range in burn rates (Dupont Index (DPI) and Relative Quickness (RQ)) that straddles either side of black powder's 'explosiveness' (pressure curve/DPI/RQ .... whatever a person wishes to call it). I'd be interested to know what the cartridge was (.40-82 by any chance?) and what powder you were using.

[flatnose]

okdee,
I seem to have missed part of your second post. You state the rifling does not extend all the way to the muzzle. If that is the case, then there is your problem. Get the gunsmith to check it out He maybe able to counterbore and then recrown it.
The gas is blowing by the bullet near the muzzle and upsetting the bullet.