Slowest Twist For Lee & Lyman 450 Grain Fifty Caliber Molds

[Good Cheer]

Need some input on shooting the Lyman and Lee .512 / .515 caliber molds.
What does experience show is the best, the slowest, the too fast twists for the 450 grain molds? No doubt distance is going to play a part in trying to answer such a question so please if you know how accuracy is typically affected by the fast versus slower twists I'd love to hear about it.
Thank you for any info.

[herbert buckland]

The original 1868 Sprinfields 50-70 had a twist rate of 1 in 42 inch and shoot quite well,I have shot this bullet in a 1 in 20 twist barrel with very good accuracy,but that was at 100 meters at very low velocity out of a Italian Spencer 56-50,it may not work at higher velocitys.It depends on what caliber rifle and velocity you want to use this bullet in for the best choice of twist rate .EG Lyman .975 long .515 bullet at 1200fps,the optum stability is achived with a 1 in 33 inch twist rate,change the bullet length or velocity and every thing changes

[Good Cheer]

Anyone else shoot the 450 grainers?
Any input on the best twist to use?

[John Boy]

Remington #1 Rolling Block - 1:26 ... shoots accurately to 1000yds with both the 450 and 515gr bullets

[Good Cheer]

Ah hah!
Sir, I thank you for that input. The barrel is going to be ordered soon and I need experience speaking rather than theory and the various formulas.

[Bob Busetti]

Use the Lee bullet in my 50/95 (1-48 twist) loaded to 1300 fps with good results.
Bob

[Good Cheer]

Wow. Never would have guessed 48" would work out.

[kootne]

My 1868 Springfield shoots better groups (<2.5"@100 yds) than any other military as-issued rifle I have ever owned or shot. Load is 70gr of 1FG swiss, compressed enough so about 5/16" Cream of Wheat between powder and bullet (Lyman 450gr.) in an unre-sized case (also compressing CoW in a second step) so case will taper crimp in front of front band. Unsized bullet (20:1) lubed with SPG dropped on top of CoW and run into FL die just enough to put enough taper crimp on to hold the bullet in. Bullets will still spin w/fingers and a little effort. Fed 215 primer.
Funny thing is, that is the only way I been able to get any accuracy out of that rifle. A fully resized case = 10"+ groups @ 100.
kootne

[Good Cheer]

kootne,
Is your 1868 a 48" twist?

[kootne]

I assume it to be 42", that is what is quoted in most references. I haven't shot it beyond 100 yards but I think they drop like a rock by the time they get to 200. About 10 or 15 years ago I had a 50/70 NYS rolling block that also shot very well. I seem to recall that they had a faster twist but do not remember at this time what it was. The sights are not the best on any of those old army rifles and I don't think you will find any that shoot as tight as the rifles the Silhoutte boys build up from selected components. There is a guy somewhere in Texas that wrote a book about making 50/70 target rifles, Clint or Craft Barker I think his name is. Might get some insight if you can find that book.
kootne

[John in PA]

Look up the Greenhill Formula for calculating twist rates. Need to know the exact length of the bullet and the bore diameter. Just remember, if you go with a longer bullet later on, you'll need a faster twist. Might want to err on the side of a slightly faster twist.

[Good Cheer]

Yo John. I use the Greenhill. However, experience trumps calcs so I'm asking around to see what results folks have had.

[EDG]

Use the Miller twist and stability factor calculator at Berger bullets web site.
It has lots of experience built into it. Go to Miller's web site and read the background.
I don't think you are going to top his caculator since a lot of BPCR knowledge went into it.
Not just his knowledge but the knowledge of the BPCR competition community.
If you have any doubts try it out on .22 LR on up.


Yo John. I use the Greenhill. However, experience trumps calcs so I'm asking around to see what results folks have had.

[Good Cheer]

Thank you for the input. And I'll check out that calculator on Berger's site.

[Whiterabbit]

I have a 1 in 14, and I think its too fast for this bullet (the 515141). Never tumbles, but the accuracy isn't what I would want it to be either, even given slop for irons only and off-hand shooting. Should be better.