Conicals work in a 1:66” twist?

[Fatelvis]

Is there any conical that will stabilize in my Lyman 54cal GPR? It shoots PRBs great, but looking to “play” with other projectiles. Thanks!

 

[Loyalist Dave]

Well the first question is how deep is the rifling?
The "rule-o'-thumb" is, Slower than 1:48 rifling means a conical won't stabilize
But then you find that the original and the repros of the full length Enfield rifled musket is a 1:78 and was used as a sniper rifle in the ACW, and is used as a target rifle today, using conical minie bullets.
So I've been told that the depth of the rifling is the key to why the Enfield rifles are such an exception to the rule...
You might try a Lee "minieball" in .54 to see if they will grab and engage the rifling. https://leeprecision.com/mold-540-415-m.html

LD

 

[1950DAVE]

Well the first question is how deep is the rifling?
The "rule-o'-thumb" is, Slower than 1:48 rifling means a conical won't stabilize
But then you find that the original and the repros of the full length Enfield rifled musket is a 1:78 and was used as a sniper rifle in the ACW, and is used as a target rifle today, using conical minie bullets.
So I've been told that the depth of the rifling is the key to why the Enfield rifles are such an exception to the rule...
You might try a Lee "minieball" in .54 to see if they will grab and engage the rifling. https://leeprecision.com/mold-540-415-m.html

LD

And what is the optimal depth ? How deep is the rifling in the GPR?

 

[josie wales]

I have a Green Mountain .54 cal 1-66 twist on my Renegade and it will not shoot Hornady Great Plains conicals. It is a tack driver with patched round balls. I tried several different combinations with no luck. I should say the barrel is a "Round Ball Special" , The round balls I use are made by Buffalo Bullet Company.

 

[rodwha]

Lyman’s .50 cal rifling is said to be about .520” with .502” lands. That’s about .009”.

 

[rodwha]

Weren’t the Hornady PA conicals meant for slow twist, deep groove barrels?

 

[Melnic]

I have a Lyman GPR. I think the kit was shipped to the guy I bought it off of around 2012

I have shot Hornady Great Plains and at 50 yards, they were "ok" but not nearly as accurate as PRB. They are expensive so working up a load and experimenting did not really happen. I just used 90grains of FFG. Accuracy was fine for hunting <50 yards. I never took a shot with them while hunting though.

I recently got a 300grain Lee REAL mold. With a 90-100gr load and an over powder wonder lube wad, it shoots same POI as my PRB at 50 yards and the groups are just as tight. Swab and cool barrel between shots to emulate a clean barrel for hunting. I have not shot the Lee REALs at 100 yards yet. I was told by someone that I needed to use the lubed wad and the stout load to get any accuracy out of the Lee REAL with my rifle. I had started at 75gr and when I got to 90, it was a world of difference so he was spot on for me.

 

[curly7557]

Played around with this years past. Used 2 rifles, both 50's one a TC Hawken and the other a Tryon.
The hawken with the faster twist "1 in 48" seem to do fine with the conicals out to about 75 yards.
The Tryon with the slower rate of twist "1 in 66" and deeper rifling just didn't care for them.
But round balls in the Tryon would always bring home the meat.
"Just my 2 cents worth"

 

[rodwha]

I sent a handful of the smaller 250 grn Lee REALs to a fellow with a slow twist as he was going elk hunting and wanted more mass than a .490” ball. He didn’t do a lot of testing but found them dismal. I ensured that he understood the need for felt wads.

I’m guessing it might take a bit more powder than a ball? In essence the reverse of shooting a ball in a fast twist and typically needing a much smaller charge?

 

[nkbj]

Try the Lyman .54 minie that was made with the extra thick skirt for heavy charges.