WMC rate of twist.

[JonnyReb]

 I guess T/C was just making sure their White Mountain carbine stayed under the "traditional" section of gbo when they designed the gun with a 1:20 rate of twist. I tried many sabots as well as other 300gr and under projectiles(80-90gr powder charges) before realizing that only the long and heavy 370gr. Maxiball will stabilize past 50 yards. Can I assume, before I spend the money, that this rifle will have a tendency to get along with most all slugs of a similar weight/length/dia. well into the 400-500gr weight ranges? Obviously the rifle is designed purely as a hunter becausewith no accurate lightweight loads to plink with, its not much fun on the shoulder. Going to make a great treestand hunter though.  J 

[P.A. Myers]

My understanding is the White Mountian Carbines are  1:48

            P.A.

[bubba.50]

i believe that along with the 1 in 20 & 1 in 48 twists there was also at one time a 1 in 30something twist.

[JonnyReb]

 From what i've read, only the .54 was 1:48. The .50 was 1:20 and then went to 1:31?.  The 1:20 is the fastest twist i've ever heard of, traditional or inline and I wish I knew what their purpose was or intended ammo, it surely can't be the sabots that were coming into vogue at that time, or if it was I wish I knew which ones will work, 240-300gr sabots were holding 1 ft groups at 50 yards. Not to impressive. If I hadn't tried my 20 year old box of maxiballs i've been storing forever i'd have already had the WMC on the block. The long 370 grainers held 3" groups at 75 yards though and showed no signs of yaw or tumbling. I will use them without any complaint but figure other longer and heavier slugs will stabilize too. I found some old posts of yours Bubba concerning a WMC you had, any idea which twist yours was and did you find it to be accurate at a distance using any particular ammo?  Jeff

[bubba.50]

i never measured the twist but think it was the 1 in 38 or whatever it was. i pretty much use maxi-balls & lee r.e.a.l.s lubed with maxi-lube in all my guns as that's what i have molds for. they've always shot as good as i can. for what it's worth, luck to ya, & have a good'en friend, bubba.

[JonnyReb]

Thanks Bubba and P.A. For your comments and yes B, 1:38 is what the late model WMC's were. I have no doubt that was a better design for ammo like sabots and miniballs. I bet too, that going to pure lead as opposed to the factory bullet hardness will futher help accuracy in my barrel. Guess i'll have to order molds to find out for sure. Thanks guys,. J

[bubba.50]

ya want yer lead so soft ya could almost chew it like bubblegum as most if not all muzzleloader molds are calculated to drop the correct diameter bullet using pure lead. any hardener at all will likely make yer bullets a couple thou oversize & hard as the dickens if not impossible to load.

[JonnyReb]

 Darned shame too as I long ago stocked up with a 5 gallon bucket worth of wheel weights that have been worthless to me ever since. In the past, molding slugs for bigbore airguns i'd use lead plumbing p-traps i'd save from remodels. I don't have a bhn tester but figure its close to pure using scratch tests. Dumb question perhaps but in my airguns i'd use .357 and .495 sizing dies after molding to insure precise diameters, do folks molding for BP not do the same?  J

[Landngroove]

The early .50 caliber T/C White Mountain Carbines did have a 1 in 20" twist.  The twist rate changed to 1 in 38"  (.50) about the time that T/C came out with the QLA barrels. The .45, and .54 caliber WMC's all have a 1 ib 48" twist. I own both a .50 with a 1 in 38" twist, and a .54. The .54 shoots a PRB with good accuracy. The .50, I have never been able to find a load that will be accurate with consistancy.

[bubba.50]

on lee r.e.a.l.s the bottom band is approximately bore size with each band up bein' a  couple thou bigger til the top band which should be about groove size so it loads straight & seals the bore as it goes. on maxi-balls the bottom 2 bands are about bore size with upper bein' about groove size for the same reasons listed above. don't know if yer idea would work with hollow-base minie-ball molds or not.
 
an option for usin' yer wheelweights is paper-patchin' handgun or rifle cast bullets. if ya go to www.castboolits.gunloads.com & look around ya can find a bit of info on it. look especially for posts from idahoron about doin' this with his "hot rod hawken". he's also posted about it on the www.muzzleloadingforum.com/fusionbb
 
again, luck to ya & have a good'en friend, bubba.

[JonnyReb]

Thank you again Bubba, excellent information from top to bottom of your post. I've been on that site before, the one where everyone calls bullets "boolits", wise folks on there, thanks for the link.  LandnGroove I know the pain of thinking the .50 was doomed to mediocrity or even worse unhuntable. Was thrilled to see the heavy bullets worked. Also, it sounds like a .45 or .54 would be the ONE to have and I see now why they're scarcer than hens teeth.  J

[Landngroove]

Thanks JonnyReb, I will have to give some heavy conicals a try in my .50

[JonnyReb]

 Just did some deeper reading online in the lyman bp volume and found the "greenhill" formula. Both point to fast twist at low/med velocity requiring long heavy projectiles. Apparently landngroove, your 1:38 will greatly benefit from loading a slug thats got 1"+ bearing surface too. My 1:21 may stabilize such a projectile at lower velocity than yours and I can go longer/heavier. Looks like powder charge plays into this as well as velocity is part of the equation. I'd like to try some of the hollow base mini's or ball-ets to try to cut back on recoil some, 370gr feels like double+ recoil compared to the same charge behind a 240gr sabot:-[.    Jeff

[quickdtoo]

http://www.gboreloaded.com/forums/index.php/topic,102791.msg1098280539.html#msg1098280539