1 in 21" twist in .45 cal ,opt weight projectile

G'Day, I have a rifle with a 1 in 21" twist in 45 cal , just wondering what weight projectile do you think I should start with ?

For starts, the fast twist will do best with a longer conical bullet. You can shoot patched ball but the rapid twist will require you to keep your powder charges down to obtain the best accuracy. To add to the mix, conical bullets, whether Minie or Maxi types will perform best with shallow rifling depth, say .003" to .005". Deeper rifling will mostly eliminate the solid based Maxi type since they need to engage the rifling and their construction will require shallow rifling depth to handle that properly. Not knowing the actual rifle we're talking about limits the help we can provide. Any further description, model type, etc. will be a big help. If you can measure or otherwise determine rifling depth, number of lands and grooves or their width will be the best info we can use. Quick rule of thumb would be you can probably get any of them to work, accuracy will be dependent on adjusting the projectile type and weight to the rifling. Good luck, but mostly have fun.

I would tend to agree you should test your gun with a few different conical bullets too for weight and see how much better they may do all with assorted powder charges.

What do you plan to do with it? Hunt? Long range target matches?

I have a 18 inch twist in a 45 caliber and it really didn't start showing target accuracy at 200 yards until I got up to 475 grain bullet and 90 grains of 2F. Hunting accuracy groups about 2 to 3 inches at 100 yards then a 350 grain paper patch and again 90 grains of 2F would work but the heavier the bullet the better it would shoot.

RB

Some thoughts...
First, to a large degree the strength of the breech and job to do determine the projectile to be used by virtue of how much powder is going behind it.
Second, I shoot a 26" long .458" bore diameter with 24" twist.

It shoots slow ball to minute of bunny, handles standard molds for a 45 revolver (paper patched)
up through standard rifle molds such as normally used for a 45-70. Depending upon the geometry of your rifling you could likely find the same to be true for the 21" twist.
Last, if you have access to machining services it might be worth having a mold altered for use with your barrel. By example, this is a round ball mold altered to be adjustable length and loaded paper patched.

Thanks guy's , My rifle is a Pedersoli whitworth ,Not to be confused with the parkerhale whitworth, It has shallow rifling, I'm only really looking at target shooting , 100m maybe further down the track Ill shoot longer matches.

If you happen to have some 45 caliber molds made for cartridge rifles you can size them down and get acceptable groups out to 100 yards. they wouldn't make for serious long range shooting but it can be done. The trick is to lube them up first and then size down in steps when you lube them up first that keeps the lube grooves from collapsing. I used the Lee push through sizing dies and they worked OK.

RB

Pedersoli recommends two particular bullets -- 310 and 485 gr. bullets (which they sell, as well as moulds)...
http://www.davide-pedersoli.com/sc...ifles-mortimer-mortimer-whitworth-deluxe.html

That's a long range competition rifle -- feed it well.

Cheers , never thought of sizing breech loading projectiles down a little .... I do have a few . I ordered a pedersoli 310g mold but the mold itself was no good so it went back .... could be a few months before it comes back.. bit slow i thought . I grabes a lee 450-294-m yesterday , going to have a go with that this arvo.

Ozt:
I use a 495gr lyman bullet for the volunteer rifle.
Awesome on moose!
Nit Wit

For poking holes in paper, I recommend using the lightest bullet that shoots well.

For my 1:18 shallow groove barrel Schuetzen in .40 caliber that works out to a 300 grain slug.

If your rifle is a Whitworth type, with hexagonal bore, it was intended for fairly heavy hexagonal bullets (in the 480 - 500 grain range)shot with moderately heavy charges.
The Whitworth can do fairly well with cylindrical bullets, but they must be cast quite soft, as they need to 'bump-up' to fill the bore to the corners, which measure ca. .490" across - that's a lot of bumping for a cylindrical bullet which can't be much larger than .451". This can be done with heavy bullets, which have considerable inertia, and full powder charges, but is not likely to work with the lighter cylindrical bullets unless charges are increased significantly (if they work at all).
In addition, you will need to use some type of wad or wads under the bullet - my friend who has and shoots a P-H Whitworth says he finds that a fiber wad, similar to a shotgun filler wad, of about 3/8" thickness works best, but, again, only with the heavy cylindrical bullets cast of pure lead and full charges.
If, on the other hand, your rifle has conventional-style rifling, you can use standard cylindrical bullets of lesser weight with reduced charges and still expect good results - my P-H Volunteer does well with a variety of bullet types sized to .451", though it, too, requires a wad under the bullet for best results.
Good luck, and let us know what results you achieve.
mhb - Mike

Just got back my .310g Pedersoli mold, its a hollow base , so no card. I cast pure lead , lubed it up sized down to .450 ...really nice fit . Shot from 40g to 65g 2FF at 100 meters , grouped 3" with 42g little lube , cleaning between shots ..... but want it to do better than that. Suggestions???

Heavier bullet and more powder I would think that a 500 grain bullet would be about right. You might want to try paper patch for me anyway they have shot better that grease groove bullets.

RB

Looking at the Pedersoli hollow base bullet mold, it does appear to be made for relatively small charges. For suggestions with that mold, try adding some tin to the mix to allow stepping up the accurate powder charge. Second suggestion would be to find a machinist to make a second base plug for a heavy as practical flat based bullet.
OK, number 3...
Try paper patching this mold with heavier charges. http://www.thegunworks.com/custprodgun.cfm?ProductID=1074&do=detail&Cat2Option=yes

Hey, by the way, just got this Lyman #451114 second hand to paper patch in the .458 bore x 24" twist New Englander.
It casts .452 -.453 with straight lead. Mine comes in right at 430 grains.
With the Loverin style design to provide plenty of lube where it's needed and lots of bullet to barrel alignment it might be a good design to try in yours if you can find one locally. Might have to add a little tin because it's tough to get to fill out.

I do have the heavier Pedersoli .451 mold comes out at 485g lent to me from a friend , , I'll try that next. I was trying to keep loads and projectiles down in size as Ill be shooting it prone....as well as on the bench. I will do as suggested, paper patch is a little new to me but ill give it a go. Thanks for the info.

I'll bet that bullet will shoot much better for you. When shooting prone try to get a shoulder pad it sure helps if you intend to shoot for any length of time.

If you paper patch that same bullet and if you have a paper that is tough enough you can wrap the bullet let it dry and then lube very slightly and run it through a sizer. It does work but you probably will tear a few. The only other thing to do would be size the bullet down first and then patch back up. I've had the best success with the second method. Good Luck and keep us posted.

RB

Yeah, depending on the diameter, the paper, some will get a little tearing. If you get too many torn then best to size the bullet down and then patch it and then size it. It can be a pain but hey, muzzleloading is hand crafting.

I have a mortimer whitworth like you. use it for hunting out to 150 yards . Vermin further (longest kill 300 yards) I use a 495 gr bullet sized to fit with a little pressure on the rod (just tighter than slip fit)It is a great gun Groups 2inch at 100yards with my old eyes would probably do better with younger eyes I found the heavier and longer bullets work best with a MV of approx 1300 f/s( goes right thru a koodoo bull in chest out hind leg smashing pelvic on exit) makes my 30-06 seem puny