Wilkinson boolits

[PoorJack]

Over the winter I'm experimenting with two muskets and would like to try some Wilkinson boolits to compare to Hogdons. Both muskets pin at 580 so would anybody out there have some 580 Wilkinsons I could try?

[ms3635v]

Let me look, I may have some left from this past season.

[Maillemaker]

I use the Moose 577-420. I did not get as good of results using the 580-450 when sizing them down to .576 or .578.

The Moose 577-420 in my P53 with Whitacre Barrel is amazing. It's the miracle bullet I have looked for for years. 50 grains 3F Goex. Off a bench it will give hole-in-hole accuracy. Performs better than the RCBS-Hodgodon. Plus it's a double cavity mold, and there is no core pin, so it casts easily and incredibly consistently. No voids. I wish they made a 3 or 4-cavity version.

It also has done well in my Richmond Carbine with Hoyt barrel, but I need to re-confirm the load workup was not a fluke.

Steve

[PoorJack]

My barrel pins at 580 and I size to 579 so if the Wilkinson drops at 580 then it won't get much of a squeeze to get to 579. I want to try some before buying another mold. That can get quite expensive. I think I read somewhere that Moose molds come with handles. That correct?

[Maillemaker]

Yes, they come with handles:

http://moosemoulds.wixsite.com/mm2013/products

Steve

[MikeArthur]

New in box. Thanks

mike arthur
hampton horse
843 412-1992 (tel:843 412-1992)

[geezmo]

Hey Jack,

PM me your address. I'll send you some.

Barry

[PoorJack]

Pm sent. I hope this works out as I'm getting a tad frustrated with the Enfield and would like to improve my 2 band.

[Maillemaker]

and would like to improve my 2 band.

I had zero luck with the Wilkinson (nor the RCBS Hodgdon) in my P58 Enfield. I think the 1:48 twist is too fast for such light, short bullets. I got keyholes with them in the P58.

Steve

[Eggman]

I had zero luck with the Wilkinson (nor the RCBS Hodgdon) in my P58 Enfield. I think the 1:48 twist is too fast for such light, short bullets. I got keyholes with them in the P58.

Steve
Well Steve Old Buddy you've upset my apple cart. Light short bullets love a fast twist, not?? Sped up the stubby in my Maynard and the group tightened. I believe the puny little .223 in the M-16 twirls itself thru like a 1:22.
On your Enfield I'd look at fit or especially lead hardness.

[PoorJack]

Uhmmmm.... Eggman, most .223/5.56 have twist rate of 1:7 down to 1:9 with the slower one being for the shorter (read lighter) bullets. Faster twist is for heavier bullets.

Back to what I'm doing. Musket one is a Euroarms P53 3 band Enfield. So far, I haven't found a bullet it likes and yes, the lead is soft and yes, they are sized 579 to fit a 580 bore. So trying the Wilkinson is on the agenda as the next experiment before giving up and calling Whitacre. The second is my two band Springfield contract and it does shoot the Hogdon into 2-3 inches at 50. Bullet is sized 579 to fit 580 bore powder charge is 43gr of 3f, lube 60/40 crisco/beeswax. If the Wilkinson works with either, then my dads Enfield will be usable and my Springfield even better. I really want to try this bullet before committing to yet another mold.

[MR. GADGET]

Never had a 1:22 twist.

Slowest twist in them for the most part is 1:12 to 1:14 for custom guns.

As stated run 1:7 to 1:9 for a.common twist.

Hard to compare something with a 40 to 64 grn Cooper jacket bullet moving 3250 fps to a 400 and 540 bullet moving a lot slower that is soft lead.

[Maillemaker]

Well Steve Old Buddy you've upset my apple cart. Light short bullets love a fast twist, not?? Sped up the stubby in my Maynard and the group tightened. I believe the puny little .223 in the M-16 twirls itself thru like a 1:22.
On your Enfield I'd look at fit or especially lead hardness.

I size my bullets to .001" under no-fit, and I only use 99.99% pure assayed lead from commercial vendors like Rotometals or Sander's.

Last time I tried to make sense of the Greenhill Equation I came away with the sense that faster twists needed a heavier, longer bullet.

https://en.wikipedia.org/wiki/Alfred_George_Greenhill

http://i.imgur.com/Xw2g4ST.png

where:


C = 150 (use 180 for muzzle velocities higher than 2,800 f/s)
D = bullet's diameter in inches
L = bullet's length in inches
SG = bullet's specific gravity (https://en.wikipedia.org/wiki/Specific_gravity) (10.9 for lead-core bullets, which cancels out the second half of the equation)


We can re-write this to solve for Length if Twist is known, which, in theory, should give the optimal bullet length for any given twist and diameter.

L = [ C * D^2 * SQRT(SG/10.9) ] / Twist

If you plug and chug the above equation with:
C = 150
D = .58
SG = 10.9
Twist = 48

You will return a L = 1.05

My RCBS-Hodgdon measures .95 long. My RCBS-500M measures 1.18. I got keyholes with the Hodgdon, and a very nice group with the 500M. My 577-520 Wilkinson measures .895.

Since the equation doesn't take into account bullet shape or weight, we can assume that length directly corresponds to weight. So faster twists seem to like longer (heavier) per the Greenhill Equation.

If you plug in a length of 1.18 (the RCBS-500M) you get a supposed optimal twist of 1:42. If you plug in a length of .9 (Hodgdon/Wilkinson) you get a twist of 56.

Which is strange, because I get great results with the Hodgdon and Wilkinson in my 1:72 P53 Whitacre. For that twist, supposedly the bullet should be a mere .7" long!

To which I conclude that the Greenhill equation is a bit simplistic, not accounting for deep grooves nor hollow cavities nor nose shapes, but I think the general idea is that the faster the twist the heavier a bullet you will want. If you run the above equation with the values above and play with different values for Twist you will find that the faster the twist the bigger a value for L you will get. Conversely the slower the Twist you enter the smaller a value for L you will get.

But, if you use this guy's stability calculator:

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

You would seem to get great stability with a 420-grain, .9" long bullet in .58 caliber with 1:48 twist!

http://i.imgur.com/RqPfQqU.png

And if you plug in the RCBS-500M data with a 1:48 twist it shows as unstable!
http://i.imgur.com/dtX8fyO.png

So, I am not very clear on how to do this computationally.

Greenhill seems to say that the longer (heavier) the bullet, the faster the optimal twist gets. My experience matches this with my Pedersoli P58 in 1:48.

Steve

[Eggman]

Uhmmmm.... Eggman, most .223/5.56 have twist rate of 1:7 down to 1:9 with the slower one being for the shorter (read lighter) bullets. Faster twist is for heavier bullets.


Hmmmmmmmm. Very very small bullet - very very fast twist. I think the comparisons are valid - the extremes illustrative better than any. I was going to compare a bullet to a football.
Sorry about that 1:22. These were numbers in my locker combination in high school.
Steve - you threw me off my apple cart again. 99.9% pure lead WILL NOT CAST!!

[MR. GADGET]

Think what you want but you were wrong and still are.

[Maillemaker]

Steve - you threw me off my apple cart again. 99.9% pure lead WILL NOT CAST!!

What? Pure lead casts just fine. Sometimes I throw a tiny pea-sized piece of tin solder in to improve fill-out but it's generally not necessary.

Steve

[Lou Lou Lou]

I have been casting the RCBS 500m in pure lead for almost 40 years. Mould temp and lead temp are the key. Did open the sprue plate up a bit. YMMV

[Eggman]

Think what you want but you were wrong and still are.
By your logic the smaller the bullet the slower the required twist -- or rate of rotation by less propellant. Logically then an M-16 should have about a 1-92 twist to go with the current high velocity cartridges.
Steve -- all kinds of evil demons lurk in your pure lead bullets.

[geezmo]

Dave,

See what you started? Anyway, Wilkies will be on their way tomorrow, check your PM.

Good luck,
Barry

[MR. GADGET]

By your logic the smaller the bullet the slower the required twist -- or rate of rotation by less propellant. Logically then an M-16 should have about a 1-92 twist to go with the current high velocity cartridges.
Steve -- all kinds of evil demons lurk in your pure lead bullets.

The smaller the bullet.

Not a term that is used for loading and reloading.

Are you talking smaller as in?

Length
Weight
Dia
BC

What?

Or you just just pulling number out of........

Kind of clear you are not sure on twist and dont know much about.

[Mike McDaniel]

The term you're looking for is 'fineness ratio'. The ratio of length to width. High fineness ratio bullets need faster twist rates to stay stable. Which is why round balls will shoot well with very slow twist rates, while modern jacketed bullets need faster twist rates.

And yes, bullet shape plays a role. A 1-in-18 twist is normal for revolvers chambered in .38 Special. Works OK with round-nose lead or semi-wadcutters, but full wadcutters need a 1-in-12 to prevent tipping.

[MR. GADGET]

Yep
I do not think he understands how much goes into it.
dia, weight, length, speed, temp, pressure and design of bullet

That is where BC comes into it to make it easy.

[Eggman]

The term you're looking for is 'fineness ratio'.

Back in Sioux County Iowa in the 50s and 60s we had to walk four miles each day to and from the public school, often thru knee deep snow. Often school had to be cancelled or curtailed so we could get home on time for milking. We didn't get to "fineness ratio" in ballistics class.