Here's a question that I'm not sure if it's ever been covered???

[Ohio Joe]

I just got through reading a July 2 post about Nessmuk and him tumbling his cast lead balls to get the spur down...

Now, the observation and question;

We know some folks will roll their cast balls between two files to load & shoot out of a Smoothbore, which can also reduce the cast ball's spur...

So, here's the question; Has anyone tried rolling their Rifle Balls between two files before doing a patch & ball load at the Range,,, and if so,,, how was the accuracy?

I guess I could try it, but if there was no noticeable difference, I'll just save my lead... 

[Winter Hawk]

What I have read is that it has the same affect as the dimples on a golf ball, to make the ball go further.  From howstuffworks.com:

"The reason why golf balls have dimples is a story of natural selection. Originally, golf balls were smooth; but golfers noticed that older balls that were beat up with nicks, bumps and slices in the cover seemed to fly farther. Golfers, being golfers, naturally gravitate toward anything that gives them an advantage on the golf course, so old, beat-up balls became standard issue.

At some point, an aerodynamicist must have looked at this problem and realized that the nicks and cuts were acting as "turbulators" -- they induce turbulence in the layer of air next to the ball (the "boundary layer"). In some situations, a turbulent boundary layer reduces drag, making the golf ball go further.

If you want to get deeper into the aerodynamics, there are two types of flow around an object: laminar and turbulent. Laminar flow has less drag, but it is also prone to a phenomenon called "separation." Once separation of a laminar boundary layer occurs, drag rises dramatically because of eddies that form in the gap. Turbulent flow has more drag initially but also better adhesion, and therefore is less prone to separation. Therefore, if the shape of an object is such that separation occurs easily, it is better to turbulate the boundary layer (at the slight cost of increased drag) in order to increase adhesion and reduce eddies (which means a significant reduction in drag). Dimples on golf balls turbulate the boundary layer.

The dimples on a golf ball are simply a formal, symmetrical way of creating the same turbulence in the boundary layer that nicks and cuts do."

So it would seem that having a patched ball or unpatched shouldn't make any difference.

~Kees~

[Hawken]

All that's gonna do is INCREASE DRAG on what would otherwise be a smooth roundball! Personally I let Hornady do away the the sprue on what I shoot!

[Ohio Joe]

I prefer the Hornady balls as well, Hawken. 

However, I've got some mighty well cast balls that give pretty darn good accuracy with the sprue up - so it's not critical IMHO, but rather more a PITA centering the sprue at times - but run what we brung. 

[Winter Hawk]

At some point, an aerodynamicist must have looked at this problem and realized that the nicks and cuts were acting as "turbulators" -- they induce turbulence in the layer of air next to the ball (the "boundary layer"). In some situations, a turbulent boundary layer reduces drag, making the golf ball go further.

All that's gonna do is INCREASE DRAG on what would otherwise be a smooth roundball!

I'm not an aerodynamicist so I can't say yea or nay to this.  Someone probably got a government grant to study why dimpled golf balls fly further than smooth balls!

~Kees~

[Nessmuk]

Since I've  been quoted in this thread, I  guess I'll  throw in my 2 cents. I tumbled my .45 round balls originally  to reduce the sprue and the occasional  minor seam line. Tumbling for 3 hour got rid of them perfectly but it also turned the balls shiny black and slightly dimpled the surface. I don't  have a chronograph  to measure the velocity but I've  noticed tighter groups and no more wild flyers. Now I'm  Tumbling every caliber I cast.

[Maven]

Joe, I cast all my bullets, but not all of my BP moulds leave a large sprue, the Lee's and Tanners, for example. I've found the RB moulds which do leave a large sprue ( Lymans and RCBS's primarily) are no more or less accurate than the others IF you consistently locate it:  I always try to load with the sprue facing up.  As for rolling a RB between 2 coarse files or rasps, all I've accomplished is increasing RB diameter a bit, and for a smoothbore at that. Did it improve accuracy?  Not one bit in my trade gun.  In fact, it grouped such balls poorly.  Lastly, take a look at the attached 50 yd. target and the 2 hits labeled "fouler," which were .618 RB's (Tanner mould) rolled between 2 coarse files.  Now look at the other 12 excepting #s 4, 9, and 10 (fouled bore; true flyer; bad aiming error, respectively).  See what I mean?  My Mike Fink target notwithstanding, I don't think there's anything to be gained by doing so in a rifle.

[BEAVERMAN]

Since I've  been quoted in this thread, I  guess I'll  throw in my 2 cents. I tumbled my .45 round balls originally  to reduce the sprue and the occasional  minor seam line. Tumbling for 3 hour got rid of them perfectly but it also turned the balls shiny black and slightly dimpled the surface. I don't  have a chronograph  to measure the velocity but I've  noticed tighter groups and no more wild flyers. Now I'm  Tumbling every caliber I cast.

 

[Ohio Joe]

It's not that big a deal to load spure up, heck back in the late 70's and into the mid 90's - I only shot "spured" balls... Didn't really get into the Hornady Balls until the last 25 years or so - but once I did - boy I was hooked!!! Heck, where I retired from I stocked our small sporting goods section and one of my perks was that I was allowed to buy at "cost" so I had Hornady balls readily available to me.

But I don't mined loading spure up, however at the Rendezvous matches I will always shoot .445 Hornady's especially during the night time snuff the candle shoot as we load in the dark - but I also think a feller could get use to loading with a spure ball in the dark (by feel)...