Spud size for 45 LC bullets.

[Changeling]

Has anyone worked out the correct spud size for there 45 LC molds in WW and in a Lead tin mixture? If so I would really appreciate hearing about your findings.

[deltaenterprizes]

What is a spud and what is it used for?

[geargnasher]

:confused: Changeling, you have really refined the 'unclear question' to an artform lately.

Gear

[Muddy Creek Sam]

I try to get my Spud big enough to hold all the fixin's.

Sam :D

[Wayne Smith]

I get different spuds for different dishes!

[beagle]

All joshing aside, are you talking about the sizing diameter of the bullet or are you speaking of the expander plug diameter in the expanding die?

If it's the sizing diameter, this will vary depending on what gun you're shooting. My Ruger BH likes .451s or .452s but will digest .454s just fine./beagle

[GLL]

For .45Colt in WW + 2% Sn in a 22" carbine:

Spud Diameter (in inches)=.75 Meplat Diameter (in inches) - .02(sized bullet diameter (in inches)

For PB + WW (50/50) multiply this by .9

Jerry

[beagle]

Now I'm really confused on this spud business.

One of you guys please "splain" it to me in terms that I can understand./beagle

[GLL]

beagle:

I look forward to the explanation as well ! :)

Jerry

[Spudgunr]

I would say I'm about a size medium?

[Changeling]

All joshing aside, are you talking about the sizing diameter of the bullet or are you speaking of the expander plug diameter in the expanding die?

If it's the sizing diameter, this will vary depending on what gun you're shooting. My Ruger BH likes .451s or .452s but will digest .454s just fine./beagle

No Beagle, the "Spud" is the small piece of metal ( like a short piece of pencil lead) that is used in a mold to create the diameter and depth of the Hollow Point when cast. It is semi built in/removable.

It's diameter/length is extremely important relative to the caliber of the bullet as well as the BHN of the metal one is using and reflects what kind of expansion can be expected from different BHN alloys at some given velocity range.

For instance: A 38/357 might need a xx size for WW and another XX size for a tin/lead alloy. However some spud sizes might work in either to an extent if the BHN is equal.

So for a Spud size in a given caliber you need to know what velocity range and alloy or tin lead mixture you are going to use to get optimum results.

[beagle]

Okay, now we're getting somewhere. I always called that the hollow point cavity pin.

In all of the moulds I've HP'd, I've always used the rule of thumb of 1/3 of the diameter of the bullet rounded up to the next common drill bit size. In the case of the .45 Colt, that works out to .156".

Depth in the cavity of the pin I determine by measuring the bullet overall length and using half that value as the depth of the HP cavity.

Neither method is written in stone and Eric makes some darn nice wide mouth HP moulds.

It also depends on whether you're using the bullet in a handgun (lower velocity) or a rifle. In the case of the rifle, the cavity diameter needn't be as big due to the higher velocity to get good expansion.

Now, these are just my opinions and many will disagree with me but they've worked for me over the years./beagle

[GLL]

beagle:

In my "formula" I use the meplat diameter as the controlling dimension rather than overall bullet diameter.

Happy "2000" ! :)

Jerry

[cbrick]

In 44 RCBS 300 gr SWC,

"HP cavity of .150" diameter at the mouth, cavity with 7 degree taper and extended .250" into the bullet with a rounded tip". From Glen Fryxell.

That's the specs that I had Erik HP a couple of 44 moulds for a pig hunt. You could do the math for a 45 boolit cavity diameter and/or depth. This is a fairly small cavity for max boolit weight retention. The rounded tip and tapered cavity "helps" keep the nose from breaking off or at least as quickly.

I've always called it a HP pin too.

Rick

[beagle]

Jerry,

Whatever works for you.

I measured all of the HP pins that I had and built a mathematical model based on diameter versus pin size. I had all kind of strange readings and my machinist said to heck with this and used the next common size up from what I asked for that he had. So far, it's worked./beagle


beagle:

In my "formula" I use the meplat diameter as the controlling dimension rather than overall bullet diameter.

Happy "2000" ! :)

Jerry

[GLL]

beagle:

Although the "formula" was meant as a spoof I do use about 2/3-3/4 meplat diameter for many of my larger diameter HP pins.

That is about the same as the pin Al uses of some of his NOE HP moulds.

Jerry

NOE photo
http://www.fototime.com/A7A9DAA1C217CDA/standard.jpg

[9.3X62AL]

That's more "JBP"--Jerry's Boolit Porn. Mighty fine photography, sir.

[geargnasher]

That's more "JBP"--Jerry's Boolit Porn. Mighty fine photography, sir.

Yikes! Al should get those dressed in some of Blammer's mauve lube before releasing them here, you know, at least bring it down to PG13. [smilie=1:

Gear

[GLL]

We can blame the "Boolit Porn" on Al (Swede Nelson) at NOE !

That is his photo not mine ! :)

The bullet is from his 358429 Group Buy Mould.

http://castboolits.gunloads.com/showthread.php?t=54306

I love the pin diameter on that mould !

Jerry

[9.3X62AL]

Ah, I see. Sorry for the mix-up, Al and Jerry.

That's more an "Air Point" than a "hollow point". I'll bet it goes inside-out in animated targets, too.