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The "Skinny" on Projectiles


Projectiles are one of the most misunderstood links in the whole sport of shooting. Most folks feel you should just be able to order up a crate of 10,000 slugs in a general caliber size. Not so. Look at a catalog that provides slugs or hand loading supplies. Just look at 30-32 caliber. Why 30-32? Cause it gives a good example.

Do you know that "Caliber", strictly speaking, should be written as a decimal portion of an inch? Thus 30 caliber is written .30"

So, let's look at a catalog ... hummm ... 30 caliber - here it is ... Lee 30 caliber rifle molds ... .309" ... what?!! Oh ... here's the Lyman rifle molds ... 30 caliber is .311". Except here's one that's .314" What the heck?

Well, here's the 32 caliber molds ... .311" Wait, wouldn't that be 31 caliber? Yes, it would. Here's another 32 caliber mold ... .314"? Wait ... didn't we just see those numbers listed as 30 caliber molds in the paragraph above? Yes we did. Oh ... here's the RCBS 32 caliber molds ... .321".

Now, above we see that .314" is 30 or 32 caliber .... I think. But ... here's a mold that's .312" ... it's called a 7.62mm. And, the British 303 is listed at .312". No ... not .303" ... don't be silly.

Here's a 32 caliber at .321" Amazing. That's actually correct. But Lyman's .323" is 8mm ... and Lee's 8mm is .324" Sure, both are 32 caliber slugs ... do try to keep up.

Let's expand to another popular slug you hear of. The 9mm.

Now 9mm is actually .354" but is .356" at Lee. It's also .358" at Lee. Of course, .358" is also 38 caliber. Well yes, .380" is actually 38 caliber ... but nobody makes a 38 caliber slug as huge as .380" ... that would be ridiculous! Here's a 9mm at .365". Good Heavens! ... wouldn't that be a 36 caliber? No - 36 calibers don't exist on the charts here. But; here's a .358" listed as a 35 caliber ... obviously a misprint!

So, can you shoot a 38 caliber in a 9mm? Well, it depends upon if they are both .356" or if one's .358" or even .365" (which would be a 36 caliber if it existed). You'd think a 36 caliber would just drop out a 38 caliber barrel - right? but, it would be waaay to big really!

OK ... Enough!!!

Now ... you just want a thousand slugs capable of MOA @ 100 yards in ... what caliber was that?

Now, to simplify more, you realize that the caliber measurement is supposed to be the measurement across the bottom of the grooves inside the barrel. That's fine. If we can determine that, we just have to decide how deep your slugs should ride into the grooves. All the way to the bottom!!! Right ... very rugged of you. Don't want any blow-by - right? So, let's jamb a .380" into your .380" bore. Cock the rifle. Careful ... all's clear. Fire! "Phunk". .....What was that? .......Where did it hit?.... What? ....Nothing? .... Stuck in the bore? Bummer. Here's a brass rod ...

Oh, you want a "bore riding" slug? So, we need the measurements across the lands - not the grooves. And you want a drive band on it? Sure - to grab the rifling some - but how much? All the way to the bottom of the groove? Oh ... maybe not. Now, you know we'll have to hit this measurement dead on the first time when we order these custom swagging dies. Why? Cause we can't size anything with a drive ring bigger than the exterior sides of the slug. The sizing die will wipe the drive ring right off. And, we'll maybe want the rifling to cut the sides of the slug some - to get good tracking down the bore? But how much?

Now. When you cast, you cast alittle oversized and then size them back to your specific size for your particular barrel. But not too much, or you will squeeze them out of round. So ... you want a .354" 9mm but you have to order an 8mm (which sounds too small) but is actually too big at .358" and size it back to the .356" which your barrel actually likes? Right then. Very simple. Glad we cleared that up.

Complicated? .... Headache?

Non-sense. You buy a Barnes rifle which Barnes himself has proofed at the range. You shoot the slugs he tells you at the size he tells you. The rifle has already proven itself. He's already posted actual groups from it. You'll shoot it very well yourself, once you learn the technique of handling the rifle. You can cast slugs in the molds Barnes will make for you or order them from Pelletman to be cast in Barnes molds and sized in Barnes sizing dies. That's if you want to do what old Barnes said. But then ... what does he know? You can always just go to the catalog and order up something cheap!

So, why on Earth is all this such a pain? I swear all of the above is true. I haven't made it up or exaggerated for the sake of a good story. Here's the reason ............ plain and simple: "It ain't simple!"

Accuracy is not easy. This is why, after I've worked out all of the above for you and provided same, I hate to see the rifles collecting dust in the safe. And why, I'm not too thrilled about providing my development work to other manufactures who can't be bothered to do their own development work. I also have rather strong feelings about any who'd use my projectiles to make somebody else's product look better. Let them do their own development work. They have 24 hours in each of their days - just as I do. If they know what they are doing ... they won't need to "borrow" my stuff. If someone would think it's fine for them to use my stuff because they don't want to bother to develop the low paying areas of their business, would you ever wonder what else they don't bother with? You know ... it doesn't pay very well to maintain a web site ... answer e-mail ... fix warrenty stuff ... etc.

Yep ... this is why I get the big bucks ... ha ha. You don't just get a rifle from Barnes. You get a complete business support system.


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A few thoughts from today's mail and catalog browsing.


"Caliber" has always been another topic of the "typical" verses what I choose to offer. The default there is supposed to be 17 or 22 cal. ... and maybe a 50 cal. in big bore. Those are THE "proper" calibers according to ... something. ;?)

So, I was reading, this morning at coffee, in a new Midway catalog. Alot of you probably get that. I hardly read it or other catalogs, because I do not buy in any parts. However; my wife Kelly had it laying there. Told me there was alot of stuff in it that I might enjoy seeing.

Check around page 722/723 in the section listing barrels for sale. Here's a quick index of calibers offered on just those two pages: 17, 20, 22, 24, 25, 26, 27, 28, 30, 32, 33, 35, 36, 37, 38, 40, 41, 45, 50, 54. Hummm. Enlightening.

Then, on the same two pages there are twist rates (for those same barrels) of 1 in 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 32, 48, 66, 70. Once again ... enlightening. There would appear to be more than one way to do things.

Hey - next somebody will tell you they can make a smooth bore shoot well. Ha!!!