Leade VS Throat in a rifle.

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I started to get confused about the exact meaning and area that comprised the leade and the throat.  Then I realized that some articles actually reversed them in their description.  Here two pictures that illustrate that, which is correct?  Or am I missing something?

Option 1 (Rifleman’s Journal article):

Option 2 (Bison Ballistics article):

Topic

[michaelburns]

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Option 2 is correct. Leade is the tapering down of the bore. Throat is the bit before the leade.

[petergallo]

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That makes the most sense, thanks.  There are multiple example of both out on the web, that could confuse many handloaders!

[michaelburns]

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The throat is sometimes also called the freebore, just for in info

[SwedeNelsonKeymaster]

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It has been my understanding, like stoats has said, that the flat coming out of the mouth of the chamber is the freebore then the tapered part down to the bore is the lead and its all together called the throat, from mouth of chamber to bore.

But if you look at a Pacific Tool reamer drawing the flat is called the lead and the taper the throat.

So go figure
Bullet maker, maker
Al Nelson

[petergallo]

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This is making my head hurt, going on an ice cream run. 

Here is a pic from Pacific Tool. I think it is what Al said.  The throat is from the mouth to the bore.  That’s different than option 1 and 2.  Now we have an option 3. Awesome:

[petergallo]

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It turns out SAAMI has an online Glossary.  What it says:

THROAT
    See Leade (Lead).

LEADE (LEAD)
    That section of the bore of a rifled gun barrel located immediately ahead of the chamber in which the rifling is conically removed to provide clearance for the seated bullet. Also called Throat or Ball Seat.

FREE BORE
    A cylindrical length of bore in a firearm just forward of the chamber in which rifling is not present. Associated with bullet jump.

According to SAAMI, these three terms mean the same thing.

The glossary is pretty handy.  http://www.saami.org/Glossary/

[adamsutherlandModerator]

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Are we any the wiser?

According to SAAMI throat and leade are the same thing.

I have be using throat to describe the bit from the case mouth to the rifling, the freebore and leade.

Looks like their isn’t any agreement across the industry.

Does SAAMI trump the other interpretations?

[michaelburns]

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Certainly the way we talk about “fitting the boolit to the throat” leaves it open to interpretation.

“size 0.0005″ under/over throat” would clearly mean with reference to freebore.
“This boolit nose is too fat for that tight throat” would clearly refer to leade, since the nose won’t touch the freebore but will touch the lands in the leade.

Meh. have a beer

[anachronism]

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I’ve always held to the exact same terminology that SAAMI is using. The unrifled portion in front of the throat area is freebore.

[Larry Gibson]

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In some things we can make do with all 3 things “meaning the same thing”.  However when we get into technical discussions they are 3 separate things and need to be considered that way or confusion abounds.  The throat encompasses the case mouth (the taper from the chamber neck to the free bore), the free bore (the cylindrical or slightly tapered portion with no lands or grooves between the case mouth and the leade) and the leade (that portion of the lands that taper from the free bore to the bore). 

With those distinctions and definitions we can have technical discussions of that area of the chamber/barrel w/o confusion.

Larry Gibson

[Author]

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