Throat vs leade vs ball seat.

[ABJ]

I'm starting this thread, to prevent thread drift on the ladder testing thread where Larry Gibson gave us some clarity on terminology.
My understanding is the chamber is where the case resides, the throat is where the case ends and the rifling begins. The Leade is the slope of the rifling before it reaches full height from the groove.
I do not know what the ball seat is. The above is referring to rifle chambers. and auto pistols.
Freebore is another term that I use as the space between the bore riding portion of the bullet and the contact with the rifling but I'm pretty sure I'm wrong on that one.

On revolvers, my understanding is the cylinder houses the chamber where the case is and the throat is where the bullet resides.
I do not know if their is a leade in a revolver cylinder unless the chamber has a sloped transition into the throat.
Tony

[popper]

I do not know what the ball seat is -- ball seat is a design of the neck/bore transition. Some guns have a square step, some a tapered step (ball seat)

[ABJ]

Popper that makes sense to me but are their not different shaped reamers for different calibers, such as 30-30 lever guns vs say a 30-06 bolt gun?
Would all the different angles still be called a "ball seat"
Tony

[truckjohn]

I think the term "Ball seat" hearkens back to the time of muzzle loaders where some had counterbored muzzles to start the patched ball without issue.

Many older military chambers use a generous taper from the end of the chamber into the rifling. The purpose there was to reduce pressures and provide a margin of safety for fouling/trash accumulation at the end of the chamber.

Some match chambers start the leade with a bullet or groove diameter straight section before tapering the rifling to full bore diameter. The purpose of this is to ensure the bullet stays straight when it exits the cartridge. The wide taper at the end of typical military chambers allows the bullet to yaw significantly before it finds the rifling, and this hurts accuracy.

[Char-Gar]

In rifles, they are interchangeable terms.

[truckjohn]

I think the term "Ball seat" hearkens back to the time of muzzle loaders where some had counterbored muzzles to start the patched ball without issue.

Many older military chambers use a generous taper from the end of the chamber into the rifling. The purpose there was to reduce pressures and provide a margin of safety for fouling/trash accumulation at the end of the chamber.

Some match chambers start the leade with a bullet or groove diameter straight section before tapering the rifling to full bore diameter. The purpose of this is to ensure the bullet stays straight when it exits the cartridge. The wide taper at the end of typical military chambers allows the bullet to yaw significantly before it finds the rifling, and this hurts accuracy.

[Larry Gibson]

Ball seat, as mentioned, harkens back to the time of the earliest breach loaders such as the flintlock Hall rifles. There was a slight area at the rear of the barrel where the ball" [a round lead ball] was seated into the barrel against the rifling. We also see, in old arsenal platte drawings for early cartridges like the 45-70 where the very minimal distance from the chamber end to the beginning of the rifling referred to as the "ball seat". The term is seldom, if ever, used or seen today.

"Throat", as generally used, is considered to be the area ahead of the chamber in rifles to the beginning of the rifling [also referred to a "lands and grooves"] of closed breech firearms such as rifles and single shot handguns. However, in definitions found in Outdoor Life's Firearms Encyclopedia, Shooter's Bible Small Arms Lexicon and Concise Encyclopedia along with definitions of terms in other firearms and military related manuals we find the terms "throat", free bore and leade are often referenced back and forth to each other further confusing the true meanings. I believe the Small Arms Lexicon and Concise Encyclopedia perhaps comes the closest as it lists the following definitions.

Throat is that tapered portion of the bore forward of the chamber where it diminishes in cross section to meet the rifling [where the leade is].

Free bore is differentiated from the tapered throat because it is cut with parallel walls instead of tapered walls.

Leade, in older manuals and drawings, generally referred to the tapered part of the rifling the bullet engages. Such as in "what is the angle of the leade the bullet engages" because it is separate from the taper or parallel portions. Confusion reigns because the two encyclopedias mentioned refer to the leade as interchangeable with the term throat.

If we concede that whole portion of the barrel is the "throat" but concede there can be two or three separate parts (we can have a tapered with leade throat, a free bore with leade throat or a tapered free bore with leade throat] to a throat, then we can better understand what is being talked about.

In revolvers the "throat" is generally thought to be that part of the cylinder between the front of the chamber and the face of the cylinder. That "throat" can be tapered [thus a "throat"] as in factory Ruger cylinders. Or it can be cylindrical [thus a "free bore"] as in some Colt and S&W cylinders. Then, if we consider the revolver as a whole, we see what is commonly called a "forcing cone" at the rear of the barrel is actually a tapered of the bore for the bullet to enter the leade. Some have a free bore reamed leading from this forcing cone/throat further into the bore so the bullet's drive bands are inside the bore before it encounters the leade.

Are we confused yet? As we see, it certainly can be confusing enough using the correct terminology without adding any made up or colloquial names be it a chingastat, a whatchamacallit or a thingamajig......

[dverna]

Now I am confused. What is a chingastat???

I was fine until then....damn you Larry!!!

[243winxb]

Saami- https://saami.org/saami-glossary/

[Larry Gibson]

Saami- https://saami.org/saami-glossary/

Thanks for posting. The SAAMI Glossary (an encyclopedia of terms) is also an excellent reference and pretty much concurs. However, even there we see the back and forth reference to the terms for "throat" used which if not using the correct term for a specific area of the "throat" then it still can be confusing.

In a rifle to reiterate;

The "throat" should be the tapered portion of the bore in front of the chamber up to the rifling. The throat can be very short or very long. The throat may or may not also have a cylindrical free bore portion between the taper and the beginning of the rifling. The angled part of the rifling at the start of the rifling is the leade.

BTW; "Rifling" is also called "lands and grooves".

[DougGuy]

Yes.. Interchangingly confusing. :guntootsmiley:

I have often heard the chamfer at the end of the chamber in a revolver cylinder referred to as the "ball seat." However inaccurate that might be, if you DO have a boolit or ball loaded into a metallic cartridge case and seated against that chamfer, then it is assumed that the throat (the freebore just ahead of the chamfer) is somewhat smaller in diameter than the ball seat, making the cylinder into a multi-port sizing die.

Also, let's break down the word freebore. Generally this is accepted as the smooth un-rifled portion of the throat between the chamber mouth and the leade-ins of the rifling. Free meaning free of rifling, but bore (being the diameter measured from the top of the lands) would not be correct, but groove would be, so why is it not notated as "freegroove" since it really is a smooth section that is basically groove diameter, not bore diameter at all, devoid of rifling or leade ins.

More confusing.

[centershot]

Yes.. Interchangingly confusing. :guntootsmiley:

Free meaning free of rifling, but bore (being the diameter measured from the top of the lands) would not be correct, but groove would be, so why is it not notated as "freegroove" since it really is a smooth section that is basically groove diameter, not bore diameter at all, devoid of rifling or leade ins.

More confusing.

Ummmm..........Oh dear........I need more coffee......

[gwpercle]

There is also a good glossary of terms in the Lyman 46 edition Reloading Handbook , starting on p.462 .
This glossary has been my "go to " for gun word terminology for many years ...
243winxb , Thanks for the saami link ... can't have too much knowledge .
Gary

[GregLaROCHE]

Saami- https://saami.org/saami-glossary/

That’s a great source of information. Thanks for the link.

[Forrest r]

A cut-a way of a modern revolver cylinder.
https://i.imgur.com/Lcmp4hk.jpg

This picture was used to show how changing the oal of a load can aid/improve accuracy. The top round has the "factory" recommended oal & you can see the freebore from the end of the case to the step cut in the cylinder walls. After the step you can see the tapered portion of the cylinder, leade.
The bottom round has the bullet seated out further so that the shoulder of the bullet is out into the leade of the cylinder.

In revolver cylinders all of this is smooth but you can clearly see the space where the cartridge brass ends, the step where the freebore ends & the taper of the leade.

[JSnover]

Now I am confused. What is a chingastat???

I was fine until then....damn you Larry!!!

The definition, the meaning, and the purpose of a chingastat were all lost when Dr. Asperly passed away.

[sundog]

What is a chingastat???

If one has to ask, one would not understand, even if it were 'splained' in layman's terms.

[Larry Gibson]

If one has to ask, one would not understand, even if it were 'splained' in layman's terms.

Agree, kind of like "if you have to ask, you can't afford it".....

[beagle]

Think it's kinda like a chingadera i beleive./beagle

[Larry Gibson]

Now I am confused. What is a chingastat???

I was fine until then....damn you Larry!!!

A 'chingastat" is similar to a "dohicky" but there is a subtle difference between them. It's similar to the difference between Marie Laveau and Nancy Palosi......