Over-bore and free-bore?

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13 July 2010, 10:38

TrophyShotPrints

Over-bore and free-bore?

What is overbore?

What is freebore and it's relationship to overbore? Freebore I would think deals with how the chamber is cut, but what's the meaning of all this and more especially why?

Could someone take me to school on this please, it's about time I learned!

Thanks!

13 July 2010, 15:58

DocEd

Overbore: The relationship of the case capacity to the bore diameter. A great example of an overbore case is the 22x284, along with a slew of others.

Freebore: the distance from the case mouth to the beginning of the rifling.

13 July 2010, 16:03

McFox

Overbore and freebore have nothing to do with each other.

Overbore is used to decribe a cartridge which as a larger powder capacity in relation to the caliber than "standard" cartridges. Please don't pin me down on what is standard and what is overbore ....

Freebore describes the clearance of the bullet ogive of a loaded round to the rifling of the barrel. It is the distance the bullet will travel before it will make contact with the fields.

13 July 2010, 16:45

vapodog

quote:
Originally posted by McFox:
Overbore and freebore have nothing to do with each other.

Fully agreed....good point!

quote:
Originally posted by DocEd:
Overbore: The relationship of the case capacity to the bore diameter.

Freebore: the distance from the case mouth to the beginning of the rifling.

Pretty good definition!

I'm not sure that either of these terms have a precise definition but what has been posted hits it pretty good.

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13 July 2010, 21:06

TrophyShotPrints

Thanks gents I got it now

13 July 2010, 21:27

SmokinJ

I believe I can tie overbore and freebore togehter.....alittle. Weatherbys's cartridges are mostly overbored magnums and to achieve the higher velocities they do safely the barrels most often had a lot of freebore to keep the pressure down and the initial beginning of the firing sequence.

14 July 2010, 15:19

DocEd

SmokinJ, good point!

14 July 2010, 18:15

TrophyShotPrints

quote:
Originally posted by SmokinJ:
I believe I can tie overbore and freebore togehter.....alittle. Weatherbys's cartridges are mostly overbored magnums and to achieve the higher velocities they do safely the barrels most often had a lot of freebore to keep the pressure down and the initial beginning of the firing sequence.

Thanks...thats what I was looking for!!!!