u.s. and u.k. ft/lbs

sir-lamp-alot

Well-Known Member
i have been having a look at factory rounds to use in my new .243 and which would be good on fox as well as being legal for roe, ive had a look at fedral, winchester and hornady ammo and i'm working on and please correct me if im wrong to be legal i need a minimum of a .240 producing 1700 ft/lbs at the muzzel which i always thought was going to be about the 80gr mark but all above makes are claiming over 1800 ft/lbs even on there 55gr bullets and wondered if u.k. and u.s. ft/lbs are both the same un-like u.k. and u.s. gallons
 
i have been having a look at factory rounds to use in my new .243 and which would be good on fox as well as being legal for roe, ive had a look at fedral, winchester and hornady ammo and i'm working on and please correct me if im wrong to be legal i need a minimum of a .240 producing 1700 ft/lbs at the muzzel which i always thought was going to be about the 80gr mark but all above makes are claiming over 1800 ft/lbs even on there 55gr bullets and wondered if u.k. and u.s. ft/lbs are both the same un-like u.k. and u.s. gallons

You seem to have misunderstood what ft/lbs are. The ft/lb energy figure is a function of velocity and bullet weight in relation to each other. To achieve a given energy level you can either get there using a light bullet at high velocity or a heavy bullet at a lower velocity.
 
i fully understand what ft/lbs are and altho i dont know the formula i understand how ft/lbs are calculated in relation to mass and velocity i was just under the impression that a .243 cartridge was unable to create the velocity needed to push a bullet under 80gr over 1700 ft/lbs hence ive questioned the u.k. and u.s. ft/lb scale but it seems to be after a bit of investigation that they are the same thing but many thanks for your help tho
 
US and UK only go out of sync on volume.

1 US Pint is 16oz by their volume measure but 20 oz by ours.

Weight is the same.

Stan
 
US and UK only go out of sync on volume.

1 US Pint is 16oz by their volume measure but 20 oz by ours.

Weight is the same.

Stan

No. A US pint is 16 (US) fluid ounces while a UK (Imperial) pint is 20 (Imperial) fluid ounces, so is almost 25% heavier. It is not quite 25% heavier because the US fluid ounce is slightly larger (by about 4%) than the Imperial fluid ounce.

This is because the Imperial system is based on a gallon being the volume of 10 lbs of water, divided into 8 pints of 20 fluid ounces whereas the US system is based on an earlier definition of a gallon as the volume of 8 lbs of wine, divided into 8 pints of 16 fluid ounces. The Imperial fluid ounce is the volume occupied by 1 ounce of water while the US fluid ounce is the volume occupied by 1 ounce of wine; as wine is less dense than water, the US fluid ounce is slightly larger.
 
Back
Top