What is a 7mm BR. I know it a bench rest load but whats it equal to? Never messed with one.

7mm BR is a wildcat that became a real cartidge when Remington started producing production firearms chambered in thiis cartridge. There is awhole family of BR cartridges- which means that some enterprising enthusiast decided that it woould be cool if this cartridge was necked down or necked up to a different caliber. the cartridge is what holds all of the components together- the primer to start the fire , the powder to create the pressure to drive the bullet from the firearm in your hand to the target. the cartridge i the easiest part of the assembly to manipulate to shoot a larger or smaller or faster or slower bullet. - of course we have to modify the firearm also but once a firearm is established to fire a round it is much cheaper and easier to modify the existing round than to create a whole new cartridge. I believe that the BR family was initially created from the 308 win by shortening the cartridge , then creating a new neckand shoulder. it is hard to say which cartridge it started from because the 308 win initially started a different group of wildcats that included the 243 win, th 7mm008 and the 358 win. simply by changing the neck diameter- the BRwas a bigger change because the cartridge was shortened , the 30-06 has a similar family of descendents 6mm-06, 25-05, 280 rem, 35 whelen- they share the same basic case dimensions- head diameter and case length, so the only major change to the firearm is the bore diameter and the chamber- which necessitated a new barrel and a new chamber reamer- but in gunsmith terms this is not difficult , just another job.

it was from the shortened .308 win case. it would be somewhat comparable to a 7tcu in power. it would be like a 7mm-08 "short".

i have an xp100 in 7BR.

i like the 6BR tremendously in my 15" encore!

Thank you never seen one just wondering what it was and compared too.

The BR was developed by shortening the 308 BR "benchrest" case to 1.5" and increasing the shoulder from 20* to 30*. The 308 BR or "basic" brass case was developed for benchrest shooting with the thought the small rifle primer would help in accuracy. Some claim the 7BR was formed from the 308 X 1-1/2" Barnes, as Frank Barnes had developed the wildcat prior to the 7mmBR. The British also experimented with shortened 30-06 cases in the 1-1/2" range as early as 1945, before the 30-06 was shortened for the 308 Win in 1952. So a short 30-06 based case was nothing new.

Remington brought out the 7mmBR in 1978 in the XP 100 platform for silhouette shooters. Remington also made a 22BR and a 6mmBR, with properly headstamped brass. The case has been necked up and down in several sizes as noted in the picture. The latest creation to come out that follows the BR class of cartridges is the 30 Remington AR. Think 30 BR. This is being chambered in the AR 15 platform and might see cahmberings in long guns.

If you need more history look in a few loading manuals as they usually have brief description of cartridge history. Or look in any of these books as they are great for info and dimensions.

Is it good for anything? besides silhouette shooting.

Oh it is good for anything you want to hunt here using good judgement of your abilities and the cartridge's. It's a very fine round. I had a 22BR in a rifle and it matched or exceeded the 22-250 velocities with ease. Accuracy was in the .250" and below.