The 7 mm Remington mag like just about everything else between a 22 long rifle, a 30-06 and a 375 H&H was created to sell guns. Winchester came out with their 338 Win mag and their 264 Win mag in 1958 and 1959 respectively in their time proved model 70 rifle. In 1962 Remington countered with their then new model 700 rifle in Remington's new chambering the 7 mm mag. So at that time there was essentially an arms race giving us a 264, a 284 (7mm) and a 338 caliber magnums and then Winchester counters in 1963 coming out with their new 300 Win mag, filling the gap with a 308 caliber magnum offering even though the 300 H&H mag had been around for decades before. Just prior to the 300 Win mag Norma came out with their 308 Norma mag but it died probably because they only offered the chambering and not a rifle. Then in 1978 Remington came out with their 8 mm Mag giving us a 323 caliber mag (my favorite) and it goes on and on to now the new rage the short magnums. Then you can throw into the mix that two guys in 1953 which pre dates all of the above came out with the 7 mm Sharp & Hart magnum after their namesake that is ballistically superior to the Remington 7 mm mag by about 150 fps even though they look almost identical the S&H has a bit more powder capacity. To my knowledge only Schultz and Larsen offered this chambering on a commercial bases. All of this is probably much more than you wanted to know but now you know it. To answer your question; yes a 7 mm mag is a good deer cartridge but it has a lot of company and the list is growing.