Most of the guys now use .223 or .22-250 due to the price of ammo, plus both calibers offer very good performance for the task at hand. The Remington Model 7, Model 700, Savage and Ruger Mini-14 are all popular choices amongst the commercial guys. Meat hunters/non-commerical fishermen taking seals for meat, will often use whatever rifle they happen to own, or a 12 ga and BB shot.
Cold salt water and lots of blubber help to keep them buoyant so very few seals are lost during the open season. Most of the guys hunting inshore have boats or use floating jiggers to retrieve their seals. Hunting off shore on the pack ice is a little easier because you often get presented with on-ice shots that sure beats the hell out of trying to hit a bobbing seal's head/neck in open water from an 18 foot trap skiff with a good lop on the water! Plus they blend into the water, so they're damn hard to see...add in a bit of slob ice or fog and you have to be a helluva shot or exceedingly lucky to make the shot. No problem on the "fair chase" in this case.
For more info, check out the thread in the "Articles" forum, where I discuss the issue in detail. For those who don't know, it is illegal to club baby seal pups (also called Whitecoats) and has been so for 20+ years. Only mature seals are taken. Harp seals are harvested for both their pelts (used in the fashion industry) as well as the meat. Seal meat is rich in iron and omega-3 fatty acides. When cooked it is very dark in color, almost black. Flippers are a delicacy and are almost 100% protein. Basically natures health food.
They are often first boiled off to get rid of most of the grease, then baked/roasted in the oven with fresh vegetable and/or covered in a dough crust or paste for "flipper pie". Seal carcass is also much in demand and is most often baked/roasted in the oven.
Seal sausage, pepperoni, salami as well as canned/bottled seal meat is produced for the local and export markets.
Health food supplements, including Omega-3 capsules are produced for the nutraceutical markets, while the inedible parts of the seal are ground up to produce meal for the aquaculture industry, along with fur farming operations including mink and fox. Almost the entire animal is used, with very little wastage.
There are 5-6 million harp seals off Newfoundland & Labrador. Each year there are barely a quarter million animals harvested...that doesn't even put a dent in the population growth. When you consider that a mature harp seal can consume 30 lbs of northern cod each day (and they don't eat the full fish, just the soft gut and other delicacies) multiplied by 6 million seals, that's a lot of fish!
Northern Cod stocks are near extinction and how Harp seals have invaded our freshwater systems! They're now eating spawning Atlantic Salmon in our rivers and ponds, along with our brook trout and sea-run German Browns. I've personally seen seals sunning themselves on the Trans-Canada Highway over 100 Kms from the nearest Sal####er!!!!
With seal pelt prices on a high the past few years, guys are getting as high as $70.00 a pelt, plus they sell the flippers and carcass separately, so a single seal can be worth anywhere from $65 up to almost $100.00, depending on the quality of the pelt. For a fisherman living on $400-$500 EI every two weeks, the opportunity to make $10,000-$20,000 in just a couple of weeks (in a good year) can mean the world to him and his family...even though he has to risk his life to do so.