as I remember the day it was back in the late 1970s or so when I was browsing the local gun-shop racks when the owner of the gun-shop walked over with a long box and said, " I just got in a barely used shotgun, I thought you might like , the previous owner fired 5 shells and decided it was far to much gun for him, I know that's all that's been fired because I special ordered both the gun and a couple boxes of ammo for it only a few weeks ago!"
At first glance it was noticeably larger and heavier than most semi auto shotguns I was used to , and it had a 21" barrel and a parkerized metal and oil wood finish and looking almost military, but it only held 3 rounds and there was no magazine extension available.
It fired 3 1/2" magnum 10 gauge shellls that threw a full 2 oz of lead shot, that meant 21 double oo buckshot vs the standard 12 gauges 9, or 12 double oo buckshot, and a 2 0z slug vs the 12 gauges 1 oz at that time, and I knew several places that deer hunting was restricted to scatter guns only!, the price was semi reasonable (TO A GUN NUT LIKE MYSELF) so a deal was quickly struck!
when I priced factory ammo (only after purchasing the gun) I almost had a stroke!, It was obvious that I was going to be hand-loading for the shotgun.
as even the cost of a press,dies and components paled in comparison to a few cases of factory ammo, so I quickly got those items and a couple manuals and 200 empty hulls, recoil was noticeable but the guns size and weight made it tolerable, the gun functioned flawlessly and while it was obvious that it hit hard I wanted to hunt deer with it, the guns weight made it not ideal to carry on long walks on hot days, so I bought a sling, which was not all that common on shotguns but it made that a bit easier.
I found by shooting full size deer silhouettes that the 21 double oo buck pattern limited me to about 15 yards more range than my 12 gauge guns but still ,shots on deer were best if limited to about 45-50 yards max if you wanted a 50% hit ratio, and I found it was possible to extend that range to about 60-70 yards if I used slugs as I could keep those in the chest area out to about 60-70 yards, with the simple bead front site!
(later I found a custom load using two 69 caliber musket balls that was devastating on deer) as the twin balls stayed fairly close and consistent, in trajectory out to almost 60-70 yards.
the first deer I killed amazed me, I was caught off guard as a buck ran by me in light brush at only about 40-45 yards, I swung out a bit ahead of him and as the rib on the barrel aligned I squeezed off a shot expecting him to drop, all manor of branches beyond the buck, under over and near the buck flew in the swarm of buckshot, but the deer stagger and kept running, a second quick shot instantly resulted in the deer doing a cart-wheel on his nose, the cloud of buck shot did exactly what it was intended to do but it certainly did not drop the deer any faster than most other deer rifles or shotguns would with a well placed shot, it was not until I was dressing out the deer that I noticed the extent of the injury's, and it became obvious that slugs or the custom load with the two musket balls was the preferred load to use on deer past about 35-40 yards , as 00 buck lacks penetration past that for clean decisive kills on deer. the deer was hit several times in vital areas but the pellets did not penetrate as deeply as would have been ideal. at 20-35 yards the 10 gauge was truly awe inspiring in its destructive force and as a weapon for close work Id prefer it over many others, but a shot guns not a reasonable mid range or semi- long range weapon until slugs or the twin 69 cal musket balls are used.
I used the 10 ga for hunting hogs in thick brush and my friends refer to it use as calling in artillery!
at those ranges its awesome, in its effectiveness , but theres a great deal of shredded pork, if you use 00 buck at less than 20 yards.
I later on fitted a large rear peep site and large front rifle site making hitting with slugs and the twin musket ball load far faster and easier but it didn,t effectively increase the range due the the 10 ga smooth barrel
if you need a one well placed shot, ends all disputes, home defense shotgun and can find a ROAD BLOCKER its a viable option in practiced hands, but its not your only option
The Mag-10 was introduced in 1977 with production lasting until 1986. The "RoadBlocker" version of the MAG-10 was designed to give law enforcement the ability to deal effectively with criminals in vehicles. It is very heavy (around 11.5 lbs loaded weight), has a 21" barrel, 2+1 capacity, and is not intended for routine carry. It has a stainless steel gas recoil system, placed at the front end of the magazine tube (hence the small ammunition capacity of 2+1) incorporates a "countercoil" system which substantially reduces what would otherwise be an extreme recoil. In military terms, it is very limited in its usefulness, due to its heavy weight and 2 round magazine capacity. Occasionally, I see one or two at a gun show and the run anywhere from $1500 to $2000.