The 100 ATR receiver is bedded into a synthetic, one-piece stock. Usually, one piece means that the stock is molded and fixtures are attached later. On the 100 ATR, the sling swivel inserts and the trigger guard are molded into the “one piece” package. This makes the stock lighter and keeps costs down. At first I didn’t care for the design but it is snag free and ideal in a drag bag, especially the integrated trigger guard. The 100 ATR has a safety that sits at the right rear of the bolt. Between the taper of the grip and placement of this safety, most users will enjoy instinctive operation. I found I could switch the safety on or off without looking at it or surrendering my sight picture. I also like it when the manufacturer makes a bolt gun that can be placed in battery with the safety on or off, which is an important quality in a tactical rifle. In fact, one can touch the center of the bolt and know the firing pin is cocked. This is truly an “eyes on target” rifle.
I like a little less taper in the forend and a higher, wider (or adjustable) comb, but this rifle was a natural fit for most shooters who tried it. The barrel is free floated over the stock and the free floating remained consistent, regardless of how much I heated the barrel. The stock did have a distinctive “ring” to it when firing, which reminded me of those one piece molded PR 24 batons on a practice dummy. I can’t stand molded batons, but the ring of the 100 ATR felt perfect.
The Picatinny rail comes standard on this model, and it is just long enough for appropriate scope mounts. It has a generous milled opening for loading, which is important because the 100 ATR uses a non-floorplate magazine.
On a bolt rifle, having a magazine without a floorplate requires that the shooter know how to unload unfired rounds without chambering them completely. If it had a floorplate, one releases the latch and the rounds, spring and follower pop out of the bottom. On the 100 ATR, it is tricky to scoop unexpended rounds out of the magazine. The most likely scenario is to let the bolt strip the rounds from magazine without chambering them entirely, kicking them out one at a time, while the rifle is pointed in a safe direction.
The magazine and follower did work as advertised, though. Shooters who practice cycling the bolt quickly for a follow up shot will find that the 100 ATR is not finicky.
The 100 ATR came bore sighted. I fired the first group at 100 yards, gambling on the rough zero. The group was on the 2 o’clock about 4 inches high, but it was on the paper. I adjusted the scope only once and shot several sub 2-inch groups with several brands of ammo. It seemed to like the Federal 165 Grain TRU. This is one of my favorite cartridges also. This rifle only occasionally produced sub MOA groups, but it could pound out 2 inches at 100 yards all day long.
For a mid range rifle, a 2-inch group at 100 yards is about right. There were several instances where the groups were sub MOA. This is what the end-user will discover on his own.
Mossberg uses a LBA (Lightning Bolt Action) Trigger System, which is has a crescent shaped protrusion from the finger pad area of the trigger. I liked the feel of this trigger. It had almost nonexistent creep, and fairly quick lock time. The instructions that came with the rifle say the trigger was adjusted at the factory. The setting was light enough for field work and the trigger was crisp enough for mid range shooting. Really, if this is a cost-effective package, I would like to try the custom models. Mossberg did its best work here.
The Mossberg 100 ATR Night Train is a moderately priced rifle with the right features for a service gun. It is simple to operate, easy to tote around and accurate enough for the job.
Lindsey Bertomen is a retired police officer who teaches at Hartnell College in Salinas, Calif. Reach him at email@example.com.