Air Arms S400 MPR FT: Part 1
by B.B. Pelletier
Before we begin, there are a couple of items to be addressed. First, Edith and I noticed that several of our readers are fans of the Three Stooges, and we thought we would share this photo we had taken in Las Vegas, when Edith, Mac and I attended the 2008 SHOT Show.
Left to right — Tom, Edith, Mac. This was the most fun picture we ever took. It hangs in Edith’s office.
Now, there is a survey to re-name the Air Arms Twice air rifle, and with a name like that I can see why. Go here to select suggested names or submit one of your own.
Next, the blog discussion about muzzlebrakes and the lack of open sights on many Beeman guns has resulted in two reader surveys. Go here to comment on the R7 air rifle. Go here to comment on the R1, R9, HW97, RX-2 and R11 air rifles.
Now, let’s get started with today’s report. The Air Arms S400 MPR FT is a bolt-sction, single-shot .177 caliber rifle made for the sport of field target. It’s based on the S400 multi-purpose rifle (MPR) and comes with a walnut-stained poplar stock. The metal parts are highly polished and finished with a deep, dark black.
Adjusting the stock to fit
The MPR platform is a 10-meter target rifle platform, so the stock configuration is set up accordingly. Fortunately, that same shape works well for field target, so it supports the intended purpose quite well. The only drawback is a rather short pull of 12-1/8 inches with the one butt spacer that comes installed by the factory. I installed the other three spacers, which extended the pull to 13-1/8 inches. While that’s still short for me, I found a workaround. I dropped the adjustable buttpad to its lowest position and lifted the cheekrest to its highest position. That gave me a comfortable fit in the offhand position.
The forearm has an accessory rail, which is perfect for fitting the knee rest that many field target competitors want. Next to the rail and deeply inset into the stock is a manometer or air pressure gauge, so you’ll always know the state of the charge in the air reservoir. That said, the S400 MPR FT operates on a maximum fill of 200 bar, or 2,900 psi.
The pistol grip is shaped with a rounded knob at the top where I want to put my thumb. I do not like wrapping my thumb around a pistol grip and normally I would expect to find a dished-out spot for the thumb in the upright position, but there is none. There is no comfortable way to position the thumb on this rifle except to wrap it around. If it were my personal rifle, I would modify that with a Dremel tool. The grip is roughly stippled to grip your three fingers when you hold the rifle.
The trigger is adjustable for the location of the blade, for the length of the first stage, location of the second-stage break and for the overall pull weight. I was able to adjust it down to 14 oz., with just a tiny bit of creep in stage two. Then, I adjusted the creep out with the second-stage location adjustment. The only thing lacking is an overtravel adjustment.
Air Arms has a proprietary filling adapter. Nothing else on the market will fit the rifle. Their adapter connects to a 1/8-inch BSPP female coupling, so that’s what you must have at the end of whatever filling setup you use — hand pump, scuba or carbon fiber tank. It’s a fairly standard connector these days and comes with a lot of pumps and scuba connectors.
The S400 MPR FT is a 12 foot-pound rifle, which is perfect for competing in field target in the international class. Pyramyd Air lists the muzzle velocity at 800 f.p.s., but I’ll test a number of different pellets to determine the actual velocity of the test rifle.
No sights come with the rifle, because the assumption is that you’ll be scoping it. As a field target rifle, there really isn’t any other way to go. The aluminum receiver has an 11mm dovetail on both sides of the bolt trough. Because this is a PCP, there’s no recoil to worry about, so no scope stop is needed.
I plan to use this rifle as the test platform for a Hawke scope I’ve been wanting to test. The S400 should be accurate enough to give us a good idea of how well the scope works, so I’ll probably add another part to the report.
The S400 MPR FT rifle seems to be a nice lightweight field target rifle. Of course, a big scope will add some weight, but this will still be one of the lightest rifles on the line. I can’t wait to see how accurate it is.