Mark Camoc­cio con­cludes his trial of the clas­sic Air Arms S400

Air Gunner - - Contents -

The two-stage, semi-match trig­ger that Air Arms fit to the S400 and its de­riv­a­tives, is the lat­est ver­sion, which fea­tures Nick Jenk­in­son’s 3-sear de­sign as stan­dard. OK, it’s a rel­a­tively sim­ple unit, with far fewer com­po­nents than that of a full-blown, ul­tra­so­phis­ti­cated match trig­ger. How­ever, it is a true two-stage de­sign, whereby the first stage does ac­tu­ally start to move the sears apart, in­stead of a pseudo de­sign, where the blade moves ini­tially just on a pivot, hav­ing no af­fect on the mech­a­nism. In­deed, with some care­ful ad­just­ment, this trig­ger can be set rea­son­ably light, with a highly ac­cept­able and pre­dictable re­lease pos­si­ble.


As men­tioned, with no reg­u­la­tor fit­ted, the S400 needs to be charged care­fully to the pre­scribed fill pres­sure. Air Arms still spec­ify that pres­sure as 190bar, but in my ex­pe­ri­ence, a fill pres­sure of be­tween 165bar and 170bar is more likely to re­turn a con­sis­tent band of shots. It’s a knock-open valve at the end of the day, which means the greater the pres­sure in­side the cylin­der, the more re­sis­tance against the ham­mer ini­tially as it tries to open the valve. As cylin­der pres­sure de­creases, so the ham­mer will open the valve more eas­ily. Over the whole charge, a power curve of sorts will be seen, but get your ini­tial fill pres­sure right and you’ll get a good num­ber of con­sis­tent shots within a fairly tight ve­loc­ity band – what’s com­monly known as ‘the sweet spot’. For the record, I charged my test gun to 180bar.

Charg­ing the S400 is via the front valve, ac­cessed by just un­screw­ing the fluted valve cover, and slid­ing on the air­line over the ‘ T’ bar valve. This has to be the safest de­sign of valve be­cause that ‘ T’ bar de­sign al­lows the high pres­sure cable ef­fec­tively to be locked in place for the du­ra­tion. There’s an in-line 20 mi­cron air fil­ter at work here too, to keep dirt from the in­ter­nals.


I’ve owned and shot a va­ri­ety of S400s over the years, so I’m fa­mil­iar with how they per­form and what to ex­pect, and the test model was no great sur­prise. The fac­tory-set trig­ger did ar­rive with a slightly heav­ier pull than I had in mind, so a ju­di­cious tweak with some Allen keys later, and I was in a po­si­tion to as­sess the ac­cu­racy of this par­tic­u­lar spec­i­men. I still find the silky grey ‘satin’ bolt han­dle very ap­peal­ing, but the bolt set-up does oc­ca­sion­ally comes in for crit­i­cism in some quar­ters. I

con­cede that it could do with a bit more re­sis­tance on clo­sure, but be pre­cise in your ap­proach, and it won’t let you down. Over the chrono­graph, from the 180bar I had se­lected, I clocked 80 shots within 19fps, which for an un­reg­u­lated gun is very im­pres­sive. You can get plenty more shots, but I was af­ter max­i­mum con­sis­tency so stopped there.

A quick zero at 25 yards to get the scope in the right area, and then back to my nor­mal zero dis­tance of 35yards – which is also a fair ini­tial test of qual­ity ma­chin­ery! Us­ing Air Arms Di­abolo Field am­mu­ni­tion, groups of sub-3/8 inch were easy to come by. Mov­ing out to 45yards, sub-half-inch clus­ters were the norm with this par­tic­u­lar ex­am­ple – a good re­turn with any ri­fle.

As with any PCP, we need to be aware of how many shots we’ve used up be­fore a recharge is nec­es­sary, and here, Air Arms make it easy to keep an eye on resid­ual cylin­der pres­sure with that per­fectly placed manome­ter, re­cessed on the un­der­side of the fore end.


As pre­vi­ously men­tioned, Air Arms pro­duce a carbine ver­sion of this model with a shorter cylin­der and bar­rel, but for the ad­di­tional shot count and neg­li­gi­ble weight dif­fer­en­tial, I’d plump for the longer Clas­sic spec’ every time. In short, the S400 re­ally is the great all-rounder – all things to all peo­ple! As men­tioned, the S400 was orig­i­nally de­signed as a hunt­ing ri­fle, and there­fore sports an ap­pro­pri­ately light, sleek pro­file. Take to the field – its nat­u­ral en­vi­ron­ment, af­ter all – and the com­bi­na­tion of slick han­dling, sen­si­ble weight, and blis­ter­ing ac­cu­racy makes it the per­fect tool for the job. It’s whis­perquiet, too, with that si­lencer in place.

Give in to the lure of hunter field tar­get shoot­ing, and this model al­lows you to be com­pet­i­tive from the start, but that smart fore end just might need some beef­ing up. Easy cus­tomi­sa­tion is of­ten part of the en­joy­ment for many shoot­ers, though, and this model cer­tainly lends it­self to sim­ple mod­i­fi­ca­tion, such as the adding of a ham­ster block or stock raiser of some sort.

Adding a reg­u­la­tor fur­ther down the line is a must for some shoot­ers, too – more for peace of mind – and again, the straight­for­ward S400 lends it­self per­fectly to that.


As with most walks of life, air­gun man­u­fac­tur­ers have to be seen to be bring­ing out new mod­els pe­ri­od­i­cally, yet look at what the S400 of­fers and you might be­gin to ap­pre­ci­ate just why this air­gun clas­sic re­mains so highly re­garded, by new and ex­pe­ri­enced shoot­ers alike.

Hunt­ing or com­pe­ti­tion? You de­cide

Class doesn’t have to cost a for­tune

That clas­sic bolt is still there

Surely, the safest fill­ing valve on the mar­ket

The per­fect place for the vi­tal gauge

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.