by Tom Gaylord
Writing as B.B. Pelletier

Air Arms S510XS
Air Arms S510XS Ultimate Sporter with Laminate Stock.

Part 1

This report covers:

  • Fill probe
  • First velocity test
  • High power
  • #3 power (one click down)
  • #2 power (two clicks down)
  • Low power (four clicks down — as low as the adjuster will go)
  • Discussion
  • Test 2 shot count
  • High power
  • Is there more?
  • High power
  • Magazine and feeding
  • Trigger pull
  • One last test
  • JSB Exact Jumbo Heavy
  • H&N Baracuda Match
  • Summary

Today we begin looking at the performance of the Air Arms S510XS Ultimate Sporter with Laminate Stock. This is the day we look at the power/velocity of this regulated PCP. The first order of business is to fill the 186cc reservoir to 250 bar. Reader Pelletpopper asked me to fill it with a hand pump to the maximum I was able, because Pyramyd lists a hand pump with this gun. I’m not going to do it. I’ll tell you right now I can fill it all the way, but after about 2500 psi it gets hard to pump. I see no purpose for filling by hand since I would never do it that way. If I wanted an inexpensive way to fill the rifle I would use the Nomad II compressor.

Fill probe

Air Arms pneumatics use a proprietary fill coupling. It works well but you have to have a dedicated hose or fit the adaptor with a male Foster fitting on the other end.

S510XS fill coupling
Air Arms fill coupling is proprietary.

S510XS fill adaptor
Air Arms fill adaptor is like no other.

First velocity test

How do you test a rifle that has adjustable power? My approach is to find out what it does on all power settings with a single pellet. That pellet will represent what it will do with other pellets at different velocities, because the relationship remains the same. Let’s see.

For this test I used the RWS Superdome because it’s medium weight and also pure lead. There is nothing to throw off the numbers. After the fill to 250 bar (tank gauge) the rifle’s built-in gauge read 240 bar. From here on I will only refer to the rifle’s gauge.

High power

240 bar start
Shot…..Vel.
1………937
2………958
3………934
4………937
5………939
6………942
7………933
8………942
9………944
10……..945

210 bar remains.

The average for the first string on high power was 941 f.p.s. The spread went from 933 to 958 — a difference of 25 f.p.s. At the average velocity the Superdome pellet developed 28.52 foot pounds at the muzzle.

#3 power (one click down from the top)

210 bar start
Shot…..Vel.
1………925
2………933
3………928
4………926
5………924
6………926
7………936
8………929
9………929
10……..935

175 bar remains

The average for this string is 929 f.p.s. It’s not that different than the first string at high power. The spread goes from 924 top 936 f.p.s. — a difference of 12 f.p.s. That’s considerably tighter than the high-power string and the power is very close. This is probably a better (more consistent) setting for the Superdome pellet when I want power. At the average velocity the Superdome developed 27.79 foot-pounds of energy.

#2 power (two clicks down)

175 bar start
Shot…..Vel.
1………833
2………828
3………838
4………835
5………841
6………828
7………834
8………837
9………842
10……..842

160 bar remains

The average for this string is 836 f.p.s., which is a big difference from the last setting. This is a useable power setting. The spread ranged from 828 to 842 f.p.s — a difference of 14 f.p.s. So the rifle is consistent at this power setting. At the average velocity the Superdome pellet generates 22.51 foot pounds of energy.

Low power (four clicks down — as low as the adjuster will go)

160 bar start
Shot…..Vel.
1………295
2………302
3………279
4………did not register
5………299
6………301
7………288
8………306
9………298
10……..303

150 bar remains

The average velocity for this setting is 297 f.p.s. In my opinion that’s not a useable velocity. The spread went from 279 to 306 f.p.s. — a difference of 27 f.p.s. At the average velocity the Superdome pellet generated 2.84 foot pounds of energy.

Discussion

This rifle doesn’t behave like a regulated rifle. Instead it acts like it has a balanced valve. Three power settings are useable and two of them — the middle two — are the ones I would select for the Superdome. The top and bottom settings have too much velocity variation with this pellet. That matters because when we find the best pellet, we should zero the rifle at those two powersettings — or at least at one of them.

The discharge sound on all settings is very low for the power generated. On the lowest setting the rifle is extremely quiet. You could shoot this rifle in most small suburban backyards at any power level without attracting attention.

Test 2 shot count

I’ve fired 40 shots since the fill. The onboard gauge still reads 150 bar, which is in the green zone, meaning there are more shots available. For this test I dialed the power back to the highest setting.

High power

150 bar start
Shot…..Vel.
1………974
2………967
3………963
4………961
5………953
6………944
7………938
8………930
9………929
10……..916

125 bar remains

The average for this string is 948 f.p.s. That’s 7 f.p.s. faster than the first string that was shot with the same pellet on the same setting. But look at how the shots all decline in velocity. The spread from this string is 56 f.p.s. That doesn’t look like a regulated rifle, does it? In fact I believe that at 125 bar the rifle has fallen off the regulator. That gives you an idea of how many shots to expect with this pellet from one fill — perhaps two magazines on high power and three on the setting that’s two clicks down from the top. At the average velocity for this string the Superdome pellet generated 28.94 foot pounds of energy.

What you should do is watch the onboard pressure gauge and refill when it gets to 125 bar. If you are shooting groups at distance (50 yards or more) refill at 150 bar.

Is there more?

Is the rifle really off the power curve? I fired 5 more shots to see what happened.

High power

125 bar start
Shot…..Vel.
1………915
2………917
3………905
4………890
5………880

Yes, the rifle has clearly fallen off the regulator. It’s time to refill the reservoir.

Magazine and feeding

The magazine functioned perfectly throughout these tests, but the sidelever did get stuck a couple times with each mag, having to be coaxed to go forward again. Once I learned that and came to expect it, I just powered through.

It is possible to double feed the rifle, so you have to watch what you’re doing. Also the magazine does not stop the bolt after the last shot, so watching the pellets feed is essential. Otherwise you’ll shoot blanks.

Trigger pull

The trigger is two stage and set up nicely by the factory. I will adjust it for you in the next report, just to tell you how it goes, but it’s working the way I like them right now.

Stage one takes 12 ounces and stage two averaged exactly 1 lb. 8 ounces. The pull is delightful and fully controllable. This is the kind of trigger I can work with!

One last test

My guess is that the JSB Exact Jumbo Heavy pellet will be the best in this rifle. I will test it now on high power to see what we get. For kicks I will also shoot a string with the H&N Baracuda Match pellet. This will give us insight into the true power potential of this test rifle.

JSB Exact Jumbo Heavy

High power
250 bar start (gauge on gun agrees with my tank gauge)
Shot…..Vel.
1………883
2………886
3………880
4………881
5………876
6………879
7………870
8………885
9………871
10……..880

225 bar remains

This test was interesting, because there was no hesitation to feed the pellets. I think the Superdomes were the problem with that — not the rifle. the low is 870 and the high is 886 f.p.s., so a 16 f.p.s. difference. The average velocity is 879 f.p.s and at that speed the pellet generates 31.11 foot pounds of energy.

Now let’s see what the Baracudas do.

H&N Baracuda Match

High power
225 bar start
Shot…..Vel.
1………832
2………826
3………827
4………826
5………826
6………831
7………828
8………824
9………835
10……..835

180 bar remains

The first thing to note is the lower use of air with these heavier pellets. Based on what I’m seeing here I think 30-35 full-power shots are possible.

The average velocity for this string is 829 f.p.s. At that speed the Baracuda generates 32.37 foot pounds. So Air Arms has hit the advertised power level. The spread went from a low of 824 to a high of 835 f.p.s. That’s an 11 f.p.s. difference. Also there was no feeding problem with Baracudas, either. It makes me think the S510 might do best with heavier pellets.

Summary

Now that I have a handle on the performance the next report will be about adjusting the rifle to suit me. For that I will need to mount the Meopta Optika6 3-18X56 RD SFP scope in the Sportsmatch 30mm high adjustable scope mounts that I’m testing in conjunction with this rifle. I hope to also report on both the scope and the mounts by that time. Stay tuned!