Friday, 10 April 2009

Airgun Magazines - Questioning Their Accuracy

Precharged pneumatics (PCPs) are extremely popular these days - you've only got to look at my poll opposite to see that they get the big vote from airgunners. In particular, multi-shot PCPs are the hot-sellers in gun shops. But are the benefits of an auto-feed magazine coming at the cost of the rifle's full accuracy potential?

I beg the question following a number of discussions I've had of late with hunting friends. It seems it's not only me who has an inkling that single-shot air rifles are slightly more accurate than their multi-shot stablemates.

That said, none of us have said that our multi-shot rifles are inaccurate; and we've all hunted very successfully with them without ever questioning their ability against live quarry. But in side-by-side tests, the single-shot usually just shades it in terms of accuracy.

My two favourite hunting rifles - the Daystate Air Wolf (.177) and Theoben Elan (.22) - are very accurate when running off their auto-load mags. I have every confidence in their multi-shot set-ups. Indeed, I've run the Elan in both calibres very successfully with 7-, 12- and 17-shot magazines over the past 11 years.

Both my rifles also offer the facility to run in single-shot mode. The Wolf takes Daystate's easy-fit pellet tray and the Elan has had its breech scalloped like the S-Type so that I can feed my pellets directly into the breech by hand.

So given how much 'shooting time' I've spent with these rifles, I can confidently vouch for the fact that each of my rifles shoots tighter groups in the single-shot configuration. It's not a great difference... but there is a difference.

For instance, I know the Elan will typically group inside 25mm at 30 metres with the mag, but it's nearer 20mm when loading ammo directly into the rifling. Both results are more than good enough for hunting, of course - but it does mean that I can push the gun's effective range by five metres or so when the mag's not deployed.

And I've also noticed that mags can sometimes make the rifle far more 'pellet fussy'. A good example of this was highlighted when I was recently testing the RWS Super-H-Point ammo in my Elan. Because the SHP's got quite an 'angular' head, it obviously suffered in the transfer from the magazine's chamber to the barrel. My 30-metre groups were a good 10mm 'looser' with the magazine than when I loaded the barrel directly. In fact, I may even have discounted the SHP as a suitable round for the Elan had I only tested it with the magazine; as it was, it proved a superb diet for the Theoben when fed into the rifling directly.

Conversely, the Daystate RangeMaster - which has a much more rounded head - must 'feed' into the barrel much better as it's hard to tell the direct-loaded and auto-loaded groupings apart.

Certainly food for thought...


  1. Thank God that at last we have Nigel given us critical reviews rather than praising everything like most of the other airgun magazines! Spiffing!

  2. I am not surprised that your rifles are more accurate in single shot mode than with a magazine. Due to their aeroballistic properties combined with the rifling on most barrels, pellets tend to be very gyroscopically overstable and hence are very susceptable to anything which affects the way they leave the barrel. A magazine will inevitably introduce another source of error making the pellet less of an exact fit. The effect may be very small but due to the pellets aerodynamic properties it has the effect you noticed.
    The gyroscopic overstability will also have the effect of making a pellet fly high or low in a crosswind, depending on the direction, something I know some gunners have noticed.

  3. Is there any further reading you would recommend on this?

    why Bl Pneumatics