Why is a single shot tray more accurate than a magazine?

[mmahoney]

I'd heard that many bench rest shooters insist on loading their rifles one of a time using a single shot tray instead of a magazine. Curious, I did extensive testing about the difference using my air rifle, and sure enough there is a very noticeable difference. My testing was done on a Daystate MK4IS that does not have a spring to cock the rifle (it is done electronically) and is smooth as butter. My only guess is that the pellet skirt is slightly deformed when the pellet is pushed past the rubber o-ring that holds the pellets in the magazine.

Any other theories?

 

[T3PRanch]

Magazines don't necessarily index to exact alignment with the bore. When they don't, damage to the pellet can occur (usually in the skirt area since that is the thin part of the pellet)!

Thurmond

 

[MarkUK]

I recently found the precision of my DS Airwolf going down the toilet.

It bugged me for several months, and it was only when I fitted a single shot tray, (to try some Polymags - rather good, not fab), that I accidentally solved my problem.

I then dug out my spare magazine from the back of the drawer, to find that that one worked fine.

I cannot see any alignment difference between the good mag and the bad mag, though it is difficult to see alignment between the back of the mag and the barrel.

To check shot pellets for damage (to compare SST and mag) someone could do a test I think Ted did on his channel:

Shoot straight down into a barrel of water then gather the pellets to check them. Prepare to get wet, and be careful.

 

[Alan]

The only time I use a magazine, is when it is too cold to handle the pellets singly. As noted, some magazines clip the pellet, but there is another issue. 

Almost everyone, me included, have more than one magazine. If you load one up, and let it sit for several weeks (not an uncommon occurrence), then remove the first pellet (the one holding the spring tension), and look closely at the skirt. Then judge for yourself!

 

[Mick-VA]

Here is a good visual example of what is being discussed above.

All the chunks in photo are lead fragments and scrapings from 2.5 weeks of shooting daily.

 

[Regal_US]

If you do single shot load routinely, check out Rowan Engineering's single shot loaders.
These are a huge improvement over the Daystate tray, and really make it easy. 
I've not missed using the magazine on an Air Wolf since I got this.

 

[2D1C]

HMMMMMM I have a Daystate AW coming and now wonder why buy more mags. This "mag" issue seems to be across all the guns. There appears to be a need for a precision mag I'm thinking? Or perhaps a better probe?

 

[Bizill]

If you have a properly designed magazine and loading mechanism, things aren't as bad. Sadly, hardly any air rifles seem to have had optimal engineering concerning magazines and their loading. Look into the Taipans. Very nice mechanics going on there. Obviously I'm biased, but for good reason. 

I also have a cheapo Chinese SPA Co2 pistol that seems to shoot better being loaded via magazine vs the single shot tray. On that pistol the oring is tight and gets pushed in cockeyed from the second you push forward the pellet probe. The magazine actually helps guide the pellet. 

For the most part, single shot trays are usually far superior to magazines as you've demonstrated.