Accuracy loading. Difference .*****

Magazines can damage the pellet. 

Great question, thanks for asking. Watching for other opinions as well. 

If you want to go to a lot of trouble to prove the point, you too can figure it out. 

A lot of airguns use Benjamin type magazines, where the first pellet loaded is holding forth the magazine's spring. Load up about 5 or 6 magazines, and let them sit for awhile before going to the range. Then shoot the first pellet on a different target than the remaining pellets. You will see the first pellet location group spread a lot more than the others. 

You can also load up a magazine, and carry it around in your pocket for a few days before shooting a group. Here too, the group opens up. 

The amount it opens up varies obviously, but if you're shooting for accuracy, you'll soon discover the reasoning behind single loading.

I have had differing experiences between single loading accuracy versus magazine accuracy. I used to own a highly modified .22 Benjamin Marauder which at first did not like to shoot accurately from the magazines. After making a couple of simple mods to the mags, the accuracy greatly improved to nearly equal that of single shot.

Of the three different FX rifles I own, all 3 shoot equally accurate using a magazine versus single shot and these rifles have tens of thousand of rounds through them.

My newest rifle, a Daystate .177 Airwolf MCT, does not shoot as accurate with a magazine as it does with single loads. It is not bad with a magazine, but single loads are noticeably a step above. 

Very interesting.

Allow me to add one more thought. 

Some regulated guns take several seconds to refill the low pressure cylinder and/or the valve assembly. If you shoot another shot too quickly accuracy will suffer a bit. 

My FX .22 Independence is non-regulated. The FX .22 Royale is regulated and several times I have shot over a chrono shot after shot, very fast to verify regulator recovery wrt velocity changes. I found it was not possible for me to shoot the rifle fast enough to affect the velocity and corresponding accuracy to any degree. Due to this, I use this rifle whenever I compete in a Gun Slinger type competition. The FX Boss is also regulated and much like the Royale, I cannot shoot it fast enough to affect the velocity any more than normally seen during slower shooting. The Daystate is non-regulated and it has most the most accuracy issues with magazines of all the PCP rifles currently owned.