In response to recent complaints concerning keyholing (when a bullet tumbles in mid-air, adversely affecting accuracy and velocity), Kel-Tec has issued a statement which includes a recommendation against using CCI Max-Mag 40 grain loads in the PMR-30 semi-automatic .22 Magnum pistol.

From Kel-Tec:

Hello!

We've had a lot of questions come in regarding possible new ammunition recommendations in response to the updated barrel design. The overall list of recommended ammunition hasn't really changed, however there is something we feel is worth noting.

After extensive testing with various ammunition we have concluded that all remaining key-holing issues have been isolated to one particular brand and weight of ammunition. Unfortunately this seems to be the most common and available ammunition: CCI Maxi-Mag 40gr.

The 30gr and 50gr varieties of CCI shoot flawlessly, as do other brands of 30gr., 40gr., and 50gr. ammunition. For some reason, though, it seems that the 40gr. CCI Maxi-Mag in particular still has sporadic key-holing. At this point in time we have deemed it ammunition specific and recommend trying a different grain or brand of ammunition if your PMR-30 is still continuing to key-hole with an updated barrel.

This in no way means that all of your CCI Maxi-Mag 40gr. will key-hole; it just means we have experienced occasional key-holing with that particular ammunition and feel we should make everyone aware of it in the event you experience the same thing we have.

We'll be sure to keep you updated if we find out anything more!

As it stands, continue to steer clear of non-USA manufactured .22WMR rounds as they have a higher risk of case-rupturing due to inferior quality.

Thank you.

The Kel-Tec PMR-30 is a full-size semi-automatic pistol chambered for the .22 Magnum (.22 WMR) cartridge. The standard magazine capacity is a whopping 30 rounds, significantly higher than typical pistols. Polymers are used extensively in the PMR-30 to bring its weight down to just 13.6 ounces unloaded. The PMR-30 uses a hybrid blowback/locked-breech operating sytem and has a single-action-only trigger with a manual thumb safety and an internal hammer.