I have two sets of Sordins (1 with the regular headband and another pair with the neckband). Threadcutter is correct...the regular headband one can be short if you have a big head (like me), and when wearing a cap or hat, it's just too short to cover the ears fully. So, that's why I got the neckband model, which is way more comfy and gives my ears full coverage. Now, as for sound attenuation, their NRR is rather poor...even with the gel ear cups. They are meant to be used so you can hear your surroundings (while blocking out most of the high dB sounds), but for a 50 BMG, I think they will not be very good to protect your hearing, even if you double-up with foamies underneath (which I do when I'm shooting indoors). I suggest doubling up with foamies AND using a non-communication headset with a very high NRR rating as others have suggested.