With the recent addition of a PTR Industries PTR91 K3P from Atlantic Firearms (TFB review pending), I have been thrust into a world of Heckler & Koch infatuation and intrigue. Partially caused by the NFA approval delay of my TPM Outfitters MP5SD, I needed a roller lock/delayed firearm to fill a void in my life. But with the recent invention of the social media platform “Instagram” (you may have heard of it) I can also lust after other people’s firearms from around the world. Keeping with the theme, one of my current favorite feeds is @rollerlyfe – an account dedicated to H&K glory.
So, whether you own a H&K roller-delayed firearm or not, give them a follow. There is some awesome imagery being passed around.
Roller-delayed blowback was first used in Mauser’s StG 45(M) and MG 45 prototypes. Roller-delayed blowback operation differs from roller-locked recoil operation as seen in the MG 42. Unlike the MG 42, in roller-delayed blowback the barrel is fixed and does not recoil. As the bolt head is driven rearward, rollers on the sides of the bolt are driven inward against a tapered bolt carrier extension. This forces the bolt carrier rearward at a much greater velocity and delays movement of the bolt head. The primary advantage of roller-delayed blowback is the simplicity of the design compared to gas or recoil operation.