I have the OSS Elite 7.62 which is not made any more. It is the two piece over the barrel model. I imagine the Helix would have similar results. It sits on my 14.5 inch 300 blk XCR-L. I bought the suppressor for the flow through technology. It is the only suppressor I have ever shot so I cannot really compare it to others, but it works for me. I rarely take if off. there have been two occasions when I forgot my shooting glasses when shooting the gun, and I never noticed the blowback at all, although my eyes were quite irritated after I got home. Overall, I am impressed with the technology. The only negatives were the price at the time and the weight seems a bit heavy at 30 oz. After I bought mine in 2017, the company went through some major management changes and disruption by firing the original designer. Just make sure they have their act together so they will service your can should anything happen to it. I doubt they would be able to service mine since the line was dropped.