I wanted to increase the length of my inner barrels on my AK 105 SMP and my ICS CXP, but I am a cheap bastard.
So, I bought $25 6.03 x 407 mm Matrix barrels. When I saw they were just SHS barrels, it demoralized me. Last year I took a chance with a Lancer Tactical rebranded SHS 450 mm. Long story short it was bad.
This time around, both 407 mm barrels were impressive. As was the 500mm I bought for my Echo 1 Covert.
I am thinking I just got a bad one with the 450 mm. I can recommend the Matrix rebrand as a good cost effective barrel at $5 cheaper than the Madbull Python 2 and made of stainless steel is more durable.