05-15-2020, 05:22 PM
(This post was last modified: 05-15-2020, 05:26 PM by lazyengineer.)
In my experience, it's an irrelevancy regarding impact on accuracy. For the grouping data I've scientifically gathered and cross-examined, gas-block; fixed or variable, had zero effect on group-sizes - for me at least. For good practice, I always offset it off the shoulder by the thickness of a dollar, so that it doesn't have variable force against the shoulder as things heat up, but I haven't actually seen that make a difference.
If you way over-torque the screws, I suppose it's possible for some force-balance or even deformation into the bore, but again, I doubt that actually applies in all but the most extreme cases.
That said, I did find it interesting that Alexander Arms in their earlier generation design barrel I bought during their quite-attractive sale a few months ago, uses an extra-thick barrel diameter under the gas block. No one else does this, and it does require their own non-standard sized gas-block, but the design concept was there's a lot more metal there to absorb any weird torque, etc. I like that. FWIW, that 1/9 twist 20" Grendel barrel is the only Grendel barrel I've been able to make really shoot well; as it's an older AA Barrel when Bill Alexander threw away all the conventional dimensions, and built a barrel with non-standard thread, non-standard gas-block, and non-standard twist rate; as he found that to be optimal for Grendel during his development. As it turns out, that barrel shoots like a dream. Most barrels now have drifted back to conventional faster 1/8 twist, 5/8" threads, and standard gas-blocks. I've never been able to make any of those sing as well as Alexander's.
Just my own experiences flavored with my own bias'. That said, you will find plenty of others with more experience than me, who've had great luck with other more standard barrels with more standard sized gas-blocks. And pretty much anything LRRPF52 (and others like KLEM and LR1955) says, take to the bank, as he sort of wrote the book and fired more rounds than anyone short of Bill Alexander himself I imagine.
But to your original question, no, in my experience gas-block has very little affect on accuracy. I suppose if it's variable, and you vary it, that might change something from different settings, but inherently when dialed in and locked down to any particular setting, I haven't found any difference. I also haven't found any need for it, either.
If you way over-torque the screws, I suppose it's possible for some force-balance or even deformation into the bore, but again, I doubt that actually applies in all but the most extreme cases.
That said, I did find it interesting that Alexander Arms in their earlier generation design barrel I bought during their quite-attractive sale a few months ago, uses an extra-thick barrel diameter under the gas block. No one else does this, and it does require their own non-standard sized gas-block, but the design concept was there's a lot more metal there to absorb any weird torque, etc. I like that. FWIW, that 1/9 twist 20" Grendel barrel is the only Grendel barrel I've been able to make really shoot well; as it's an older AA Barrel when Bill Alexander threw away all the conventional dimensions, and built a barrel with non-standard thread, non-standard gas-block, and non-standard twist rate; as he found that to be optimal for Grendel during his development. As it turns out, that barrel shoots like a dream. Most barrels now have drifted back to conventional faster 1/8 twist, 5/8" threads, and standard gas-blocks. I've never been able to make any of those sing as well as Alexander's.
Just my own experiences flavored with my own bias'. That said, you will find plenty of others with more experience than me, who've had great luck with other more standard barrels with more standard sized gas-blocks. And pretty much anything LRRPF52 (and others like KLEM and LR1955) says, take to the bank, as he sort of wrote the book and fired more rounds than anyone short of Bill Alexander himself I imagine.
But to your original question, no, in my experience gas-block has very little affect on accuracy. I suppose if it's variable, and you vary it, that might change something from different settings, but inherently when dialed in and locked down to any particular setting, I haven't found any difference. I also haven't found any need for it, either.