I've been searching for definitive information regarding the effect of gas tube length in 20 to 24 inch barrels. All I've been able to find is general information.
It seems to me that gas tube lengths designed for 223 would be pretty random choices for a 6.5 Grendel, and it's further evidenced by the +2 gas tube. It implies that a longer tube is better, but seems also to imply that that tube length is best for everything 24+ inches.
Rifle or rifle +2 simply can't be the best choices for long Grendel barrels. I doubt the rifle length is even best for 20 inch barrels. The best tube length would be a balance between cycling and velocity. The pressure of Grendel is lower and volume of gas is greater than a 223. I would think volume would be more important than pressure in cycling if PSI is in the 55,000 to 65,000 range, if that's true, Grendel should be an easier cartridge to work with than the 223. I'm not sure how the greater volume would affect dwell, but my instincts tell me that dwell should be longer on the Grendel.
Then there are the questions of secondary pressure peaks, slower burning powders, bullet weight, twist, (many others I'm sure) and how they should be considered in the location of the port. Lots and lots of variables, I know.
What it all comes down to is whether there has ever been an valid study done regarding tube length on any impingement system that is based on research instead of, for lack of better word, dogma?
Thanks!
It seems to me that gas tube lengths designed for 223 would be pretty random choices for a 6.5 Grendel, and it's further evidenced by the +2 gas tube. It implies that a longer tube is better, but seems also to imply that that tube length is best for everything 24+ inches.
Rifle or rifle +2 simply can't be the best choices for long Grendel barrels. I doubt the rifle length is even best for 20 inch barrels. The best tube length would be a balance between cycling and velocity. The pressure of Grendel is lower and volume of gas is greater than a 223. I would think volume would be more important than pressure in cycling if PSI is in the 55,000 to 65,000 range, if that's true, Grendel should be an easier cartridge to work with than the 223. I'm not sure how the greater volume would affect dwell, but my instincts tell me that dwell should be longer on the Grendel.
Then there are the questions of secondary pressure peaks, slower burning powders, bullet weight, twist, (many others I'm sure) and how they should be considered in the location of the port. Lots and lots of variables, I know.
What it all comes down to is whether there has ever been an valid study done regarding tube length on any impingement system that is based on research instead of, for lack of better word, dogma?
Thanks!
Comment