03-07-2023, 07:32 AM
Both will give some extra fps by being longer... one advantage the sixfive has, is it's designed with a tad more freebore to allow better seating of some of the tangent ogive bullets. Now faxon and uintah (I have all three) also have the same feature more or less. Some earlier barrels by (?? it's discussed on here somewhere, but it's 2:30 am and I just let the dog back in lol, so memory is still sleepy) had a tighter, tougher chamber freebore to use. Made seating pills like the 105 hornady bthp real short, ~2.200 or less. These 3 however allow seating out to ~2.220 with an OAL to lands of ~2.277 for that bullet. Secant ogives like 107, 108, eldx 103 are all fine, with max to lands of 2.300+.
Watch for rifle length gas on these barrels, a 20" with rifle gas is fine, some mfrs want to go to rifle+1 or 2... might be good but for a 20 I haven't seen any need for that. For a 22" that's a different story. Also twist rate. 1:8 is a min, 1:7.7 or 7.5 is better. 1:7, not really needed but that's just my opinion.
As I recall each inch of barrel in 6Arc gives you something like ~30-35 fps so a 20 would get you around 65-70 more than you're getting with an 18. Hornady has a comparison chart on their pdf of the gas gun 108-110 loads. You can kind of extrapolate to the lighter pills from its 108-110 "data by barrel length."
Watch for rifle length gas on these barrels, a 20" with rifle gas is fine, some mfrs want to go to rifle+1 or 2... might be good but for a 20 I haven't seen any need for that. For a 22" that's a different story. Also twist rate. 1:8 is a min, 1:7.7 or 7.5 is better. 1:7, not really needed but that's just my opinion.
As I recall each inch of barrel in 6Arc gives you something like ~30-35 fps so a 20 would get you around 65-70 more than you're getting with an 18. Hornady has a comparison chart on their pdf of the gas gun 108-110 loads. You can kind of extrapolate to the lighter pills from its 108-110 "data by barrel length."