No problem easier for old eyes to readSorry for the bold text , not sure how i did that. I didnt notice when i was typing it , old eyes are fun !
No problem easier for old eyes to readSorry for the bold text , not sure how i did that. I didnt notice when i was typing it , old eyes are fun !
Not necessarily applicable in this situation but very real.1-7.5 would be my choice for the 140 class bullet you say would be used most of the time ,and the option for the 156 gr
especially if your not going to be shooting through transonic with the 156 ers at mile targets
in my opinion the 1-7 tw with 140's can turn pressure up before reaching max fps
again not a game changer depending where the barrel likes the accuracy note , but having to take the next note down because of pressure signs ,sucks.
its a balancing act on intended max range shooting (transonic)
and how important max fps is to hunting , which this rifle seems to be for ? ( #3 at 24" ) no one should be hunting at transonic .
time of flight can out run a higher BC for a while , but BC always wins if shot far enough. Run some velocity numbers with both bullets and see where the time of flight beats the higher BC in wind drift and impact fps which directly effects bullet performance On game.
case in point i run a 130 gr vld in my 260 rem gas gun , magazine length limits case capacity with 140's ,so the 130 at faster fps runs passed the 140 in max range i need for impact velocity for hunting . Shooting targets out to 1K yrds the slower 140's are king
but i dont hunt at those impact velocities .
a gain tw barrel, in theory ,can get your target tw rate and help keep pressure curve flatter .
i have no experience with them so i cant offer an opinion on them.
i have often wanted to try one , maybe the next blank i order
As to the left hand tw barrel it is a great idea to use. But how do you keep the barrel from loosening up with right hand threaded action and barrel tendon? Do you use a pin or set screws to secure it ? Years ago i asked many smiths about making a left hand tw barrel work on righthand threaded actions , no one was interested in helping me
hope this helps and doesnt cause more questions on the decision
In my gun (Desert Tech SRS-A1) the barrel is clamped in a 5" long section of receiver so Lefthand / righthand torque is not a problem. The barrel extension is righthand but does not see torque. I tend to load to the higher pressure end of the spectrum most of the time. I do see less pressure indication with the gain twist of 1 turn, and the 5R rifling is said to be easier on the jackets reducing friction too. The bullet continually sees engraving to the muzzle and lessens gas blow by. I have not seen any negatives in my barrels, accuracy is superb. I will continue to use this formula in future builds, and highly recommend it.1-7.5 would be my choice for the 140 class bullet you say would be used most of the time ,and the option for the 156 gr
especially if your not going to be shooting through transonic with the 156 ers at mile targets
in my opinion the 1-7 tw with 140's can turn pressure up before reaching max fps
again not a game changer depending where the barrel likes the accuracy note , but having to take the next note down because of pressure signs ,sucks.
its a balancing act on intended max range shooting (transonic)
and how important max fps is to hunting , which this rifle seems to be for ? ( #3 at 24" ) no one should be hunting at transonic .
time of flight can out run a higher BC for a while , but BC always wins if shot far enough. Run some velocity numbers with both bullets and see where the time of flight beats the higher BC in wind drift and impact fps which directly effects bullet performance On game.
case in point i run a 130 gr vld in my 260 rem gas gun , magazine length limits case capacity with 140's ,so the 130 at faster fps runs passed the 140 in max range i need for impact velocity for hunting . Shooting targets out to 1K yrds the slower 140's are king
but i dont hunt at those impact velocities .
a gain tw barrel, in theory ,can get your target tw rate and help keep pressure curve flatter .
i have no experience with them so i cant offer an opinion on them.
i have often wanted to try one , maybe the next blank i order
As to the left hand tw barrel it is a great idea to use. But how do you keep the barrel from loosening up with right hand threaded action and barrel tendon? Do you use a pin or set screws to secure it ? Years ago i asked many smiths about making a left hand tw barrel work on righthand threaded actions , no one was interested in helping me
hope this helps and doesnt cause more questions on the decision
Shorter barrels do not reduce rpm. A 8T is one turn in 8". Two turns in 16".In my 6.5creeds and 260rems all are 8's including the 6.5prc (limiting myself @ 135ish grains). A purpose built 264wm 7.5t for 150smk's. The shorter barrel can keep the rpm's down to not blow up the bullets if going faster twist?
Sure shorter barrels will have less ram with the same twist due to less velocity. That's how it works. Are you trying to say a bullet going 2k fps and another going 3k fps with the same twist will have the same rpm. I guess there's no reason have rev limiters controlling your coil then.Shorter barrels do not reduce rpm. A 8T is one turn in 8". Two turns in 16".
However- velocity becomes a unit of time. If I move a greater distance in a standard time (lets say 1sec) more revolutions will have occurred in that unit of time.