So much for that theory. Not to worry. I will have another tomorrow.
Even barrel twist mentioned above does not play the same game ...
If you want a m77 compact in 7-08 I have one I'd sell. It is a Ruger M77 Hawkeye Laminate Compact. It has been bedded, free floated and given a trigger job by a Brian Ott. It shoots Win brass, Win primers, 41gr of Varget with 140gr accubonds at less than 1/2" and is topped with Leupold vx3i 2.5-8x36. I don't like the short Bbl and when shot a doe at last light was blinded by the muzzle flash.
a 1:10 16.5" barrel won't perform very close to a 1:12 in 20"? I might need a lesson in twist rate and velocity.
Calculated using a Hornady 165 grain SST...
@400 yards RPM is 113,400 for 1/12" 20" barrel
@400 the 1/10" is 131,200 RPM
SG number is 1.49 for 1/12" which is marginally stable (1.5 minimum)
SG number is 2.44 which is fully stable for 1/10"
The 20" barrel (1/12")will be barely stable at 400 yards (with a 165 grain Hornady with a muzzle velocity of 2650) ...
The 16.5" with a 1/10" ( MV 2578) will be fully stable with same bullet ....
Please keep in mind that these are "Calculated" using estimated velocities ... a rifle in your hands may be faster ... or slower ... the only way to know for sure is to shoot across a chronograph...
Calculated using a Hornady 165 grain SST...
@400 yards RPM is 113,400 for 1/12" 20" barrel
@400 the 1/10" is 131,200 RPM
SG number is 1.49 for 1/12" which is marginally stable (1.5 minimum)
SG number is 2.44 which is fully stable for 1/10"
WOW!! I understand like your saying there's always variables. But in a summery this new to me knowledge completely capsizes my original concern for 400 yard hunting!!
That's why I appreciate y'all so much! Thanks GON forum
factory ammo will vary more round / round than the difference between the 16.5 and 20.0. you can see 100 fps between factory ammo round/round or more
Factory ammo sure can & does vary....
but it won't pick or choose which length barrel it varies in...
So the variances affect both barrels ... but as a general rule the shorter barrel will also yield less velocity on top of variation ...
Stacking "tolerances" can be Not good especially when the 20" barrel is already at marginal stabilization ...
Hopeful that I have answered some of the questions that arose during this thread ... I am sure that the numbers bored some folks along the way ... maybe some of the links I shared will be useful to some folks ...
Seatrout ... go get that gal a rifle and tell us about it ....