Free: Contests & Raffles.
Quote from: Bushcraft on August 22, 2016, 06:58:08 PMGreat idea for a thread!Where is the best/correct place to measure sight height (center bore to center scope) when using a base with 20 MOA built into the base? And, how much does it really matter?Here is an easy way to do it. Lets use the following scenario:You barrel shank is 1.25" diameter, so half that is: .625"Your scope is a 30mm tube or 1.181", so half that is: .5905"The distance from the top of your barrel at the recoil lug area to the bottom of the 30mm tube section is: .729"Add those all together and you come up with 1.9445", round that to 1.95" and put that into you ballistic app. A slight difference in height won't make that much difference, but if you leave it at the default number of 1.5" of most apps, you would be a bit off at distance using this example.
Great idea for a thread!Where is the best/correct place to measure sight height (center bore to center scope) when using a base with 20 MOA built into the base? And, how much does it really matter?
Midlength of the scope would give you an average. On a long action 30 MOA rail your talking about .042" of slope roughly in the length of the rail. Using the mid point of the scope would get you and average, but like I said, its not a huge bearing on impact whether you measure at the lug area or the eyepiece.
Reloading .308 using BLC2 powder, BR2 primers. 165gr HPBT Sierra GameKings loaded at 2.626COAL.Powder weights from 40.5gr to 43.5. First 2 shots would touch. 3rd shot varied between 1/4 to 1inch apart from the first 2. And never straying in the same direction. For example 40.5 gr first 2 shots would touch. 3rd would hit upper right 1/2 inch away from the first 2. With 43.5 first 2 would touch. 3rd was 3/4 in lower left.Any ideas on what would cause this? There was about a 3-4 min break between shots with 10min between groups. Using a Savage 10t with a 1-10 twist.
Quote from: rbros on August 23, 2016, 03:23:23 PMMidlength of the scope would give you an average. On a long action 30 MOA rail your talking about .042" of slope roughly in the length of the rail. Using the mid point of the scope would get you and average, but like I said, its not a huge bearing on impact whether you measure at the lug area or the eyepiece. I think I can safely say that I know less about long range shooting than anyone. I'm a sight it in a couple inches high at 100, and don't shoot past 20 kind of guy. But I've always wondered what a "20 MOA rail" or "40 MOA rail" was. Is it actually slanted towards the muzzle so you have some built in elevation?
Quote from: Jolten on August 23, 2016, 03:41:15 PMReloading .308 using BLC2 powder, BR2 primers. 165gr HPBT Sierra GameKings loaded at 2.626COAL.Powder weights from 40.5gr to 43.5. First 2 shots would touch. 3rd shot varied between 1/4 to 1inch apart from the first 2. And never straying in the same direction. For example 40.5 gr first 2 shots would touch. 3rd would hit upper right 1/2 inch away from the first 2. With 43.5 first 2 would touch. 3rd was 3/4 in lower left.Any ideas on what would cause this? There was about a 3-4 min break between shots with 10min between groups. Using a Savage 10t with a 1-10 twist.It could be a matter of cheekweld. You may be able to be consistent for a couple shots then you position changes. You might try shooting 3 shots in a row and not pick your head up of the rifle while working the bolt. Try to find a reference point on your face where it touches the stock and keep that position the same. Identical concept to an anchor point in archery.I am leaning towards form since you are always getting two shots to touch and there is no consistency where the 3rd is going.
building an AR10 (DPMS) looking for a 22" 7.3 or 7.5 twist barrel in 243. Want it to be relatively light, but also hold zero for strings up to 15 rounds per stage. Using a JP lightweight carrier, and a adjustable gas block.what contour on the barrel, and will you build the barrel assembly?
