Can this be right? I zeroed at 100 yards and required 13 moa up on my sight to shoot 600 meters. I ran these numbers in the ballistics calculator powered by G7.com and came up with the above. I'm shooting 5c Parker Hale sights on a #4 with a 26" 1/11" twist .306" Envoy barrel. Using Lapua cases and CCI primers with no signs of being too hot. This velocity sounds pretty high to me but I am just starting to shoot again after a long dorment spell. Any thoughts ????
308/155 Amax/46grns Varget= 3160+fps ?
- Thread starter R1200GS
- Start date
In my 308 with 28" barrel a 155gr berger targetr vld with 47gr varget gives me around 2920 fps chronoed , 3160 does seem awful high.
Your best bet would be to chrono it to be sure I know the rear sight aperature and the front globe need to be the right distance apart if they are to close together will give you a false elevation maybe this is the problem ??
Your best bet would be to chrono it to be sure I know the rear sight aperature and the front globe need to be the right distance apart if they are to close together will give you a false elevation maybe this is the problem ??
stevesummit
CGN Regular
- Location
- spruce grove
My load of 45.5 of varget and 155 scenars gets mt 3020 with no pressure in a rock creek 1/11 twist , I am not sure which reamer was used but it's tight and short throated
rnbra-shooter
CGN Ultra frequent flyer
- Location
- New Brunswick
What is the distance from your eyepiece to the front sight element (i.e. what is your sight radius)? It's possible that your "sight minutes" are not exactly "true"; no problem with this, BTW.
With a tight 26" barrel, something in the 2875-2925fps neighbourhood would be what you'd expect.
If you want to know your m.v., you need a chrono; back-calculating from observed drops is pretty imprecise
With a tight 26" barrel, something in the 2875-2925fps neighbourhood would be what you'd expect.
If you want to know your m.v., you need a chrono; back-calculating from observed drops is pretty imprecise
Sight radius
Interesting, Coyote also mentioned sight radius, the trig could have a large effect on sight calibration. My sight radius is 31.5" I guess I assumed the 5c Parker Hale would be correct
as this setup was the standard for long range TR shooting back in the day. It will be interesting to shoot some groups at 100 and measure sight performance. I wonder how many folks shooting the target rifle game test their sights? I guess I need a crono 
Interesting, Coyote also mentioned sight radius, the trig could have a large effect on sight calibration. My sight radius is 31.5" I guess I assumed the 5c Parker Hale would be correct
as this setup was the standard for long range TR shooting back in the day. It will be interesting to shoot some groups at 100 and measure sight performance. I wonder how many folks shooting the target rifle game test their sights? I guess I need a crono
rnbra-shooter
CGN Ultra frequent flyer
- Location
- New Brunswick
Most British sights move 0.010" per "sight minute". At a 36" sight radius, this results in 1.000" at 3600" (which is also known as 100 yards ;-)
Your "sight minutes" are therefore a bit coarser; one of your sight minutes will move the bullet 1.14" at 100 yards (36"/31.5" = 1.14286).
Applying this to your "13 moa up frmo 100y to 660y", means you added 14.85 minutes. See what sort of speed that would correlate to...
Your "sight minutes" are therefore a bit coarser; one of your sight minutes will move the bullet 1.14" at 100 yards (36"/31.5" = 1.14286).
Applying this to your "13 moa up frmo 100y to 660y", means you added 14.85 minutes. See what sort of speed that would correlate to...
Mathmatics
These numbers produce a more realistic 3018 fps which is in line with Stevesummit's experience. Thanks for the info as I'm trying to come up with a drop chart for my rifle, sight and load combo. I ordered a shooting jacket today from Center The Group so the crono will have to wait a bit or I may take advantage of Coyote's offer.
These numbers produce a more realistic 3018 fps which is in line with Stevesummit's experience. Thanks for the info as I'm trying to come up with a drop chart for my rifle, sight and load combo. I ordered a shooting jacket today from Center The Group so the crono will have to wait a bit or I may take advantage of Coyote's offer.
R1200
I would be careful shooting a No.4 with a full Palma load. Varget can vary from lot to lot so you need to reassess for each lot. I think that 46gr is over the max. which may not mean anything in a modern action but in a No.4 with a tight barrel, things can build up very quickly. The Envoys were proofed for 7.62 and not 308 and the max pressures are not the same. With the 155s you may even be approaching max pressures even for a 308 and especially with older lots of Varget.
I have also read that the No.4s were banned for fullbore shooting in NZ and probably Australia and the UK when the move was made to the 155s.
They are fine with NATO ammo although pretty scary when wet. In terms of older actions, I would choose the P14.
Good to have you back, Be Safe, we can't afford the exposure.
I would be careful shooting a No.4 with a full Palma load. Varget can vary from lot to lot so you need to reassess for each lot. I think that 46gr is over the max. which may not mean anything in a modern action but in a No.4 with a tight barrel, things can build up very quickly. The Envoys were proofed for 7.62 and not 308 and the max pressures are not the same. With the 155s you may even be approaching max pressures even for a 308 and especially with older lots of Varget.
I have also read that the No.4s were banned for fullbore shooting in NZ and probably Australia and the UK when the move was made to the 155s.
They are fine with NATO ammo although pretty scary when wet. In terms of older actions, I would choose the P14.
Good to have you back, Be Safe, we can't afford the exposure.
Thanks for the head's up I'll keep an eye on the bolt lugs, I'd hate to wreck a 1950 Longbranch action
. It never rains on shooters in N.B.
