velocities for 1000 yards

[lucho]

I have been trying to work up loads for my new rifle. It is a 6.5x08,Rem 0.260) with a 30 inch barrel on a remington action and a MCMillan A5 stock. I am using Norma 130 grain HPBT's with VV N160.

I have gotten sub 0.5 inch groups at low velocities, around 2700 ft/sec.

But nothing better than 0.75 inch groups at high velocities like 2900-3000 ft/sec.
At 3000 ft/sec I start seeing pressure signs so I stoped there.


I have used a trajectory calculator and have gotten the following.

BC=.62
v1=2900 ft/sec
at 1000 yards
10 mph wind

V=1600 ft/sec
drop = 290 inches
drift = 65 inches

BC=.6
v1=2700 ft/sec
at 1000 yards
10 mph wind

V=1400 ft/sec
drop = 340 inches
drift = 75 inches

So do I have to go to the 2900 ft/sec load or do I go with the better groups at 2700 ft/sec?

I figure if I know the drift and dorp and it is consistant it doesn't matter how fast it is going.
Provided it stays supersonic.

Please let me know wht you think.

Lucho

 

[Forum Boss]

Try the Lapua Scenar 123s .020" jumped or .010" into the lands. Try H4350. Work up a load in the 2940-3000 fps range.

The Norma 130s are good bullets but many guys aren't able to get them to shoot as well as the Scenars. The Scenars aren't fussy about seating depth. I just gave you starting points. Mine made nice round groups jumped about .020". I was able to get 2950 fps comfortably with a 24" barrel. I think with a 30" you should be able to hit 3000.

What brass are you using? I used Lapua and Norma .243 necked up and had to ream/neck-turn to eliminate doughnuts. You might try the Winchester 7-08 necked down.

 

[Clarence]

lucho Sir:
The MOD has addressed your question correctly, I would add only one thought and that is the BC advantage of the bullet being that you probably don't need the SPEED of warp factor three.

An Example is my Palma rifle will shoot well at 2960fps and also at 3030 but the stress on the Equipment is not worth anything in my opinion.

Clarence

 

[Toms]

I have been trying to work up loads for my new rifle. It is a 6.5x08,Rem 0.260) with a 30 inch barrel on a remington action and a MCMillan A5 stock. I am using Norma 130 grain HPBT's with VV N160.

I have gotten sub 0.5 inch groups at low velocities, around 2700 ft/sec.

But nothing better than 0.75 inch groups at high velocities like 2900-3000 ft/sec.
At 3000 ft/sec I start seeing pressure signs so I stoped there.


I have used a trajectory calculator and have gotten the following.

BC=.62
v1=2900 ft/sec
at 1000 yards
10 mph wind

V=1600 ft/sec
drop = 290 inches
drift = 65 inches

BC=.6
v1=2700 ft/sec
at 1000 yards
10 mph wind

V=1400 ft/sec
drop = 340 inches
drift = 75 inches

So do I have to go to the 2900 ft/sec load or do I go with the better groups at 2700 ft/sec?

I figure if I know the drift and dorp and it is consistant it doesn't matter how fast it is going.
Provided it stays supersonic.

Please let me know wht you think.

Lucho

I shot a 260 for sillhouett. Wanted a load for elk hunting.i could not get over 2800 with 140 gr bullets. I don't think 3000 ispossable with safe loads.

 

[1bamashooter]

Holy necropost

 

[Steve Blair]

Holy necropost

That may be the oldest resurrection I've seen.