140/142 gr bullets too much for 6.5x47 Lapua?

[montana_native]

Looking for a good 800-1000 yd bullet for this gun. It has a 26" barrel and 1:8 twist. I am curious if these bigger bullets will be moving too slow out of this gun to justify the added BC.

Thx.

 

[2644ever]

You may run into some troubles compounding heavy bullets, slow twist and moderate velocities. The only 140 grainer that should work is the Sierra Matchking. I doubt the 142 grainer can stabilize.

 

[montana_native]

It's actually a 1:8 twist barrel. Fixed my mistake.

 

[robbin]

I've got a 6.5X47 Lapua with a 1:8 28 inch Hart tube. It loves the 140s, that's all I shoot out of it anymore. It likes both the Berger 140 BT and the Berger 140 VLDs. I've found RL-17 to be the best, both in velocity gain and accuracy.

 

[ThunderDownUnder]

I shoot pointed 139gr Lapua Scenars (Pointed G7 BC = 0.300) bullets at all ranges but I checked using a ballistic program to see if they were better than the 130gr VLDs. Check using the free to download Berger ballistic program, its a great little program.

http://www.bergerbullets.com/Ballistics%20Program/index.html

You can also use a spreadsheet I put together to predict the velocity change when shooting different weight projectiles from the same cartridge. It assumes pressure to be the same for both projectiles being launched and this can be pretty close to right if both are being shot at close to max pressure.

http://www.safclass.com/Spreadsheets/Bullet%20Velocity%20Predictor.xls

Hope this helps you make an informed decision.

Ian

 

[Obtunded]

yes, they work, but they don't go very fast. 1:8 twists work fine. It is comaprable to using 90 brain bullets in a 223

 

[flatlander]

I've gotten pretty decent preliminary results with Berger140 LR BT Match bullets out of a 28" 1:8 Krieger, using RL17 at 2800fps. Can run them up to 2900fps out of a 30" Bartlein, but the accuracy wasn't anything special, and based on casehead appearance, that load was a little warmer than I'd feel comfortable using. I'm looking forward to some decent spring weather to get in more testing with seating depths.