260 Remington Long Range Load Development

[dc.fireman]

Do any of you have any of the 120's or 123's that you have tested? I am curious if others play with the lighter bullets in the .260?

I shoot the Nosler Custom Comp. 123's in .260, with Starline brass, Fed 210M's, and 37.5gr of WIN 760. It chrono's out @ 2515 fps, and 5 shots can be covered with a dime at 100 yds.

I started off a little higher - one of my reloading manuals (Lee, 2nd ed.) listed the starting point 38.0 gr.s, but I couldn't find the accuracy node, and I began to flatten primers around 40 gr's. When I dropped it to the 37.5, rainbows and unicorns appeared, and angels began singing from the corners of the range.

It's my calm day 300M prone load. On windy days I have a load for the Nosler RDF 140's.

I have never been able to find any of the 105/106/107 bullets locally to try in the .260.

 

[ranger3]

In my 260, I use 41.5 H4350, and any 140 or close weight bullet. I have found CCI BR 2 primers to be the most accurate. 42 gr gets a bit warm. Lapua brass

 

[dstoenner]

My 140 Berger Hybrid load with a COAL of 2.950 (as I chase the lands) is 42.5 H4350 in Lapua brass with BRT-2 primers. Out of my 1:8 30 inch McGowen I am getting 2841 for velocity. I shoot this F-Class and this load shoots better than I can read the wind at 1000.

David

 

[Hoosier]

My 260 has a 28" barrel and I have had my most accurate load around 2800 fps. I have used 139gr Lapuas, 140gr Bergers, and 142gr Sierras all with the same charge.. I use Lapua brass, CCI BR2 primers, and IMR4350 Powder...yes iMR4350. The powder charge is 41.8 grs. I have shot this load at intervals of 500yds out to 1260yds with steel plate targets. The results are 1/2 MOA out to 500yds with paper targest, but I have never shot for precision accuracy beyond that range.. I full length size every case, but I have reduced the OD of the expander ball in the sizing die.
Hoosier

 

[barefooter56]

SP, you answered my next question--what seating depth to start with. My only other experience with Berger VLDs is the 105 6mm. I must have gone through 50 rounds of various "jams" with no luck. Then I started backing off the lands. .030 off was magic.

Berger VLD BULLET SEATING DEPTH TESTING INFORMATION : http://www.bergerbullets.com/vld-making-shoot. Please change all references to COAL to CBTO = Cartridge Base To Ogive. Information on the effects of bullet seating depth can be found here: http://www.bergerbullets.com/wp-content/uploads/2013/03/COAL.pdf
Any bullet seating depth testing should be done at the starting powder charge listed for the bullet/powder/cartridge combination you are testing. If yo need load data please contact us here : support@capstonepg.com

 

[dsculley]

For seating depth, I first use the Berger method which as a pretty coarse test. You are testing a wide range with large increments so it doesn't take much ammo. FWIW, my load development is:

1. Run the Berger seating depth test using a moderate charge.
   
2. Use my best seating depth from that test for testing powder charge using the OCW method.
   
3. After settling on a charge, I then test seating depth in small increments on either side of the seating depth I used for testing.
   
4. The only thing left is to test this load at distance.