.260 Remington load Data HELP!!

[Terrapin]

First let me apologize, I know how squirrely people get about posts on the same topic (don't know why though) some stuff is too hard to find. I have searched but not coming up with the right results.

I'm new to long range shooting, been learning about this game for a year now, and settled on a .260 Remington, built on my Savage action, bedded action, 30" Shilen Select Match 1:8 I thought I had found a nice accuracy node with 41.8 gr R17, new Lapua .260 Brass, Fed Match 210 primers, 139 Lapua Scenars. Problem is the group opened up from a pretty little group, 3/8' at 100 to over 2.5" at 300. I have also tried H4831sc, but find the R17 easier to work with, and no crunching as the powder settles better, and fills the case less. What happened?? What should I do?

Anyone have any good data they can share? I'm thinking I need to start my development at the Range, and start at 300 yards instead of 100. I would like to stick with the Lapua's or 140 Bergers, lots of folks getting great results with those, high BC's, and readily available in Canada.

I'm also finding the primers sometimes don't seat deep enough in the New Lapua brass, I guess I'll have to do a little primer pocket uniforming, but they are super tight primer pockets, good for brass life, not so good when reloading.

 

[brian427cobra]

H4350 is my go to powder, 139's seated at the lands, CCi primers, I use Win 7-08 brass sized down and neck turned, I leave my brass in the grass at the matches I shoot so Lapua is out of the question for me.

 

[dennisinaz]

If you like using powders that don't crunch, you might try using Mag Pro or 100V. Both work fine with the 140s. If the 140s are still opening up, try the 142 SMKs and see if they do better for you. I mostly stick with the 130s myself but never had much luck with R17 until I rechambered to AI.

 

[Redhighpower]

I would suggest 142 smk, powder R-19. I use the Sierra Manual go and use max recommend load. Start ar 43.0gr go up in .5 gr increaments. Give it a .20 jump to the lands, velosity 2820f/s ,very accurate. My .260 is just like yours, so I would think you would get the same results.

 

[Shynloco]

Terrapin,
Since you ask, I'll throw this out for your consideration, even though I know rifles that are similar, don't necessarily mean they will shoot the same. One of my shooting buddies shoots a rifle very similar to yours that is also built on the Savage Target platform in .260 with really great accuracy for us old farts. His barrel is also a Shilen with (I think) an 8.5 twist (sorry he's out of town for the holiday and can't confirm whether its an 8 or 8.5 twist Shilen). But I know he's using both VVN 160 or H4350 pushing either Berger 140 VLD's (Target) as well as SMK HPBT 142's. The results are almost indistinguishable out of his rifle with the 142's just a tad better. Just some food for thought.

 

[Wildboar]

Try doing a ladder test at 300 yds with RL-17. I set all my bullets a .01 off the lands until I find a node (powder charge). Then I test bullet seating at a 100 yd to see if I can tighten anything up. You could be just at the bottom or top of a node. I found my node on my .260 Savage CBI 26" 1/8 at 41.5 gr of RL-17 with the 140 Barnes Match bullet. 41.3, 41.5, 41.8 measured 3/4" at 300yds with a horizontal deviation under 1/2". Tried to chase a higher node but no luck. I think I'll be hanging around 41.5.
The 300 yd ladder test is the best tool I've learned for developing a load.

 

[dennisinaz]

I like the 500 yard ladder test even better- stuff shows up a little easier.

As for Shilen, I don't think they make or have ever made an 8.5" twist- at least not in .264. I recently bought and installed an 8 twist "ratchet rifling" barrel on a 6.5-284 and it shoots as good as any I have tried. No complaints at all.

I personally prefer an 8.5" twist as I think it moves the nodes to just a tag higher velocities- especially with the 130s but I took what I could get.

 

[jonbearman]

One note about the matchkings(142gr),they may give you bigger groups at 100 yds,but at 200 and beyond they really shine.