260AI, 140RDF loads?

[Fast14riot]

I'm still getting things together to finish off my 260AI and I picked up a box of Nosler 140rdf recently as the few reports I have been able to find seemed positive, but I'm hoping someone here has had a chance to try these out. If so, what was your load?

I've got Lapua 260 brass, H4831, fed 210 ready to go for this gun, hoping this combo will work well enough for me and I can get right around 3k. I'll probably start around 47.5gr and work up to a pressure limit at -0.010.

 

[ShootDots]

I would NOT start at 47.5 and work UP.. You may find that you are already at or very near the top of pressure. Start at 46.0 and work towards 48.0grs. I have found that with the "regular" .260 brass (L/R primers) 48.0 will be at the very ragged edge of top. My guess will be right at 47.4grs will be about right. However, I know nothing of that bullet. The powder charges I am referring to are with either the Berger 140 LRBT or the Berger 140 Hybrid..

 

[JLT]

It is almost certain that you will find a very accurate load with H4831SC. I have two .260 AIs and both shoot the same load very accurately. More velocity and equivalent accuracy tends to be a good thing, so I'm just starting to experiment with RL-23 and RL-26. I have had spectacular (for me . . .) results with RL-26 in my .243 AI with 105s and 115s, so well see what happens.

I agree with ShootDots. I had pressure signs assert themselves around 48.0 grs. of 4831. Starting at 46 and working up is prudent.

Edited to add: I got over 3,000 fps with a 140 quite easily with RL-17, but this powder can be a bit fussy when the temperature changes. My experience, anyway.

You're going to LOVE your .260 AI!

 

[Fast14riot]

In my barrel, 48gr of 4831sc gave 2900avg with no pressure signs using the 140vld seated at 2.990. I haven't compared bearing surface between the bullets yet, but should be close.

 

[Geno C]

I'll have to check my notes but I know I was out of case capacity with 4831sc before I ran into pressure signs. I wanna say 50gr... don't hold me to that number though. I'm getting better accuracy out of H4350 though. 44.5gr give or take a 10th.

 

[ShootDots]

I'll have to check my notes but I know I was out of case capacity with 4831sc before I ran into pressure signs. I wanna say 50gr... don't hold me to that number though. I'm getting better accuracy out of H4350 though. 44.5gr give or take a 10th.

Question: Are you using .308 Palma brass necked down? If you are using regular L/R primer .260 brass, you have an EXTREMELY slow lot of H4831.. In one of my .260A.I.'s, I am presently using H4350 at 44.0grs. However, I am using the Palma brass and I have some bolt lift resistance, and the Palma brass is FAR stronger than regular .260 brass. Those charges you are quoting seem awfully H-I-G-H to me, especially if you are not using the Palma brass.. Just wondering..

 

[Geno C]

I'm using regular 260 Lapua brass. Not Palma. I was wondering if my memory was correct so I checked and it is... 44.6gr of 4350 is getting me 2925fps with a 140vld. I didn't chrono the 4831sc because it didn't shoot as tight. It is possible that my powder is a slow lot. How does my velocity with 4350 compare to yours even though I'm .6 higher?

I didn't check what my coal is but the reamer was a .060 freebore and they fit in a FN TBM mag

 

[ShootDots]

I'm using regular 260 Lapua brass. Not Palma. I was wondering if my memory was correct so I checked and it is... 44.6gr of 4350 is getting me 2925fps with a 140vld. I didn't chrono the 4831sc because it didn't shoot as tight. It is possible that my powder is a slow lot. How does my velocity with 4350 compare to yours even though I'm .6 higher?

I didn't check what my coal is but the reamer was a .060 freebore and they fit in a FN TBM mag

My figures are right there with yours velocity wise. You probably have a VERY slow lot of powder and a barrel on the "loose end" of the SAAMI spectrum..

 

[Geno C]

Now you've got me interested. I might have to go load up a couple at 50gr and see what the speed is. Maybe later this week