260AI - load data?

[Gollum]

Got a 27" long 260AI barrel 8.5 twist, Rem brass,plan on fireforming with the cream of wheat method), dies, and 139gr Scenars.

Searched for load info, not coming up with a whole lot.

What powders and load range seems to work for your 260AI?

Are there any load manuals listing loads for this cartridge to buy?

 

[RichE]

I shoot 46.5 grs od R22 in std. 260 you could go from there.
Also 43.0 grains of H4350 is another good load.

both shoot about 2800 + fps 24" in Krieger and Pac NOR barrel.
I know a guy getting 2900 with that same load with std. 260.

 

[BHarvey]

Several powders work real well.

46-48 grs of H4831SC- 48 grs gave 2935 fps- Hot on pressure
47-49 grs of N165- 48 grs gave 2925 fps- Not hot
45-46 grs of A3100- 46 grs gave 2930 fps- Little warm
46-48 grs of N560- 47 grs gave 2970 fps- not hot at all.

I could go higher on the N165 and N560 as both were good on bolt lift and the primers still had radius.

The H4831SC had slight sticky bolt on the top side but still had radius. Also had slight ejector marks.
A3100 was similar to the SC.

I was using necked up 243 Lapua cases, 139's and BR2's.

Barrel on my rifle is 24.875"

Chrono was a PVM-21 at 10' from muzzle.

This cartridge can get it done. A 28" should put you in Heaven.

 

[2644ever]

This cartridge can get it done. A 28" should put you in Heaven.

Right on! With a 28" or a 30" it gives a hard time to the 6.5-284.

 

[BHarvey]

I've shot a 260 for about 3 years now but back in May I switched to the AI. From what I have seen with my short barrel, a 28" barrel should easily get 2950 fps from a variety of powders, good brass life and be right there with the 6.5-284.

We cut the barrel threads off and then rechambered to the AI in a Broughton that had 1700 rds through it. I figured I'd burn this one out while getting some data before putting on a new tube. It has 2360 through it now and still shoots well.

I settled on a load that gives 2875 fps with no pressure signs.

 

[Rootshot]

I did load development today for my 6.5-08AI with formed Lapua 243 brass, 210M primers, and H4350 powder. I loaded 10 rounds each starting at 40.0gr and ending at 45.0gr incrementing at .5gr. Bullets were seated about .01" off the lands. This was shot out of a 26" Broughton 5C barrel chambered by Terry Cross.

All loads perform reasonably well. There appears to be an accuracy node at 43.5-44.0gr. Pressure signs,minor cratering and ejector flow) develop at 44.5gr and 45.0gr.

I have no chrono data. Standard reloading safety disclaimers apply - especially in a wildcat chamber.

--Rooshot

 

[280man]

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