Thread: My 260AI Load Development Begins

Originally Posted by Mathias

Nice velocities! What length barrel are you running?
As R93 said, you won't see normal pressure signs like a standard case shows. My 257 AI would indicate high pressure with a stiff bolt handle and the primer still looked ok.

24" barrel. What I couldn't figure is 44gn with the LRABs was fine but 43gn with the Amax had stiff bolt lift. I think it must be because the LRABs were seated with 20 thou jump but the AMax's are into the lands as I didn't change the seating depth from the LRABS.

What shot is the "one" out of those 3. Just wondering about the 1 and 2 patterns

The bottom right group is from a 7mm08. The LRABS ES was in the 20s, the Amax's were 7. I found the LRABs vary in weight a fair bit so will weight sort next lot.

Where did you get your magneto? Bloody awesome bits of kit

I got it from Wilson's for $899. They were great to deal with.

Thanks. None im stock atm.

Will this wind ever go away...probably can't tell from photo but blowing so hard the MS is shaking on barrel. 1" 100 yard group with 44.5gn RE17 2959fps av and SD 15.1. Still 45.0gn and 45.5gn to try.

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Looking good.
I use a bit more powder to achieve similar velocities but I coat my projectiles.

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Yep sitting here waiting for the wind to die (not likely) and v.happy to have 2950fps from 24" barrel with 142gn. Will try others but might then sit on that and play with seating depth...these are 0.01 jump so quite close. 100yard zero and nowhere near 1 rev on the NF F1 Moar for 1000y.

A photo of where the MS sits relative to the muzzle. Have found it likes to have the muzzle a fair way forward.



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45.0gn RE17

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Originally Posted by Tikka7mm08

45.0gn RE17

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45.5gn RE17 3007fps av and 10.7SD. Group opened a little but was most likely me rushing. No hard bolt lift, no difference from mild load. Thinking I will play with seating depth with 45.5gn...?

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That's what I would be doing now too. Speed is there so adjust seating depth until you find accuracy your happy with.
The last few load developments that I have done, I have found where I wanted to be speed wise with acceptable pressure, then just played with seating depth to get the accuracy I wanted.
Has worked very well!

Originally Posted by Tikka7mm08

45.5gn RE17 3007fps av and 10.7SD. Group opened a little but was most likely me rushing. No hard bolt lift, no difference from mild load. Thinking I will play with seating depth with 45.5gn...?

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You possibly won't get meaningful load development groups with the MS attached, hard to say if the Carbon barrel will be effected as much as a SS one or not ?