Thread: Kimber Montana Ascent 280AI Load Development

0.5 and 3/4MOA groups shows patience pays off...to be fair I should have got it bedded much sooner.

Did Nathan bed this one ? I have just ordered two of his full length bedding kits, only fourty something bucks per rifle

No Zach did it. Also done the Montana 308 as I figured might as well even though I was happy with how it was shooting. Can't wait to try the 308.

Group shot this evening. 180gn ELDM with 58.6gn RE26, CCI LRM primer, Norma brass. COAL 3.380" per @burtonator.




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Lovely.
Been a hard road.

Watching with interest

180eldms at over 2800fps is going to be devastating

Drop table with 180gn ELDM @ 2850fps 100y zero. Note BC used is 0.796. This BC is from the hornady website. I'll be able to try real world test on 600y gong at home.

Absolute hammer.

That down range energy is impressive

Yep it thumps the 162gn on energy but the 180gn isn't flatter shooting until 1000y. Still, very little given away by the 180.

What a relief to finally get a load sorted aye mate, and mag fed


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Yeah, watch out for Internet sourced advice.

COAL adjusted to 3.340" for mag fit. Unlike 3.380", which is not mag fit. FFS.

58.4gn (0.5 MOA first shot cold clean barrel to left) and 58.8gn shot well. Going to try 59.0gn to see if group comes in or holds nearer to 2850fps. Only 12-13deg today.





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59gn did much the same as 58.8gn. Interesting the 40 thou shorter COAL has (I think although small sample size) reduced pressure as speed has dropped from 2850fps. No pressure and I feel there is another node above 59gn but going to now settle at 58.4gn and 0.5 MOA a little over 2800 fps.

Anyone able to confirm the BC of the 180 eldm? Seen two Hornady sources quote .777 and .796.



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LOL ... Anyone able to confirm the BC of the 180 eldm? Seen two Hornady sources quote .777 and .796.
Glad to see its not just me.
Hornady like to make it as confusing as possible with BCs for different twist rates and different velocities.
I've seen G1 numbers quoted from 0.810, 0.796 (original hornady claim) to 0.703 (Litz).
I've come up with my "own" BC based on twist, muzzle velocity and range out to 1000 yrds for my N28 = 0.756.
As stated on the box by Hornady ...
180ELDMs >2500 fps 0.777
2230 - 2500 fps 0.748
1500 - 2200 fps 0.731


Have verified this on gongs at 625 yards but you'd probably want to stretch further out to really verify the number.