Quick 140 Berger Hybrid Load - New Rifle...No Time.

[PhilM]

So I have just picked up a new 6.5 Creedmoor Accuracy International AT rifle - it looks good so far.

I have a few rounds of factory Hornady 140 ELD-M ammunition to get the thing sighted in, but I need to quickly load 100 rounds for a shoot shortly afterwards, and I won't have time to properly load develop it.

I have a box of 140 Berger Hybrids, and looking at the bearing surface length on the 140 Hybrid compared with the 140 ELD-M match ammunition, they shouldn't need to be loaded too long so as they won't fit in an AW/AT magazine.

For simplicity sake I am considering using the following load (without development), Lapua 6.5CM Brass, 140 Berger Hybrids, CCI BR4 primers and to 41.5gr of H4350 (which is what Hornady use in their 140 Amax ammunition). I'll seat them jumped, but not sure how far until I get the lands measured in the rifle later. I'm hoping I can do say a 20thou jump and still be at AW/AT mag length?

So aside from the "you really should develop a load....", or spending out on another 100 ELD-M factory rounds ; does anyone think this will work well?

Obviously I am going to develop a load ASAP, but to get me out shooting ASAP I am considering the above to be 'conservative'. I'll watch for pressure signs of course (it is book max according to the Hornady 10th Ed, but then is also the factory charge for their 140 AMax ammo? - it'll suck to have to pull all 100 if they did show to be hot).

Any thoughts?

Thanks!

 

[Marksman10x]

You'll probably be fine. But any way you can load one or two and shoot them in your back yard, on a logging road, in a field, etc to check for pressure?

 

[Niles Coyote]

If your using lapua brass you can use 41.5 but 41.3 may shoot a little tighter as the Lapua brass has just a little less case volume. If you got a black marker seat a bullet long and paint it, then chamber it. if you see land marks in the black seat it back .01 at a time until you don't. On your next bullet do it again but now seat it back at shorter increments. I've had real good luck with them jumping .015-.025"

 

[Fursniper]

The Berger hybrids like a jump, in my loads for the calibers I use the hybrids for, I jump them all at .040 off the lands with excellent results.

 

[PhilM]

Thanks for the replies!

i have managed to get Monday afternoon off work, so will hit the range and do a quick OCW with the 140H.

I will keep an eye on pressures as I have a few that are over the 41.5gr book max. I do consider that conservative though as Hornady are using the book max as their factory load on the 140 amax ammo, and just about every 6.5/140H load uses more H4350 than 41.5 - but I appreciate some of those loads will be pre Lapua brass being available.

I have seated them all at 0.030" jump for the OCW test.

That will at least get me a bit more in the game for 1000yds on Thursday than my original plan!

Thanks again for the advice

 

[Fursniper]

Good luck, let us know how your accuracy at a 1000 turns out!

 

[Darkside-Six]

With Lapua brass and 140 Hybrids you'll find a nice load between 41.7-42 H4350.


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[tpe187]

Here is an OCW with my AI AT using an 24" AI 6.5 CM barrel. New Lapua brass sized .288, CCI 450 primers, H4350 and Berger 140gr Hybrids jammed .05 into lands. 42.5gr put 5 shots into 1.2" at 300yds with 4/5 in 3/4". Moving forward I'm going to .290 bushing for the Lapua brass (.288 is really for Hornady brass) and testing OAL to fine tune and reduce ES. I don't really like jamming, but figured it would give highest pressure and I could work back from there.

 

[PhilM]

Thanks guys.

Well, it was a new rifle and it took a little getting used to with the heavier AT trigger. So some of the group size may be down to the me, and also the fact that the rounds fired were the first through the barrel; I am expecting things to run in a bit over the next 100 rounds or so.

But I managed a quick OCW test anyway that will allow me to develop a bit more of a load for 900m on Thursday, and also to give me a good set of data for further OCW testing.

Looking at the POI shift, in this case I have labeled it as Horizontal/Vertical offset (from the point of aim); we can see the curves flatten out nicely in both the low charge region 40.3-40.7gr (Groups 1-2), and also again later at around 41.5-41.8gr (Horizontally) and 41.8-42.1gr (Vertically). It's all bunched around that area and the velocities should be a fair bit higher than with the lower charge regions of curve flattening.

I consider the vertical component to be a little more important (it was an outdoor range, with some wind afterall), and also that ties in nicely with the bonus that 41.8-42.1gr (Groups 5-6) have the smallest group size also, although thats not too important for OCW development with a fixed seating depth.

Unfortunately the range's chrono broke, so I didnt manage to gather any velocity data. (No, I didn't shoot it!).
I think I'll be loading up some 41.8gr rounds for my 900m shoot, and exploring the 41.8-42.1 area for further OCW testing once the barrel has run in.

Would love to know your thoughts.

PS. Credit to YouTuber GHog Hunter for the idea to present the data this way, although his spreadsheets look far prettier than mine! (Excel v Numbers!)

EDIT: Click here for an original size attachment: https://www.dropbox.com/s/rgpeomjlm9...0140H.png?dl=0