7x57 AI Highly Abbreviated Ladder Test

Ltbull01

Ltbull01

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Don't laugh... I did 4 round ladder test. Actually, it doesn't qualify as a ladder test. But, I have a limited number of bullets and they are hard as f*** to get!! So I need to be bold.

I did a lot of research on the internet for 7X57 Ackley Improved loads with H4350 and 140/45 grn bullets. I want to load up the Barnes 7mm 145 Grn LRX bullet and I found that H4350 and like powders are a good place to start, and fortunately I have lots of H4350.

The research suggested that 52 grn+/- H4350 could be a 'node' as several sources seemed to come back to this. So, in the interests of preserving what precious few 145 LRX bullets I have (1 box -), I boldly loaded 51/51.5/52/52.5 grn with the said bullet seated to a .05" jump as per Barnes recommendations and a Fed 210 primer and went to the range.

This is what I got...

All impacts were within 1". The MV are:

51.0 gr = 2900
51.5 gr = 2922
52.0 gr = 2968
52.5 gr = 2987

The last one went to the right about an inch and that could be my shooting as I am not confident in my rest and I did pull some similarly at the range on the same shooting session. Do you think I'm safe to say that I should load up 3 more each at 52.0 and 52.5 grns for further testing? I'm also pretty much at a compressed load at 52.5 so don't want to go beyond that. Besides, the 145 LRX gives ample down range performance at 500M for sheep - MV still above 2000 fps at that range.

 
Alpheus said:
What distance did you shoot that at? 100yds? The velocities aren't indicating much of a node.
Click to expand...

Agree, like to see at least 200 yard's when doing a ladder test. 100 yards won't really tell you much, unless that's all you have for a shooting range thing I guess it's better that nothing.
But those are some nice velocity's with the 7x57AI & a 140gr pill , going to make a very decent mid range sheep slayer.
 
If you want to save bullets, try this. Buy some cheaper, more commonly available bullets as close to weight and bearing length surface to the LRX, and do a full ladder test with them. Keep the jump/jam, powder and primer the same. Do it at at least 300yds if possible. I like to do two rounds at each powder charge, helps me spot flyers. Half-grain increments are a little course IMO, for a 50gr case capacity round, I'd go for .3 to .4gr increases. Go from 49gr to 52.5gr or thereabouts. Using these results, you then do a much tighter ladder with your actual bullets.
I did this with my 6.5x47L, first with 140gr SMK and then 140gr Berger hybrids. The Berger node was .3gr higher then the SMK node. Saved some match bullets, fireformed some brass, broke in my barrel and got it nicely fouled.
Though, as always, YMMV.
 
Just a little advice , you may want to stretch it out to at least 200 yard's/meter's it will tell you more. But defiantly showing potential, keep up the good work.


Cheer's
 
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Looks promising, but there's no real story in that target. Shoot some more, 4 shots can't tell you much especially if you think there might be some flyers. Looks like you might be in a good place already.
 
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for a ladder test I shoot 10 round in .5 increment and i also determine my max load with it
exemple if your published max is 53, I load 49gr to 53.5gr and I shoot them At 200m to see better result and if you have pressure sign @52.5 you stop

after that I do an OCW on the node and after that when I have the load I play with seating depth
 
Thanks for the info everyone. I've done proper ladder tests before but as I have a limited supply of bullets - 35 - I really didn't think I'd have scope to do a full test. Different sources indicated that 52 gr H4350 gave good results with 140 gr bullets. So I went plus and minus of that to see what a grouping might look like with 145 gr LRX bullets - not a proper ladder test. Anyway, 51.5 gr gave a sub-moa group and 52 gr was moa+. Back to the range to see what more firing of 51.5 produces. Then I can tweak from there at more suitable ranges when I get more bullets if it looks promising. MV was 2950 fps too, with a decent MV spread, at 51.5 gr so it will be above 2000 fps at 500M, all things working out.
 
Ltbull01 said:
Thanks for the info everyone. I've done proper ladder tests before but as I have a limited supply of bullets - 35 - I really didn't think I'd have scope to do a full test. Different sources indicated that 52 gr H4350 gave good results with 140 gr bullets. So I went plus and minus of that to see what a grouping might look like with 145 gr LRX bullets - not a proper ladder test. Anyway, 51.5 gr gave a sub-moa group and 52 gr was moa+. Back to the range to see what more firing of 51.5 produces. Then I can tweak from there at more suitable ranges when I get more bullets if it looks promising. MV was 2950 fps too, with a decent MV spread, at 51.5 gr so it will be above 2000 fps at 500M, all things working out.
Click to expand...

Not sure how set you are on the LRX bullet's , but a little cheaper option might be the 140gr Berger VLD's. Got a buddy in Dawson Creek & he is smacking things long & far with that bullet in his 7mm. Just a thought, not trying to break your way of thinking or trying to convert people to the Berger's.
Just trying to help a fella shoot more that's all.

Cheer's
 
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