Ladder Test Results .308 WIN - PIC heavy

L

longarm21

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So I got out to the range today. Was a great day for it and I had a good productive day of ladder testing. Figured I would ask for assistance in analyzing my results. Got most of the shots on the Chrono with the exception of 3 errors, which is likely because the round didn't pass directly over the sensor.

Rem 700 PSS 26" Barrel 1:12 twist. AICS chassis, RAZOR HD 5-20x50.

Load - Hornady .308 WIN 168gr MATCH, Lapua Brass, CCI BR2 Primers. Powder loads from 42.0 - 43.8. Range 400m. 10 shot strings, 3 loads each. Up, down, then up allowing barrel to cool.

I'm thinking i have two nodes here. Between 42.2-42.6 and 43.6-43.8 +

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Taste the rainbow!
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I don't see it. Your nodes still have 3-4" of vertical. That's a lot.
Was the wind strong and gusty? There is a lot of horizontal spread too.
I assume you shot at 300m/yards?
 
Wind was calm below 5 mph. Horizontal spread is likely my trigger control. Trigger is nearly 5lbs I've been wanting to put on my timney for ages but I don't have a punch set.
 
Okay, is a bit better at 400m. 43.6-43.8 is probably your best bet.

I would now shoot 3 5rd groups with 43.6, 43.7 and 43.8gr. Have the point of aim of each group on the same horizontal line so you can directly compare vertical position and spread.

You've got a nice scope and chassis. She deserves a nice trigger.......
 
I'll do that pushing out to 500m next time. I think for point of aim I will draw a dot in the middle and like you said for horizontal reference draw a line to keep my point of aim consistent
 
I think if I had no pressure signs I would keep going. It looks like the groups are getting smaller as you go up.i think I would go 44-45 g then play with seating depth.
 
hometownhero said:
In that range is where most people end up.
I would also go higher in charges
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I generally find "the best" loads with the biggest accuracy node in a 308 tend to be 1.5-2gr below max loads in the imr website. Not always true but generally the case. Just keep an eye out for pressure signs.
 
Assuming you shot 3rds groups, I would test 44, 44.2 and 44.4 the same way. Shoot 3rds groups at each level. Obviously work on trigger control and follow through.

Looking at your velocities, you are just getting close to desired velocity.

Jerry
 
Before I go any further, I have to admit to never having fired a ladder test in my life. Further, If I play my cards right, I hope to be able to say the same thing when the end comes.
In addition, I don't weigh out powder charges to the closest tenth for testing. Why not? Because that is not the way I load my match ammo so I don't test that way. I throw charges from the measure and, if I have too much vertical, I must not be anywhere near a "node". If I have too much vertical, I'll go up until I'm pushing max. If it's still there, I might try switching primers. How much vertical? If i'm shooting at 300M (and that's what I have in my yard so that's where my developement takes place), I'll accept 1 1/2 inch of vertical for a ten shot string but I won't be going into the match with a lot of confidence.
I've been messing around with some ball powder for which there is no data for the 308 so I'm kind of winging it. My first load was too mild and produced 3 inches of vertical at 300M. Next load was better and vertical went down to 2 1/4 but still too mild. Todays load have been bumped up another full grain and I'll see what I get. This is as close to a "ladder test" as I will ever come. If I was testing with Varget, I would simply have loaded 44 and shot but with this powder I'm only guessing so I have to work up.
With a second just-completed rifle (a 30/40 Krag), that is just what I did. 44 Varget and 168 Lapuas gave me an inch and half of vertical. Hopefully I can tune this down a bit and it will be a fun rifle to shoot (inaccurate rifles are not fun!).
When it comes to velocity levels, it may not be too critical out to 600 but at long range, it can matter.
 
you had 40 rounds loaded for this test, you could have shot 8 5 shot groups and had more of an idea what tail to chase, with the millions of dollars of powder burned and bullets launched most good loading data is already published for a lot of target rifle/target loads, you just have to fine tune those loads to your rifle, personally I'd only run a OCW test if there was no data for a given powder. The real feat is to shoot over the crony and just get your ES into single digit numbers, get the vertical to as close to zero as you can and then figure out how to beat the wind to get rid of the horizontal.
 
yodave said:
you had 40 rounds loaded for this test, you could have shot 8 5 shot groups and had more of an idea what tail to chase, with the millions of dollars of powder burned and bullets launched most good loading data is already published for a lot of target rifle/target loads, you just have to fine tune those loads to your rifle, personally I'd only run a OCW test if there was no data for a given powder. The real feat is to shoot over the crony and just get your ES into single digit numbers, get the vertical to as close to zero as you can and then figure out how to beat the wind to get rid of the horizontal.
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There ya' go. In addition, if the heavy trigger is affecting your groups, fix it! No point in testing a rifle if there is something wrong with it.
 
Leeper said:
There ya' go. In addition, if the heavy trigger is affecting your groups, fix it! No point in testing a rifle if there is something wrong with it.
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when Mr. Leeper gives you solid advice it's best to write down notes, in some parts he's a legend.........and he has spilled more powder then I have burned....
(are we all crashing the party this year in Powell River Jim????)
 
This isn't Jim but is the younger version, Bill. He's got 23 years of experience on me but I've got a little.
 
Leeper said:
This isn't Jim but is the younger version, Bill. He's got 23 years of experience on me but I've got a little.
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LOL.......I knew it was one of you.....

Say hello to your Dad for us, and what I said stands, any load development or tips from either you or your dad should be taken as gospel
 
Everything I've ever read says that every rifle is different and work up is required as taking load data from someone else is dangerous. I don't think saying "take your loads from the Internet" is good advice.....I understand that you're saying don't waste powder but I am trying to find a node for my rifle... I'm not sure how else I can do that.
 
The differences are within how you do the load work up. It remains a test and retest option until you have satisfied your criteria.

A competitive F class shooter is vying to place as many shots into the V (1.2" at 300m, 2.5" at 500 and so on.) I use three shots at distance to confirm a node, then 5 shots or more to verify node and vertical at the distances you want to shoot at. Some rifles may show exceptional results at 300m but at 500 all hell breaks loose. So it pays to test your loads at varying distances. Just because you find a node you cannot stop there and must verify at your intended target distance.

Find a node by adjusting loads 0.5 grains(coarse method) then +/- 0.3 at say 200m for a 308 win. For a 223 you will need more fine tuning at 0.3 for coarse test and =/- 0.1 grains fine tuning.
Once you find a suitable node, adjust your load accordingly for distance shooting. Example. Your node lies at x at 200m testing. Test three loads +/- 0.2 grains of powder from your node for 308 or and 0.1 for 223 at 300m or more. You will see how vertical holds at distance that the shorter tests will not tell you. You will know you have hit the sweet spot when you can keep the shots within your specified criteria (ie 0.5 MOA at distance or better).

I am finding more often than not that the mid nodes perform better than the top nodes because they seem to behave better. I find more fliers using the top nodes so have been baking off on powder. Your loads will vary by season and temperature. Generally I have found the mid node to behave more for these seasonal changes than that very appealing top node. Oh yeah....be sure you are within 15 seconds of the shot when closing the bolt...the longer you have the cartridge in that hot barrel...the more wonky you will see the results. I would look hard at that 42.2 load as a node to test further.

My 2c.
 
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