Choosing ladder test max loads ** now with test results**

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VinceMarksman

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Hi Guys

I am starting a new recipe for my tikka t3 varmint 308. I will be using lapua brass, sierra TMK 175g bullets and varget powder.

I want to shoot a ladder test but don't want to make unecessary ammunitions. The hogdon website gives me a starting load at 42g and a max load of 46g. I am going to build this into 0.3g increments.

How would you proceed to avoid making too hot loads? Should I stop well below the hogdon website max load? Say 45.5g or so?

thanks for your advice, it will be my first ladder test.
 
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I always load a little past book max. Because what may be hot in one rifle, may be fine in yours. I'd go 46-46.3gr Examine each fired case carefully, and compare each on to an unfired case, and to the fired case with the lowest charge. I find holding them next to each other helps see the primer flattening/cratering. Stop when pressure signs appear. At worst you have to pull a couple of rounds.

Remember further is better, 300m minimum, and I like to do 2 rounds at each powder charge.
 
thanks guys!

Yes I plan on doing this at 300 yards and 2 ladders. One ascending and one descending

can't wait. Hope those bullets will group well.
 
Also, I'd start with 0.5 gr increments for the first go, then narrow it down once you find a good node. I only use 0.3 increments on small calibers like 223. It might save you some powder and a few bullets. Good luck.
 
ok then further questions

0.5 increments for my 308 gives me 5-6 load to work with and 0.3 increment with my 223 gives me 4 loads to work with.

Is that enough loads to justify a ladder test?
 
Yes buy a bullet puller. I also doubt you will get more than 46 grains of varget into that case with 178's. Unless you're single feeding it, the Max Mag length for you're tikka is about 2.810 or thereabouts. That will already be a very compressed load.
 
savagelh said:
Yes buy a bullet puller. I also doubt you will get more than 46 grains of varget into that case with 178's. Unless you're single feeding it, the Max Mag length for you're tikka is about 2.810 or thereabouts. That will already be a very compressed load.
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2.810 to the rifling???

Im loading my Amax 168 at 2.815. I have not measured my rifling.

Tonight I loaded the TMK at 2.850 and 4 loads out of 7 are compressed. I hope I can shoot most of them with no pressure sign untill the higher loads

I loaded a painted bullet at a COL of 2.900 and I don't think I was seeing any marks on the bullet paint

Edit: I hope I understood badly. Now rereading it I think you mean 2.810 is the magzine length, right?
 
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I try to get 10-12 loads , just what has worked best for me.

To do this I broaden my load range and how I do this is I find the LOWEST published load and start there and usually below , I then increase to highest and go a bit beyond that by a grain, I don't always finish the test either as I stop at pressure signs and like others do , pull those apart.

Widen that load range and you may open up other safe accuracy nodes.

VinceMarksman said:
ok then further questions

0.5 increments for my 308 gives me 5-6 load to work with and 0.3 increment with my 223 gives me 4 loads to work with.

Is that enough loads to justify a ladder test?
Click to expand...

P.S. - COAL varies pressure as does charge weight.Depending on if you need to mag feed or single shot has a bit of a bearing on what COAL you can work with.If mag feeding I ensure proper function , if single or no mag I go with recommended depth as per manufacturer.You will find an accuracy node either way, they are there, just pressure and lengths will vary.
 
VinceMarksman said:
ok then further questions

0.5 increments for my 308 gives me 5-6 load to work with and 0.3 increment with my 223 gives me 4 loads to work with.

Is that enough loads to justify a ladder test?
Click to expand...

That's a little coarse imho. You are trying to find a range of powder charge that clusters together vertically. I'd go 0.3gr in 308 and 0.2gr in 223. Don't worry about the number of rounds.
 
VinceMarksman said:
2.810 to the rifling???

Im loading my Amax 168 at 2.815. I have not measured my rifling.

Tonight I loaded the TMK at 2.850 and 4 loads out of 7 are compressed. I hope I can shoot most of them with no pressure sign untill the higher loads

I loaded a painted bullet at a COL of 2.900 and I don't think I was seeing any marks on the bullet paint

Edit: I hope I understood badly. Now rereading it I think you mean 2.810 is the magzine length, right?
Click to expand...

Yes. 2.810 Mag length.
 
Test analysis

Ok back from testing. You guys analysis is very welcomed.

First picture is ascending test loads at 300 yards. I could not find the 43.5 hit, I think it is in the same hole as the 43 one. 44.5 and 45 showed ejector marks on the ascending test but not on the descending test.

From those results I think I should pick something between 42.5, 43 and 43.5 right? Should I try 5 shots groups with all these loads. Should I discard 43.5?

Im not sure about this analysis. Maybe 43g is the sweetspot that would forgive a bit of scale accuracy if there is 0.1g more or less in the loads.

What would you guys pick and what would be your next step in this load development? Really keen on you guys input.

32947030140_acbb9e13fc_k.jpg
[/url]20170308_141220(0) by devincification, sur Flickr[/IMG]
20170308_141129 by devincification, sur Flickr
 
42.5 to 43.5 imho. First ladder looks nice, have 41-42 lower, 42.5-43.5 middle then 44-45 higher up the paper. Second ladder a little messy, but still has 42.5-43.5 with what, an inch of vertical spread?

I generally do a follow-up ladder, focusing around a promising range. So in this case, I would do 42.4 to 43.6, 0.2gr increments. If you have a chrony, now's a good time to use it.

But you can load up some 5rd groups if you like, entirely up to you.

As for the ejector signs, how quickly were you shooting? If you left the 44.5 and 45gr rounds in the chamber for a while, they can absorb heat from the barrel and shoot warmer then they would if you loaded and fired right away.
 
Alpheus thanks for your comments.

Sun came out before the 2nd ladder and mirage started to show up slightly so that might explain the second ladder messyness.

Not sure about how long they stayed in the chamber. I was shooting pretty consistant but the barrel had time to cool off before the second ladder.

I do not have a chronograph but I can rent one at the local store once I narrow down my choices of loads.

Should I try 5 shots groups starting from 42.5 and bumping up in 0.3 increments?
 
42.5-44

I also look at clusters, not just the ladder(vertical) , horizontal dispersion also means something in my opinion.

Target one you have around an inch horizontal in that load range.

Target two about the same maybe slightly more in vertical.(minus the 44 load)Doesn't take much to throw out a little flier and with only one charge weight we blow that shot.

You are onto something there.


I wouldn't waste on groups yet unless you are very confident in what you have produced.
42.5 , 42.8 ,43.1 ,43.4 ,43.7 ,44 ,44.3. Load em up twice, shoot two ladders , report back. :)

https://www.canadiangunnutz.com/for...sults-June-13-2015-FINAL-LOAD-CONFIRMED/page4

A ladder test journey I posted on one of my rifles.This was after re-barrelling a rifle.Might be something you can take from there.
 
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