Please help with my load testing

[clrems77]

Looking for some advise on choosing my best load. I did two, three round groups with Amax 168's over IMR 4064 powder. Grains were set at 41.5-44.4 at half grain increments except for the last 2 at 44.2 and 44.4 grains (Only one 3 round group with these two on the first target). Seating was done at the ogive at 2.177 with a Hornady gauge. Temp was 58 degrees with a pretty constant head wind of about 10 mph on a 100 yrd range. And sorry, no chrono yet.

From the look of the groups, I think the 42 and 42.5 groups were the best, but i'd like your seasoned opinion to steer me in the right direction. Any advice is greatly appreciated!

Thanks in advance,
CJ

 

[09cs]

Looks like you got something from 41.5-42 grains.

 

[richardca99]

42.0 is where I'd be.


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[lobo56]

Can I ask, maybe a stupid question, what is wrong with the 42.5 group in the second picture?

 

[richardca99]

Nothing, but 42.0 was consistently tight on both targets, and it's between two charge weights that show there is room to move up and down pressure-wise. I'd experiment with OAL at 42.0 grains.


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[427Cobra]

Your lacking the critical tool to properly determine your powder charge, where are your chronograph numbers, while the 42.0 group looks great, what if the ES/SD are 100fps apart, I would fine tune the 44.2 charge by adjusting seating depth based on Ojive lengths of .003 at a time, shoot 5 shot groups, start with the pills loaded at max mag length, then seat each 5 round group .003 deeper, this is Erik Cortinas method of load development as discussed here Long range load development at 100 yards.

 

[clrems77]

Your lacking the critical tool to properly determine your powder charge, where are your chronograph numbers, while the 42.0 group looks great, what if the ES/SD are 100fps apart, I would fine tune the 44.2 charge by adjusting seating depth based on Ojive lengths of .003 at a time, shoot 5 shot groups, start with the pills loaded at max mag length, then seat each 5 round group .003 deeper, this is Erik Cortinas method of load development as discussed here Long range load development at 100 yards.

Thank you for your input! May I ask what the es and sd are? I will be getting a chrono soon. And why are you choosing the 44.2?

 

[Aimsmall55]

Stop worrying about it. Load up 42.5 grains, charge , shoot and enjoy. There's really no reason to tighten up something that's shooting in the .2's

 

[richardca99]

I differ with aimsmall55...42.0 is where I'd focus my OAL testing. A chrono will help, but repeatedly cutting one ragged hole doesn't often wind up with a high ES, though it can happen. You want room on either side of your charge to accommodate pressure variation...42.0 looks to give you that AND best accuracy, at least over two targets (a small data set to be sure).

You'll wind up with an acceptable load either way.


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[Aimsmall55]

I differ with aimsmall55...42.0 is where I'd focus my OAL testing. A chrono will help, but repeatedly cutting one ragged hole doesn't often wind up with a high ES, though it can happen. You want room on either side of your charge to accommodate pressure variation...42.0 looks to give you that AND best accuracy, at least over two targets (a small data set to be sure).

You'll wind up with an acceptable load either way.


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I see what your saying, and with all due respect... But I wouldn't really consider 42.5 grains as being too hot a charge to rely on in fluctuating temperatures. I'm no expert on this OCW stuff, hell, I've never even tried it. Generally speaking , if I'm popping 1/2" groups at 250 yards I don't do anything but write down the dope, load data and go to work on the bench.
I've just never seen the point of trying to improve something that is totally acceptable. And if one is worried about temp fluctuations, bad news.... THEY ALLLLL FLUCTUATE!!

 

[427Cobra]

So I read through all those posts in that thread I linked, it's basically a streamed lined version of OCW, since all your groups are all on the same verticle plane, indicating a powder sweet spot, I would go with the higher charge because ES(extreme spread) and SD(standard deviation) are usually less as powder charges near max, single digit ES/SD are the goal of all us who shoot long range.

 

[shoot4fun]

If this were a true OCW test, which it appears it isn't, I would say you accuracy node is indeed 42 grains. Now, lets look up the ladder for the next node. At 44 grains I see possibilities. The max load for 168 and IMR4064 is 45.9 grains. I would keep moving toward that number is slightly smaller increments to find a higher node that works as well as the 42 grains. It is there and you really, IMHO, need to push those 168s faster than the 42 grains will do it. As of now, you are likely in the mid 2500 FPS range.

 

[jsthntn247]

Load 44.2 up and go play. You will have another sweet spot at 45.5 but brass life will be reduced. I would do a seating depth test at 44.2 in .005 increments starting at a jam and work out to at least .035 off.

 

[clrems77]

Thank you everyone for your help. I found a chronograph to borrow for the next shoot day. My question would be where do I start for load charge and how many rounds of each? 42 and work my way up? Increments? I will also try to work up to 45.9 grains as suggested.

 

[jsthntn247]

Thank you everyone for your help. I found a chronograph to borrow for the next shoot day. My question would be where do I start for load charge and how many rounds of each? 42 and work my way up? Increments? I will also try to work up to 45.9 grains as suggested.

The test you already shot shows you everything you need to know. 42 shoots good but will be slow as turtle piss. Load 3 rounds each at 44.2 at your max ogive distance to the lands then back off .005, .010, .015, .020, .025, .030, .035, .040 with 3 rounds each for 36 rounds total. Shoot them over the chrony and you will find a sweet spot where E.S. is low and groups well on the target.

 

[richardca99]

I see what your saying, and with all due respect... But I wouldn't really consider 42.5 grains as being too hot a charge to rely on in fluctuating temperatures. I'm no expert on this OCW stuff, hell, I've never even tried it. Generally speaking , if I'm popping 1/2" groups at 250 yards I don't do anything but write down the dope, load data and go to work on the bench.
I've just never seen the point of trying to improve something that is totally acceptable. And if one is worried about temp fluctuations, bad news.... THEY ALLLLL FLUCTUATE!!

You're right...42.5 isn't high pressure. I was talking more about pressure variation due to case capacity, temperature, etc. I also agree with others who said it's a lower node. It is a node nonetheless. I guess it depends on what the OP wants to do with it, right? If he's trying to get to 1000, then he should keep going...42.0 grains isn't likely to get him there. If he just wants to cut neat little holes and save wear on his brass, he's probably already there.

 

[clrems77]

I'll definitely take your advice and at least try to get a higher charge node. I'm looking to get these out to 900 Yrds when it's all said and done. Thanks again everyone!!