Need help with load workup... Stumped

[Unofficial Gun Addict (UGA)]

Hello gentlemen,

I need some help determing which load to pursue tweaking. The problem is that for one load... the groups are more consistent, and for the other load, the velocity is more consistent. Right now I am in the process of determining distance from lands, and once I settle on this, I will begin working on powder loads. It's just that I've never had this much variation between consistent groups and velocity before.

Here's what I mean:
Both loads are the same, except load #2 is seated .040 off lands and #3 is .080 off lands. Both 308, once used Win Brass, WinStd primers, Varget 42gr.

Load#2 = Very consistent (2) 3-shot groups. .44" and .47"
= Inconsistent velocity. Min 2478, Max 2508, SD 13.5

Load #3 = Inconsistent (2) 3-shot groups. .04" and .92"
= Very consistent velocity. Min 2508, Max 2525, SD 7.0

So... normally, the best (2) 3-shot group typically provides me with the most conistent velocity and that would be the one that I would choose to work up power loads for. However, this time, the most consistent group load (#2), is less consistent velocity-wize, and the best load velocity wise (#3) is much less consistent group-wise.

I plan to shoot the final load at distances out to 600 yards, so a consistent velocity matters... however, so does group size.

Would you go back to the drawing board, or which would you select for powder tuning?

Any input and reasoning would be greatly appreciated.

Oh.... And I finally broke 1 tenth of an inch for a 3 round group. It's been like my own personal brick wall for all my years of shooting... So I'm having a good night regardless of my conundrum as to which load to start working up!!!!

James

 

[Rick Richard]

Depends on what your happy with.

I have a load that will shoot .195 at 100, .457 at 200, but 2.25 at 300. This is a product of "inconsistency" in MV.

I would much rather have a load that is not as tight up close, but remain the same down range. Hence, consistent MV.

I would continue to test until I achieved the desired results further out.

 

[USCGLongBow]

Just my .02, I might try Load #3 one more time, and see if I get a third group like the first string or the second string. I've had pieces of brass in my .270 that gave me bad results every time I used them and I had to remove them from my lot. I also might try to load six at .060 off and see if it makes any difference, probably not, but for me it's worth the effort to know.

 

[Unofficial Gun Addict (UGA)]

Thanks for the feedback Rick & Longbow. I think you both are right, however, I think I will go ahead and work up some powder charges for #2, redo some rounds for #3 to recheck, and shoot all of them out to at least 210 yds which is as far as our local range goes. If something stands out positively at that range, I know A guy that has steel out to 1000 and I can do final verification there.

Appreciate it...

James

 

[FearNoWind]

Here's what I mean:
Both loads are the same, except load #2 is seated .040 off lands and #3 is .080 off lands.

With a variation of .040 seating depth (.040 to .080) there is no way you could possibly use the collected data as definitive of load capability. ln your place I'd work with Load #2, adjusting the seating depth about .006 at a time closer to the lands and see what that data reveals, looking for a SD under 10 (if possible) in the MV.
How reliable is your chronograph?

Right now I am in the process of determining distance from lands, and once I settle on this, I will begin working on powder loads.

Work on the load first, then the seating depth. Working on seating depth before selecting a powder charge with potential is counterproductive.

 

[blacknzr1]

what he said ^
the powder charge with the best es 1st!(in saying that you might compromise between es and velocity a little, at least I do.) then start seating depth to improve group size.

 

[Unofficial Gun Addict (UGA)]

It's been my experience, that seating depth remains consistent over a variety of powder charges... In by that I mean that once I've found a seating depth that provides consistent (roughly the same sized groups), then I work uo the powder which either increases or decreases group size as I work along the the powder load band. Typically... There is a sweet spot somewhere during, or just before I reach my max load. I usually go in 1/10 max load increments and once the sweet spot is located, adjusting the seating depth typically only widens groups.

I've heard of people loading powder first and then fine tuning with seating depth, but with the VLDs that I shoot, working seating depth first typically reduces the amount of time and ammo I spend trying to get a round that shoots consistently accurate. They are sort of finicky. The only reason I created this post, is that when going over my previous load workup data, I don't have one instance where the most consistent group, didn't also have a very consistent MV (unlike #2). And vice versa, I've not had a load workup with a highly consistent MV, that had such a wide variation in group size (like #3).

I sure appreciate all the input... But I think the plan of action above should lead to a decent load. I'll post back results and methodology once I've gone through this next workup.

Oh... And I'm using a magnetospeed v3 chrony. It's one purchase I'm really happy that I made. Been rock solid and compares (I think favorably) to my buddies ced2.

 

[HarryN]

I am not qualified to recommend improvements, but congrats on breaking your previous record for grouping.

 

[TXshooter]

Looking at the first picture I immediately went why mess with it those are good loads. Then I read that they are .44 and .47 inches. And I'm confused I would have said they are more like in the .28" range so I wanted to ask if you measures your .44" outside measurement or is that center to center. Either way I like them but if that is an outside measurement, my advise is to quit messing with it you'll screw it up ha

 

[Unofficial Gun Addict (UGA)]

LOL... thanks Txshooter. I actually was pulling my hair out attempting to replicate that shot.... but I found that with my MagnetoSpeed attached to the barrel... I kept getting really inconsistent flyers... which I thought was just the VLDs being finicky. It's the first time I've loaded Berger... and I've heard they can be temperamental. Glad a played a little with the loads though... this is what I shot last night at 200!!

Sometimes you just get lucky!! (though I wasn't on that last shot... my heart was beating pretty hard looking through the scope at the first 5... and wanting the last one to puncuate it). Well.. it did... just not where I was hoping! LOL. Think it was me!!