6.5 Help Me Interpret Data and Move Forward (See Target)

[Badbob]

This is a repeat post from my Fireforming post with a hope to get some feedback.

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Folks, I need help interpreting my target and picking some next steps. The attached target is from March. I switch powders from IMR4350 to H4350 simple because I use the H for m 6x47 and don't want to have to locate and stock another powder. It appears to me that was mistake since my groups opened up and are not as tight as the IMR (target posted above). So I'm thinking about switching back to IMR and heading back to the range. I shot 3 pill each: 47, 47.5, 48, 48.5, 49, 49.5 (no signs of pressure). Wind was 5-8mph coming down the range from 11:00 O'Clock position. I used flags and monitored the wind.

Particulars:

Stiller Predator Action
Carbon Fiber Bench Stock
Sightron SIII 5-32x
CBI 26" 1:7.5 twist Heavy Varmit
Jewel Trigger
Lapua Brass
BR-2 Primers
Seated .010" off
140 Berger VLD Hunting

Any suggestions or help interpreting my data so far would be greatly appreciated.

Thanks, BB

 

[jdj71]

Run 48.5(two in the same is nice) to 49.5 with .2 spread and see what you get. Chronograph would be helpful.

 

[6mmstalker]

Personally I would go with 47.(3)
Then the load above and bellow are more or less same point of impact.
Then I would play with seating depth to tune for a tighter group looking for low ES over the crony if the load is to be used long range
Atb

 

[dkhunt14]

H4350 is slower then IMR4350 so i would try more powder. I also would check out seating depth. None of those groups stand out to me. Matt

 

[Badbob]

We had a nice break in the weather on Friday so I hit the range and did load work using IMR4350. Really not much better than the H4350. Please help me interpret the data and move forward. Wind was 0-3mph, mirage was challenging. I did not see any pressure signs working up to 48.5grains of IMR4350. So I think I might be able to get to 49.5 and perhaps into ther 2950fps sweet spot folks talk about.

Any help with interpreting the data would be helpful and any help pointing me toward next steps would also be help.

140gr Berger VLD Hunting
BR-2 primers
IMR4350
Lapua Brass
Tight neck chamber
.010" off

Many thanks, BB

 

[Zero333]

2 nodes...

Between 45 & 45.5

And between 47 & 47.5

Pick one of the nodes (or both) and play with the seating depth.

I did not look at the xlsx file.

 

[Badbob]

Shou

2 nodes...

Between 45 & 45.5

And between 47 & 47.5

Pick one of the nodes (or both) and play with the seating depth.

I did not look at the xlsx file.

Should I push to max pressure to find another higher node?

Should I be concerned about the vertical stringing?

thanks for your input, I appreciate your time! Bb

 

[Zero333]

You can play with the seating depth around 47.4(ish) gr.

But Honestly... the ES and SD are rather high considering they're derived from 3 shot strings.

I hate to say it but... H-4831 / H-4831sc would be my #1 choice for this cartridge/bullet combo.

I would load some with H-4831 from 50 to 53 gr.

 

[JFrank]

Personally I would go with 47.(3)
Then the load above and bellow are more or less same point of impact.
Then I would play with seating depth to tune for a tighter group looking for low ES over the crony if the load is to be used long range
Atb

I was thinking 47.2 just because of the surrounding strikes
J

 

[Bart B.]

Are those 3-shot groups statistically significant enough to represent what 9 out of 10 with each load would be?

I don't think they are.

If Badbob does, so be it. Same with everyone else.

 

[Badbob]

Are those 3-shot groups statistically significant enough to represent what 9 out of 10 with each load would be?

I don't think they are.

If Badbob does, so be it. Same with everyone else.

Ya they are 3 shot groups--I'm trying to retain my precious barrel life.

 

[Badbob]

I was thinking 47.2 just because of the surrounding strikes
J

What do you mean by "surrounding strikes"?

So it worth staying with IMR4350 or should I just try H4831 and see if I get better initial results?

 

[ShootDots]

In my humble opinion, the 4350s, be they IMR or H, are a bit on the fast side. It has been MY experience that ANY cartridge where either the fastest OR slowest powders that should even be considered are used, the "accuracy window" becomes very tight, usually not more that a tenth on either side of the charge weight that initially produced the best group. If I were you, I would go to either RL-23 OR H4831SC. Both of these powders are just about ideal for the 6.5 x 284. H1000, believe it or not, is another excellent powder, albeit right on the edge of too slow. I just finished finalizing work on my 6.5 x 284 for 1000 yard F-Open. I am using RL-23 with 142SMKs. It is going right at 3000f.p.s. and shooting SUPER nice groups. AND I can go 1/2 grain up or down and the groups essentially remain the same. That is a W-I-D-E accuracy window.

 

[JFrank]

What do you mean by "surrounding strikes"?

So it worth staying with IMR4350 or should I just try H4831 and see if I get better initial results?

I have no experience with two powders, I'm just looking at the vertical between 47-47.5 both groups are about the same, the bullets at poi or (strikes) I used that term for no special reason, appear to have a nice .5 gr window compared to the other samples vertical ' I would test a little further around that powder charge. TJM
J

 

[Badbob]

In my humble opinion, the 4350s, be they IMR or H, are a bit on the fast side. It has been MY experience that ANY cartridge where either the fastest OR slowest powders that should even be considered are used, the "accuracy window" becomes very tight, usually not more that a tenth on either side of the charge weight that initially produced the best group. If I were you, I would go to either RL-23 OR H4831SC. Both of these powders are just about ideal for the 6.5 x 284. H1000, believe it or not, is another excellent powder, albeit right on the edge of too slow. I just finished finalizing work on my 6.5 x 284 for 1000 yard F-Open. I am using RL-23 with 142SMKs. It is going right at 3000f.p.s. and shooting SUPER nice groups. AND I can go 1/2 grain up or down and the groups essentially remain the same. That is a W-I-D-E accuracy window.

Ben, thanks! Ya, I'm starting to get the itch to try H4831sc, especially since I have a bunch. However, with the Berger backlog, now I'm out of projectiles. I really don't want to complicate the mix by changing bullets. I thought about the lapuas or SMKs.

 

[ShootDots]

Ben, thanks! Ya, I'm starting to get the itch to try H4831sc, especially since I have a bunch. However, with the Berger backlog, now I'm out of projectiles. I really don't want to complicate the mix by changing bullets. I thought about the lapuas or SMKs.

No thanks needed Bob.. With any of the 140 class bullets, especially in a "pretty stout" overbore cartridge like the 6.5 x 284, the "slower end" of the powder burn rate scale, will give you more flexibility and a wider accuracy window than either at the edge of either too fast or too slow.

 

[Badbob]

Been a while since I posted. I need to re-bed my action so it was sitting square in the stock which also helped square up my reticle. I also purchased a drummer stool so I can adjust my sitting height at the bench. I ran out of Berger 140 VLDs so decide to try the Lapua 139s.

Please help me interpret this target and my speeds. I think there is a node between 48.5 and 49.5. Do you agree? Should I load up 48.1, 48.4, 48.7, 49, 49.3, 49.6, 49.9, 50.2 of H4350? I was running BR-2, seating was touching the lands. Nothing brilliant but seems solid. It was windy, but the wind was very consistent and steady. 8-12mph, quartering from the 8 o'clock position.

I'm curious if 4831sc would do any better. Until then I'll explore this node.

Any help would be greatly appreciated. BB

 

[Bc'z]

I like 47.5 super wide window looking at poi of the 3 targets.
I'd play with seating depth at 47.5.
The upper node might not be giving you pressure signs in cooler weather.
But in a couple few months when things warm up? Things could change.
Edit, I just deciphered scope adjustments
I'd play with seating at 49gr
48.5 & 49.5 charge weights show more vertical 49 is mo flatter. Adjust seating depth and shoot it.

 

[Badbob]

Thanks Bc'z. So you'd bypass playing with the charge any further, or even switching powders and go right to seating depth.

yes, for 48.5g I wanted to adjust up .75moa, and turned the turret down and instead of up. At 49g I went back to zero and up .75moa. I like 49g cuz that is more in line with the speeds I'm looking for. Lots of folks report the 139g Lapuas shooting well at 2950-3000fps. Thanks for your help! BB

 

[Bc'z]

I'm learning speed isn't everything.
There is a definite flat spot between your upper charge weights seating next, fine tune powder if showing vertical after seating.
I sometimes play with neck tension instead of tweaking powder.