Long range load development at 100 yards.

[M14AMU]

Aha! Folks are still drinking the 'cool aid'!

 

[Erik Cortina]

I posted more detailed instructions...........
.
.

10. Final step is to load the new seating depth and load 5 shot groups in 0.1 gr. increments 0.5 gr. on each side of node (if pressure limits are not reached). This will cover an entire grain of powder and you will be able to pinpoint where the powder node starts and ends. In the summer, load towards the low end of the node, and do the opposite in the winter.

HAPPY SHOOTING! [/b]

Why 5 shots in this final test segment instead of 3?

Because I like to verify consistency and get a larger sample for ES over chronograph.

 

[edwin_velocity]

Hi Erik,

Finally managed to get brand new Lapua case.
Neck turned to get loaded OD .337" with neck bushing 335, no fire forming, my chamber neck is .340"

Attached files are my powder test, and I choose 44.25gr (hopefully correct). I stopped at 44.5gr as the case is almost filled up and can't squeeze anymore powder as my chamber throat designed for magazine length.

And I continue with seating depth test, from jump 0.005" thru 0.035".
Do you think the node is somewhere between 2.252" - 2.261" ?
All grouping around 0.2"-0.3".

Is brand new case without fire forming causing this inconsistency?
What should I do next? Should I load 5 rounds each?

Thank you very much Erik

edwin

 

[Erik Cortina]

You are correct. 2.261" is what I would load.

 

[edwin_velocity]

You are correct. 2.261" is what I would load.

Thank you for your input Erik.
With that high ES,is it because of brand new case without fire forming?

 

[Erik Cortina]

You are correct. 2.261" is what I would load.

Thank you for your input Erik.
With that high ES,is it because of brand new case without fire forming?

Possibly. Check again after you fire form your brass.

 

[Brians356]

6. Examine target and find the place where consecutive groups line up vertically and ES is the lowest and speed increases the least from one group to the next.

Erik,

When looking for flattening out of speed increase, do you simply compare the 3-shot averages?

 

[Erik Cortina]

6. Examine target and find the place where consecutive groups line up vertically and ES is the lowest and speed increases the least from one group to the next.

Erik,

When looking for flattening out of speed increase, do you simply compare the 3-shot averages?

Look at each individual shot as one bad shot can throw the entire thing off. It's a small sample, but a good place to start.

 

[Brians356]

6. Examine target and find the place where consecutive groups line up vertically and ES is the lowest and speed increases the least from one group to the next.

Erik,

When looking for flattening out of speed increase, do you simply compare the 3-shot averages?

Look at each individual shot as one bad shot can throw the entire thing off. It's a small sample, but a good place to start.

So are you saying toss an obvious outlier velocity from a group?

Let's say two successive powder charges yield:

Chg. 1: 3330, 3300, 3305 (avg 3312)

Chg. 2: 3330, 3350, 3340 (avg 3340)

Lacking a better approach, I have been concluding the speed increase between these charges is 28 fps (using averages).

But in Chg. 1, the 3330 could be consider an outlier.

 

[Brians356]

Thanks for (tacitly) confirming. Take the average velocity of each 3-shot group, compare to adjacent group averages to note velocity change resulting from powder charge change.

 

[edwin_velocity]

You are correct. 2.261" is what I would load.

Thank you for your input Erik.
With that high ES,is it because of brand new case without fire forming?

Possibly. Check again after you fire form your brass.

Hi Erik,

Here's the result at 300m with 10mph wind from 1 o'clock. Only test 4 each...1 for sighter/fouler.
Will test again after all cases have been fire formed...hopefully will be better

Thank you for all your input!

edwin

 

[284driver]

Well, here's my stab at this method. The groups weren't great. I don't know what the deal is. It's a new to me rifle. Couldn't get comfortable mainly because I didn't have tools to adjust the chassis because I was rushed and forgot said tools at home. I feel confident they would be tighter after I make adjustments. This was shot prone from a bipod and rear bag. Looking for a600 yard f class load. Thoughts. Opinions.

6br. 105 berger vld. .010 jam. CCI 450. New Lapua cases. Bartlein 8 twist no turn neck. SIII 8-32

Would anyone pick one of these, load it up and head to a 600 yard match?



Seating depth adjustments commenced this morning. Positive I pulled a couple of them. Got the chassis set up better last night. I'm going to try a rest as opposed to bipod this weekend at butner. Shooting minute of steel plate is totally different than high power or f class shooting for sure.

Update. I took the 30 grain load jumping .015 and headed to to a match. My best scores were 2 197's. Dropped some points after the wind started hammering. I've got a lot to learn with wind reading but overall, had a great time and think the load development works.

 

[snowpro440]

Heres the pic of my PPC

 

[Erik Cortina]

Heres the pic of my PPC

28.8 - 29.0 look really good. I assume this one will be 100-200 yard gun?

 

[snowpro440]

Heres the pic of my PPC

28.8 - 29.0 look really good. I assume this one will be 100-200 yard gun?

This will be set up for 200-400 yard Groundhog Match Gun as soon as my benchrest stock gets finished ... Now shooting off a 40X stock ,should have it done by spring

 

[Brians356]

This was the seating depth test in .004" increments (not .003" as planned - long story). No chronograph data. Crosswinds 5-10 mph, no attempt to dope wind, I concentrated on holding consistent vertical aim.

All 3-shot groups @100 yds. 223 Rem, powder charge 28.9 gr CFE 223, bullet 50-gr TNT.

Note that the #1 target in the sequence is center top row.

Bullet jumps: 1: .010, 2: .014, 3: .018, 4: .022, 5: .026, 6: .030

While #6 is one neat hole (and would have been my choice in the past!) I note that #2 and #3 are both at the same vertical displacement above POA, and vertical spreads are both less than 0.220", while #6 printed at a higher vertical displacement, and came after the erratic groups #4 and #5. Perhaps #6 is on the edge of a good node? Or #2 and #3 are bookends of a stable node?

 

[Erik Cortina]

Brians356, I believe if you tried .033 jump it would shoot just as well as .030", which I believe will be your node.

Try it and see how it shoots.

 

[Brians356]

Brians356, I believe if you tried .033 jump it would shoot just as well as .030", which I believe will be your node.

Sold! I like the deeper seating anyway, since with these bullets, the neck engagement at .018" jump is slightly less than 1/2 caliber.

Suppose you were to test a few longer jumps starting at .030, would you choose .003 or .002 increments?

 

[Erik Cortina]

Brians356, I believe if you tried .033 jump it would shoot just as well as .030", which I believe will be your node.

Sold! I like the deeper seating anyway, since with these bullets, the neck engagement at .018" jump is slightly less than 1/2 caliber.

Suppose you were to test a few longer jumps starting at .030, would you choose .003 or .002 increments?

I would start at .028" jump and test out to .040" jump in .003" increments.

 

[trailrider121]

I got some 123 scenars for my 260 rem. Loaded some up and tested them at 100 yards. It was windy today (maybe 8mph) and my target blew away, so I found a nice target someone left behind. No Chronograph as it was super busy today.

260 Rem Lapua Brass
123 Scenars
.020" OTL
H4350
CCI- BR2 Primers.

Top Left / 44.0 grs
Top Right / 44.5 grs
Lower Left / 45.0 grs
Lower Right /45.5 grs
Center bottom 46.0grs (point of aim was bottom of target)