Long range load development at 100 yards.

[Erik Cortina]

SS86, I like -.015 to -.020" but I agree with Donovan about exploring -.035" to -.040" as well. You might finally have it tuned!

 

[Erik Cortina]

Has anyone here tested their load at longer ranges using Erik's method? Just curious if its worked out from some. I have done 100 yard load development and 50% it works out for long range.I'm sure I could have messed up somewhere giving false feedback.

I plan to do a seating depth test in .003" increments from jam-.010" to -.030", but just not sure if 100 yards is enough to evaluate seating depth pattern. I could be wrong. Would 200 yards be better?

100 yard is enough, hence this thread! ;D

 

[Erik Cortina]

Nice shooting Johnnyi!

 

[savageshooter86]

thanks Erik and Donovan. Both of you for the help on here. Praying I may have a decent load now that is repeatable, which I think is big thing for Fclass

No telling, but the wind was pretty switchy and I could have induced/wind induced the shots out of 25,30, and 40. If those would have been in the group, they appear the center of the groups would have all hit on the horizontal line
**looking back it actually appears I was coming into a good seating "node" at -20 to -40. **

Will take these seating depths to a match and test them out and see which does better

 

[Mr. Ten-X]

A friend used the 100yd test and then swung out to 600/1000 to verify. His rifle is a Savage with an aftermarket, 30" Shilen in 12" twist, that was pre-chambered. Using Varget, Russian primers and the Berger 185 Jugg jumped .025". All firing done from the bipod.

 

[lawrence97]

Trailrider, go back to page 41 reply #611 and Erik posted his powder, seating depth and 1000 yard match results using his method! A 199 at 1000 is impressive!

 

[SWThomas]

Hey Erik. Can you check this out and let me know what you think....

I took my 308WIN GAP-10 out yesterday to conduct an OCW test. I'll list all the specifics and if you could give me your thoughts on what you think that would be great.

Conditions:
Temperature: 54
Humidity: 37%
Pressure: 29.89 in
Visibility: 10 Miles
Elevation: 335 ft

Load:
Bullet: 175g SMK BTHP
Brass: Lapua
Powder: IMR 4064
Primer: CCI #34

Velocities:
43.5: 2604, 2619, 2604
43.8: 2640, 2650, 2619
44.1: 2635, 2619, 2640
44.4: 2682, 2661, 2645
44.7: 2677, 2677, 2645
45.0: 2682, 2699, 2666
45.3: 2699, 2715, 2704
45.6: 2721, 2726, 2726

It started to cool off a few degrees for the third round robin, so the velocities seem to have taken a small hit.

I'm thinking somewhere between 45.3 and 45.6. They seem to be pretty similar in relation to the center, they're tight, and the ES SD and AV velocities look pretty good too.

What do you think?

 

[dannyjbiggs]

Has anyone here tested their load at longer ranges using Erik's method? Just curious if its worked out from some. I have done 100 yard load development and 50% it works out for long range.I'm sure I could have messed up somewhere giving false feedback.

I plan to do a seating depth test in .003" increments from jam-.010" to -.030", but just not sure if 100 yards is enough to evaluate seating depth pattern. I could be wrong. Would 200 yards be better?

100 yard is enough, hence this thread! ;D

I use a similar method to this, but at 200 yards. Using the REVERSE side of a standard NRA 200-yard target face (laid by a level to a cardboard backed target frame), I affix a 2-inch blaze orange aim-point dead center on the reversed target face to serve as an offset aim-point for my trial...I call it a "horizontal" ladder test!! I do a few test/warm-up shots to get on paper and to be horizontally on line with the aim point. I then put on enough L windage to be on the left margin of the target face and enough elevation (1-2") to ensure clearance and non-obstruction by bullet holes of my constant aim-point throughout the trial. If I am trying to find an accuracy load and pressure limits, I'll commence shooting 3-round shot groups putting 1' of R windage between groups going straight across the paper...using powder loads increasing by .5 grains for each group. When I find something interesting, I'll elevate up (or down) 1' or 2' and "push the carriage return to the left side margin". Then shoot three 5-shot groups loaded .5 grains under/on/over that of the promising 3-shot group powder load. If things still look good, I'll elevate up (or down) 1' to 2', push the "carriage return" back to left margin, and shoot three 10-shot groups loaded .2 grains under/on/over the most interesting 5-shot group powder load. This generally will nail the accuracy load down (maybe a .1 grain tweak?) that I take to the 1,000-yard line.

But first, while still at the 200-yard line; I work out a 1,000-yard windage zero for that accuracy load. This consists of simply adjusting a shot group to center up about 3/4 minute to the left of my aim-point, which should put me center at 1,000 yards.

Dan

P.S. Although I always seem to get best accuracy right out-of-the-bag seated "just into the lans" with Hybrids for my .284/7mm SMs, I would use the offset aim-point to explore that, also...and similar manner adjusting the seating depth between groups.

 

[FeMan]

Here are the results of my first try at this with my new 284 with the 180 Hybrids. From my read of this, 51.0 grains of RL17 looks like the place to work from (third from left on top row) even though the best group (52.0 grains second from right) had the smallest group size. If anyone else has other suggestions I am all ears. Thanks.

Note: For reference, the groups run left to right and top to bottom. They start at 50.0 and go up in 0.5 increments to 53.5 where I stopped due to pressure signs. The lower row is sighters/foulers.

 

[mr45man]

Fe Man
Need a better picture.
John H.

 

[FeMan]

Fe Man
Need a better picture.
John H.

That should be better. Thanks.

 

[diego-ted]

My Turn Again

Took the GAP Hospitaller out with the new tube for some load development. I was pleased with the first round. Eric, Steve, Where would you go with this? Assuming the one round at 47.5 is a flyer, I think the waterline from 46.5 to 47.5 is good so 47 looks like the load to go with. What do you guys think?


I do like the fact that all loads printed under a dime!



Diego

 

[Erik Cortina]

Diego-Ted, I'm afraid I won't be able to help you. Apparently that gun will never shoot good enough. I'll help you out and buy it from you so you don't have to suffer with that gun anymore.

Joking aside, 47.0 is what I would use. Nice shooting!

 

[Dos XX]

Diego Ted,

That's awesome. You can certainly not blame the equipment when using that gun.

What bullet and powder is that?

 

[Steve Blair]

I think you should definitely sell that gun to Erik before it embarrasses you in a match! And, whatever you do, don't risk bringing it to the match next month. [br]
You should run those loads over the chrono and take both grouping and ES into account. Send me an email if you need anything.

 

[Minox]

Ciao Erik,
I'm following you and your interesting topic from Italy.
Today I was at the range and I shoot with my 6,5x47Lapua GAC rifle a Berger BT Target 120gr with N150.
Can you analyze my target?

Thank you
Sergio

 

[Erik Cortina]

Minox, I agree with Donovan. Based on the target, I would pick between 38.5 and 39.0.

Nice shooting!

 

[SWThomas]

Erik,

Any advice on my post from the previous page?

 

[Erik Cortina]

Erik,

Any advice on my post from the previous page?

Sorry, I missed that one.

I'm thinking somewhere between 45.3 and 45.6. They seem to be pretty similar in relation to the center, they're tight, and the ES SD and AV velocities look pretty good too.

I agree with you, 45.3 and 45.6 look the best. Without knowing what it looks like past 45.6, I would pick 45.5 and test it.

Good luck!

 

[LRCampos]

.

Erik, I am following your topic from Brazil since day one and found it very informative!

My question is: I see that almost all shooters use just one group per load to determine the accuracy of that load in particular. Is it enough?

I saw too many times that a single group does not tell reliable the accuracy (or even the position of the center of the group as based on your method) of a single load.

Would it be better to produce 2 groups of 3 shots on each load, instead of 1 group of 5 shots?

Or in you experience, just one group is enough to point to the right direction?


Thank you very much,

LRCampos.