Long range load development at 100 yards.

[6BRinNZ]

sure - if you had good es/sd numbers around 44.1 - 44.5 I would be more than prepared to re-look at it. Maybe go from 43.9 - 44.8 in .3s over a chrony.

 

[Piotrowski]

So, I shot 100 yards with my F/TR for the first time today, trying to get in the Cortina Testing. (Zeroed it and broke in the barrel at 200 yards and almost all of the rounds thru it since then have been at 600. In fact, my dials are set for a 600 yards zero.)

A few things were pretty obvious:
1. I'm too embarrassed to show all of my targets.
2. I don't like shooting off of a bench and I think that resulted in me jerking a lot of shots.
3. I did a pretty poor job of adjusting the scope down to 100 yards (and think it may not be in correct alignment because everything was hitting way-wide-right.)

So, I think I'll reload with more focus on building better rounds. Maybe run a plumb line test on the scope.


I have a question: Do you guys do the testing Prone so that load development is the same as Match Shooting? Does position even matter?



And, a couple of comments about Dan Newberry's OCW:

1. For IMR4064 in Federal GMM Brass, he says that there is a node at 41.8 (which happens approximate the GMM 175 load):

2. He also states that there is another node at 43.0:

Anybody care to make a suggestion as to what I should load? Primers were going really flat at 43.5 and the look of them at 44.0 scared me (plus the fact that the bolt got tight at 44 - had to whack it with a fist for one round). The target also looks like a scatter-gram. I'm thinking 41.5 - 43.5?

 

[savageshooter86]

really would help if we had all the charges pictured so we can tell. Can't tell by 2 groups so far apart

 

[Marksman]

Figured I'd give this a try as well. I've got a 6.5x47L that I've had bad luck getting to shoot consistently.

I tried 123 Amax right at the lands, using RL-15. I started at 37.5 grains and went with 0.4 grain steps. I shot 3 shots, then gave the barrel time to cool. I went round-robin for the first shot of each, then reverse round-robin for the second, then random for the third.

The shot numbers are listed, but might be a little small. I'm mostly concerned with how shot 2-5 kept rising, then the rounds settled back down.

It looks like 37.5 and 37.9 provided groups with the most similar center.

I think I'll stick with 37.5 and try seating 0.010", 0.050", 0.090", 0.130". I'll shoot two 3 shot groups of each and see if anything stands out.

 

[Erik Cortina]

Marksman, I would advise you to try different powder/bullet before going any further. None of your groups look consistent enough. Might also want to check your scope rings to make sure they are tight.

As far as the bullet jump test, I would advise against such coarse adjustments. Read first page of this thread and you'll see what I suggest.

 

[jimbo88mm]

I started a thread a few weeks ago with my concerns on the 260: http://forum.accurateshooter.com/index.php?topic=3849707.0

Since then I cleaned the hell out of my barrel and picked up some lapua brass. I still don't have the Hornady OAL gauge/comparator but will order those next week.

The loads:
33.5-35.5 in .5 increments of AR-Comp
Nosler 123 customer competition
Lapua 260 brass
cci 200 primers

Alliants website gives ~35gr max for 120gr class bullets. The 35.5 gr load showed no signs of overpressure. It was over 100° yesterday so I'm thinking about pushing out past 35.5 to see where the max is.


As I look at my targets I realize I made another mistake. I made slight adjustments on the scope which is going to make it difficult to see which groups are in the same plane.

Left set of targets, you can see where 34.5 was nearly off the paper so I adjusted my scope. 35 and 35.5 look to be in the same neighborhood. I'm not sure why the 35 group on the right target group is to the left of center.. I can't remember if I made a minor windage adjustment.

In the past I would have locked onto the 35gr load but this time I'm second guessing myself a little. What do you guys think:

The left set.. bottom row is 33.5 and 34. Top row is 34.5, 35, 35.5
The right set.. top is 35.5, mid is 35, bottom is 34.5
groups sizes are 3 shots. The measurement written on the target is edge to edge. Subtracting .264 for actual group size.

 

[savageshooter86]

Erik I worked up a load back in March when it was 70F. Now it it is mid 90s and I re-checked charge window and seems my window is about 0.5gr lower now. That normal with Varget?

With that much temp variation should I work up a "fall/spring" load and a summer load?

 

[Erik Cortina]

Erik I worked up a load back in March when it was 70F. Now it it is mid 90s and I re-checked charge window and seems my window is about 0.5gr lower now. That normal with Varget?

With that much temp variation should I work up a "fall/spring" load and a summer load?

I load to the bottom of my node in the summer, which is probably where you ended up isn't it? I load to the top of node in winter.

 

[Erik Cortina]

Jimbo, 35 looks ok but hard to say without chronograph numbers. Adjust seating depth and see if group tightens.

 

[savageshooter86]

My initial window was 43.9-44.5. So I have shot 44.2 with success in a few matches with temps no higher than 85.

My test today indicated my window is now 43.3-43.9.With 44.6 showing promise

http://i135.photobucket.com/albums/q138/astone6/DSC_0928.jpg
**photobucket is acting crazy and will not rotate the picture and save it**

This was when I first got barrel and had a little bit of old lot Varget to shoot up. So this barrel will shoot the 185s

 

[Erik Cortina]

My initial window was 43.9-44.5. So I have shot 44.2 with success in a few matches with temps no higher than 85.

My test today indicated my window is now 43.3-43.9.With 44.6 showing promise

My point exactly. 43.9 overlaps in both temps.
Make a note and you'll know what your window is for different temps.

 

[Camaro80z]

Any idea where the node is here? I started at the top and worked right to left then dropped down and worked left to right. The powder charges were 65.2, 65.5, 65.8, 66.1, 66.4, 66.7, 67

 

[Erik Cortina]

Any idea where the node is here? I started at the top and worked right to left then dropped down and worked left to right. The powder charges were 65.2, 65.5, 65.8, 66.1, 66.4, 66.7, 67

66.4 and 66.7 look good.

 

[Camaro80z]

Thank you sir. This is a 300 wsm with 230 bergers jumping .015. Where would you recommend I start with seating depth? Touching then work out?

 

[Link]

My initial window was 43.9-44.5. So I have shot 44.2 with success in a few matches with temps no higher than 85.

My test today indicated my window is now 43.3-43.9.With 44.6 showing promise

http://i135.photobucket.com/albums/q138/astone6/DSC_0928.jpg
**photobucket is acting crazy and will not rotate the picture and save it**

This was when I first got barrel and had a little bit of old lot Varget to shoot up. So this barrel will shoot the 185s

Can someone tell me what happened at 44.3 , is it just a flyer or is it a blowout ? Will it happen every time or is it a 1 time thingy ?

thanks

 

[Erik Cortina]

Thank you sir. This is a 300 wsm with 230 bergers jumping .015. Where would you recommend I start with seating depth? Touching then work out?

Start .005" from touching and work out from there in .003" increments.

 

[Camaro80z]

Will do thanks again

 

[savageshooter86]

Can someone tell me what happened at 44.3 , is it just a flyer or is it a blowout ? Will it happen every time or is it a 1 time thingy ?

I believe it was pulled shot. Because it was my last one of the group and all the others were very good groups/POI

 

[jimbo88mm]

Jimbo, 35 looks ok but hard to say without chronograph numbers. Adjust seating depth and see if group tightens.

Thanks Erik

 

['Freak]

‘Bout time for a bump.