Chronograph vs actual results?

[dinmax82]

Developing a load for a 300WM shooting the Berger 215.

One load of 77.6 gets me better then 1/4 moa but SD is 10-12 with ES between 20-30.

Another load gets me 3/4 moa at 77gr but SD is under 3 and ES around 5.

Both loads tested two different days with 20 degree difference between days.

I anneal, chamfer, debur and lube necks before seating.

Live with one load or play with bullet jump on both? Currently .015 off lands. If I play with jump how much to play with at a time?

Don't want to waste too much barrel life, time and money though. I shoot out to 1200 yards only.

 

[watercam]

You could do a bullet jump ladder test. Jam .005" to jump .050" in .005" increments. Drop your load a bit as pressure will be higher when jammed or close to it. That would be 11 bullets. I'm betting jumping about .025" will look good.

 

[harv50]

Developing a load for a 300WM shooting the Berger 215.

One load of 77.6 gets me better then 1/4 moa but SD is 10-12 with ES between 20-30.

Another load gets me 3/4 moa at 77gr but SD is under 3 and ES around 5.

Both loads tested two different days with 20 degree difference between days.

I anneal, chamfer, debur and lube necks before seating.

Live with one load or play with bullet jump on both? Currently .015 off lands. If I play with jump how much to play with at a time?

Don't want to waste too much barrel life, time and money though. I shoot out to 1200 yards only.

That's a NO brainer... Believe what the target says is best. I wouldn't waste that barrel, I mean you're shooting in the top of the top with the better than 1/4 MOA... 1200 yd would be better than 3.14 inches and at 1000 yd would be better than 2.62 inches..
Take the gun to every event you can, you'd get alot of wood and $$$$ in prizes..

 

[dinmax82]

That's a NO brainer... Believe what the target says is best. I wouldn't waste that barrel, I mean you're shooting in the top of the top with the better than 1/4 MOA... 1200 yd would be better than 3.14 inches and at 1000 yd would be better than 2.62 inches..
Take the gun to every event you can, you'd get alot of wood and $$$$ in prizes..

You make it sound so easy lol. 1/4moa at 100 is different then holding 1 moa at a thousand...

 

[dsandfort]

Holy Toledo!! Your rifle and load (and you) would have won the Cactus Classic in Phoenix this year, and likely the Arizona State Championship. Trust your target.

http://azbrs.com/downloads/results/2016-Cactus_Classic-Light_Varmint_100yd.pdf

 

[CharlieNC]

What technique did you use to develop the loads? What you report are major differences in SD for 0.6gr, how many shots? See if you can reproduce 1/4 vs 3/4 moa. I assume with 300WM you are going for long distance where the impact of SD will override the 1/2 moa difference.

 

[dinmax82]

Whoops one was 79 gr for the 3/4 moa.

I load up about 6-8 different powder charges, keep seating depth the same between them all. Just 3 rounds each. Find ones that shoot well then concentrate on any loads that shoot half moa by loading 5 rounds each and going out again.

 

[Dusty Stevens]

Forget the chronograph nobody scores them

 

[CharlieNC]

I would confirm the groups and SD with at least 10 shots for your two loads to draw a better conclusion. And try at longer distance if possible.

 

[savagedasher]

I work hard to keep my ES and SD as low as possible. I use seating depth to lower then.
When I get them as low as possible That is when I let the tuner do its job. Same as is done in Rim fire. Larry

 

[dcali]

What do you mean by ES and SD? For how many shots? A lot of folks quote "single digit ES", but then you find out it's over 3 shots, which is sort of like showing off a single 3 shot group. Cool, but hardly predictive.

I don't get worked up over velocity stats unless it's over a large number of shots - 20 to 30. But it's just as easy to shoot at range and observe the vertical, and a heck of a lot more fun.

 

[hogpatrol]

Have you checked out this thread? A lot to work with in it.

http://forum.accurateshooter.com/threads/long-range-load-development-at-100-yards.3814361/

 

[savagedasher]

What do you mean by ES and SD? For how many shots? A lot of folks quote "single digit ES", but then you find out it's over 3 shots, which is sort of like showing off a single 3 shot group. Cool, but hardly predictive.

I don't get worked up over velocity stats unless it's over a large number of shots - 20 to 30. But it's just as easy to shoot at range and observe the vertical, and a heck of a lot more fun.

When shooting or working up loads ever round is shot over a crony.
I don't know how you can expect a 100 yd tune to shoot at a distance with high Es.
Larry

 

[wedgy]

I agree with shooting them out further than 100 yards as the long bullets can take a bit to stabilize. Pierce's development with the Berger 195's is a perfect example, nothing shot well at 100 yards but further out it's in the .3's & .4's
I shoot a lot of copper bullets and find it is even worse.

 

[Zero333]

Like Damoncali said, at least 10 shots over the chrony to get real world ES.

Test as far as you can if you play on poking things at long range.

 

[amlevin]

What do you mean by ES and SD? For how many shots? A lot of folks quote "single digit ES", but then you find out it's over 3 shots, which is sort of like showing off a single 3 shot group. Cool, but hardly predictive.

I don't get worked up over velocity stats unless it's over a large number of shots - 20 to 30. But it's just as easy to shoot at range and observe the vertical, and a heck of a lot more fun.

This is why I now don't even drag out the Chrono until I have the load worked up for best accuracy. Then, during a practice session, I may put as many as 50 rounds over the chrono to see what the REAL ES/SD numbers are. Then I have a nice accurate number to use in all future ballistic's calculations for that load when changing distances.

 

[Mr.Knowit all]

Developing a load for a 300WM shooting the Berger 215.

One load of 77.6 gets me better then 1/4 moa but SD is 10-12 with ES between 20-30.

Another load gets me 3/4 moa at 77gr but SD is under 3 and ES around 5.

Both loads tested two different days with 20 degree difference between days.

I anneal, chamfer, debur and lube necks before seating.

Live with one load or play with bullet jump on both? Currently .015 off lands. If I play with jump how much to play with at a time?

Don't want to waste too much barrel life, time and money though. I shoot out to 1200 yards only.

That is so crazy because I have several loads like that for my 300 also. It seems that my ES is very low (between 7-11fps) but my groups open up a bit and my best groups are with an ES about 30-35 fps. I thought I was the only one.

 

[Lapua40X]

Another load gets me 3/4 moa at 77gr but SD is under 3 and ES around 5.

I'd work with .002 adjustments in seating depth forward, same to the rear. Keep moving in the direction (to or fro) that gives you the best results and stop when that group finds a comfortable 1/2 MOA or less; no vertical, and smile.

 

[dinmax82]

I'd work with .002 adjustments in seating depth forward, same to the rear. Keep moving in the direction (to or fro) that gives you the best results and stop when that group finds a comfortable 1/2 MOA or less; no vertical, and smile.

Went and jumped the 79gr group big,. 030 and. 045. . 045 a definite no go. Will try around the. 030 range for a winner hopefully