• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Confused about powder test results... help!

Try reducing your powder steps to .3 grains till you find the best one and then go down to .1 (rule of thumb is 10% of your load)

When you get the best load, do seating depth tests, then

Get a tuner break
 
Solve your problem with a barrel tuner.
Load up that 4ES charge, and dial in the barrel to shoot tight with it.
 
Thanks for all the replies and things to think about.

Sorry guys, tuners aren't allowed in this sport. I will be deciding on my loads based on powder charge and seating depth only.

I've made my decisions on what charges I'm going to investigate further. Going to do 0.2 grain increments around the best candidates and that should get me to a point where I'll do larger batches of each to confirm the performance, then on to some seating depth tests.

I've got a better front rest on the way and I'll put out some wind flags for my next testing session, probably in three weeks. I'll check back in here with an update once I've compiled the results.
 
Last edited:
If your farthest target is 500m. I wouldn’t worry to much about ES 40 fps = .3 moa =1.5” @ 500m. That should be easy to manage down to 20fps. Some disciplines just don’t cross over the same your far better off spending more time shooting than reloading. Unless you just love spending money and time at the reloading bench.
 
Or it will drive you bat shit crazy one
here was the first test that got me out of the ES/SD rabbit hole and destroyed my faith in the chronograph god. All rounds were loaded at the same time, weighed to .02 grain on a A&D, primers seated to minus .004 from the same sleeve. This load shot 195+ scores @800 yards in several F class matches.

Groups 1 and 2 I had to break cheek weld to use the spotting scope so I could log the position of the POI, the middle group I was waiting on cold range and never broke cheek weld. Even with double digit ES/SD that load was sub MOA out to 800 + yards. This was during my pre shot marker days, I have seen similar results since on the Shotmarker, again only to 850 yards. On the spreadsheet notice faster shots hitting low and slower shots hitting high. My guess is shooter error, but we all know we are all perfect shots don't we, and any thing like that can be cured by a new bench toy

Believe it, don't believe it . It's your barrel life and components, you can chase es/sd until your primer drawer is empty and your throat looks like a BBQ grill if it makes you happy. Me I just let the holes on the paper tell me all I need to know
 

Attachments

  • case prep.jpg
    case prep.jpg
    30.9 KB · Views: 21
  • spreadsheet case prep.jpg
    spreadsheet case prep.jpg
    83 KB · Views: 20
I wrote a huge dissertation on reloading to post on another tread but canned it. Basically this summarizes what it went into:

When you boil it all down developing a load at 100yds is optimizing the rifle/powder combination to either duplicate Point Of Impact over a charge range or looking at tight group size. Either way the end result is the muzzle is pointing at a repeatable location with respect to the point of aim. You minimize the external effects of wind and shooter induced error and minimize the velocity variation effects. When a load doesn't hold up at distance it's an indication that velocity variation is the likely cause. Given a sufficiently stabilized, quality bullet there isn't much else in terms of internal ballistics that can result in an accurate 100yd load "falling apart" at distance.

If it falls apart then the chronograph can help.
 
My view is that the data the OP shows is still developing... meaning that if those test charge samples were increased we would see even wider dispersion around each step in both the velocity and the group size.

This is why there are such dramatic differences between steps. Put enough samples out and the stats will smooth out but they will all grow. (BTW, not the end of the world in silhouette.)

It is most likely because of the attempt to download on a 6BR case using a 95 VLD with N135.

It is just not going to do the same being downloaded as it would being leveled up, at least not with this recipe.

In my experience, those that ran the 7mm-08 and 6 BR were doing so in order to reduce recoil fatigue and to increase their concentration. There is a game to the balance of minimizing the recoil energy and muzzle blast, versus being able to knock down the plate.

In silhouette, you don't just hit the plate but you must knock it down. So there is also a motivation to bring enough gun the line to knock down the ram at 500m (597 yards). The standard ram weighs between 50 - 55 lbs. It takes a good punch to knock it over. If it just turns, you get a miss.

If the OP stops testing at charge levels lower than the usual for a given recipe, then we may not see the best that combination can run when leveled up. Not every primer/powder/bullet/gun combination will download gracefully. (I would try H4895 some day.)

Now, to find out the potential of this recipe combination and the gun, the OP just has to bring the load up to normal pressure. It may or may not make him happy if the goal is to download, but it will at least show him if his brass prep and loading techniques still need work, or if he just needs a recipe change.

A VLD will also take a session or two of seating depth to determine if the load is jump tolerant or needs to be jammed.

Not every rig will shoot a 95 VLD to the same level, but I will add that if the OP can get a reliable 0.5 MOA then he should take it and run. This is silhouette not F-Class or BR. The OP stands and delivers offhand and that takes enormous focus and lots of practice if done at the competitive level. The point being, the biggest gains don't come from the difference between a 0.25 MOA load versus a 0.5 MOA load, if the shooter is still a 5 MOA effect.

I would test that barrel with a 105 Hybrid and some Varget to baseline it. If it won't shoot that under 0.5 MOA, then we know something. YMMV
 
Last edited:
The point being, the biggest gains don't come from the difference between a 0.25 MOA load versus a 0.5 MOA load, if the shooter is still a 5 MOA effect.
For targets that are a min of 2.5 MOA, I would go further and say that getting a load from .5MOA to anything less will make no difference in score. [Yeah, I know, there is that edge case way out there]
 
Circling back as I finally got to do the second round of testing. While I won't bore you with the results, I do have another question about some very confusing results...

How can an increase in powder yield a drop in velocity? I'm talking about three shots that are well under the previous two loads with 0.2 grains between each load?

Out of 10 different ladder tests (over the past two months) I had three clear examples of this effect. These were with three different bullets and two different powders, so not unique to one set of circumstances. One example (the most dramatic one) shown below.

What is going on here?


115:N140 Dec'23.jpg
 
Circling back as I finally got to do the second round of testing. While I won't bore you with the results, I do have another question about some very confusing results...

How can an increase in powder yield a drop in velocity? I'm talking about three shots that are well under the previous two loads with 0.2 grains between each load?

Out of 10 different ladder tests (over the past two months) I had three clear examples of this effect. These were with three different bullets and two different powders, so not unique to one set of circumstances. One example (the most dramatic one) shown below.

What is going on here?


View attachment 1503597
I believe that the ES of the previous two increments are skewing your point of view. Dis regard those numbers and judge point of impact on the target. You’ll find that once in tune a small volocity increase won’t change the poi.
 

Attachments

  • IMG_2052.jpeg
    IMG_2052.jpeg
    343.5 KB · Views: 8
Last edited:
Circling back as I finally got to do the second round of testing. While I won't bore you with the results, I do have another question about some very confusing results...

How can an increase in powder yield a drop in velocity? I'm talking about three shots that are well under the previous two loads with 0.2 grains between each load?

Out of 10 different ladder tests (over the past two months) I had three clear examples of this effect. These were with three different bullets and two different powders, so not unique to one set of circumstances. One example (the most dramatic one) shown below.

What is going on here?


View attachment 1503597
That is just a typical example of under-sampling and the noise in ballistic testing.
An SD on so few samples is meaningless, so my advice is to carry on and ignore it. When and if you were to put enough samples into each step, two things would happen.

The line would tend to straighten out and the ES around each step would fully develop.

ETA: I agree with JFrank, watch the chrono, but study the target.
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
165,833
Messages
2,204,150
Members
79,148
Latest member
tsteinmetz
Back
Top