Do you test to pass or test to fail?

[JEFFPPC]

That target is only good at that one distance. A nice little group at distance A will not carry through to distance B unless velocity spread is small.

Well the 1000 shooters have proven that incorrect quite often.Current set up in my PPC had ES of 1 for 10 shots last time I checked. 6BRA was 4. I do little with the Garmin. It never won a match. Tuning loads to zeros or very low ones does win matches. But fortunately for all of us there is often more than one way to skin a cat. Good luck, keep your battery charged.

 

[ELR LVR]

Do you look for passing data and stop or do you continue to see if things fall apart? This applies to all aspects of handloading...
My latest testing has been looking for low ES... consistent low ES. Do you shoot 3 or 5 shots and plug that into your ballistic calculator and never test again or do you check your ES with every shot? I have found that consistent low ES is elusive (including different days, different temperatures, different humidities, moon phase, star alignment).
Anyone else seeing this in the real world?
Thanks!

for 10 years I didn't even use a Chrono
I used the Target at 600 yds to develop loads that do this
And that particular one is from a Gen 1 Ruger American rebarreled with a Krieger
Good components are the big factor (good bullets, right powder matched with the right primer etc)
And --- Seating Depth
---
I recently started using a chrono again once in awhile
all it did was confirm what my targets were already telling me
If my ES or SD was out of tolerance...
...I don't see how I will be able to improve anything, since there is no better Bergers
there is no Better Primers etc
---
with the new Garmin Xero, thats a different story, I just hate setting up and lining up my Chrono in front of the gun is all

 

[moondog]

I strive for low es, but as others have stated, it doesn't necessarily produce consistent small groups. I keep track of groups with my Shotmarker at 600 for most guns. 1200 yards for the bigger ones. I was just recently comparing 220s to 215s over 5 sessions. The 215s consistently had lower es, but the 220s consistently shot smaller at distance.

 

[jackieschmidt]

As a Short Range Benchrest Shooter, I tend to agree with @JEFFPPC in that the only thing that I am concerned with is the actual grouping capability of a given combination at 100/200/300 yards.

I was practicing at 200 yards with my 6PPC last Sunday, and had my Garmin on the Bench. I was able to nail several sub .300 groups where the ES was as much an 25fps and the SD’s were averaging in the 9 range.

Now, that is a .150 MOA agging capability. Those ES/SD numbers would be unacceptable at 600 plus, but it tells me (once again), that tuning for group size and tuning for ES/SD are two entirely different creatures.

I tend to get better ES/SD numbers with my 30BR. Some quite well. The accuracy between it and my 6PPC is really about the same as far as each combinations ability to shoot Sub.200 groups.

I have no explanation for this.

 

[Dave Way]

I mostly shoot 600 and 1,000 yards so I do my testing at those distances. I guess you could say I test to pass by failing. I’m looking for “windows” where the rifle is happy. With any particular bullet, primer and powder, that means a powder charge, seating depth and neck tension “window”. In other words I not only want to see where the rifle is happy but I need to know where it falls apart both below and above that window. Do the same with neck tension and seating depth and you can come up with a pretty forgiving load should temperature, humidity etc. change.

I do all of this on paper. Electronic targets have too much variability for my purposes. That’s a nice way to say they suck. Find the middle of those windows and you and your rifle will be happy.

What are all these ES’s and SD’s people keep talking about?! Meaningless to me except for verification of your loading practices. Do it right and all you will see is low SD’s. I have gone to some big matches and shot the smallest groups more than once and I had never chronographed the load. When people asked what my velocity was they looked at me like I was crazy when I told them I didn’t know. Remember, I’m shooting at known distances. Other disciplines may have different needs.

Dave.

 

[old_heli_logger]

Thank you for all the excellent replies! This is exactly the information that I was hoping this thread would reveal...
Awesome!

 

[Evan]

For context, I shoot 600 and 1000yd BR. I went down the chronograph rabbit hole for about a year just about 10 years ago now. I was convinced of the theory that statistical relevance could be attained and that small spreads would yield the best groups. I eventually came to my senses, set aside my dogma, and pragmatically began watching only the target again. Year after year now, I shoot smaller and smaller.

The best barrel life is always behind you. The barrel gets worse with every shot. I test to success because testing to failure wastes a good barrel. At $1000 to my door for a chambered barrel, I want to shoot small. I don’t want to try and prove it won’t shoot big.

 

[SGK]

Well the 1000 shooters have proven that incorrect quite often.Current set up in my PPC had ES of 1 for 10 shots last time I checked. 6BRA was 4. I do little with the Garmin. It never won a match. Tuning loads to zeros or very low ones does win matches. But fortunately for all of us there is often more than one way to skin a cat. Good luck, keep your battery charged.

Good. Then you have both. One without the other isn't enough.

 

[dellet]

The problem with relying on ES/SD at the muzzle is that it is only half the information. It doesn’t really transfer down range, unless you have velocity on target.

If you look at the outputs of a ballistic calculator there are some patterns at different distances. Basically if you plot your load and check it to 1000 yards, a 10fps change in velocity has the same change in point of impact as a .005 change in a G7 bc.

So even if your ES/SD numbers are single digits or zero at the muzzle, inconsistent bullets will show up as vertical spread and higher numbers on target. By looking at the changes over distance, you can have a pretty good idea of when the numbers matter.

One of the things learned shooting slow bullets, is that velocity hides a lot of problems.

 

[JFrank]

At $1000 to my door for a chambered barrel, I

Hope you’re getting a great barrel, I couldn’t afford to shoot at those prices.

 

[Evan]

Hope you’re getting a great barrel, I couldn’t afford to shoot at those prices.

$480 barrel +$30 to ship it to the gunsmith + $450 to chamber and another $30 to ship it to me. $990 - it’s painful but I try to look at it like this: I want the small but important industry of precision gunsmiths to make a safe, comfortable living so that we all have gunsmiths to call on in the future. Same for barrels and the guys who have learned how to lap them in. I don’t think any of the barrel makers are getting rich right now.

 

[GetReal]

I test till I get the results I want and dont test anymore until I stop getting the results I want.

" Take the win."

 

[Varminterror]

Over the last few years, I've done a little method validation exploration for several popular "load development methods," and ultimately, the only answer is that MOST folks assume they are doing deductive testing (seeking this better than that), but in reality, are not completing sufficient science to prove out the minutia they think they're seeing, BUT... luckily... the processes deployed are actually quite effective INDUCTIVE experimentation.

So in this context, most folks think they are "testing to fail," meaning they expect most loads to fail to achieve the level which is demonstrated by ONE load, but through successive rounds of testing, they effectively prove out that at least one thing has been "tested to pass" enough times to satisfy their curiosity...

Personally, I just "test to pass" these days. I don't do comparative testing for almost anything I shoot, I simply put together some loads in a pressure ladder to ensure my neck tension is good and my load spectrum is within the acceptable window for pressure tolerance of the brass and rifle, then I pick a load. Almost unilaterally, all of them pass at the same determinable quality, so picking any one of them to carry out to distance is typically valid.

 

[tom]

The only thing that guarantees small groups at distance B is small groups at distance B. And that goes the same for distance A. You "might" get great groups crossbreeding the distances, but you won't know until you know.

Depending on what you "need" the rifle to do, barrel life is not forever. So test enough to see a pattern and be confident, but not so much you shoot all of the great out of it lol. Like Dave said, your ES or SD should both be within reason if you're doing all the other things right. I never used a crony before they had these bench top units, and I did plenty of damage at 1k Benchrest then, and still today....I just happen to know what velocity I'm roughly at when someone asks nowadays.

Tom