Strange occurence during load work up

[dieselten]

I tried a new powder in my 243 yesterday, H1000. It is a heavy Krieger 1-8 and I used Sierra 107 Matchking. I just wanted to find out where my max was going to be. I loaded one round each at 44.0, 45.0, 45.5, 46.0, and 46.5. The first 4 rounds went into about .25 at 100 yards, the last one 46.5 hit about the same elevation but about .5" left. Velocity varied from 3000 - 3120.

Would you read anything into this? Is this common to have rounds from this wide a powder charge all hit in the same spot?

 

[Immike]

You may have a hummer barrel. Take your testing out further so you can see a difference in loads. Be methodical and save it for the matches. Good luck!!

 

[Lapua40X]

One round each of any given load doesn't provide enough data to work with. Three, five is better, of each load (preferably each on a separate sighting point) would give you more to work with. That one wide point of impact could be caused by a lot of factors other than load.
Ain't them Krieger barrels nice? Push anything through them and they still seem to find the bullseye.
PS
Because you selected 100 yards for your test I hadn't considered that you might be trying to do a ladder test, in which case I would agree with the series of single loads over a range of 300 yards. However, IMO, the ladder test relies on consistency in handling of the rifle for every shot fired. One "oops" with the hold on the rifle or other simple error can generate a ghost or two that don't fit the pattern and result in confusion. So, for ladder testing, I usually prefer to use a sled to reduce data errors.

 

[pdq5oh]

From what I've read about the ladder method is 200 yds minimum. 300 yds is better. At 100 yds you won't see much difference in impact point. This IS the ladder method you're using.
http://www.desertsharpshooters.com/manuals/incredload.pdf

 

[smoooth]

pdq5oh,

Thanks for posting that very informative article.


Dieselten,

That is a heck of a shooter there, plus you are getting the same velocities as my new 6-284 with the same bullet. Looks like I'm burning a lot of extra powder for nothing What is your barrel length ?

Good shooting,

Smoooth

 

[BigDMT]

I've noticed in the past that the slower burning powders can be more forgiving provided your rifle likes them in the first place. I've had a 7mm mag produce two one-hole 3 shot groups during testing with 1 full grain difference in charge weights using Reloader 22.

Eventually the POI will change like yours did. But I do agree that 3 or 5 shot groups in ladder testing will provide you with more truth to your rifle's characteristics because who knows, maybe your rifle will always throw the 5th shot as a flier?

 

[ar10ar15man]

you need to confirm with more shooting..but it is exactly what some of us are looking for...a sweet spot in the powder load where a small change in grains does not change point of impact.
this mean you could load on a progressive or strraight out of a powder thrower without weighing every load.....
lets say in the end you see that 44.6/45/45.4 all hit about the same with similar velocity.
and you can throw this powder at 45.0 plus or minus .2 or even .3.....so do it and your accuracy does not suffer.

i had a mosin nagant scoped rifle that did the same..4 shots in one hole at 100 with .5 grain steps.....great milsurplus match rifle.

 

[dieselten]

The barrel is 26" mounted on my AI AE MKII. I was not shooting a ladder test, just some basic pressure test to see where my max is, then work the ladder down from there. I just thought it peculiar that the first 4 went into just about the same hole with 2.0 grains of powder spread.

Thanks for the input.

 

[CaptainMal]

My thoughts are it's the "blind squirrel finding the acorn." You shoot enough and most anything can happen.

The small number of shots and close range probably came together out of statistical significance. More testing needed to come to a conclusion.

Always interesting to me how many have a nice group they keep in their pocket. Then when it's shooting time the excuses fly. I have a Krieger barrel for my 6.5 AI and it has shot one hole groups. In general it's a failure that shoots 3/4 MOA or worse over 960 rounds. But, for four or five shots, it can look like a winner.

Shoot more and move out to at least 300 yards.

 

[normmatzen]

My first BR rifle was a 243 WIN and it liked 46.0 gr H1000 and it was a 28" barrel, 107 SMK's and I used hBN. I got only about 2900 fps with hBN.

Now I shoot a 6BRX and get 3050 fps using hBN in a 28" barrel with only 33.8 gr VARGET.

 

[Laurie]

i had a mosin nagant scoped rifle that did the same..4 shots in one hole at 100 with .5 grain steps.....great milsurplus match rifle.

My M-N 1891/30 sniper was the exact opposite as you'd expect from a rifle with a long skinny barrel and minimal bedding. I'd have to keep moving the elevation setting shooting 100yd 5-shot groups over 2-grain charge ranges and each move to a new bullet and/or powder lost most of the first group off target and requiring resighting due to a combined elevation and windage shift that could run as large as 6-inches in each plane over the maximum load of the previous combination.

Smallest group was a shade under an inch though - amazing for such a vintage piece of military equipment with a 3.5X scope and pointed-post reticle that made it very difficult to keep a tight aim.