Strange day on the ladder test

Green,

Now you're talkin.....

Regarding inconsistencies in where the bullet struck;
We human folks are a wierd bunch. We want to "wish" the bullet hole into a more reasonable placement that it actually is. Bottom line it that it is where it is and must be left there. We can rationalize all we want but it only helps the bottom line of Primer/Powder/bullet makers.

As we, here at LRH, tend to gravitate towards more extreme cartridges, barrel life is becoming a major consideration.

It is in all of our best interests to be able to "work up" a load w/as few shots as practicable.

Personally, I am really enjoying the tail end of this thread. It looks like some of us are catching on just a bit more. When the tide raises all the boats float a little higher. Except those boats with too short of an anchor chain....

Again, the forum, is pulling through for the betterment of the shooters.

I don't have either the ladder test or the OCW method figured out yet but what I have noticed is that whenever I am testing two or more loads I ALWAYS (now) shoot the shots in a round robin sequence. There's something about the round robin thing that "rings" true.

If I'm going to do a latter test as above, with two loads, I'd even consider doing it simultaneously.

Thanks for your analysis. I was going to post mine, but was hesitant. I think you and I came up with the same results. I liked your words better than the way I would have said it.

PS: In my OCW testing I seems to show that the mass of the powder(grains) makes more difference than the velocity that it produced (unless its grossly different)?

That is, when shooting round robin, a load of say 74.5 grains produces a velocity of 2800fps and a load of 74.7grs produces 2800 fps the 74.5 grain POI is in the 74.5 gr target's group and the 74.7gr POI is in the 74.7gr target's group. And the groups are centered on signifcantly different positions on the two targets. Make sense?
 
4ked,

Tell me about it. I was lucky with the 3-6 mph winds. I will graph the vertical tonight when I get home for now though I can do the velocities.

We will have to get together. I will be shooting in one form or another from now til hunting season is over.
 
[ QUOTE ]
[ QUOTE ]
A little bit of unburned powder follows the bullet through the sky screens and a read error occurs.

[/ QUOTE ]

Man, how close are you putting that chono? If the powders not burned @ 10 ft you've got problems that no load developemnt is going to fix!!

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Come on Bill gimme a break /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif
Stuff some powder in them there cartridges /ubbthreads/images/graemlins/laugh.gif

I'd cover it with duct tape but then couldn't see the numbers/ubbthreads/images/graemlins/grin.gif
332Chronoy-Screen-med.jpg


PS: I loan it out some /ubbthreads/images/graemlins/crazy.gif
 
Dan,

No offense taken. If you have a better method by all means I am all ears. I tried this because it was a better method than what I was preivously doing. If there is a much more effective and simplier way let me know. I did try to read that website you linked on here, but I don't know if my eyes were just hurting I could read more than a paragraph.

Maybe you could email me a condensed version?

For now though I would like to understand this data before moving on.
 
Sorry, I guess I'm blind. Even w/the data, it's still kinda murky. Take this for what's it's worth, which is nothing I'm sure, but I would load up 50.4 gr or 50.5 gr behind the 125 and go try it. This is from looking at the velocities only.

I'm @ loss looking @ the velocities on the 75 gr. There doesn't ever appear to be more than 4 shots in a node.
 
Either will give you an idea, but I like a 5 shot group. Just let the bbl cool between shots.

Let us know how it does. Either I'm going to look smart or like a dumb@ss!!! I'm leaning towords the latter. /ubbthreads/images/graemlins/blush.gif
 
Sean, I appreciate you looking at the OCW webpage. If you don't want to read through the theory, just go right to the OCW load development instructions on page one, print them off and do a round robin test. Here is a piece I wrote on the "scatter group," and its significance during OCW load development--and also the effect of the scatter group on a conventional ladder test: http://snipersparadise.com/sniperchat/index.php?showtopic=13860
Also, I think if you'll read over some of the posts and look at the target photos in the Handloading and OCW section here--> http://practicalrifler.6.forumer.com/ ...things will begin to make more sense.

Roy, thanks for the encouragement. /ubbthreads/images/graemlins/smile.gif And by the way, the front of my Chrony looks just like yours! I did that with RL22 in a 6.5 x 55 Swede... the chronograph was ten feet from the muzzle. I asked the Chrony folks about the issue and they advised me to place the chronograph 15 feet from the muzzle for cartridges which exceed 3000 fps (true, the Swede wasn't going anywhere near 3000)... just an inefficient powder burn...
 
srhaggerty, If the guys are done argueing I'll read your test.

The 75gr load 1st target.

Shots number 15,16,17 shot into about .5" at 300 yards with a velocity spread of only 21 fps. This is so obvious don't let it bite you in the ***. /ubbthreads/images/graemlins/grin.gif Load up with 58.8 grains and shoot some groups.

The second target

Shots 8,9,10 look to be about 1/2 MOA. But the velocity spread is 85fps. Ignore that velocity for now load up 49.7 grains. Shoot and record your velocity and check group size. If this load groups well and velocity is a little inconsistant do one of 2 things; change your seating deapth slightly "experiment", Or change your primer. Do one or the other not both at the same time.

When I load a promising looking load I make at least 10 rounds, that way I shoot them on 2 different days. Sometimes I just have a difficult day concentrating or whatever and reshoot the load another day.

I hope this helps.
 
Coyboy,

I can't argue with your logic on the first target. 58.8 grains might be where to be... It will be interesting to see if the recipe repeats. There should have been at least two accuracy nodes in that string, however.

On the second target (125 grain bullet) it may be that the barrel just isn't going to get along with that bullet. I don't see anything to hang a hope on there...

Dan
 
Hey Green ,

Your remark on the 125 bullet just not cutting it with this bbl could be the deal. However he could change the seat depth radically in one direction or the other and find a load that will shot this bullet .

Just a thought , Jim B.
 
Jimm,

The only published data I have on the 25/284 is in the Hodgdon Annual Manual. It shows their max of H4831 at 49.0 grains with the 120 grain Nosler Partition. From a 26" barrel, they were getting 2978 fps at max pressure with the 120 grain bullet.

I'm thinking that slowing the 125 grain bullet down and going to a slower powder with better case fill (but lower pressure) might get that bullet looking better.

3000 fps for the 125 grain bullet would sound about right--I would think.

I would try 4831, either Hodgdon or IMR. They're not really slower than RL22, but may end up working better here. The RL22 does not appear to be promising with the 125--but it could simply be that the charge weight range and velocity are too high...

Dan
 
green 788, The 125 vld load does not look real good, but he may be able to salvage something from it. If not an accurate load then maybe a little experience. I also agree if he continues to have trouble with Rel 22 and that bullet he should try a different powder. Don't over look H-1000
 
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