6.5 CM ladder/ ocw work up and range results

[doctnj]

So Ive heard several theories about finding the proper charge. Some stand behind the OCW guidelines and some the basic ladder. Well I did a blend of both as the first part of my work up today.

Initial load up:

5 charges x ten rounds each. 5 to be shot at 100 yrds and 5 to be shot at 300 in round robin fashion.
caliber : 6.5 CM
Bullet : 140 gr Berger hyb.
Powder: H 4350
charges starting at 38.5 and increasing by .5 up to 40.5 (.2 gr below max load) I picked these loads because this rifle showed to be extremely accurate with winchester loads right off the shelf. I was pretty sure they were no where near max load so I started in the middle and went up from there. This is a rough test and my hope was to find a charge and work by 0.1 grn around that load.

Unfortunately, like so many, I ended with a bit of confusion over which load to pick. I have my favorite but am open to voting.

Here is pic of range.

http://i1075.photobucket.com/albums/w435/doctnj/Mobile%20Uploads/20151206_130013.jpg

zoom in to see 300 yrd target

http://i1075.photobucket.com/albums/w435/doctnj/Mobile%20Uploads/20151206_130056.jpg


I am going to show the top 3 results for both 100 yrds and 300 yrds and give average velocity and extreme spread for those charges.

This is the first 2 targets at 100 yrds charges are at the top of each target

http://i1075.photobucket.com/albums/w435/doctnj/Mobile%20Uploads/fb5ae071-d9cc-498f-b9a4-224fbad6bee6.jpg

third and final good result at 100 yrds.

http://i1075.photobucket.com/albums/w435/doctnj/Mobile%20Uploads/a29b6950-dc5f-4ad3-8729-7301d8d59b2f.jpg

Now for 300 yrds, (at the bottom of target 1 is a called shank. rushed because of wind changes. more on that later)

http://i1075.photobucket.com/albums/w435/doctnj/Mobile%20Uploads/20151206_144426.jpg?t=1449356443

last good 300 yrd target

http://i1075.photobucket.com/albums/w435/doctnj/Mobile%20Uploads/20151206_144457.jpg?t=1449356879


I dont know if you can tell from the photo but my range is in a valley surrounded by hills and there is always swirling wind, and today was no exceptions. Today was 7 to 14 switching in direction every couple minutes. That one called shank i instantly knew I had pulled it. The wind was changing and I could hear it roaring up behind me so I rushed the shot. I knew that target was shaping up nicely and now it cast a shadow on the results. Since I knew I messed up I did not count it especially considering they were five shot groups anyhow.

And lastly is the velocities for my top three pics.

38.5 - average - 2598 ES - 112
39.0 - average - 2633 ES - 95
39.5 - average - 2670 ES - 95

Tell me want you think

[Rob01]

You can go higher in the powder charge. Most people find a good load between 41.5-43grns with the 140 weight bullets and H4350. The original Hornady 140 AMAX load was 41.5grns of H4350. The books are very conservative. Work up slowly watching for pressure.

[LongRange]

Just to be clear doc...you were getting 100fps extreme spreads?

[doctnj]

Yes that is what I said. I had at least 9 errors so some of the columns were short. There was at least one weird low number in each charge column which skewed the results but even if I take those out it only improves from the mid 90's to mid 60's. Also I wasnt real good on waiting between strings as I should have so Im sure the barrel heated a bit over the 55 rounds. I did wait but not near long enough which is backed up by bad data. Dont know why so many errors though. I thought first maybe it was too close so I moved it further back between 100 and 300 groups. Also raised it up so that the bullet was passing closer to the sensors. you can see in the picture how I have it set up. What do you think on distance? Maybe bad battery. Its a head scratcher for sure.

It did cause me to pull up my data book and look at the averages from some of the store brands and the winchester brand was a lot faster so I have to bring up the charge. At the same temp and atmospheric conditions the winchesters were moving at an average of 2758, where as my fastest load averaged a meager 2732. Also the accuracy of the highest charge I loaded went way down at 300 yards to 1.34 moa.

I have some hand loads from chad in texas that had single digit ES but accuracy was also low. The average speed of those loads were 2769 at 85 degrees but only shot 1 moa. The length of those cartridges were .006 shorter than sammi minimum. Either way, Im going to bump up the load and do it all over again keeping in mind that low end node. And I think Im comfortable calling it an accuracy node.

Beside the crazy velocity spread I thought I had some impressive groups at 300 anyhow. How long would you say I should wait between strings?

off the subject but just found out today that the 20 moa rail for my build gun was not found so we will have to get one sent from Canada. oh well.

[LongRange]

Ok doc please dont take any of this wrong as its meant as help.

First like i said you have a big problem some where either with the chrony or your loads....with that said you shot both the OCW and the ladders wrong...when shooting ladders you shoot one round at xx charge weight then shoot your next higher charge weight at the same point of aim and so on until you have shot all of your charge weights at the same point of aim....what your looking for with a ladder test is charge weights that group vertically...your not looking for tight groups and you dont care where they hit on the target your only looking for vertical....so say 38.5g 39g and 39.5g all group within a 1/2 vertically your charge weight would be 39g+ or - a little.
Now the problem with ladders is you need a good range and good conditions to have good results...you didnt seem to have any of those today.

To shoot an OCW test you shoot 1 sighter at target 1 then one sighter at target 2 then one sighter at target 3 and then your done with those targets...let the barrel cool and then start your test...shoot 1 round of your lowest charge at the new target 1 then give the barrel 5mins or so to cool...then shoot 1 round of your next charge weight at target 2 then give the barrel 5mins or so to cool....you continue until you have shot one round of each charge weight at different targets.
Then you start back at target 1 which is your lowest charge weight and shoot one round of the lowesr charge weight at target 1 let the barrel cool then go to target 2 with the same charge weight yoh shot at 2 the first time....you continue this until you have shot all of your rounds....so youll end up with 3 rounds on each target.

The only time ive had ESs that high is with very light neck tension....the chrony will cause the same thing if the light is coming in at a hard angle...you can take a big box and cut the top out and tape visequeen over the top or a piece of frosted plexiglas will work too.

With all that said none of those groups would sit well with me...a 100fps ES is going to give you 15 to 20 inches of point of impact shift at 1000yds.

Do you know how much neck tension was on those loads?

Id figure out whats causing the high ESs first and then shoot either a ladder or the OCW over but not both...id suggest the OCW with the range conditions you have where you shoot.

[LongRange]

http://optimalchargeweight.embarqspace.com/ocw-instructions/4529817134

Another thing id suggest is to use smaller dots or squares for your targets...a 2" square is hard to hold the same point of aim on.

[doctnj]

You may have just put your finger on it as far as neck tension. You know I had that light tension issue on the other load. I more than likely errored on the light side on these as well. I can remedy that real easy. That also could be responsible for lower velocities. Yeah I knew I didn't follow either but instead did a basterdized version. I'll go by the strict letter next time. But I do think we found an issue that would have ruined it no matter what I did today. I absolutely didn't wait that long between shots. That's about how much I waited between strings. And don't worry man say it as you see it. That's how I learn. I say "hey this is what I did". And you say " well you f'ed that up real good!"

Considering the pressures and velocities will increase with more neck tension, would you just Re run the same charges or start near upper end and go higher?

[LongRange]

As Rob said 41.5 to 43 is where guys are finding loads...id set 43 as my max charge and follow the OCW test to the letter and i bet with in 30 to 40 rounds youll find a one hole load if you do your part.

[doctnj]

Well then I will address the neck tension issue and go that direction. See its all a learning curve.

[LongRange]

try .003 .004 tension on your necks and you should be good.

[Texas10]

Looks like you're settling in for some pretty serious precision load work up. For me, that is the really cool part of target shooting, that and looking back on previous targets and measuring the improvements I've made.

I am no way at precision shooter, especially when compared to some of the sharp shooters on this site that can shoot the legs off a fly at a mile, if you believe everything you read…LOL. But I'd have to agree with LongRange about target size. "Aim small, miss small".

FWIW, you might try downloading some targets from the internet, and print them on Card Stock copy paper. Go to the 6mmBR website and check out the free targets tab. You can find Card Stock at most stores that sell copy paper. It's also called 110 lb. bond. I have found it to be tremendously helpful to have a consistent target picture, and ability to directly compare previous outings. And the heavier weight paper makes for cleaner holes and helps with record keeping.

Good luck!

[LongRange]

tons of free targets here just print them out...

http://www.targetz.com/targets01.htm

i use these...cheap and easy to see...

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/1449495889.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/1449495889.jpg.html)

[doctnj]

Im sure my tension was prob half that or less. I will be checking that step next. Unfortunately I wont be able to get back out to shoot for two weeks. Going out of town next weekend. But I feel pretty confident that even though the test method was "from hell" I uncovered a big problem. I sure my lapua mag test box I have loaded up will more than likely suffer the exact same problem. Mistakes are fine if 1. I learn from them and 2. avoid repetition.

One reason I lowered the tension is because redding actually updated their stance on that issue and suggested only .001. Glad I bought extra right from the get go.

[doctnj]

One more question. How did ammo with such various velocities shoot half moa at 300 yds?

[LongRange]

you jerked the trigger just right lol!

seriously with the riffles your shooting the 1/2 MOA groups arent that great and had you not had 100fps ESs all of those groups might have been much tighter.
as far as the lapua you have loaded if it was me id pull it all apart and re-neck size it as thats not cheap ammo to shoot and no sense wasting it and barrel life when youre most likely going to have the same issues.

[doctnj]

Good point

[Rob01]

More free targets. http://www.accurateshooter.com/shooting-skills/targets/

I like using these at 100 and for 200 and out I use the diamonds on page 8 and 9 in the link from LR.

[jonesturf]

What's your barrel length? I've run 24 and 26 and most of my sweet spots were between 42.6-43.3 gr with the 140 hybrid...typically 42.8-43.0 is a solid load. This is through 4 barrels. Maybe start at 41.5 and work up.

I only run about .002 of neck tension in mine but every rifle is different. I usually jump the hybrids about .040-.060.

I've done the ocw on all 4 barrels and they all end up in that range. I typically run my tests at 300 and go based on POI. Never had a load I picked at that distance that didn't shoot well out to 1k. I don't care much what it does at 100y because it's usually plenty good for me.

[doctnj]

Well Ill let my daughter know this evening that I wont need her to color in anymore target squares for me. lol

Those really are some good ideas, thanks. I made my targets with 6 one inch squares. one for sight in/ foul shots and 5 for loads to be tested.

I was just thinking about it and although my velocities were all over the map, there were down relative to my drop chart I brought with me. I was .2 mills low at 100 and an additional 1/2 mill at 300. So I guess what Im saying is that my chrono was probably accurate because the change in drops went with the slower velocities averages.

Just an observation.

[justinp61]

http://optimalchargeweight.embarqspace.com/ocw-instructions/4529817134

Another thing id suggest is to use smaller dots or squares for your targets...a 2" square is hard to hold the same point of aim on.

I learned years ago while shooting a bow that if I want to shoot small I have to aim small. I normally shoot 1" squares but I aim at the corners, this gives me a defined aiming point. Your mileage may vary.