Which Powder Charge Would You Go With?

[mjl650]

Newby here working up loads for my 6.5 CM. Shot these test loads yesterday at 100 yards. Hornady once fired brass neck sized only, Federal 210m primers, H4350 powder with Hornady 120 ELD-m bullets. From previous testing powder weights between 43gr and 43.5gr seem to group well but 44.8gr was the best group here(maybe just luck). Should I stay in the 43/43.5 range or venture into the higher charge weights? I'm only a casual shooter competing against myself with a goal of bettering a 3 shot clover leaf(all 3 touching)at 300 yards with factory ammo.

 

[dsculley]

If 43.5 was a good node then I would expect the next node to be ~44.8. 44.8 has similar point of impact to the charges above & below it. I would test 44.8 some more. If it were me, I would now load up 5 - 10 rounds at 44.6, 44.8 & 45.0 and shoot these at distance to see how they hold up and if they all share the same point of impact. If it were me, I would set up 3 targets at 300 - 600 yds, whatever you have available and shoot a blind bag test round robin style. Just remember that the longer the range, the more wind and mirage will affect the results.

 

[Prose]

I would expect the next node to be ~44.8

DSculley, why do you expect the next node to be at 44.8? Asking because I don't know.

 

[mjl650]

If 43.5 was a good node then I would expect the next node to be ~44.8. 44.8 has similar point of impact to the charges above & below it. I would test 44.8 some more. If it were me, I would now load up 5 - 10 rounds at 44.6, 44.8 & 45.0 and shoot these at distance to see how they hold up and if they all share the same point of impact. If it were me, I would set up 3 targets at 300 - 600 yds, whatever you have available and shoot a blind bag test round robin style. Just remember that the longer the range, the more wind and mirage will affect the results.

Thanks, good info. I'll get some loaded for my next trip to the range and see what happens. I know what round robin style is but what is a blind bag test? I need to be educated, like I said Newbie.

 

[Mikemci]

DSculley, why do you expect the next node to be at 44.8? Asking because I don't know.

Typically, nodes are 3% apart and 43.8 is 43.5 plus 3%.

 

[Prose]

Typically, nodes are 3% apart and 43.8 is 43.5 plus 3%.

I’ve never read anything about nodes being 3% apart and haven’t seen it referenced here before (May have missed it). Can you point me towards a technical article or thread on the subject?

 

[Tommie]

I’ve never read anything about nodes being 3% apart and haven’t seen it referenced here before (May have missed it). Can you point me towards a technical article or thread on the subject?

Watching...

 

[AJC]

I’ve never read anything about nodes being 3% apart and haven’t seen it referenced here before (May have missed it). Can you point me towards a technical article or thread on the subject?

I would guess this is either highly technical and would be in a barrel resonance article which takes a huge effort to understand or just his experience. If it's the article brew a big pot of coffee because there no fun IMO.

 

[AJC]

http://forum.accurateshooter.com/threads/is-node-spacing-predictable.3928025/

 

[Dusty Stevens]

Got 3 words for you- carolina load. Tweak that powder charge a bit and youll like it way better than 4350

 

[dsculley]

I got the 3% from Dan Newberry of the OCW test method. He has a lot of data from loads that have been developed over the years and he has found that typically nodes will be ~3% apart. When testing, if you don't see where you need to be you can identify a scatter and 1.5% either side of that should be close. It has worked for me.

Dusty, what was the 3rd word?

 

[Raythemanroe]

I don't see anything printing similar


Ray

 

[Doom]

The charge increment should be 0.3 grains.

 

[Forum Boss]

Well, 44.8 looks excellent, but honestly I don't think you can conclude much from this. You haven't mentioned seating depth? And are you single loading vs. running from magazine?

What is your rear rest/rear bag? What is your front rest, or bipod? What is the stability of the bench, or are you shooting from the ground?

Are you using wind flags?

Do you contact the rifle with your face/head during shooting?

If you are not using flags, if you don't have a really good rear bag and a quality front rest or F-TR type wide, stable bipod, I honestly don't think you can conclude anything whatsoever from the target you posted.

Honestly, for some of the 6 groups, there is way more vertical at 100 yards than would come from a small load change -- you are outside NODE tweaking. That tells me there are rifle support issues, bipod hop issues, gun handling issues. Also, what is the barrel, what trigger? If you are shooting a factory barrel in a tactical style chassis off a small-footprint bipod, you'll never do better than this, so just load for good brass life.

With those Hornady bullets, you should also be checking base to ogive lengths. You may be surprised.... Also, with Hornady brass, it may be kind of pointless to do elaborate load testing -- after a couple more firings, that brass is not going to be working so well. Also you state you have neck-sized only. Another reason you can't conclude very much... as you will have to start FL-sizing and that could change EVERYthing.

 

[mjl650]

Well, 44.8 looks excellent, but honestly I don't think you can conclude much from this. You haven't mentioned seating depth? And are you single loading vs. running from magazine?

What is your rear rest/rear bag? What is your front rest, or bipod? What is the stability of the bench, or are you shooting from the ground?

Are you using wind flags?

Do you contact the rifle with your face/head during shooting?

If you are not using flags, if you don't have a really good rear bag and a quality front rest or F-TR type wide, stable bipod, I honestly don't think you can conclude anything whatsoever from the target you posted.

Honestly, for some of the 6 groups, there is way more vertical at 100 yards than would come from a small load change -- you are outside NODE tweaking. That tells me there are rifle support issues, bipod hop issues, gun handling issues. Also, what is the barrel, what trigger? If you are shooting a factory barrel in a tactical style chassis off a small-footprint bipod, you'll never do better than this, so just load for good brass life.

With those Hornady bullets, you should also be checking base to ogive lengths. You may be surprised.... Also, with Hornady brass, it may be kind of pointless to do elaborate load testing -- after a couple more firings, that brass is not going to be working so well. Also you state you have neck-sized only. Another reason you can't conclude very much... as you will have to start FL-sizing and that could change EVERYthing.

Thank you for the candid response, much appreciated. Like I said newbie to all this and I'll take all the pointers I can get.
More info on my setup:
Seating depth .020" off the lands.
Single loading.
Front rest is a Bald Eagle Triangle. F class bipod is on my bucket list along with numerous other items
Rear bag is a Protektor #13 rabbit ear.
Shooting off a heavy unanchored wooden bench.
No wind flags but there was an estimated 3-4 mph wind.
Try to shoot with as little face contact as possible, learned that from shooting air guns.
Barrel is a K&P 24" Sendero with a 1 in 8.
Trigger Tech Special set at 1lb 8 oz.
Stock is a B&C LR.

I'm basically using up the Hornady brass I've collected shooting factory ammo and once I'm confident enough with my reloading process I'll spring for better brass. Having shot 300yd sub .25 moa groups off an Atlas bipod with factory ammo with this rifle I'm just trying to get to that point again with my reloading.

 

[Mikemci]

.25" at 300 yds, or .25 moa ?
If you can do that with factory ammo, why do you want to reload?

 

[mjl650]

.25" at 300 yds, or .25 moa ?
If you can do that with factory ammo, why do you want to reload?

You beat me to it MOA, fixed. Although I did get a 0.183"/.058MOA once off the rest.

I ask myself the same question sometimes. Keeps me busy and my mind active besides being fun.

 

[Forum Boss]

Thanks for details. Sounds like you actually have a decent set-up (though I'm not real familiar with K&P Gun Co. barrels (http://kandpgunco.com/). Perhaps I went into too much detail, but I often see much worse OCW charts and I find the guy is shooting with a $200 scope on a Chinese bipod, with a 4-lb trigger, with a factory barrel and he's trying to discern load differences to the tenth of the grain.

As noted, looks like 44.8 is promising. My advice though -- get some Lapua brass. Nothing wrong with Bald Eagle rest and Protektor bag. If you don't have one already, you might configure a front bag rider if that B&C stock isn't flat in front.

You wrote: "Having shot 300-yard sub .25 MOA groups off an Atlas bipod with factory ammo." -- I know that is possible, but you should know that is pretty extraordinary. Quarter-MOA at 300 is what Championship level F-Class shooters try to achieve with their $5K+ rifles. To do that with factory ammo is pretty amazing. Maybe that's a very exceptional barrel.

You wrote: Front rest is a Bald Eagle Triangle. F class bipod is on my bucket list along with numerous other items
Rear bag is a Protektor #13 rabbit ear.
Shooting off a heavy unanchored wooden bench.
No wind flags but there was an estimated 3-4 mph wind.
Try to shoot with as little face contact as possible, learned that from shooting air guns.
Barrel is a K&P 24" Sendero with a 1 in 8.

 

[riflewoman]

One other thing...you need far more data to be conclusive. So of that 44.8 load, duplicate it and shoot Three 5 shot groups of that load and two 5 shot groups at 44.6 and 45.0 . Look for 4 data points. Mean Point of impact, maximum height, maximum width, and group size for each group and the aggregate group.

if you do this at 200 yards it might be easier to see the individual shot holes clearer.

 

[lawman29]

The most important point is that you have a "process/method" that you are going to use to develop a load. There are many opinions on what that should be...but you should have one before you start. (I'm going to do test A, then B, then C, etc...). Sit down and write down your process...if you follow it you should get a positive result.