Rifle load development methods compared

[Varminterror]

What caliber are you shootin

6 creed

 

[Nature Boy]

6 creed

I’ve read that they can be finicky to tune but it doesn’t look it based on your target

 

[Varminterror]

I’ve read that they can be finicky to tune but it doesn’t look it based on your target

I have a gas gun and two barrels down on a bolt gun, plus an RPR I’ve loaded it for. It’s probably fair to say the 6 creed is more finicky than 6 Dasher or the x47 case, but yeah, it’s not picky. I’m not a good shot, and wasn’t trying to be that day, just trying to collect chrono data. And that happened...

I’m hoping a few more folks would play, and I’ll share more data to go with the targets, see if it changes anything for you guys.

 

[JFrank]

My outlook,
There’s a bit of information missing , such as Bullets weight.
You could easily need a few mores increments added to your test.

 

[Legionnaire]

Well, from an OCW perspective, the centers of the 41.2 and 41.4 groups look to be almost identical. That's probably where I'd start, even with the vertical dispersion in the 41.4.

 

[Varminterror]

My outlook,
There’s a bit of information missing , such as Bullets weight.
You could easily need a few mores increments added to your test

I’ll give a little more info on the load then: 105 hybrids, seated in Hornady brass, virgin, BR2’s, seated 6thou off of the lands, COAL 2.785”, H4350, about 300rnds on the 26” barrel at that point, Bartlein 7.5” twist, these groups fired with a SiCo Omega 300 and anchor brake, direct threaded, and a Magnetospeed V3 on the can. Charges thrown by a Chargemaster, and confirmed to +/-0.015grn on a Mettler Toledo MS-603 (yes, counting kernels with a dosing spatula). None of this being information which should be pertinent for analyzing that target under Ladder or OCW paradigms.

This wasn’t the first set of load work up, just a confirmation/repetition to see if my node had moved/shrank/grew/changed as the barrel sped up. The range there is enough to define the node within it, and the target COULD be enough information to make a decision, but a bit of supporting information seals the deal for my uses. But I didn’t need to do a full work up, my increments are smaller and my total range smaller than I normally use for prelim work up.

So @South Prairie Jim - what’s your preference based on that target? And why? Or what’s missing that precludes you from making a pick? I was hoping @NATO Reloadingwould give some input as well.

@MCMXI - I’ve studied a bit in OBT over the years, and share your sentiment that “Quickload is theoretical, but usually does a great job of predicting real world performance.” You noted the variation in dwell time caused by seating depth which isn’t easily explained in OBT theory. One breakdown I have not been able to explain away in OBT theory is the fact nodes typically don’t move despite the barrel time shrinking, then growing again through the life of a barrel as it breaks in, and then wears out.

 

[JFrank]

Well for me since I’m not familiar with that cartridge I would test until signs of pressure, as the test sits 41.4 is ok but
42.4 makes me want to see a bit more

 

[Legionnaire]

42.4 does show the least vertical, but it's center is significantly(?) different from 42.2.

 

[MCMXI]

As I read it it’s 41.0 to 41.6

Yes, I would agree with that based on the group centers not changing much over that range. Now the big question is whether or not the velocity changed much for those four loads. An "OCW" load might not coincide with a velocity "flat spot" .. right?

 

[Varminterror]

Well for me since I’m not familiar with that cartridge I would test until signs of pressure, as the test sits 41.4 is ok but
42.4 makes me want to see a bit more

Good observation, so I can explain, a bit at least, why I stopped at that particular top end limit.

Max loads out there, general consensus at least, for the 105 Hybrid and H4350 is 42.0. I do not have sticky extraction or flattened primers at 42.8grn, but I do exceed the 3200fps speed limit of Precision Rifle competitions to reach the highest node I have tested in 6 creed (highest node is also narrower than the other two I have shot). That 42.4grn load runs ~3160fps, and a hint, it’s not in the node.

As I mentioned, this was confirmation of a single node, so I wasn’t doing a full work up spanning minimum charges up to sticky extraction.

 

[Nature Boy]

Here you go.

http://2poqx8tjzgi65olp24je4x4n-wpe...audettes-20-round-string-load-development.pdf

I stand by what I said. It totally doesn't work. It goes against the laws of physics. If you load more powder with all same conditions, you will get more pressure. This is common sense. More pressure = more velocity. all those flat spots are because of inconsistent loads. That is a fact, not an opinion.

Let me reiterate the reason for my making this post. These are opinions with data to back them up.

Here’s the 100 yard target again. Note the last 2 charges on the bottom right. There was zero change in the average FPS across those charge weights. POI was also identical.



Now, here they are again shot at 500 yards. Low and behold, those last 2 charges show the least amount of vertical.



I use Lapua brass. I don’t weigh sort it because I don’t see the need to. The cases are pretty consistent. Besides, I’ve not seen any evidence that case weight correlates to case capacity.

I use an A&D FX120 scale with Auto Trickler and weigh charges to the individual kernel.

I don’t believe the results noted above, duplicated using 2 different methods, can be attributed to inconsistent loads.

 

[JFrank]

Very good work Gentlemen,
I’m always appreciative of people who take their time and resources to test and post their results.
I was first and not all that many years ago’ introduced to the vertical ladder system. It’s not for everyone and certainly can be difficult to interpret.
Each discipline has there preferred method of load development as it seems to arrive at a common goal.
I’m a big fan of Nature Boy and now Varminterror as well.
Shoot Small y’all
J

 

[JFrank]

Had a bit of wind and mirage today ,
This is shot at 550 in preparation for a 1k coming up , 30.gr at 1.794 gave me 1.7 with 1/2 vertical
That’s the best I could muster today, I’m not sure if it’s gonna be enough’ probably not...LOL

29.9 had a really light neck tension ( note to self- don’t do that again)

 

[Varminterror]

Well, my Sunday afternoon wasn’t quite as lazy as I had hoped. I dug out my sump pump drain line in the yard, completely full of grass roots, and buried a new one. Had water pooling along my foundation every time it ran, and our ground is absolutely saturated, so it ended up pushing through into the basement. No in-flow today so far, but lots of drywall and carpet to get dried out and Kilz treated....

But anyway....

Here’s the Satterlee Velocity curve to go with the OCW target I shared a few days ago. Since these loads aren’t meant for 100yrd shooting, but rather 300-1400yrd matches, minimizing vertical dispersion is critical.



What jumps out at me is the fact 41.6 and 41.8 only show 7fps total spread and 1fps between their averages. The 41.0 and 41.2grn load share an equal average, but I have less confidence in the low count data there, since the SD and ES are considerably larger.

This was my 3rd confirmation with this barrel, so again, I didn’t shoot anything above or below this range that particular day. The objective was to make sure the node was still centered around 41.7, and still running consistently. More shots per load, and a larger range were used originally, and more shots per load are taken to improve the validity of the statistical results, but this is data I had at hand which illustrates a combination of methods which I believe works very well for the particular rifle games I play.

 

[murf]

the static coefficient of friction for those two scenarios is very different. the bullet jammed into the lands should have a much higher coefficient than the bullet .040" off.

just an fyi.

murf

 

[Nature Boy]

This might add more confirmation on the 100 yard load development method’s merit.

Shot a mid range 600 yard F Class match this morning. First match I managed to put all 5 sighters and 20 shots for record inside the 10 (the 10 rings is 6”, or 1 MOA)



Also cleaned the 2nd and 3rd match as well ending up with a 600 - 36x for the day.



I think I’m going to stop tinkering with this load

 

[Walkalong]

I think I’m going to stop tinkering with this load

Ya think?

Great shooting, the load is only the first half.

 

[Nature Boy]

the load is only the first half.

Let me tell you. During the last 6 shots of that last string I was hanging on by the skin of my teeth. There was a light breeze from 12 o'clock that would come over the berm and push the bullet to the bottom of the 10 ring. You couldn’t feel it or see it in the wind flags. The only way you could tell was the intensity of the way the mirage would boil.

On my last shot of the day I was holding 11 o’clock on the top of the 10 ring and it just clipped the outside of the 10 ring at 5 o’clock.

 

[WelshShooter]

I'd say "unbelievable" just because of how awesome that group looks but then I remember that this is @Nature Boy so it becomes completely believable!

It's great seeing all this information and data to support the notion that this style of load development just works.

 

[Nature Boy]

I'd say "unbelievable" just because of how awesome that group looks but then I remember that this is @Nature Boy so it becomes completely believable!

It's great seeing all this information and data to support the notion that this style of load development just works.

That’s kind of you to say.

BTW, my 600 - 36x was good enough for 2nd place.

1st place scored a 600 - 38x. There’s some guys out there that can flat shoot.

 

[murf]

congratulations!

murf

 

[MCMXI]

Yes, great shooting for sure and way better than anything I ever did at 600 yards in F-Class.

I'm hoping to do a 6.5x47mm Lapua bullet seating test for my AX tomorrow at a private range. I have to shoot a couple of Proof barreled Kimber rifles first but I think I'll have time to do my own testing. I put the loads together over the weekend but it's been way too windy at my home range to shoot a meaningful test.

 

[Nature Boy]

Looking forward to seeing it

 

[MCMXI]

Looking forward to seeing it

We spent most of the morning shooting some new rifles and then right at the end when everyone had to get back I shot the five loads shown below. I should have packed up and headed back to the office rather than shoot the AX but it is what it is. The only thing I learned is that the pressure was excessive with .020" jump to the lands, and that I like using Varget for this rifle rather than H4350. I'll repeat the test this weekend at my home range if the wind lets up.

 

[Nature Boy]

We spent most of the morning shooting some new rifles and then right at the end when everyone had to get back I shot the five loads shown below. I should have packed up and headed back to the office rather than shoot the AX but it is what it is. The only thing I learned is that the pressure was excessive with .020" jump to the lands, and that I like using Varget for this rifle rather than H4350. I'll repeat the test this weekend at my home range if the wind lets up.

View attachment 844957

Touching looks good. I get a lot of internet advice saying not to load at touch. Either in or out but not touch. I don’t necessarily subscribe to that but I understand the logic, particularly when you’re shooting long strings in a competitive format. The throat is changing.

Having said that, my .308 shoots its smallest at touch so that’s where I load them.

Have you done a primer test? If not, I’d take that load at touch and shoot some with different primers