Anyone know what happened in this ladder?

[flyfisherman246]

I ran (2) 10 shot ladder test with my .308 watching the magneto speed. Not sure if anyone has done this 10 round ladder test as seen in this video.



But as you can see, the first time I ran through it (column on the left) there seems to be a velocity flat line between 43.0 and 43.6. There is also another one between 44.4 and 44.8. Things are going as planned. Then 15 minutes later I shot it again and that is the column on the right. There seems to be a node between 43.6 and 44.0 which is exactly what didn't look good in the first test. The far right column shows the ES's between the first round and the second round. All this ammo was loaded at the same time. The only think I could think of possible making a difference was my rifle came out of a warm truck for the first set and then sat out in the cold for a bit for the second set. The ammo was all cold except for the 10 minute ride to the range. This is all once fired, trimmed and uniformed lapua brass. Any ideas what any of this means and where to go from here?

Thanks

 

[mheimer_45]

I have no idea what happened but if it were me I would load up 5 of each of 42.8, 43.0, 43.2, & 43.4 and shoot for groups. Anything over 44 grains of Varget seems like a lot in Lapua brass to me. If you want to try the higher node go for it. But that’s what I would do.

 

[IanHusaberg]

I would wait until it warms up to the temp range you normally shoot. Is the barrel brand new?

 

[flyfisherman246]

In Montana. 17 degrees isn't that far from normal a lot of the year. (Have hunted and shot in 40 degrees colder) The barrel is pretty new, but it has been broken in and not copper fowling. It has about 150 rounds through it.

 

[flyfisherman246]

Forgot to mention the barrel had about 40 round through it since it was cleaned last also. So not an issue of clean vs dirty bore.

 

[Sheldon N]

I find it best to visualize with an excel graph...

If it were me I'd be looking at around 43.2. 44.0 is another good option. Things flatten out around 44.4 again but for my purposes that's too close to pressure especially since you're doing load development in the winter.

 

[Diver160651]

How are you judging neck tension between the rounds?

I have a Abor with a force gauge that shows differences not seen (felt) when seating in my Forester or Redding. The smallest amount in neck tension resultes in velocity changes. With such a small sample it is hard to know what is causing your ES.

Just look at how lower charges are producing as high as velocity as some of the groups above.

I’d bet you have neck pressure influenced (if not other) velocities.. so if you’re going to use such low round count to identify a flat spot, you’d better have perfect brass, bullets and confirmed seating pressure.

I done kinda the same for ELR loads when looking for max pressure only 1 round per charge weight over sorted weight, o2 brass and bases to Ogive or solids. But if the seating is not exact that round gets a new piece of brass.. I only test those with the same seating pressure etc.

 

[steve123]

I ran (2) 10 shot ladder test with my .308 watching the magneto speed. Not sure if anyone has done this 10 round ladder test as seen in this video.



But as you can see, the first time I ran through it (column on the left) there seems to be a velocity flat line between 43.0 and 43.6. There is also another one between 44.4 and 44.8. Things are going as planned. Then 15 minutes later I shot it again and that is the column on the right. There seems to be a node between 43.6 and 44.0 which is exactly what didn't look good in the first test. The far right column shows the ES's between the first round and the second round. All this ammo was loaded at the same time. The only think I could think of possible making a difference was my rifle came out of a warm truck for the first set and then sat out in the cold for a bit for the second set. The ammo was all cold except for the 10 minute ride to the range. This is all once fired, trimmed and uniformed lapua brass. Any ideas what any of this means and where to go from here?

ThanksView attachment 6877434

You've spent all this time thus far with no concrete results, that's assuming you didn't shoot at distance while doing this test.

Do a real ladder test at 300-400Y, on a calm morning, and let the barrel cool between shots, foul and warm the barrel with 2-3 shots beforehand. Finalize by doing a seating depth test at 200Y.

Sometimes the least vertical at distance does not correlate with the smallest ES, or a flat spot in velocity, because a node is based more off when in the barrel timing the bullet exits from the muzzle. Also just because a load shoots good at 100Y doesn't mean it produces the least vertical at distance.

Let the paper show you what the barrel likes, and to make sure, do the real ladder in .1 grain increments. You already know from your work so far that 44.8 can be omitted from the test so that saves some time and it wouldn't be a bad idea to stop at 44.6 because summer is coming. I'm putting my bet at 44.5/literally just guessing, because it's usually the high node that shoots best. Besides with a 308 you need all the speed you can get and barrel life isn't as much a concern.

 

[MarkLeupold]

You shot two at each charge weight. Now, I'm not doubting your reloading skill, but this method is HARD to do in 10 shots. You basically have to have every charge, every case, everything perfect, otherwise you're not getting a good look at what's really going on. I am going to use this method myself, but with 5 shots at each charge. It's more work, it's more shooting, it's more barrel life, but I believe it's worth it until I really dial in my reloading technique for this particular method.

 

[schmi015]

load up 10rds at 44 grains and go shoot 5 at 100yds and 5 at 200yds

 

[flyfisherman246]

Thanks so much for all the help. I really do appreciate all the advice. I went out today with 43.0- 44.8 and shot 4 shot groups. Once again its all contradicting itself. The best group today was at 43.6 but looking at the velocities, that was right between the node of the first time firing and the second time. So it wasn't even close to the middle of either of the velocity nodes. Also looking at the es of the first round of testing between the first firing and the second, 43.6 had about the worst es between the two firings. So I just don't understand what the correlation is here. Nothing is lining up. I think I'm just going to load some 43.6 up tomorrow, shoot 5 over the magneto speed and then shoot some at distance to see what happens. From what I am seeing, my best accuracy is about where the worst velocity consistency is. Any ideas? Thanks again.

 

[flyfisherman246]

Also forgot to mention, I came up .2 mils after the 43.0 group.

 

[supercorndogs]

Thanks so much for all the help. I really do appreciate all the advice. I went out today with 43.0- 44.8 and shot 4 shot groups. Once again its all contradicting itself. The best group today was at 43.6 but looking at the velocities, that was right between the node of the first time firing and the second time. So it wasn't even close to the middle of either of the velocity nodes. Also looking at the es of the first round of testing between the first firing and the second, 43.6 had about the worst es between the two firings. So I just don't understand what the correlation is here. Nothing is lining up. I think I'm just going to load some 43.6 up tomorrow, shoot 5 over the magneto speed and then shoot some at distance to see what happens. From what I am seeing, my best accuracy is about where the worst velocity consistency is. Any ideas? Thanks again.View attachment 6877798

You don't find a node by looking at velocity, finding a node is OCW. It is about common POI at 100y. It based off what Steve was explaining, that your POI is changed by harmonics, not just velocity.

 

[Sheldon N]

I would personally choose around 43,9 or 44.0g, then tweak seating depth to see if you can tighten groups further. You can see POI of your groups move from 43.3 to 43.6 and again from 44.2 to 44.5, but around 43.9 the group position stays the same both above/below. That's likely to be more forgiving. Then if you look back at the velocity data, there is a bit of a flat spot around 44g where the velocity spreads also tightened back up.

Problem with all these load development methods is that you're reading tea leaves trying to figure out what will shoot best at distance. Only real way to know is go shoot at distance.

 

[Diver160651]

Just tossing that out that 43.5 Varget pushing a 175 lead core bullet is about as standard a 308 load you will find. I am running, 43.6 Lapua brass 175 SMK

It generally will works on 18” -28” barrels equally.. OWC, Ladders, or OBT as used in Quick Load all work with barrel timming. Ladders or additions of chronos add in velocity windows. In the end, they get to the same point. If you look at Quick Load and predict Barrel Timming.. you’ll be surprised how close the OCW will conform. Rather than shooting the ladder, the Chrono can step in and predicte the large velocity spreads that show up at 300-400.

The point being, if you model with QL, you can load only a few in your predicted velocity needs, shooting as an OWC over a chrono, you get to your load just as fast as the video. Plus you have the warm feeling of all methods agreeing.

 

[IanHusaberg]

Nice shooting. 43.6 looks good to me! The paper is telling you it's a good load at 100y. Maybe you should move it out to distance? 200,300,400?

 

[supercorndogs]

If I was reading your 4 groups as an OCW 43.5-43.6 would be where POI is consistent. You might keep an eye on primer pockets though. I got ejector marks on about 15% at 43.5 in Lapua brass. 43.5 was my load in Hornady Match brass.

 

[Conrad]

I would personally choose around 43,9 or 44.0g, then tweak seating depth to see if you can tighten groups further. You can see POI of your groups move from 43.3 to 43.6 and again from 44.2 to 44.5, but around 43.9 the group position stays the same both above/below. That's likely to be more forgiving. Then if you look back at the velocity data, there is a bit of a flat spot around 44g where the velocity spreads also tightened back up.

Problem with all these load development methods is that you're reading tea leaves trying to figure out what will shoot best at distance. Only real way to know is go shoot at distance.

This analysis is correct. Run 44 and be done with it.

 

[flyfisherman246]

I went out yesterday to reconfirm accuracy at 100 yards and chrono. Fired 6 rounds over the chrono and the es was 24. The accuracy great. All rounds touching. One 3 shot group was in the .1's. Not too happy with the es's though. Thinking about trying the same thing with 43.5 and seeing if the accuracy and low es's are there.

 

[Diver160651]

I went out yesterday to reconfirm accuracy at 100 yards and chrono. Fired 6 rounds over the chrono and the es was 24. The accuracy great. All rounds touching. One 3 shot group was in the .1's. Not too happy with the es's though. Thinking about trying the same thing with 43.5 and seeing if the accuracy and low es's are there.

Until you use something that either segregates by seating pressure or somehow otherwise control near uniform neck tension your ES will most likely be higher than you want on a 3o8 with large primer. That s an issue the guy in the video did not address and frankly often way overpowers .3 grain increments.

This is way many BR guys uses Arbor seating dies. Going a step further, you can add force gauges. K&M and 21st Century both have force gauge seating presses.

 

[flyfisherman246]

The brass is neck turned and using a redding bushing to size down 2 thou. I usually anneal after the third firing so it should be pretty factory like at 2 firings. This should be pretty consistent neck tension, shouldn't it? Thanks again for all the help

 

[Diver160651]

The brass is neck turned and using a redding bushing to size down 2 thou. I usually anneal after the third firing so it should be pretty factory like at 2 firings. This should be pretty consistent neck tension, shouldn't it? Thanks again for all the help

Not always. On my K&M with force gauge I can easily get some seating at 20lbs one others at 70 doing the same as you, but sort. While I can feel the seating difference on my Forster or Redding between <20 and >70lbs, I can NOT really in between.

If I anneal every time, they get more consistent, but seat with to low of seating pressure for positional matches were you do NOT want to be jammed. If you jump and have much lower seating pressure 40bs on a 308 with a large primer, ES is about where you are. If you have with jump, a small case like a 308 with large primer and really low NT, it appears (my guess from logging seating pressure vrs velocity) that with the larger primer, ultra low seating pressures and jump allow for less even ignition as the bullet can be push out a bit premature. Of course, if you are a bench rest guy you can soft seat into the lands and most likely use small primer cases or cartridges with higher powder to primer size..

 

[isofahunter]

My 2 cents is 44.2 gr but shoot it at distance 400 yards. I look for vertical dispersion first when adjusting powder, look for a load with the smallest vert then tinker with seating depth and sometimes add a crimp to see if that improves things. 44 to 44.2 based on your data is where I would start, but as has been said shooting at distance reveals more than at 100 but seeing a flat spot in velocity and very little vertical dispersion in that 44-44..2 range based on what you have shown so far.

 

[Diver160651]

My 2 cents is 44.2 gr but shoot it at distance 400 yards. I look for vertical dispersion first when adjusting powder, look for a load with the smallest vert then tinker with seating depth and sometimes add a crimp to see if that improves things. 44 to 44.2 based on your data is where I would start, but as has been said shooting at distance reveals more than at 100 but seeing a flat spot in velocity and very little vertical dispersion in that 44-44..2 range based on what you have shown so far.

Guys you can not look at the flat spots and make an educated guess as the noise (ES) at the same charge weights is way to high and the sample size to small. That’s is the problem with this particular method.

Besides 44.2 is crazy hot for Lapua brass, 175 to use as a middle load.. 44.2 is on the edge of the move... what happens it he drops a bit more kernels? POI change

 

[flyfisherman246]

That seating pressure makes a lot of since. However, I am not willing to go through all that effort for what I do. I shoot rocks and steel and like to shoot 100-200 rounds a week in the summer time. I shoot in prs matches, and I long range hunt. I just shoot too much to be worried about all these little bench rest loading techniques. That being said, what is an acceptable es for I guess what you could call a "tactical" style bolt gun with my loading techniques? Thanks again.

 

[steve123]

That seating pressure makes a lot of since. However, I am not willing to go through all that effort for what I do. I shoot rocks and steel and like to shoot 100-200 rounds a week in the summer time. I shoot in prs matches, and I long range hunt. I just shoot too much to be worried about all these little bench rest loading techniques. That being said, what is an acceptable es for I guess what you could call a "tactical" style bolt gun with my loading techniques? Thanks again.

I feel the same way and have been plenty happy with the same type of shooting you do with 6-7SD - square in the middle of the high node.

 

[Greg Langelius *]

I don't correlate Velocity, ES, or SD to accuracy, and my Chrony has gathered dust since moving to AZ going on two years ago. I pay attention to pressure signs, weigh every charge to .1gr, and count solely upon the target to indicate where my OCW turns out to be. I shoot five round groups and average 3 of them for each increment to take random variation at least into some account.

When I have my accuracy load, I usually assemble up at least 100 rounds of it, maybe several hundred of it, to have onhand for future needs; and then move on to the next load development project. So doing as many groups as I do is a reasonable investment in reliable accuracy.

Greg

 

[isofahunter]

That seating pressure makes a lot of since. However, I am not willing to go through all that effort for what I do. I shoot rocks and steel and like to shoot 100-200 rounds a week in the summer time. I shoot in prs matches, and I long range hunt. I just shoot too much to be worried about all these little bench rest loading techniques. That being said, what is an acceptable es for I guess what you could call a "tactical" style bolt gun with my loading techniques? Thanks again.

As this thread demonstrates everyone has a different way of doing it and everyone had a different standard of what is acceptable. I like to shoot more than reload much like you. My method involves a ladder test at 300-400 then picking the node. I then shoot 5 shot groups varying the load up and down .2 gr either side. Usually I stop there but sometimes will tinker with the seating depth and crimp. My 308 load has ES of 16 and SD of 8 and is .75 MOA out to 950 yards if the nut behind the rifle is tight. I use Lee Dies, Cabela's electronic scale and a 40 year old RCBS powder thrower. My time is better spent shooting than trying to get those numbers smaller.

 

[Diver160651]

That seating pressure makes a lot of since. However, I am not willing to go through all that effort for what I do. I shoot rocks and steel and like to shoot 100-200 rounds a week in the summer time. I shoot in prs matches, and I long range hunt. I just shoot too much to be worried about all these little bench rest loading techniques. That being said, what is an acceptable es for I guess what you could call a "tactical" style bolt gun with my loading techniques? Thanks again.

I was not activating that you should go slower or need to drive down your SD/ES. Actually, you do NOT need to go slower to lower the ES.

I'm just answering the questions.. I am saying if one is to use the 10 round thing in the video, well then it all has to be loaded perfectly or neck tension issues and case volumes will override the small powder charge changes and hide the results in the noise. New brass might actually be far easier choice on this one, or cull-out outliers by seating pressure.

But ya, I shoot Prime and other factory in steel matches.. I can no longer keep up by hand loading for two shooters. But, I am still hand loading for other systems.

That said, again, if you are hand loading In a single stage, you’re not giving up speed by seating on an arbor press. Sorting is ultrafast just by how you drop them into your MTM ammo box or ammo binder easy to keep them organized.

I Print inserts for the MTM boxes and can track each cell or row, or just toss in lightest to hardest... for ammo binders I use yellow masking tape.. or do the same lightest to firmest. In the Ammo Binder see the yellow tape in the upper left binder showing the row of unacceptably light rounds. I'll try to get a better image up later these were all I had on flkr. There are a bunch of different calibers in the ammo binders (Tab Gear and Softcock's).

Softcock's ammo binder F/S here on the hide https://www.snipershide.com/shootin...binders-223-to-50.6257976/page-2#post-6927390
Tab Gear are the larger ones -- open on the right