Ladder test question or thoughts?

[mtmojo]

Question on ladder tests and picking a load:
69.1 - 2873 very slight primer flattening but not the top end of where I could still go.
68.9 - 2875
68.7 - 2862
68.5 - 2828
68.3 – 2823
I’m shooting a SA where due to the limits of my mag I don’t even try to find the lands. I start off seating a bullet to find what fits max mag length and start my ladder test. Then from the results above I’d typically choose 68.9 (in this instance) being that it’s the bottom end of the node. I realize with a new barrel I have a lot of barrel life with this load, but as the barrel breaks in and I get some erosion my pressures will change, and I’ll have to make changes. But if I were to go towards the top end of the node I will stay “inside” the node longer and not fall out of the node as fast. So, my thinking is that after I’m past the speed up it might prolong my accuracy node to be in the higher side of the powder charge to stay in the node longer.
I’m setting aside the thoughts of in warmer temps and that I might get into more pressure signs once it’s warmer. I also realize it might be better to seat maybe 10K deeper into the mag to allow for throat erosion and adding seating longer later, thus giving me an additional option to get back into the node. Right now, I’m just thinking of staying inside the node longer before I must make changes. I also realize there's a node around 68.4 but not looking at that at the moment. Thoughts?

 

[Marbles]

I'm of the opinion nodes are an artifact of small groups, so only do ladders to check for pressure.

Unless you are talking average velocity for 10-30 rounds, those numbers probably don't mean much.

That said, I'm a dirt bag reloader that tries to keep it simple as I can over think how to walk down a hallway. So, feel free to chase what tickles your fancy.

 

[WeiserBucks]

This is hunting, nodes don't exist. Ladders are for insurance claims.

 

[Koda_]

What am I missing or there are no nodes in that list just a velocity ladder?

 

[Jason Snyder]

Ladders are for insurance claims.

And Christmas lights to keep my wife happy.

 

[Legend]

You would have to shoot a lot of rounds to see a meaningful difference in a 0.2 grain ladder. Like a lot. Maybe a 100 would do it....in each ladder....maybe. I wouldn't bother with anything more detailed than 1.0 grain increments for a relatively high weight load.

With respect to nodes. I hate to say it but I am with the hornady guys and don't believe it is a real thing. I think it is too small of sample and makes for happy coincidences. That is what I see in your velocity data.

 

[jfk69]

Why are you wasting components running a velocity ladder in .2 grain increments on a case taking almost 70 grains of powder?!? And how do you determine a “node” exists with one shot?

 

[Megalodon]

you said node 9 times in that post

 

[Harvey_NW]

you said node 9 times in that post

I node-iced that too

 

[TaperPin]

Speed nodes (velocity flat spots) are interesting - Gavin at UR did a 50 shot and it would have been cool if he went clear to 100 shots. I’ve not spent any time on it since a fella could shoot 100 rounds with 3 different powders, burn up 1/3 the barrel life, and not have a load that is accurate. I don’t knock anyone who enjoys burning powder, Lord knows rifle ranges are full of engineers doing calculus on all kinds of results - whatever makes someone happy.

 

[SDHNTR]

.2 gr increments? Are you a hunter? If yes, you are wasting your time.

 

[BBob]

What am I missing or there are no nodes in that list just a velocity ladder?

I suppose he’s thinking he found a “node” due to a flat spot in velocity. Is this a one shot ladder? Three shot ladder? Was it repeated with the same results? A velocity flat spot doesn’t necessarily indicate a “node”. Not enough info to even form an opinion.

 

[sndmn11]

Question on ladder tests and picking a load:
69.1 - 2873 very slight primer flattening but not the top end of where I could still go.
68.9 - 2875
68.7 - 2862
68.5 - 2828
68.3 – 2823

Thoughts?

I'd bang away at 68.3grs and quit fiddling around.