I usually seat the bullet for what it calls for from the book or bullet makers website, then I start low on charge and work up till I get good groups but what if my es is high say 30 fps it would mean my load is not good cause the high es. So Cortina says to start with seating depth 20 thousands shorter than what your bullet jams into lands, for 223 that would put me at 2.290, work up charge till you get low es and don't worry about group till you get that, once you do then go down on seating depth till groups are good and pretty much your done, besides getting at least 2 good and seating accordingly. Well the bullet manufacturer is saying to seat at 2.225 so it will take a lot of shots to get there from 2.290 if it does shoot better at 2.225 so now let's say I have a good powder charge and my bullet shoots best at 2.225, well the pressure is going to increase and is my es still gonna be good like when I started at 2.290 to find that charge. I will also say that I'm getting good groups at 2.225 and I tried making it longer and the groups fell off more the longer I made it, I went to 2.250 and stopped there cause it kept getting worse. Because of the cold and lots of snow here I haven't been using the Chrono so my groups are good at 100 and hopefully my spreads are low, if not, then what, change powder, primer? But my main question is why not seat or at least start where manufacturer recommends and if my final seating is very far from where I worked up charge will the charge stay the same, I don't think it would.
Powder charge and seating depth
- Thread starter 6pakzak
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Without getting to far in the weeds watch Scott Satterlee's video on Load Delepoment and see if that helps. The powder test is looking for nodes where velocity levels off and the the charge increases. And then you start the Seating tests as Cortina suggest..
If you are measuring the 20 tho off jam and then working it down in 3 tho increments looking for that node, don't worry about what the book calls for on COAL.
If you are measuring the 20 tho off jam and then working it down in 3 tho increments looking for that node, don't worry about what the book calls for on COAL.
WildRose
Well-Known Member
I like to keep it simple. I work up the most accurate load I can starting with bullets loaded to just short of mag length.
Once I have an accurate load, then I try tweaking seating depth.
Once I have an accurate load, then I try tweaking seating depth.
When doing the powder tests I normally take 20 to 30% under what the book says is the "Max" charge and then work back up in .3 gn incriminates to pressure
Always start as close to the lands as possible. Then you only have one way to go.... shorter.
Some rifle and bullets combos you can't reach the lands [most factory rifles] then load them as long as that combo allows.
Some rifle and bullets combos you can't reach the lands [most factory rifles] then load them as long as that combo allows.
Mikecr
Well-Known Member
Your concerns are right, and what you're seeing is typical in that approach.
The reason grouping falls apart with your seating testing is because your doing the testing from your powder node.
That testing is then collapsing the powder node -causing 2 big changes at once.
It's tail chasing.
My approach is to mostly follow Berger's recommended full seating testing. A key point in that is to lower the charge considerably for the testing. I don't know, they may suggest that for safety, but it's actually critical to best results. It should reasonably take you away from any powder node, and with that you can focus more on results of seating, even while grouping is large at that point.
THEN, with best coarse seating, you can move into powder testing for either tightest grouping or low Es, or best cold bore accuracy, etc. Your choice. THEN after powder with best coarse seating, move to fine tweaking of seating (inside it's window) for tightest group shaping.
This doesn't take more shots, as full seating testing can be done while fire forming brass, and it doesn't take a lot of shots for coarse testing with Berger's recommended increments.
Another worthy point in this approach is that you'll be going into powder with tested seating, instead of something pulled out of somebody's butt. After all, how can a bullet maker or anybody else predict where your COAL should be? They know nothing of YOUR chamber throat.
If you go by their guess then how do you know your seating -during powder testing- was not the worst possible? This, potentially causing really crappy ladders, and masking best powder load.
The same applies to primer swapping. It's likely a waste of effort to do that from a good powder node..
The reason grouping falls apart with your seating testing is because your doing the testing from your powder node.
That testing is then collapsing the powder node -causing 2 big changes at once.
It's tail chasing.
My approach is to mostly follow Berger's recommended full seating testing. A key point in that is to lower the charge considerably for the testing. I don't know, they may suggest that for safety, but it's actually critical to best results. It should reasonably take you away from any powder node, and with that you can focus more on results of seating, even while grouping is large at that point.
THEN, with best coarse seating, you can move into powder testing for either tightest grouping or low Es, or best cold bore accuracy, etc. Your choice. THEN after powder with best coarse seating, move to fine tweaking of seating (inside it's window) for tightest group shaping.
This doesn't take more shots, as full seating testing can be done while fire forming brass, and it doesn't take a lot of shots for coarse testing with Berger's recommended increments.
Another worthy point in this approach is that you'll be going into powder with tested seating, instead of something pulled out of somebody's butt. After all, how can a bullet maker or anybody else predict where your COAL should be? They know nothing of YOUR chamber throat.
If you go by their guess then how do you know your seating -during powder testing- was not the worst possible? This, potentially causing really crappy ladders, and masking best powder load.
The same applies to primer swapping. It's likely a waste of effort to do that from a good powder node..
Some of my most accurate loads in my 223 bolt rifle are longer than the Hornady reloading book says.
I load 3 at a time and start with book max OAL and load 3 a tad longer and keep going up until I reach a positive node.
Some loads on 77 gr Sierra are just inside mag length.
Try different seating depths and see what happens
I load 3 at a time and start with book max OAL and load 3 a tad longer and keep going up until I reach a positive node.
Some loads on 77 gr Sierra are just inside mag length.
Try different seating depths and see what happens
waveslayer
Well-Known Member
Don't follow the book, it is to keep everyone from getting sued. Do your own work ups for powder charge. Seating depth will be decided on what YOUR barrel likes and if you have mag restrictions.
Read on a proper OCW test by Dan Newberry. Find a good node and then do a seating depth test. I always start all load development at .030" off the lands. when I measure touching the lands, I always subtract .003" for a safety factor... so in reality I am starting at .033" off the lands.
Most of my guns are loaded to max or above what is published.... Most nodes are towards the high end of the powder charge or too low that the velocity isn't there.
Read on a proper OCW test by Dan Newberry. Find a good node and then do a seating depth test. I always start all load development at .030" off the lands. when I measure touching the lands, I always subtract .003" for a safety factor... so in reality I am starting at .033" off the lands.
Most of my guns are loaded to max or above what is published.... Most nodes are towards the high end of the powder charge or too low that the velocity isn't there.
I watched video, did he first adjust the seating and then do powder?
waveslayer
Well-Known Member
You can do it either way in reality, there is no magic load. There is a big discussion on this over on the Hide. Bryan Litz basically said neck tension doesn't matter, etc etc. to summarize, there are several loads that will just work with all guns, look at the FGMM bullets... they shoot in almost 98% of rifles, from .223 to 338. goes to show that this isn't super magical.
do seating depth sure, then find a powder charge that works best for you. often times you shoot a node and go back and shoot it and you will find other nodes or it is not repeatable. Also one big take away was the 200 rounds until they found bad nodes outperformed the good nodes. lot to digest there
do seating depth sure, then find a powder charge that works best for you. often times you shoot a node and go back and shoot it and you will find other nodes or it is not repeatable. Also one big take away was the 200 rounds until they found bad nodes outperformed the good nodes. lot to digest there
So when you start .033 off the lands that's where you get your powder charge and once you get the charge it stays the same even if you had to seat it let's say .080 off the lands for your final round for accuracy ?
Check your PM
WildRose
Well-Known Member
Not that I would ever encourage anyone to do anything unsafe but keep in mind that all our load manuals pass through the hands of the liability lawyers before they go to print so their maximums are usually 10-15% reduced over what is actually safe.
Caveat: If you are loading into the lands very close or even jamming pressure spikes will be much greater with a given load than if you give the bullet some jump.
waveslayer
Well-Known Member
Yes, I find a node, for example in my 6.5 SAUM using 153.5 Bergers, I found a node at 58-58.9. I use .3 increments. I had a nice little group going up and up and then it opened up. On that node I used 58.5 gr. It was right in the middle of the node and groupings. I then tested seating depth and found that the .033" off grouped the best and .083" off. Always go with the closer to the lands seating depth. because as the throat wears down you know you can seat them longer and still get good accuracy.
going with the middle node allows for certain factors, warm barrel, warm weather, cold weather, etc... Dan Newberry goes into good detail about it
