Load development

todbartell

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Massive subject, maybe too broad for one thread on the subject as there is so many different techniques or ideology that can end up at the same end goal - a good accurate recipe for your rifle

  • Satterlee flat spot velocity nodes
  • Optimal Charge weight / OCW
  • Optimal Barrel time / OBT
  • Ladder loads
  • Seating depth tests
  • 3 shot groups, 5 shot groups, right up to 30 shot groups

What's your beliefs?
 
Tod...I've always been a "groups" guy..ever since the late 70's when I got started into reloading. Usually 5 shots groups for me on the first go round. Same thing on the next one too, once I get the nodes I'm after, then I'll finesse it some more. Sometimes, that'll work well enuff that the seating depth game is a moot point for me/the rifle/that load...so I leave as is and enjoy !
I starting playing with jumps and jams, seating depths, throat leads, pressure nodes about 20 something yrs ago.
Health is got me slowed down to nearly a stop now. BUTTT...it HAS Been great fun over the years !

*** seen and followed a lot of your stuff / hunts over the years..thanks for posting and sharing for the rest of us !!
 
There is no such thing as a velocity flat spot. When you add powder, it goes faster. To see it for yourself, load the same 1 shot per charge ladder and do it multiple times, it will be a steady line increasing in velocity as charge weight increases.

How in depth your load development is depends on what you are looking for in terms of accuracy and precision and how capable your system is of producing that. (Bullets, barrels, brass, rests, scopes, shooter skill etc..)

Where you start also depends on what information you have. There is so much info available out there for so many different bullet/powder combos, research it a little. Pick the bullet you want to shoot and see what are people using for powders/primers/brass. If you have quickload or Gordons reloading tool, you can also get an idea from that AS LONG AS YOU PUT IN THE CORRECT INFORMATION. A little rant, too many people use this incorrectly and then exclaim to the internet how someone else is loading so dangerously etc.. Well, if you put in the wrong information to the calculator, you'll get the wrong result. If you put my powder charge in a 308 case at 2.800" mag length, well, it wouldn't be able to fit first of all, but would also tell you it's probably 90,000psi. Well that's just wrong, since my OAL is almost .500" longer, the pressure is under 58,000. It's still a .308, just not your .308. I'll say it again IF YOU USE GRT, YOU MUST HAVE ACCURATE INPUTS.

On to the real question, I suppose. Once you pick you bullet, brass, primer and 2+ suitable powders, a single seating depth, figure out a safe starting point and load a one shot per charge "ladder" (For anything like a 308, no need to go less than .5gn increments). Shoot the ladder either at the same aim point (and keep track of bullet holes per charge) or separate aim points next to each other. As you do this, you will see the point of impact shift as the charge increases as well as keeping an eye on pressure signs. You should see a point where ~3charges form a nice group at the same point of impact. Load some 3 shot groups in that area to confirm, then choose the lowest charge that shoots the best. Now you can play with seating depth if you choose, again in 3 shot groups, in .005" increments (if your system is capable enough, do a finer test in .003" increments then load to the longest). From here, you can go as far as you wish, if you want to play with different primers, primer seating depths, neck tensions etc.. If you do different primers, expect to also play around with powder charge a little. Once you really start dialing a load in, then you can start doing 5-10+ shot groups to confirm it will hold up. I don't like doing more than 3 at the start because it's just a waste of expensive components. If you shoot a big group with 2 or 3 shots, it won't get smaller by shooting more.

Being able to load at the range in some capacity makes this process much easier and you also don't need to possible damage bullets if/when you need to pull them from loaded rounds. If you can't take a scale with you, I use small glass vials off amazon that I pre-charged at set amounts and dump powder into primed cases as needed, seat bullets with a little Lee press and get to it. Also, keep track of everything. I have a Garmin chrono and use it every time I shoot, no reason not to. Keep track of how your loads changes with weather.

Just my opinions and works for me.
 
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Being able to load at the range in some capacity makes this process much easier and you also don't need to possible damage bullets if/when you need to pull them from loaded rounds. If you can't take a scale with you, I use small glass vials off amazon that I pre-charged at set amounts and dump powder into primed cases as needed, seat bullets with a little Lee press and get to it. Also, keep track of everything. I have a Garmin chrono and use it every time I shoot, no reason not to. Keep track of how your loads changes with weather.

Just my opinions and works for me.
Those are some awesome points. Thank you. The one about the pre-packed charges is a great idea.
 
Taking a press to the field works well. I use plastic containers with snap lids and my pan with the pour spout.
I also seat long on the bench and adjust seating in the field. Occasionally I take my beam scale, but if it too hot outside, it’s not possible as the truck windows have to be up for the wind.
 

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I’ve left the best part of too many barrels in the dirt berm; trying to make rifles shoot better than they need to. I often find myself doing a greatly simplified method now. Find the lands, and load up a pressure sequence with just 1 cartridge per charge; then walk out the shop door to the bench and shoot them all at the same target and watch the hits. Its so easy to use the Garmin that there isn’t much reason not to.I suppose I could pretend its a ladder test; but its mostly just to find a good working maximum load. I’ll load up maybe 5 or 6 of those; and then try for group n a way that reflects the way the rifle will be used, if its a hunting rifle some effort will be made to keep it cool, winter helps with that. If there’s any potential I’ll load up maybe ten and go to the other side of the road and do a 10 shot group at 5-600 yards. Lots of times when I’m looking for a 5-600 yard hunting load I’ll find that I already have one😄
Target and varmint rifles are done to a higher standard; usually some variation of OCW. I find it’s more important that small differences in charge weight shoot the the same zero and group then the last bit of precision.
 
Well Ive developed loads for so many different rifles 100 or so with new barrels but a lot of the same cartridges….

In the past I’ve used the SATERLEE method but always go up in .3gr increments until I get pressure and have worked around flat spots in the velocity, it has worked for me,

Now a days I load 3 rounds at each charge weight starting below max and working up until I get pressure, groups will open and close with consistency and I’ve done this time and time again with success using the charge weight with the most accurate groups with the least amount of vertical spread,

For me the target does not lie !

One thing that Im a firm believer in is for a hunting rifle there is nothing a 5 or 10 or 20 shot group will tell you that a 3 shot group can’t,

simply if a a 3 shot group is not accurate another shot isn’t going to make it any better, with that being said I do shoot a lot of 3 shot groups to see and confirm consistency,

So in the end you can call it what you want, OCW or OBT, rightly or wrongly I refer to it as accuracy nodes (my slang)
In the end it’s all about consistency with your hand loads, good brass, consistent neck tension, consistent charge weights, lastly I will play with seating depth if needed

Here’s the last five shot group out of my 7-6.5 PRCW with 175gr Berger Elite Hunters overtop of 57.7grs of N555/210M/new ADG 7-6.5 brass
2899/2900/2900/2901/2904

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3 shot can tell you how bad a load can be, but not how good it can be
IMHO it tells me enough about the rifles accuracy,
I have 6.5 PRC that I did a test with 6 different factory ammunitions,
I shot 6 3 shot groups and measured the group size and followed with 6 five shot groups only one group(ammunition) opened up larger than the 3 shot group, so for me it’s just a waste of components in a hunting rifle.
 
3 shot can tell you how bad a load can be, but not how good it can be
Yep. You can look at a single 10 shot group and see that there are 120 possible 3 shot groups in it. If you’re one of those guys that think the order they hit is significant then there are 720 possible combinations of 3 in that single 10 shot group. Statistically speaking it would be miraculous if a 3 shot group conclusion was rIght. That doesn’t prove that 3 shot groups are useless though; but just might suggest that accuracy isn’t nearly as important as we think sometimes.😂
 
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Only people that think you should shoot 20 shot groups apposed to a 3 shot group because it isn’t statistically representative for development/accuracy purposes is companies selling components 🤣
You probably wouldn’t be happy with a single 3 shot group either. What’s the right number of three shot groups before you say good I’m gonna load out a couple hundred because this load is proven? Would it be 3? At that point there isn’t much difference between you and me; except I shot them all at the same target or stacked the targets and looked at them all at the same tme😂
 
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