When testing new hunting loads how many rounds of each load?

[diamond hitch]

Like many of you I load groups of three at 0.1 gr increments. The groups will open up and then tighten up. Then they will open up again. I load the recipe that gives me the tightest groups. A friend of mine weighs each bullet and finds a number of rejects. I'm not good enough to worry about it to that detail.

 

[GlockZ]

I do 5 shot strings. I feel it tells a better story than a 3 shot string. I also clean the barrel between each session.

 

[Addicting]

This is for a wildcat cartridge so the starting point was lower to ensure a safe load. Next step is 3 shot ES confirmation of the two highest nodes. Then on to paper at 100 and seating depth adjustment if necessary.

 

[Gunner46]

I've look over the books, checked the net, the forums, etc. Then I took that knowledge and selected at least 3 powders taking into consideration what others mentioned. My next step does not include loading accuracy test loads, but to load up strings of velocity loads and run them over the chrono. No sense in wasting my time & $$ burning off rounds that are mega sub-par, regardless of what someone other rifle has shot.

My next step is to load up 6 rounds of each .5 gr increments of my chosen powders +/- the middle range charge load posted in the manuals and do two 3 shot groups, making allowances for my know F'Up's along the way. I usually find that they all group pretty close, but I take the best avg. the two three round groups and then start +/- seating depth. Then primers.

I've pulled in a finiky .308 from 3"-4 " into 7/8", my 7REM down to 2 MOA @ 300yds, the 7mm-08 to 3 shots covered by a dime, and the 338Fed (1st accuracy test round ) to around 1", without ever getting to changing the seating depth.

No, they are not screamers by any means but they are plenty fast enough and I know where the bullet will be going when I tap the trigger........

 

[Jordo5220]

I go with 5 shot groups starting at the low end of the powder charge in .5 grain increments up to the max. Once I find a group or maybe 2 groups that shot well I go back and load those again, after I settle on a charge I start adjusting off of the ogive.

 

[std7mag]

Ladder test for me, going up 0.3gr of powder for each shot, leaving the chrono at home.
I'm not concerned about velocity at this stage, that comes later.
I've heard of people looking for velocity nodes, but it doesn't tell the whole truth about how the bullet leaves the muzzle.
Is it at the top of the barrel harmonics, or the bottom?

Ladder followed up by seating depth.
Then the chrono comes out & test at least 10 shots. SD for 5 shots i feel is too small of a sample.
Example was my 7mm-08AI.
140gr Berger VLD Hunting.
Alliant Power Pro 2000MR
ES-6
SD-2
That for 10 rounds.

Then out to 600-800 yards to true my readings.

 

[ImBillT]

.1gr is a waste of time, bullets and barrel life. .3-.5gr is fine unless you’re talking about a pretty small cartridge. No reason to shoot groups at each interval either. Look for nodes. You should see one to three depending on how low you started. Load up five shots at a powder charge near the middle of the node or slightly below. If the group has vertical in it, add a few tenths to your powder charge, and try again. If it still has vertical, you screwed up somewhere...or you and/or your gun aren’t good enough for this to matter.

 

[Losing_Sanity]

Here is one of the early videos on the topic:

10 Round Load Development Ladder Test

www.65guys.com

Very interesting video. I'm still scratching my head and a bit confused. But with more exposure to this concept, it will make more sense. Thanks @VikingsGuy for sharing that information.

Seems the "nodes" are a little difficult for me to see. They seem pretty subtle.

 

[VikingsGuy]

Very interesting video. I'm still scratching my head and a bit confused. But with more exposure to this concept, it will make more sense. Thanks @VikingsGuy for sharing that information.

Seems the "nodes" are a little difficult for me to see. They seem pretty subtle.

Here is an example of one velocity chart I did for my .308Win Tikka T3X. I did some 0.1 grain by grain testing of the 44.5-45.1 "node" and the 45.4-45.7 "node" and found a good spot at 45.6gn with MOA of 0.65, velocity sd of 9, for 10 shot group.

 

[Losing_Sanity]

Here is an example of one velocity chart I did for my .308Win Tikka T3X. I did some 0.1 grain by grain testing of the 44.5-45.1 "node" and the 45.4-45.7 "node" and found a good spot at 45.6gn with MOA of 0.65, velocity sd of 9, for 10 shot group.

View attachment 140733

By utilizing the graph makes it easier to see and determine... The 45.4 and 45.7 probably would not have stood out otherwise. Thanks, that is a big help.

 

[VikingsGuy]

By utilizing the graph makes it easier to see and determine... The 45.4 and 45.7 probably would not have stood out otherwise. Thanks, that is a big help.

Notice in both cases the higher load was below the lower load. Graph lines can trick the eye, I usual look at shot to shot delta looking for no (or negative) gain between points.

 

[Losing_Sanity]

Notice in both cases the higher load was below the lower load. Graph lines can trick the eye, I usual look at shot to shot delta looking for no (or negative) gain between points.

I do see that, in the velocity. And so, that is where the harmonics for the barrel is optimal for that bullet and powder range.

 

[Jasher]

I have moved to "velocity ladder 10 bullet" approach. I make one bullet each of powder increments of 0.3gr (0.5gr for magnums) from max book load down 10 increments. I then start on the light end and shoot each over a chrono while watching for pressure signs as I go up. I then look at the resulting velocity plot to find one or two promising "flat spots" - suggesting loads which are somewhat load insensitive ("velocity nodes"). At these nodes I go by 0.1gr increments 2 loads above, 2 loads below and midpoint - I make 3x of each of these (15 bullets) and shoot over chrono looking for both low ES/sd velocity numbers and also low MOA on paper at 100y. If a node looks iffy, I drop it. If a node looks promising I pick the best load(s) and make 5x to confirm over velocity and paper.

When I first tried I wasn't sure if I trusted my loading process and did the velocity ladder 3x at each load, but after a few time through I was very comfortable that there was little noise in my loading process and that I could comfortably rely on the single bullet approach.

This process lets me get from no info to really solid round in 25-50 shots depending on whether I test one or two nodes and if either or both are worth confirming with 5x. If using for target rifle I would then play with seating depth to ekke out final improvements.

When you are starting with a new rifle or barrel do you break in the new barrel first? Do you try to get on target? Or do you do it all at the same time?

 

[VikingsGuy]

When you are starting with a new rifle or barrel do you break in the new barrel first? Do you try to get on target? Or do you do it all at the same time?

I don’t do the formal break-in process (there is another thread in that topic on HT) but I typically get 40-50 rounds through the rifle with various factory ammo options just to see if there are bullets it really doesn’t like and to set up the zero, get comfortable with how the rifle fits/feels, get the feel for the trigger tweak pull weight) etc before trying to handload. I typically clean the barrel at around 50 shots so I will usually give it a good cleaning and then fire 2-3 fouling shots before testing the handloads.

 

[88man]

Just a question, if a bullet is properly stabilized and there is zero wind, what could cause a bullet to change trajectory after 100y of travel? I can see a stabilization problem, and I can see a wind causing more effect over distance and creating a perception of lower precision, but not sure what law of physics would cause a bullet on a certain ballistic line from the barrel to 100y target to begin to change its angular direction mid flight. Similarly I have heard guys say a 2MOA load at 100y would tighten up to 1MOA at 200y. I don't understand how, once the trajectory has been determined, it varies except for wind effects and bullet instability.

I have seen/witnessed this with three different guns all shooting Berger 7mm 180grn vlds. 1 to 1.3 Moa groups at 100yrds then .75 to 1moa at 200yrds then at 500 to 700 yards .5moa or better 5 shot groups

 

[VikingsGuy]

I have seen/witnessed this with three different guns all shooting Berger 7mm 180grn vlds. 1 to 1.3 Moa groups at 100yrds then .75 to 1moa at 200yrds then at 500 to 700 yards .5moa or better 5 shot groups

I am not doubting what you saw, just trying to figure out what law of physics accounts for it.

 

[1100RemingtonMan]

I have started doing the 10 shot but I also 2 additional above Max because Max is different for every rifle and there is no need going to far because 50fps does not mean anything in field shooting. If the Reloading book says max 60.0gr I space my charge weights 1% or like with this example 0.6gr which is 1%.
I check the chrono and look for flat spots where the velocity does not change.
Last Rifle I did was my .264 Win Mag with Retumbo and Noslers 130 AB I then loaded 9 shells in the flat spot and shot 3 three shot groups. And they averaged .665 inch groups at 100 yards at a little over 3200fps. This is Good enough for any big game hunting, as one Caribou found out with one shot.
Might not be the best way but worked for me. Just FYI I never fired the two above Max as I started to get pressure signs.

 

[AlaskaHunter]

I like 5 shots so you can compensate for a flyer in the group. Once I find a couple of strings I like, I'll go to 3 shot groups to find a winner.

I also like five shot groups, but for the opposite reason...sometimes with a 3-shot group I get 2 holes which can be deceiving
A 5-shot group gives a better portrayal of the actual precision of a load.

 

[antelopedundee]

A member from another forum was kind enough to run some QuickLoad numbers for a 6.5 Sierra 130 grain Tipped Game King bullet in a 6.5-06AI. From that I chose 6 or 7 powders to try either because I already had them or they were easy to get. So I plan to load 5 of each using IMR7828; H1000; Reloder 22; H4831; IMR4955; N165; IMR4831 and IMR7977. I may skip the IMR4955 if I can't get it cheap close by. From there I will tinker with powder charge and seating depth.

 

[1_pointer]

I am not doubting what you saw, just trying to figure out what law of physics accounts for it.

There is none. Bryan Litz has asked for anyone that could prove it would get a prize. IIRC, he's used multiple acoustic targets to show that the flight path does not change over distance. Not saying it's not seen on paper, but that's different shots being compared.