How many rounds for load development?

[Spitpatch]

I'd differ (at least) with the order of powder and bullet toward influencing accuracy. I've shot a lot of chitty bullets that any change in powder choice would not save. Conversely, an agreeable bullet usually shows its accuracy when propelled by more than one choice of powder.

 

[Koda]

Ive always heard to choose the powder based on the bullet.

And as for #6 if the bulk of any size group was concentrated I would work on lowering my standard deviation (see chrono data)

6. Zeroing should be done on 20 round groups. Otherwise, you may incorrectly center your crosshairs out of the "true" center point of dispersion. This explains some wandering zero/change in zero.

 

[PiratePast40]

Interesting conclusions from the Hornady podcast report

1. If you shoot enough rounds for statistical relevance, there is no accuracy difference (or minimal) between book minimum and book maximum charges.

2. All of the sinusoidal "nodes" discussed vanish if you fire enough rounds. The nodes are an artifact of low sampling error.

3. Powder choice makes the biggest difference.

4. Bullet makes the second biggest difference.

5. You can find good loads using the classic methods.

6. Zeroing should be done on 20 round groups. Otherwise, you may incorrectly center your crosshairs out of the "true" center point of dispersion. This explains some wandering zero/change in zero.

That's an eye opener!

 

[dangerranger60]

@orygun ,

If you've ever practiced yoga, you've probably heard the joke, "when you're life is out of balance, your balance is out of whack." Same holds for shooting. Some days, can't slow anything down and thus shoot like shizzle.

I have those days once in a while. I just concentrate on picking up brass on those days! DR

 

[orygun]

I have those days once in a while. I just concentrate on picking up brass on those days! DR

I used to smoke cigars. Any morning that I had a few cups of coffee then smoked a cigar on the way up to shoot, group sizes were horrible. Things settled down after I stopped with them stogies, but there are still days I'm just wasting time with my gun.

 

[Ben B.]

I'd differ (at least) with the order of powder and bullet toward influencing accuracy. I've shot a lot of chitty bullets that any change in powder choice would not save. Conversely, an agreeable bullet usually shows its accuracy when propelled by more than one choice of powder.

Have you shot a lot of chitty (wrong) powders that were saved with a good bullet?

 

[Ben B.]

Ive always heard to choose the powder based on the bullet.

And as for #6 if the bulk of any size group was concentrated I would work on lowering my standard deviation (see chrono data)

The guys on the podcast say, if working up a load for personal use, they pick their powders based on reports of what powders are working best for that cartridge. Then they try a bullet, and if is not satisfactory, try a different bullet. After a few bullet trials and no satisfaction, they would switch powder and try again. They reported definitely seeing some bullets working well in a barrel, but powder made a larger effect than bullet.

I think I understand what the 2nd part of your post means = tight group with a few flyers. If it was a 5 shot group with 3 stacked in one hole and 2 flyers, I would suspect that a 20 or 30 shot group would show that the dispersion was a lot more than you'd guess based on the 5-shot group that was "beautiful with just a few flyers". Because of small sample errors.

I have seen myself that SD doesn't have much relation to tight groups until the ranges get pretty long for that cartridge, in that some loads with tight groups had loose SDs, and some tight SD loads gave garbage groups. For instance, we saw last month that a load with an SD=8 yield a 2 MOA group, vs an SD=14 that was a .7 MOA group. Granted, SD and group size was based on 5-shot groups, which are insufficient.

When I was doing rimfire benchrest, SD of Eley or Lapua match ammo showed no relation to grouping at the range of 50 yds at which the game was played. The podcast guys did state preference for SDs of 12 or less for CF rifle loads.

 

[Member 5605]

judging by watching 'hunter sight in' at local ranges; one round is enough if you twitch in the right direction.

 

[Koda]

The guys on the podcast say, if working up a load for personal use, they pick their powders based on reports of what powders are working best for that cartridge. Then they try a bullet, and if is not satisfactory, try a different bullet. After a few bullet trials and no satisfaction, they would switch powder and try again.

My take on this is going to be a bit different than most because my only interest in reloading is to develope a hunting load centered around the exact bullet I want. The idea of changing bullets to find accuracy doesnt make sense to me even from a target shooting perspective though, but Im not that experienced at developing precision/benchrest groups....

I think I understand what the 2nd part of your post means = tight group with a few flyers. If it was a 5 shot group with 3 stacked in one hole and 2 flyers, I would suspect that a 20 or 30 shot group would show that the dispersion was a lot more than you'd guess based on the 5-shot group that was "beautiful with just a few flyers". Because of small sample errors.

I have seen myself that SD doesn't have much relation to tight groups until the ranges get pretty long for that cartridge, in that some loads with tight groups had loose SDs, and some tight SD loads gave garbage groups.

I dont fully understand yet how SD affects tight groups, Im still learning. But I discovered with some factory ammo that Id get a few fliers in the 30/70 range (3 out of 10 shots would not group). I was frustrated trying different expensive brands of ammo or thinking it was my marksmanship when it was neither, I eventually zeroed on the 70% group and started getting better results on average and tight groups at longer ranges. But it nagged me that I couldnt sort those 30% rounds from my hunting ammo.... That was my first lesson on Standard Deviation when trying to troubleshoot if the factory ammo was bad (worth using) I chronographed some and found large SDs, so I simply assumed the SD meant inconsistent loads.

I was watching an Eric Cortina video on this and he claimed we "need ES" (low extreme spread) before tight groups but I didnt get why.

 

[Spitpatch]

Have you shot a lot of chitty (wrong) powders that were saved with a good bullet?

The guys on the podcast say, if working up a load for personal use, they pick their powders based on reports of what powders are working best for that cartridge. Then they try a bullet, and if is not satisfactory, try a different bullet. After a few bullet trials and no satisfaction, they would switch powder and try again. They reported definitely seeing some bullets working well in a barrel, but powder made a larger effect than bullet.

I think I understand what the 2nd part of your post means = tight group with a few flyers. If it was a 5 shot group with 3 stacked in one hole and 2 flyers, I would suspect that a 20 or 30 shot group would show that the dispersion was a lot more than you'd guess based on the 5-shot group that was "beautiful with just a few flyers". Because of small sample errors.

I have seen myself that SD doesn't have much relation to tight groups until the ranges get pretty long for that cartridge, in that some loads with tight groups had loose SDs, and some tight SD loads gave garbage groups. For instance, we saw last month that a load with an SD=8 yield a 2 MOA group, vs an SD=14 that was a .7 MOA group. Granted, SD and group size was based on 5-shot groups, which are insufficient.

When I was doing rimfire benchrest, SD of Eley or Lapua match ammo showed no relation to grouping at the range of 50 yds at which the game was played. The podcast guys did state preference for SDs of 12 or less for CF rifle loads.

Bullet choice is driven by purpose for the load. Powder to a less degree, other than optimum velocity balanced with accuracy that works with a suitable bullet for the purpose. I found it intriguing that "the guys on the podcast" are quick to switch bullets when the first is "not satisfactory".

This is a contradiction toward their priority list (and happily describes my process exactly: working on the premise that the bullet choice will change things relatively dramatically if a suitable powder is already in play). The bullet is the first thing "the guys" change, and yet they claim it is less influential than the powder.

If one believes that taking the cell phone away from a teenager will most greatly influence his poor behavior, why would one deprive him of the car keys instead?

I avoid "wrong powders" just as "the guys in the podcast" do. I begin to select powder candidates based on the books. I previously have selected bullet candidates based on the load's intended purpose. A bullet agreeable to the rifle (accuracy-wise) that fulfills the load's terminal purpose (penetration? expansion? paper-punching only?) will very often continue to demonstrate its agreeability even if powders are then switched in search of better performance (such as increased or more consistent velocity).

A bullet that is agreeable to the rifle GRANTS easily a fair choice of powders to achieve the goal of the load. A bullet disagreeable to the rifle may certainly be helped some by a change in powder, but making it work exceptionally in a gun not compatible is an (unnecessary) uphill climb.

Rick Jamison had this priority figured out 30 years ago. So did I.

(And, apparently by their actions, so do "the guys in the podcast".)

 

[Ben B.]

Too many "scare quotes" and hairsplitting for me. I suggest listening to/watching the data and summaries presented in the podcast. It is an interesting presentation based on a LOT of data. Episode 50 and the followup is episode 52. Great for a 1-2 hour drive. You might find it agreeable.

 

[osprey]

Them poor bassturds at hornady of course would say powder has more influence as they only can pick bullets with their branding.

 

[415DET]

How did that 25g of H335 do for you?

 

[AMT]

How many rounds are people loading to test different powder weights to determine a good, overall load? The ammo will be used in standard AR platform rifles for general range use, plinking, and running drills. My plan is to load 9 rounds at each powder weight. 3 will be for shooting across the chrono and will be used to determine pressures by inspecting primers and cases, velocity, and ability to cycle. Will be getting a rough idea of accuracy by putting a target out at 15 yards. Will shoot another 3 at 50 yards and 3 more at 100 for accuracy.

55g FMJBT, H335 powder, 2.225" OAL, range brass. Will be testing 24.7, 25 and 25.3grain loads.

I've got different powders to try and more sophisticated projectiles, but for this first go round, I'm just looking for general purpose ammunition. Any comments or recommendations?

I've done plenty of testing and reloading with 9mm so am familiar with the process, just beginning with 223 and thought I'd ask around.

I read your initial post. Then I read it about 4 more times. Each time I am trying to figure out what you are really trying to do. I've highlighted and underlined the confusion.

1. If it's for general plinking and running drills why are you concerned with accuracy?

2. In this first go around you say you are looking for general purpose ammunition. Again, what do you care about 100 yd accuracy for? If you take a 12" paper plate (or 12" target) and set it out at 100yds and hit it anywhere "while running drills", isn't that good enough? Seriously, take a 12" paper plate (or target) and hold it up to your chest. If there is any hole in it, I'd say your shots will be good.

3. If you are looking at just plinking this first go around, wouldn't you be more concerned with proper cycling and hold-open on last round?

4. Why chrono plinking rounds?

Now, if you are looking at accuracy, then yes, many posts have stated start low and go up in .2gr increments until you reach your desired result for your setup. As you know, what it good for 1 setup may not be good for another setup. You'd have to "play" with rounds in each of your different setups.

For accuracy, I'd guess that a minimum of 5 rounds of each powder load starting low and going up in 0.2gr increments.

So..... are you looking at running drills and plinking - OR - are you going for accuracy?

 

[PiratePast40]

I read your initial post. Then I read it about 4 more times. Each time I am trying to figure out what you are really trying to do. I've highlighted and underlined the confusion.

1. If it's for general plinking and running drills why are you concerned with accuracy?

2. In this first go around you say you are looking for general purpose ammunition. Again, what do you care about 100 yd accuracy for? If you take a 12" paper plate (or 12" target) and set it out at 100yds and hit it anywhere "while running drills", isn't that good enough? Seriously, take a 12" paper plate (or target) and hold it up to your chest. If there is any hole in it, I'd say your shots will be good.

3. If you are looking at just plinking this first go around, wouldn't you be more concerned with proper cycling and hold-open on last round?

4. Why chrono plinking rounds?

Now, if you are looking at accuracy, then yes, many posts have stated start low and go up in .2gr increments until you reach your desired result for your setup. As you know, what it good for 1 setup may not be good for another setup. You'd have to "play" with rounds in each of your different setups.

For accuracy, I'd guess that a minimum of 5 rounds of each powder load starting low and going up in 0.2gr increments.

So..... are you looking at running drills and plinking - OR - are you going for accuracy?

Looking for both. If I buy general use factory ammo, even something like American Eagle, I expect consistency, and accuracy near 3-6" at 100 yds. If I'm making my own ammo, I should be able to get better accuracy if I only perform a few extra steps, even with 55 grain fmj. I'm not looking for MOA at 100 yards but do expect something better than a shotgun pattern. I expect the ammo to at least be accurate enough at 100 yards for me to zero the rifle when I put a scope on it. This is my first time reloading rifle ammo and I just can't bring myself to load a significant quantity without checking for consistency. I realize that people have been using 25 grains of H335 for decades, just like 2.4 grains of Titegroup over a 124 grain bullet has been the defacto standard in USPSA. For me, I think it's appropriate for me to take the time to check my work. Perhaps not necessary, and perhaps many feel that a grain or two either way doesn't matter, but I feel uncomfortable not doing some verification on my own. I also enjoy it, and it gives me peace of mind.

Some people don't care about pressure signs or chrono results. No criticism there, but it's just not for me, especially the first time around with this type of ammo. When I first started loading 9mm, I did quite a bit of testing for function, OAL, accuracy, consistency, power factor, recoil, and OAL for my guns. It just seemed like the right thing to do and it certainly made me feel better about my final product. Discovering light recoil while maintaining a respectable power factor with 147 grain bullets was an enlightening experience for me, and a very enjoyable aspect of the sport. I still do some testing when I try a new powder for 9mm or using projectiles I don't normally use. My thought is that if I'm taking the time to reload, might as well be putting out the best produce I can with the chosen components.

 

[Spitpatch]

" If I buy general use factory ammo, even something like American Eagle, I expect consistency, and accuracy near 3-6" at 100 yds."

You should get a lot better than that (even with cheapo stuff, and even out of a carbine). But to be honest I did not expect much more out of my DPMS AP4.
It produced 1.5-1.75" groups out of the box with the ammo you describe. I was pleasantly surprised and motivated to improve upon that.

With careful handloads, Timney trigger, accu-wedge and optics, groups now average .81". It is my workhorse for coyotes now.

You can expect the same, unless there is something wrong with your gun (such as being a Ruger Mini-14).

 

[Crockett9]

I load 3 to 4 loads (usually 4) of 3 rounds each starting slightly above minimum in equal steps up to maximum. To determine minimum and maximum, I will take the average of all the reloading books I have using the same bullet weight and powder that I want to try! Then I shoot 3 shots over my chronograph (Oehler 35P) at targets 100 yards away. I let the barrel cool between shots and I'll often try a number of different bullet weights and/or powders at the range in one sitting. I also record every shot I take including the acuracy and any notes on conditions. I also usually go to the range all day as I clean the barrel between loads -- so it often takes all day! Shooting at 15 yards then at 50 yards for accuracy is a waste in my opinion! Also shooting over a chronograph without shooting for accuracy at 100 yards is also a waste -- in my opinion! Once you compare your data, you will see which loads are giving better accuracy and lower SD's. Then for my next trip to the range I'll experiment with seating depths on the more accurate loads from the previous trip -- including 5 shot groups -- once I find the more accurate loads!

 

[orygun]

Them poor bassturds at hornady of course would say powder has more influence as they only can pick bullets with their branding.

I've read that ballisticians at bullet companies can be quick to change powders if the one they are testing isn't showing good accuracy within a few test loads, believing that some powders just aren't a good fit with certain cartridges. The instance I'm referring to was recent, with 7mm PRC at Hornady. A change to a different, apparently more suitable powder, made a dramatic improvement in accuracy.

Looking for both. If I buy general use factory ammo, even something like American Eagle, I expect consistency, and accuracy near 3-6" at 100 yds. If I'm making my own ammo, I should be able to get better accuracy if I only perform a few extra steps, even with 55 grain fmj.

Improving on factory ammo is not always as easy as many make it out to be, especially with the ammo that's been produced in the last 20 years.

 

[osprey]

I guess I take that hornady podcast with a grain of salt. They are using test barrels in fixtures and we are shoulder firing our rifles with different rests and bedding situations. I have had repeatable results showing a rifles definite preference for a certain powder charge and a certain seating depth. Over a 100 shot group would those parameters be null and void ? Maybe. Since they say it doesn't matter I will stick with my findings and have the confidence to place a bullet where I intend. Moving forward I may do some testing with some of their concepts in mind when developing a new load.

 

[oremike]

I'm just starting this process with a 7 1/2" Ruger 480 SRH. In reading on the internet and looking at factory Hornady ammo they load a 325gr bullet to about 1400 fps. The youtubers describe the recoil as sharp and painful. This is not something I want so here is what else I've read and where I want to go. Some might call it setting the paramitures for my first loads or establishing a benchmark. Looks like using 400gr bullets at about 1000 fps has a recoil described as stout but not brutal and able to shoot thru an Elk end to end so that is much more to my liking. Not that I plan on shooting Elk end to end but I do expect better terminal performance as compared to say a 1911 in 45 acp. The bullets I've ordered are Rim Rock plain base 410gr wide flat nose and I've got 4 of the recommend powders to try out. W-296, AA 4100, Hodgdon Longshot and Lil'gun. The bullets should be here next week sometime so until then I'll go shoot the gun just to see what it's all about and zero the scope probably at 50 yds so I can see the holes easily.