Powder load: What's YOUR acceptable variance?

[45fan]

Something that may be of interest, last winter I had 400 or so Korean? surplus .308 rounds I wanted to try and tune in a little tighter in my CETME. Accuracy wasnt terrible before, along the lines of consistent man size hits at 200yds. When I pulled them all down, I weighed the charges and found consistancy along the lines of +-6 grains or so, with an ocasional +charge over a grain high. There were a few that ran almost an entire grain low.

After pulling them down, and re weighing the individual charges (I weighed individual charges to - .1gr. under the average) Even in my CETME, wich is not any sort of spectacular target, the load went from man size target capable to producing 2 MOA groups consistently.

 

[Yeah]

I'll take 0.2 grain and I seldom know where I'll be when I fire that one particular round, so it applies to them all.

Most of the powder I use is extruded and if I can't hold 0.2 grain with it I blame the thrower not the powder, as there are several on the market capable of doing it.

 

[Litlratt]

The .9 would probably make me nuts, regardless of what I was loading for.
However, I would think you would be fine loading for the ZA as long as your median wasn't at the max for your particular rifle.

Have you tried unhooking the powder measure from the progressive part of the press? Try manually cycling the powder measure, leaving the lever in the drop position until the next case is in the receiving position. This method will prevent any settling of the powder due to vibrations in the press.

 

[longbarrel]

I would say you will be fine.. So long as you have no chance of exceeding your maximum powder charge.. After cutting apart some core-lokt and winchester 30-30 shells, I found more than a grain of difference between the winchester and .8 of a grain between the core-lokt. If that is acceptable to the manufactures, then it should be fine with your application.

 

[indyjohn]

The .9 would probably make me nuts, regardless of what I was loading for.
However, I would think you would be fine loading for the ZA as long as your median wasn't at the max for your particular rifle.

This load is for my M1A & I am a full 2 grains below recommended max load, so that's not a concern.

Have you tried unhooking the powder measure from the progressive part of the press? Try manually cycling the powder measure, leaving the lever in the drop position until the next case is in the receiving position. This method will prevent any settling of the powder due to vibrations in the press.

I didn't try this but I ran some more throws and paid a lot more attention to the speed & force I was working the handle. My variance got better.. still not great. Average is +/- .3 grain which is well in the acceptable range according to this thread's general concensus. But I still am getting the occasional .5 - .6 spread. For what this load is for, I'm going to have to live with it...

 

[Skip]

Well, I do this very thing on a Dillon XL650. My favorite load for the 223 is a maximum load of Varget with a 69gr bullet. My level of tolerance for that load is nill, or null or zero or whatever. Since, I know my progressive equipment will not load to that tolerance, I handload those cartridges. Problem #1 solved.

Problem #2 is to have lots of range ammo in the same caliber. My fix? Change powder to BLC-(2), a fine grained ball powder that flows through my Dillon like water AND keeps near the same tolerances as my manual loading for the heavier bullets does only NOW I am doing it on a progressive.

If you know the equipment can't perform with the components selected, let the equipment win and change the components. You already stated that you didn't care if this was sub MOA ammo, right? Use a powder that will flow through the progressive press.

In answer to your question: 0% variance is the goal. I get that with both methods that I use in loading my 223 ammo.

Gotta be smarter than what you are working with! Sometimes, it is a real chore for me!

 

[bobn911]

My Lyman DPS lll will about 60% of the time throw +.01 gr over whatever is entered in. I'll let that go. If it is +.02, it goes back into the hopper. I always look at what the readout says after the beep. Ball, Flake , or extruded powder, doesn't seem to make a difference. Later, Bob

 

[indyjohn]

If you know the equipment can't perform with the components selected, let the equipment win and change the components. You already stated that you didn't care if this was sub MOA ammo, right? Use a powder that will flow through the progressive press.

Gotta be smarter than what you are working with! Sometimes, it is a real chore for me!

I appreciate this. It is a sensible approach to my problem. Others may have already said the same thing but this one clicked.

I did say I didn't care if it wasn't sub MOA, but I'm having remorse over that. Highpower Rifle Competition has ruined me... I tested this round today; the groups are big and the muzzle velocity averages 2533 fps. So I'm reducing the jump by .010 and increasing the load by .2 grain.

 

[xring62]

With the powders I use for 223 i get .1 variance. I do use lots of 4064 in larger cases,a variance as much as .5 -.9 would bother me greatly if near max load.ever think of volume instead of worrying of a certain grain charge that can drive you nuts trying to maintain? Ive been told much of it by old timers deep into reloading that its mainly the volume that matters,no matter what the variance of weight. just like you charge a muzzleloader.Lee makes lots of them yellow dippers for a good reason.

 

[Skip]

I appreciate this. It is a sensible approach to my problem. Others may have already said the same thing but this one clicked.

I did say I didn't care if it wasn't sub MOA, but I'm having remorse over that. Highpower Rifle Competition has ruined me... I tested this round today; the groups are big and the muzzle velocity averages 2533 fps. So I'm reducing the jump by .010 and increasing the load by .2 grain.

My pleasure, John.

I'm with you too! Once you have the accuracy from a rifle that is sub MOA it is really hard not to get it everytime you shoot it, no matter what you tell yourself as you load the ammo!

My BLC-(2) loads are with a lighter bullet but still turn in some incredible groups, easily sub MOA.

One thing about using the Dillons, and I am sure the LNL is the same, if I can get the powder to meter correctly, my ammo is going to be just fine.

There are lots of ball powders out there. Accurate Arms has a great line of them, there is the Hodgdon powders too (H335 & BLC-(2). H322 is a fine grained stick powder that meters great) as well as some of the short cut stuff out there now. I am not sure what the Alliant line has. Use a lot of their pistol stuff, just not much on their rifle powders yet.

Enjoy! Let us know how things work out!

 

[Meister]

To Meister: I had similar good experience with the RCBS.

To All: Thanks for the input, this is what I suspected. I plan to test some more today; I have some varget and Tightgroup; I'm curious how they measure.

Varget measures marginally better than 4064. It's cleaner than 4064 as well. For 223 in the Dillon 650 I use a pulled ball powder of BLC(2) speed or #7. Meters great. Precision 75,77 & 69g 223's get a pet load of varget that is dropped and trickled.

Nothing that I would consider precision or near the load limit goes through the Dillon, ever! Not enough control to the application IMO.

Edit:

In addition to less residue, I can get 20fps max spread out of 10 rounds using varget in precision 223 and 308.

 

[Grizhicks]

While I'm fairly new at reloading, I look at it as a percentage: if you accept 1 gr on a 42 gr load, then that only 2.4% variance; however loading my wife's cowboy loads with only 3.5 gr with a 2.4% variance is .08 gr. How much variance is acceptable? And how much will affected the round performance?

-- Greg/Grizhicks

 

[Skip]

While I'm fairly new at reloading, I look at it as a percentage: if you accept 1 gr on a 42 gr load, then that only 2.4% variance; however loading my wife's cowboy loads with only 3.5 gr with a 2.4% variance is .08 gr. How much variance is acceptable? And how much will affected the round performance?

-- Greg/Grizhicks

That is one way of looking at it, for sure. The difference is in the required accuracy of the loads. MOA=minute of angle, roughly, 1.04" @ 100 yards, 2.08" @ 200 and so on.

For Cowboy Action shooting, MOSPACR=minute of steel plate at close range ( ) is acceptable.

If you are trying to hit a square foot piece of metal @ 25 yards, the percentage thing might work. Longer distances, not so much.

With high power rifle shooters, 1MOA is the biggest group size acceptable. Much different that MOSPACR!

 

[youngda9]

Find a powder that meters well. Stay down a bit from max charge.

OH...and sorry, but a .223 won't stop a zombie...you guys are kidding yourselves.

 

[teddy12b]

My standards for deviation don't change, but the tools I use to get my desired result do. I want exactly what I want, and if my equipment can't produce that then I'll start making changes. I couldn't just load round after round with give or take .2gr. That would just feel disgusting to me. It's either right (+ or - .0gr) or it's not. That's just me though.

I reload on a Dillon 550b and there's no way I'm going to go back to trickling. For example, the other night I gave my brother in law and father in law a little demo on reloading. I loaded up some 223 loads using my 550B and used the powder dispenser because using Ramshot Tac it get's me the exact load that I want every time and even after a hundred or more load it's still right on where I want it to me. Then I loaded up soem of my accuracy loads for my 30-06 using IMR 4350 on my dillon. When the brass case gets to the powder dispensing stage I remove it and use a RCBS chargemaster combo to get me exactly the amount that I want.

The powder dispenser on the 550B won't get me as accurate as I want to be with IMR 4350 so I made a change in the equipment that I use, not my standards.

 

[Leo]

.9 gr in a 50 gr load is a lot less significant than .9 in a 12 gr load. Distance is a big factor in John's question also. He is talking about a max of 2% powder weight difference in a 30 caliber rifle that is probably not tighter than 1 or 1-1/2 MOA anyway. On a 100 yard target, the natural inaccuracy will group larger than the elevation variation of a 50 -75 fps extreme spread. As you go farther out, the elevation changes will be pronounced, by 600 you can measure them with a ruler. Go ahead and shoot it with thrown charges, if the group is a lot taller than wide maybe he needs to tighten up the charge accuracy. I'll bet the group will still be round at 100 and 200 yards.

BTW, the year I shot my M1a Super Match for service rifle, I ended up loading with Varget. Varget is close enough to 4895 that the gas system had no problems and the rifle was very accurate. Even a fresh Supermatch only shoots about 1 MOA average for ten, ten shot groups in a row. When I shot Palma with it, I weighed EVERY charge because that distance is hard enough with a service rifle, I was not going to give up any points due to reloading inconsistant ammo.

 

[DRob]

Charge variations.

My loads need to be capable of 1 MOPD (Minute of Prairie Dog). If the PD in question is 350 yards away that's fairly small. My Dillon throws plus or minus .1 grain of AA2230 & BLC-2 which is close enough. It does get a little more critical with the small charges in the .17 Fireball but I generally stay .5 gr or more below a max load. Once I get it set and have checked a few charges, I'll run 100 before checking it again. It has never needed to be reset.

 

[indyjohn]

.9 gr in a 50 gr load is a lot less significant than .9 in a 12 gr load. Distance is a big factor in John's question also. He is talking about a max of 2% powder weight difference in a 30 caliber rifle that is probably not tighter than 1 or 1-1/2 MOA anyway. On a 100 yard target, the natural inaccuracy will group larger than the elevation variation of a 50 -75 fps extreme spread. As you go farther out, the elevation changes will be pronounced, by 600 you can measure them with a ruler. Go ahead and shoot it with thrown charges, if the group is a lot taller than wide maybe he needs to tighten up the charge accuracy. I'll bet the group will still be round at 100 and 200 yards.

BTW, the year I shot my M1a Super Match for service rifle, I ended up loading with Varget. Varget is close enough to 4895 that the gas system had no problems and the rifle was very accurate. Even a fresh Supermatch only shoots about 1 MOA average for ten, ten shot groups in a row. When I shot Palma with it, I weighed EVERY charge because that distance is hard enough with a service rifle, I was not going to give up any points due to reloading inconsistant ammo.

Man, Leo, I opened up a can 'o worms on this one. I got my new press, had 100 SMK 175's, an unopened pound of 4064, and plenty of fired brass laying around. So, I thought "what the heck". Sadly, after being out of the reloading game for 10 years, I had forgotten how caught up in precision I tend to get.... And so I got all my INGO friends caught up in it too.

The initial idea was a 100 yd "need to knock it down" recipe. But when I out of curiosity started weighing loads.. Oh-my-god I started losing my mind. So, I'm going to build the 100 rounds, weighing about every 3rd and then put the 4064 away for another day...

As for your Super Match, sounds like fun! So, what am I looking at with a 155gr at 600 yds and a crosswind?

 

[dcahsr23]

i found that less then .5 grains is pretty good and keeps the spread together pretty good at 100yrd

 

[Leo]

John, Since I never made the big time in Palma to go International, I did not have to be limited to the 155 gr Sierra Palma bullet. (a good thing because I never got a load to stay supersonic that could be shot in a rifle with a fully functional gas system) I was able to have success with 175 gr bullets, which are legal in any match that does not specifically require the Palma bullets. It was a lot of fun. I ground a front sight blade down to about .010" high as well as removed my rear sight elevation rack and with a three cornered file I cut additional teeth for more adjustment. The 168 wind charts work pretty good with the 175 gr bullets. Palma is one application that you can use single loaded AMax bullets with good success in the M1a chassis. Good Luck