How much does powder charge affect accuracy?

[em9sredbeam]

Alright I just started loading 38 spc. My first set of loads, were running a little hot, but were accurate. So I backed off to the minimum charge, using the same bullet and same oal, and it seems like it shoots consistently to the right. I thought maybe it was me, so I shot some factory and it was perfectly center, so I am pretty sure that it is not my form. I was shooting maybe 7-10 yards. What am I doing wrong? Do I need to change the charge, or oal, or powder? Or is it somehow me? I am using Hodgdon Titegroup powder.

[blockfort]

Alright I just started loading 38 spc. My first set of loads, were running a little hot, but were accurate. So I backed off to the minimum charge.....What am I doing wrong?.....

Well for starters, you are supposed to make your loads at the weakest charge and work your way up. This way you don't blow up your gun and your hand along with it.

[blockfort]

Anyway, you should make up 12 rounds or so of each charge in steps of 0.1 or 0.2 from minimum to maximum and test them all bench rested or on a sand bag. You'll find out what works and what doesn't.

[stand125]

It very well could be muzzle jump that is causing the grouping off to the right. You have less muzzle jump with the lighter load and if you usually are pulling or pushing left to get centered, you will be right of center with less muzzle jump. Try placing your finger farther left on the trigger and see if you hit more center. You want you finger to pull straight back on the trigger so the barrell only moves up and not in a up/side direction. I have no proof but just a thought.

[SWalt]

It can be one of the things mentioned or all of them. Every firearm has its own characteristics and 1 load in your firearm might not work as well in another, being the same make and model . But the best place to start is as Blackfort said. Find the load that fits your particular firearm. Time and experience will help also.

[stand125]

Anyway, you should make up 12 rounds or so of each charge in steps of 0.1 or 0.2 from minimum to maximum and test them all bench rested or on a sand bag. You'll find out what works and what doesn't.

Do you know what powder he is using? 0.1 or 0.2 would make no noticable difference in most powders and unless you are trickle charging you case with a very precise scale you are not going to get under .1 variences anyways.

[22popnsplat]

What i do is shoot groups , when i find my pet load i regulate the sights to that load. different loads can produce different points if impact

[Sac-AR15]

I usually start at .2 grains above min. Work my way up at .2gr increments till I find the right amount. That's just me. I am not a veteran reloader. Have loaded 3k+ with no issues yet. Knock on wood. Plus this forum helps out alot.

[Fjold]

What you are describing in your post are changes in the point of impact, not accuracy. If the new reloads are shooting 6" right but putting all the bullets into a 1" group then they are more accurate and you move the sights to center the new load on the target.

It's hard to see minor variations in accuracy with handguns unless you are shooting them from a Ransom rest or something. Because you react differently to changes in recoil, it's hard to judge the accuray of individual loads sometimes.

With rifles it's easier to see how small changes in powder charges affect accuracy. In the picture below you can see that a change of just over 1/2 of 1% in the powder charge changes the 5 shot group size by over 100%. The load at 33.3 grains is around 1/2 MOA, when the powder charge is increased by .2 grains the groups open up to 1 1/2 MOA. Then when the powder charge is increased another .2 grains the group shrinks back down to 1/2 MOA or better. In this gun the changes in the powder charge don't seem to affect the point of impact much. The groups are staying just over an inch above the point of aim, even though the accuracy changes signicantly.

[blockfort]

Do you know what powder he is using? 0.1 or 0.2 would make no noticable difference in most powders and unless you are trickle charging you case with a very precise scale you are not going to get under .1 variences anyways.

I did a test with loads from below min, up to max, by 0.1gr increments, and the results were consistent within a load, and linear from load to load.

Within one load, the average deviation was 11fps (out of 1000+).

From one load to the next, a difference of 0.1gr changed the velocity an average of 25fps.

So from the data, I feel like I can consistently load to +/- 0.05gr of my target.

[Dark Mod]

Do you know what powder he is using? 0.1 or 0.2 would make no noticable difference in most powders and unless you are trickle charging you case with a very precise scale you are not going to get under .1 variences anyways.

Your right but i still do it anyway, the wisdom being you will get an average out of all of each set that is .2 less than the average of the next set.

Still not a ton of noticeable difference, maybe 10 fps or so, but im still able to find a sweet spot (slightly sweeter than the rest).

For me the bullets make the most difference, but in plinking loads i can still wring some acuracy out of the cheap projectiles by sorting weight and loading at the charge my gun likes the best.

Using the cheapest possible components i can make some damn fine ammo.

[stand125]

I did a test with loads from below min, up to max, by 0.1gr increments, and the results were consistent within a load, and linear from load to load.

Within one load, the average deviation was 11fps (out of 1000+).

From one load to the next, a difference of 0.1gr changed the velocity an average of 25fps.

So from the data, I feel like I can consistently load to +/- 0.05gr of my target.

Did you get those results using a LEE powder drop and frankford arsenal digital scale or are you using more precise equipment to finely tune your powder drops and weigh under .1 grains. I think that alot of people who start reloading try to get to in depth and think that they are more precise than what most equipment can actully accomplish.

[blockfort]

I'm using my lee and frankford scale, which are both only listed as accurate to within 0.1gr, but based on the velocities I got in my testing session, I feel like I am very consistent.

[CGT80]

starting a couple grains above minimum charge can be very bad. My pet 9mm load is 4.2 grains. 2 grains over is +50%. My gun will not cycle properly at 4.0-4.1. I load for 4.2 and error on the side of 4.3 rather than 4.1. My dillon powder measure is .1-.2 of my goal with WIN 231. My pet load is 970 fps-a very light load built for speed and consistency in shooting the gun at mostly close ranges. Accuracy is good, but my smallest target is 3" at 30'. I haven't shot groups in a while.

I found hotter loads of trail boss powder to be less accurate in 45lc and 460, than low to mid loads of the same powder. This is based on shooting 6" steel plates at up to 50 yards.

I loaded up some light 38 spl loads. They are very soft and work well on steel at close distances, but the bullet just falls straight down from the target when hit-very low velocity. At longer distances there is too much drop. I think a hotter load would help.

I can tell you that it does make a difference, but I have not measured it. It also depends on the individual gun and components.

[Sac-AR15]

starting a couple grains above minimum charge can be very bad. My pet 9mm load is 4.2 grains. 2 grains over is +50%. My gun will not cycle properly at 4.0-4.1. I load for 4.2 and error on the side of 4.3 rather than 4.1. My dillon powder measure is .1-.2 of my goal with WIN 231. My pet load is 970 fps-a very light load built for speed and consistency in shooting the gun at mostly close ranges. Accuracy is good, but my smallest target is 3" at 30'. I haven't shot groups in a while.

I found hotter loads of trail boss powder to be less accurate in 45lc and 460, than low to mid loads of the same powder. This is based on shooting 6" steel plates at up to 50 yards.

I loaded up some light 38 spl loads. They are very soft and work well on steel at close distances, but the bullet just falls straight down from the target when hit-
very low velocity. At longer distances there is too much drop. I think a hotter load would help.

I can tell you that it does make a difference, but I have not measured it. It also depends on the individual gun and components.

Oops. Edited my post. I meant .2gr not 2gr above min. 2gr above min would be bad to start.