Accuracy of Powder Throwers?

[cephas]

I am thinking that thinner... more dust like powder... might produce less of a variation in throws? as oppose to big flake powders?

Note what Guns N"at is advising. In a general sense the smaller the powder kernels, the more uniform the powder measures.
Usually ball (spherical) powders first; then flake powders; and then the stick powders. The various stick powders vary in length. Here is some photos of powder, found in most reloading manuals: http://stevespages.com/powderappearance.html

[tsafa]

My concern was more along the lines that I have been experimenting with loads right up to the do not exceed load and testing their velocities. I noticed the variations in throws and became concerned with overthrows will trying to stay at the "do not exceed mart". Clearly I need to measure every single load at that level from the information I have received here.

[SharpShooter88]

If my research is correct, your OAL and how deep you set the bullet into the casings is just as important as a good accurate powder measure, maybe even more so. If you set the bullet too deep, my understanding is, you can cause pressure variances with the load that will effect your accuracy just as much if not more than .2 gr of powder. Just some thought, FWIW.

[yukon375]

yes you are right about bullet seatin' depth. and working up loads using the ladder method to find an accuracy node will make slight variances in charge weights moot.

If my research is correct, your OAL and how deep you set the bullet into the casings is just as important as a good accurate powder measure, maybe even more so. If you set the bullet too deep, my understanding is, you can cause pressure variances with the load that will effect your accuracy just as much if not more than .2 gr of powder. Just some thought, FWIW.

[tsafa]

If my research is correct, your OAL and how deep you set the bullet into the casings is just as important as a good accurate powder measure, maybe even more so. If you set the bullet too deep, my understanding is, you can cause pressure variances with the load that will effect your accuracy just as much if not more than .2 gr of powder. Just some thought, FWIW.

yes, I have been able to increase energy significantly while staying at or under the "never exceed load" by seating the bullets as deep as the book allows to seat them. Here is an example from yesterday reloading .45 ACP. My Lee book shows the never exceed load at 6 gr for Unique, although the Alliant Website shows a 6.5 gr max for unique on a 230 FMJ... anyway... at 6 gr and seated to a length of 2.09 I obtained 311 ft/lbs. With the same load and seated to the minimum length in my book of 1.19 I obtained 387 ft/lbs. Of course at 1.19 the cartridge looks silly and 1 in 8 jammed in my 1911. Regardless of jams, that is an increase of 76 ft/lbs in .45 acp.

[SharpShooter88]

yes, I have been able to increase energy significantly while staying at or under the "never exceed load" by seating the bullets as deep as the book allows to seat them. Here is an example from yesterday reloading .45 ACP. My Lee book shows the never exceed load at 6 gr for Unique, although the Alliant Website shows a 6.5 gr max for unique on a 230 FMJ... anyway... at 6 gr and seated to a length of 2.09 I obtained 311 ft/lbs. With the same load and seated to the minimum length in my book of 1.19 I obtained 387 ft/lbs. Of course at 1.19 the cartridge looks silly and 1 in 8 jammed in my 1911. Regardless of jams, that is an increase of 76 ft/lbs in .45 acp.

That just goes to show, that seating depth can greatly affect your loads. I would work on an OAL that your gun likes, once you find it, stick with it. Then you can start experimenting with powder. Staying consistant with your OAL will allow you to experiment with different powder types and loads of powder. One of the formulas to better accuracy overall is quality and consistant handloaded ammo. Thats why I am getting into it.

[glocknick]

i have a rcbs powder thrower which seems to be within .2 grains.

[Pete D.]

When you write .03 grain variance, you mean 0.3 grain variance.....is that correct? Three hundredths of a grain (0.03) would be hard to detect on a scale and have virtually no effect on measurable velocity.
Even a variance of three tenths of a grain in a rifle or large pistol load is going to have little to no effect on velocity or consistency.
There are other things to pay attention to that are more important than whether your measure is dropping 47.0 grains/47.3 grains/47.6 grains. Certainly that difference is not going to result in 100 fps velocity swings. It may be somewhat important in pistol loads of six grains or so - 0.3 grains is 5%. But..... I suspect that the difference in performance of a load even 10% off would be difficult to notice.

I am fortunate enough that I have acquired - over the years -thirteen powder measures (eight different types) - 5 Lee Perfects, three Lyman, two RCBS, two Dillons, and a Redding. I cannot say that any one of them is more accurate than any other.
As to weighing every charge - you either have a lot of time to load or you aren't shooting much. If I need 100 .45 ACP this week and 40 .30-06 and 100 t0 200 shotshells, you can be sure that I am not weighing out each charge. Life is too short, that's why progressive presses were invented.
Pete

[ham385]

When you write .03 grain variance, you mean 0.3 grain variance.....is that correct?

I was also wondering about this, if you've got a .03 grain variance than your measure is extremely consistent. I'd like to hear back from the OP to see if this was a typo.

[tsafa]

Sorry about that. I meant .3 grains. I edited my first post to avoid further confusion.

My understanding from what I have read in the Lee Book is that a 1% increase in powder yields approximatively a 13% increase in velocity. That is the reason why exceeding the max load can be dangerous. Because of this danger I am seeking to find out how other people here minimize the dangers of overthrows when working at max loads.