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Posted: 4/30/2009 1:55:02 PM EDT
I was wondering how many rounds to load when you are working with a new powder or bullet?  And what intervals to increase on powders from a starting point?
Link Posted: 4/30/2009 2:00:45 PM EDT
[Last Edit: 4/30/2009 2:02:18 PM EDT by AshesToAshes]
Originally Posted By BStreet18:
I was wondering how many rounds to load when you are working with a new powder or bullet?  And what intervals to increase on powders from a starting point?


Six.

Edit: At least that's what Berger recommends.

In terms of powder, I'd move around 1 gn at a time until you get the perfect load, then fine-tune. This, presuming your'e staying within recommended min/max range.
Link Posted: 4/30/2009 2:10:59 PM EDT
Originally Posted By BStreet18:
I was wondering how many rounds to load when you are working with a new powder or bullet?  And what intervals to increase on powders from a starting point?




I usually increase by half grain increments. A full grain can make you pass over a sweet spot. At the least a 3 tenths increment is necessary.
Link Posted: 4/30/2009 2:23:22 PM EDT
I start at 10% below max charge. Usually 0.3 gr increments. 5 rounds at each.
Link Posted: 4/30/2009 2:34:17 PM EDT
[Last Edit: 4/30/2009 2:36:40 PM EDT by Elwood_Blues]
This may not give you enough information statistically, but I load 3 rounds below my target in ~ 1/2 - 1 grain increments, 5 rounds  around my target (charge or bullet position), and 3 rounds above.  Half grain for pistol rounds up to .223, a full grain for 308 and larger rounds.

My theory is that 3 rounds is enough to tell you a load is no good, and five rounds is a decent minimum for groups.  Shoot all on the same target, watching for elevation and group changes as you change the variables.  yeah, I know there is a chance to confuse a 3 round group with a good shooting group.  A single "good" group may or may not be a sweet spot - gotta use judgement whether to pursue this load next time at the range.


When a cluster of close increment changes gives you good results (pressure, groups, minimal elevation changes, etc.), you have found a point worthy of closer investigation - say 0.005" change in bullet position or 0.1 gr. charge changes instead of 0.025" and 0.5-1 gr increments if you are so incliined.  

I think Ken Waters wrote an article on this, called something like "Developing Pet Loads" or such in Handloader a long time ago.  Audette wrote up load development as well.  Check out these guys for a "better," or statisticially valid, answer.

Link Posted: 4/30/2009 2:36:02 PM EDT
Originally Posted By jmarthsr:
I start at 10% below max charge. Usually 0.3 gr increments. 5 rounds at each.


I use this method as well. Then when I get within a range that appears to have some promise I up the number to 10 for a better StdDev Average Vel and real grouping.
Link Posted: 4/30/2009 3:43:51 PM EDT
[Last Edit: 4/30/2009 3:50:01 PM EDT by AeroE]
Link Posted: 4/30/2009 3:55:59 PM EDT
Don't know that it's the "right" method but I usually load at least 30 rounds and shoot 3 10-round groups when trialing a new load. Of course, if there is any doubt as to the safety of the load, I'll not bother to load that many.

I used to load only 1 5-round batch of trial loads until I shot an excellent group one day and under identical conditions using identical loads, the next attempt opened up by an inch . Thereafter, I increased my batch size to help confirm consistency during one firing session.

I step my charges by .5 grns.
Link Posted: 5/1/2009 2:34:29 AM EDT
Marine, I understand what you are saying but how does one do it if they are using Titegroup where the min and max powder charges only differ by say .5 g? I'm new to reloading, and just did some 9mm. Reloaded 6 rounds from 4.1 to 4.6 (if my memory serves me correct) and one group seemed really tight and the rest just okay. This was shooting from 8' away standing. Maybe it was just my skill at the time..how does one know the load is the "sweet spot" as you guys call it? (I don't have a chrono)..

Link Posted: 5/1/2009 2:50:57 AM EDT
[Last Edit: 5/1/2009 2:52:17 AM EDT by Hebrew_Battle_Rifle]
Originally Posted By BadLuther:
Marine, I understand what you are saying but how does one do it if they are using Titegroup where the min and max powder charges only differ by say .5 g? I'm new to reloading, and just did some 9mm. Reloaded 6 rounds from 4.1 to 4.6 (if my memory serves me correct) and one group seemed really tight and the rest just okay. This was shooting from 8' away standing. Maybe it was just my skill at the time..how does one know the load is the "sweet spot" as you guys call it? (I don't have a chrono)..



Most of the posts in this thread are referring to rifle loads. Pistol loads require smaller increments.

All barrels vibrate as the bullet travels along the bore. The objective for those looking for the utmost accuracy is to find that projectile speed that will allow the bullet to exit the barrel when the muzzle is at the very top or very bottom of the vibration wave. It is at the top or bottom of the wave that the muzzle is stationary.  The very top or very bottom of the wave is the sweet spot. You will know when you have hit the sweet spot when the groups turn into one ragged hole.
Link Posted: 5/1/2009 4:00:32 AM EDT
[Last Edit: 5/1/2009 4:01:20 AM EDT by AeroE]
Link Posted: 5/1/2009 6:22:01 AM EDT
Originally Posted By Hebrew_Battle_Rifle:
Originally Posted By BStreet18:
I was wondering how many rounds to load when you are working with a new powder or bullet?  And what intervals to increase on powders from a starting point?




I usually increase by half grain increments. A full grain can make you pass over a sweet spot. At the least a 3 tenths increment is necessary.


Depends on the size of the round I guess... a grain isn't much in a .338 LM or a .50 Cal but is huge on a .223
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