Load Development

blkexp98 · #1 02-17-12, 10:50

Reading a few of the current posts on new loads and such I came up with a couple questions.

1. Is powder charge the best variable to start with on load development assuming brass and bullets have been chosen?
2. What is the next logical step? Change the seating depth, neck tension or the primer?
3. How far off the lands is considered a good start for seating depth and how will that change effect your velocity? If it does effect the velocity do you go back after changing the seating depth to revisit powder charge?

I haven't done any real changes in seating depth so I only assume it will change the velocity due to case pressure changes.

Raven Armament · #2 02-17-12, 11:09

When I work up a load, I set the OAL to the longest that will feed from the magazine and chamber reliably. Then I start with the starting charge for the powder and work it up until I either get desired results or pressure sign shows.

If you shorten the OAL from the data, you will increase pressure. If you lengthen the OAL from the data, you will decrease pressure.

Neck tension is set with the sizing die and I like to use bushing dies to adjust this to provide for proper tension on the bullet. If you mean to trim the neck to fit the chamber, unless you have a tight neck chamber (ie custom benchrest stuff), turning necks for a SAAMI chamber is a waste of time and money.

I don't ever mess with changing primers. I use CCI only. I used to have different primers for different loads and it's just a PITA over time.

ICANHITHIMMAN · #3 02-17-12, 12:35

It depends on the bullet and the rifle used. If its a bullet thAt I know is going to be sensitive to seating depth test. I will do that part first but a ladder test can tell u a lot.

dth4lf · #4 05-22-12, 19:10

Rather than starting a new thread I figured I'd just post under this one.

I'm trying to work up a load for my Stag. Nothing special, 1:9 twist with a cheap Sightmark rear optic... My first AR.

This load will be my mass production/ plinking/ varmint load, so I'm looking to achieve decent accuracy without getting too scientific about it. During production I'll be loading all of this with my normal RCBS powder measure which varies slightly (perhaps around 1/10 gr. or so), so I'd like to look for the charge that will give me reasonable accuracy even if I'm slightly high or low in charge from cartridge to cartridge.

I'm currently working with Hornady 55gr fmj-bt w/c and Ramshot TAC with CCI primers seated to 2.200" per the Hornady manual.

The other night I made up a group of cartridges charged with 23gr, 23.5gr, 24gr, and 24.5gr... 5 of each charge.

Results of the first group:

It seemed obvious that the gun liked the hotter loads closest to the 24.5 gr. load, so I decided to run another group, this time in smaller increments starting at 24.2 gr. (also moved my sight a bit... Too far.)

Results of the second group:

Again, the best group was the result of the highest charge (24.6 gr.). Max load (per the Hornady manual) is 24.7 gr. so I decided not to go any hotter. I decided to dial in my powder measure for a charge of at least 24.5 gr. but no more than 24.6 and run a group of ten or so rounds for testing. This time I sighted my gun at 50 yds. with this load.

After shooting this group I bumped my sight down one click and left it at that. I'll load up some more for a follow-up visit but I'm pretty happy with the results. For me personally, to do much better I'd need a better optic, my eyesight isn't that great anymore so my own ability is the limiting factor here.

duece71 · #5 05-22-12, 20:52

I am glad to see threads like this. I am a new to reloading person and have only started to dable in handgun reloading. Rifle to follow someday.

ICANHITHIMMAN · #6 05-23-12, 11:13

dth4IF

The issue I see right off the bat is your optic. I would if you can use a scope to shoot your ar for load development. If you cant its going to be a lot harder on you trying to work with the red dot. After you have a load switch back to the red dot.

Also when doing a load do not adjust your optic at all! Zero it with some factory ammo and shoot your load from there. Get a big sheet of paper (I have a role of flooring paper it will last forever). Now shoot a ladder test, after every shot mark where it hit and the charge weight on a smaller pice of paper you have with you at the bench. Start your charge weight on the low end of the scale all the way to the max you will only need one round at each charge weight.

Ironman8 · #7 05-23-12, 11:44

Quote:

Originally Posted by ICANHITHIMMAN

Also when doing a load do not adjust your optic at all! Zero it with some factory ammo and shoot your load from there. Get a big sheet of paper (I have a role of flooring paper it will last forever). Now shoot a ladder test, after every shot mark where it hit and the charge weight on a smaller pice of paper you have with you at the bench. Start your charge weight on the low end of the scale all the way to the max you will only need one round at each charge weight.

You wouldn't want to shoot a 5-10 shot group for each charge weight? Why not?

What does one round tell you, when compared to factory ammo, that a 5 round group won't?

Or is this only done from an economical standpoint?

dth4lf · #8 05-23-12, 12:53

Quote:

Originally Posted by ICANHITHIMMAN

dth4IF

The issue I see right off the bat is your optic. I would if you can use a scope to shoot your ar for load development. If you cant its going to be a lot harder on you trying to work with the red dot. After you have a load switch back to the red dot.

I should have done this, good point. I was having a tough time seeing the target clearly, especially at 100yds. I was basically just putting the dot in the center of the paper.

Quote:

Originally Posted by ICANHITHIMMAN

Also when doing a load do not adjust your optic at all! Zero it with some factory ammo and shoot your load from there. Get a big sheet of paper (I have a role of flooring paper it will last forever). Now shoot a ladder test, after every shot mark where it hit and the charge weight on a smaller pice of paper you have with you at the bench. Start your charge weight on the low end of the scale all the way to the max you will only need one round at each charge weight.

Thanks for the tips. I may have to run through the process again utilizing this method a little better. Fine by me, just gives me another excuse to do some more shooting.

TucsonFX4 · #9 05-23-12, 14:32

Quote:

Originally Posted by ICANHITHIMMAN

Also when doing a load do not adjust your optic at all! Zero it with some factory ammo and shoot your load from there. Get a big sheet of paper (I have a role of flooring paper it will last forever). Now shoot a ladder test, after every shot mark where it hit and the charge weight on a smaller pice of paper you have with you at the bench. Start your charge weight on the low end of the scale all the way to the max you will only need one round at each charge weight.

Like Ironman8, I don't quite understand what you are saying. What does firing just one round tell you? I haven't gotten into reloading yet, but plan to in the next month or two. What is the ladder test?

Thanks.

Raven Armament · #10 05-23-12, 15:42

I'm thinking the ladder test is a way to match the vertical POI with your handloads to the POI of the factory ammo you zeroed. In theory the rounds will walk their way in equal increments with each .1gr powder charge increase.

Seems that's a good way to do it if you are duplicating factory ammunition performance without a chronograph.

ehryk · #11 05-28-12, 19:15

what you are looking for is a point where several of the rounds cluster together (3 or more). You then chose the midpoint powder charge and load 5 or so to see how those group. If all is well, you have a good load that will work well even with powder and temp variations.

ETA: The drawback to using this meathod is you need to do it from at least 300 yards so you get a definate point of impact reading. For closer, say 100 yards, I load 6 loads, 3 of each and have 6 targets lined up horizontaly and shoot each one once in sequence allowing the barrel to cool each time. After doing this 3 times, find the center point of each group and compare targets. There should be 3 that have center points VERY close together. The mid charge is your best (in theory anyway lol). load 5 of that and see how they group.

ICANHITHIMMAN · #12 05-28-12, 20:52

Quote:

Originally Posted by ehryk

what you are looking for is a point where several of the rounds cluster together (3 or more). You then chose the midpoint powder charge and load 5 or so to see how those group. If all is well, you have a good load that will work well even with powder and temp variations.

ETA: The drawback to using this meathod is you need to do it from at least 300 yards so you get a definate point of impact reading. For closer, say 100 yards, I load 6 loads, 3 of each and have 6 targets lined up horizontaly and shoot each one once in sequence allowing the barrel to cool each time. After doing this 3 times, find the center point of each group and compare targets. There should be 3 that have center points VERY close together. The mid charge is your best (in theory anyway lol). load 5 of that and see how they group.

What he said I test at 200 plus yards. Its the slower way of doing a ladder test looking for nodes with the chronograph. It just narows down the accuracy potental and saves time and money.