How do you work up a load?

[Spots]

So I'm ordering reloading equipment while I'm gonna this summer, and I'm going to start rolling my own this fall when I get back. So here is my question. I will be reloading .223 and .308 and I was wondering how you guys go about load development? I know a reloading manual gives you the baseline, but after that? I plan to build an M1A Springfield into a DMR style rifle and want to work up my own loads for it that are as accurate as possible. Do you guys make 10 with the same specs, shoot them off a bench at 50 yds, check results, tweak one thing and do it again? Or do you use 25 yds or 100 yds to start? Do you make 10 to baseline, or 50? Just wondering what the most efficient method to go towards working on a load that fits one rifle perfectly

[Hozzie]

I do all of my general testing at 100yds, but the best load could change over varying distances.  After my rifle is sighted in with one of the loads, I will then shoot 2 - 3 shot groups with all other loads, each with different bullet types and/or weight.  I don't sight in for each load, just the first typically as I usually only vary my loads by a grain or two depending on what I am loading and the hits don't move far.  I actually prefer to not hit where my crosshairs are as I want to make sure I am exact each time on target.  Hitting an inch high or low is good for me as I can see the group but not open my aiming point.  Once I shoot all of them and measure them, it is usually fairly easy to determine a powder or bullet that a rifle seems to like better.

 

How much I vary each load per powder depends on the overall spread shown for that powder in that bullet/caliber combination.  For example, if the min to max spread is 20gr to 25.5 gr I would probably load them at 20gr, 22gr, and 24gr, only going up to max if I saw significant evidence that the higher powder charge was giving the best accuracy of the 3.

 

For example, I would load (assuming they are within the manual max).

 

6rnds - IMR3031 (X gr), Sierra 55gr HPBT

6rnds - IMR3031 (X+2 gr), Sierra 55gr HPBT

6rnds - IMR3031 (X+4 gr), Sierra 55gr HPBT

 

 

6rnds - IMR3031 (X gr), Sierra 50gr HPBT

6rnds - IMR3031 (X+2 gr), Sierra 50gr HPBT

6rnds - IMR3031 (X+4gr), Sierra 50gr HPBT

 

6rnds - IMR4350 (Y gr), Sierra 55gr HPBT

6rnds - IMR4350 (Y+2 gr), Sierra 55gr HPBT

6rnds - IMR4350 (Y+4 gr), Sierra 55gr HPBT

 

 

6rnds - IMR4350 (Y gr), Sierra 50gr HPBT

6rnds - IMR4350 (Y+2 gr), Sierra 50gr HPBT

6rnds - IMR4350 (Y +4 gr), Sierra 50gr HPBT

 

and so on.....

 

 

If I can easily determine it is a powder the guns like best, I do more tests with a broader range of loads/bullets in that powder.  If it is a particular bullet that seems to do better across all powders, I will do more tests with just that one bullet.  Bullet weight and barrel twist will have a big impact on accuracy.

 

Another factor that affects the accuracy as well is OAL.  Some guns like to have the bullet off of the lands, some like the bullet seated right on the lands.  Depends on the gun.  I recommend getting an OAL gauge and knowing what your OAL for each gun is.  I use the Hornady which works fine.  I usually start with an OAL .010 off of the lands and go from there.

 

It is basically a process of elimination.  I have OCD so I have to try a bunch of combinations, but if you want to start with one powder and one bullet weight, just start with a conservative load based on the reloading manuals you have and increment up in powder not to exceed the max load. There are of course many other things that can affect the load (primer, runout, etc,), but this is how I do it based purely from a powder/bullet perspective.

 

Actually, load development is one of my favorite things about shooting.  It's a challenge to really see how well I can make a gun shoot based on just changing some very small details.

Edited May 21, 2013 by Hozzie

[R_Bert]

Get a chronograph if you are going to actually develop non-published loads.

 

roughing in, I do much the same as described above, except 5 rd sets, 0.5gr powder increments, and .025" OAL jumps.

 

On unknown-load powders (common in .204 Ruger), usually I find a similar burn rate powder, derate ~ 25% and get a baseline chrono measurement and scale up or down (usually a fairly linear function) to the projectile velocity I want (1-3 rds).  From there, I go to process above.

 

In unknown territory, absolutely use safety goggles. watch for squibs, watch your primers and cartridges for over-pressure signs, watch your chrono for excessively slow or fast velocities.

 

I do not zero the scope during testing, but do cover the target back-board with newspaper (to cover up all the old holes).

 

Once I find a relatively sweet spot, I reduce the delta in variables and tune it up.

 

And yes, test one powder, and one projectile at a time.  Its less complicated.

Edited May 21, 2013 by R_Bert

[Dolomite_supafly]

I use a chronograph to load. There is a correlation, I believe, Standard Deviation and vertical stringing when shooting at longer distances.

 

Everyone has their own routine for accuracy testing. I do it this way to minimize my time at the range. I can shoot at my house so I can determine SD's without being at a range. With my testing all components are as close to being identical as humanly possible. Cases the same, bullets the same, primers the same and all are loaded in the same setting. The only variable when I test will be the powder charge and overall length of the bullet.

This is how I test loads for accuracy. I will load 3 rounds with the bullet I plan to shoot starting at the minimum powder charge and at the maximum overall length. Then I load 3 more but I add .3 grains of powder to the load and again at the maximum overall length. I do this, .3 of a grain at a time, until I start to see signs of pressure. I record the results then move on to the next powder and do the same. And once I find a load that has a SD I feel is small enough I start the load development.

 

With the same powder you will find a point where the SD numbers drop significantly. I think this is where the powder has reached is perfect efficiency. I have a 223 load that has a SD of 1.73 fps, which is amazing. I thought my chronograph was broke or the batteries were dead but after replacing the batteries it ran the same numbers again and again.

And because the bullet exits at a certain part of the whip you need to find the position where the bullet exits at the same time. I normally load the 3 that had the smallest SD. Then I load 3 more with the same charge except I seat the bullet .01" deeper in the case. Then 3 more that are .01" deeper than the previous. Seating .01" deeper will change where the bullet exits during the whip of the barrel. I will generally start out seating .01" and stop at .10". That is unless I see pressure signs first.

Then I take these loads and shoot them at a horizontal line on the target. I am not worried about lining up with a vertical line at this point. I try 100 or maybe even 200 yards. You are not worried about the horizontal, side to side, group size but vertical group size. That is if you have 3 rounds that are spread out over 2" vertically that means the bullets are exiting at different times during the whip. If you find that 3 rounds that are on that horizontal line, even if they are spread out horizontally, that means these are exiting very close to the same point during the whip.
 

I also prep my brass when I am trying to squeeze the absolute last amount of accuracy of the the gun. I buy brand new brass and use brass from the same lot. I trim them all then weigh then all and throw out any out of the norm. Then I uniform the flash holes and chamfer the flash hole. I uniform the primer pockets so they are identical. Then I neck size the brass followed by body sizing the brass. And when seating my primers I seat them using a die that allows me to set the depth so all primers will be the same height.

 

For my Savages I set the headspace at 0 using the sized pieces of brass. That is I loosing the barrel nut and tighten the barrel down onto the sized piece of brass without anything providing some clearance, like tape or paper or gauges.

 

What did all this work get me? A factory Savage barrel that shot .3's at 100 yards pretty consistently.

 

I haven't used this method for probably a year since I went to the 300 Blackout. I no longer shoot for the smallest groups on paper but do shoot for fun. I enjoy shooting clays and other reactive target so as long as my handloads are able to to that I am happy.

 

 

[Hozzie]

I agree with both above.  I also chrono my loads.  Didn't get into that much detail in my example, but if you have one, use it.  It isn't required, but it will help get to the best load the quickest and assists with shooting safe loads.  If you don't have one, you can still get good loads, just don't push it if you don't have good load data.  If you will just be loading for 223 and 308, you should be able to find plenty of loads in manuals and online.  Just be sure to double check anything you find online with a manual to see if you are within a safe range.

[TripleDigitRide]

First, I go to YouPor....oh, that kind of load. :lol:

Carry on!

[TNMTBik3r]

My process (this is for my 30-06 deer rifle mainly) is to start at the minimum load (average across my 3 books is 54 grains for example) and increase by 1 grain until I hit the maximum (ended up with 54, 55, and 56). I load in batches of 7.

My rifle is zeroed with factory ammo, I test at 100 yards. I shoot the first group of 7, spaced 30-60 seconds between shots. Measure the overall group, measure the best 3 shots. Record results, wait 10 minutes for barrel to cool and then shoot batch 2. Repeat, batch 3.

I take the best powder load and then adjust the OAL slightly and load another batch of 7.

This process has worked well for me. I just finished finding the right recipe for my Savage using Barnes TTSX bullets last weekend. The 7 shot groups seem to be a better test than just 5 shot groups, and I can get an average of the overall and best 3 in the group to compare.