Sequence for working up new loads

[Newtosavage]

I could use some advice here...

Since there are nearly infinite combinations of bullet design/weight, powder and charge, bullet seating depth, etc., etc., does anyone have a good formula or approach for working up a new load?

If a person just tries 3 powders and 3 types of bullets seated at 4 lengths, assuming they work up the charge in 5 steps, that's already 180 possible combinations.

Assuming you're shooting 5-shot groups to test, then you're looking at 900 shots just to test three bullets and three powders.

 

[LiveLife]

For load development, I try to adjust only one reloading variable at a time.

I first determine the OAL/bullet seating depth then adjust powder charge while monitoring accuracy trends/chrono data.

Determining bullet seating depth - http://www.sinclairintl.com/GunTech/Determining-Bullet-Seating-Depth-/detail.htm?lid=16131

Ladder testing - http://www.6mmbr.com/laddertest.html

 

[Newtosavage]

Of course, one variable at a time makes sense.

What I was looking for is the order of priority. It seems you favor seating depth, and that's not the first time I've heard that.

 

[Reloadron]

Of course, one variable at a time makes sense.

What I was looking for is the order of priority. It seems you favor seating depth, and that's not the first time I've heard that.

One variable at a time and I generally start with powder, only a single powder but working up the charge. Depending on the span it could be 0.2 grain increments or 0.5 grain or even 1.0 grain. I load 10 rounds with each and shoot over the chronograph looking for consistency in my loads. You can normally see if a powder will work or not inside 50 rounds. Once I have a good load or one with promise I work into another variable like seating depth or neck tension. The idea is only one variable at a time. Last sumer I spent weeks on .308 Winchester and weeks on .223 Remington to come up with a few loads I liked.

Ron

 

[Newtosavage]

I forgot about neck tension. LOL. So instead of 900 shots, now we're talking 2700 shots.

At what point do you shoot out a barrel going through all the possibilities, and then have to start over?

With my .308 that I've owned for about 4 months, I've already put approx. 500 rounds through it and don't feel I've even scratched the surface.

 

[LiveLife]

I forgot about neck tension. LOL. So instead of 900 shots, now we're talking 2700 shots.

With my .308 that I've owned for about 4 months, I've already put approx. 500 rounds through it and don't feel I've even scratched the surface.

And don't forget commercial vs military cases with thicker walls for reduced internal case volume. Now you may have to test 5400 rounds!

That's where online forums can help.

You can ask, "For X brand rifle with Y barrel length and Z twist rate and such and such brass/bullet/powder, what has worked for you?" And based on the consensus of replies, you can narrow the OAL/powder charges down to possibly reduce the number of test rounds.

When I started reloading .308, I searched the forums and asked for consensus of what worked well. I tested different batches of commercial vs military cases with 168/175 gr bullets and Varget/H4895/RL15. Once I got in the ballpark, I began fine tuning my loads for smaller shot groups.

 

[Doc7]

At some point you encounter a load that will make you determine for your particular needs you don't need to test the remaining 168 possible combinations.

Continuing to shoot those may be an enjoyable hobby for you, while you use your current "best" load for whatever your shooting activity is.

 

[HEAVY METAL 1]

You have to determine what you plan to shoot at----targets or hunting. Which bullet weight to use can be determined by barrel twist rate. Reloading manuals will give powder recommendations/charge weights to use. I have found that the best loads for me have been those that have a high loading density. Some folks suggest determining maximum COAL first after the bullet type /purpose has been defined.

 

[macgrumpy]

1. Pick a bullet based on what you want it to do (target shooting, hunting, general use, FMJ, OTM, solid copper, etc.).
   
2. Using a reloading manual that was produced by the company that manufactures the bullet you chose, pick a powder and powder charge weight.
   
3. Using the reloading manual's ammo specs (cartridge overall length, manufacturer for the case, primer), fire test groups and make adjustments to the powder charge weight in 0.3 grain increments until you find the optimum results.
   
4. Staying with the same powder charge weight from the step above and adjust the bullet's seating depth in increments of .010", both longer and shorter, until you find the length that produces optimum performance. Magazine length may limit the max length.
   
5. Staying with the same powder charge weight and cartridge overall length from above, change the primer and see if the ammo performs any better or worse, choose the primer that produces the optimum performance.

A chronograph is a good tool for this process as it provides an indication of changes in chamber pressure. Muzzle velocities higher than the manual lists would indicate unsafe max pressures.

Pay attention to the components and the weapons used in the reloading manual's load listings. A top end load developed using a universal receiver would most likely be too hot for weapons of weaker design (like an old lever action design or some military firearms). Some bullets of the same weight but from different manufacturers can produce higher max pressures (the bullet's base may extend further in to the case which will reduce volume and increase pressure).

Or buy a copy of QuickLoad and use it to help bracket the best loads which will reduce the number of rounds needed to find the ammo that works best.

 

[Newtosavage]

Very useful stuff here guys. Thank you!

At some point you encounter a load that will make you determine for your particular needs you don't need to test the remaining 168 possible combinations.

Continuing to shoot those may be an enjoyable hobby for you, while you use your current "best" load for whatever your shooting activity is.

This is where I'm at right now. I have a good, accurate "hunting" load now for each of the three rifles I reload for, and I tinker with other variables as time and money allow. I'm sure that's a common approach, but I do appreciate seeing the thought that goes into a sensible load development sequence.

And I agree that my chronograph has proved invaluable in my process - showing me just where pressures are starting to spike based on the jumps in velocity. It also allows me to plot bullet drop over distance so I can match that to whatever reticle I have in the scope on that rifle, and determine where to set zero or which scope to use for which round.

After toying with several "holdover" reticles, I've gone back to the good 'ol Duplex and fixed power scopes for most of my hunting rifles. If I choose the right reticle and magnification, putting the 300 yard zero on the top of the bottom duplex post (where the wire thins) almost always works out perfect for a 100 and 200-yard useful zero. Without a chrono and ballistic software, I'd have to shoot a lot more ammo to learn the same thing.

 

[Nature Boy]

Newtosavage,

You and I are on the same journey right now with .308 and asking very similar questions.

When I got my FN SPR in April, I figured the "10,000 round chrome lined barrel" would last me for a good long while. At my current rate I'll be lucky to get 2 years out of it.

 

[pcgunner]

What I do and have always done is...

• Figure what weight bullet I'm working with - sometimes I just buy one weight at a time to minimize the work load and confusion
• Check the manual for the max's - Overall length, crimp width etc.
• Next I work out the powder weight range from the manuals - I always start with my top 3 - Win 231, Alliant Bullseye, Hogd. Universal
• Start with dies preset - I seldom change the length once I have it set. Starting with Win 231 powder
• Set the powder charge to the lowest, load 20, increase powder to next highest charge load 20 - rinse and repeat until I get to the max
• Move on to next powder - rinse and repeat.

That's how I do it at least - right or wrong, it works for me with the least amount of effort and confusion.

What I mean by effort - I enjoy the process of reloading, but I do NOT enjoy being overwhelmed by technicalities - so I try to minimize them to keep them manageable and retain the enjoyment of reloading.

 

[spitballer]

Not sure which model you have but I'm jealous if it's a .223 with 30' heavy barrel! Savage would have been my first choice if I'd had the bucks for a production target rifle. Instead I made a homegrown target rifle of my own out of a Rem 700. The finely crafted 30" aftermarket barrel turned out to be both a blessing and a curse: the little .223 case hardly holds enough propellant to take advantage of a barrel this long. I ended up having to use a .222 Rem-Mag style half-and-half load with mag primers, H414/BL(C)-2 and 55gr bullets, in that order. I've caught flak for using this technique but when it comes to using tiny cases with very long barrels (the .223 Savage comes to mind) you may not have much published precedence to go on. And for good reason: duplexing with smokeless powder is one of the few techniques that IMHO can be truly, truly dangerous to if it's not done with a lot of forethought. I only though it appropriate to mention this because choosing a powder to match barrel length is where I would start when creating a load. I can only vouch for the exact recipe I've described above, and our moderator has every right to lock out my post for even discussing this technique if he feels it's appropriate. Good luck to you.