How to develop an accurate load? Development process?

[BillyGoatGruff]

Hey Guys,
I got into reloading to save money. Been doing it about 4-5 years.
Now I'm tying to get more into developing more accurate loads.

What I'm looking for is what process guys use to get there? Don't need every step by step of prepping brass and all that. More of trying to find the right powder and charge? Bullet? Seating depth?

Do you find a powder first? or do you find a bullet first? I'm under the impression that a guy could take any high quality bullet and develop an accurate load ( when I say accurate, I'm talking sub 1/2 moa)

Do you start with finding the best seating depth first?

I little info on what I'm trying/wanting to do.
Have a new Rem 700, 7mm mag w/ a custom barrel 1:9. bedded into a Manners stock.


I've been playing around with some berger 180's and have a decent load going, but I'm out of 180's.
I have two boxes of the new Nosler AccuBond LR's (168's and 175's). A good assortment of powder and primers. I have way more Retumbo than anything else and it has been good with the 180's. So I would like to stay with that if I can

I want to start up a new load with this new bullet but with components being still difficult to get. I want to shorten the steps up IF I can? Try to get in the ball park as quick as possible and then fine tune.

Do you guys have a procedure to find a charge and the best seating depth for a particular bullet?
I've read the seating depth procedure for Berger bullets. Do I do that first?
With the Nosler LR being so similar to the Berger, will they be as sensitive to seating depth?

Is there any way to try to duplicate a factory load?
I shot some commercial HSM with Berger 168's and they shot really well. I have two boxes of those that I figured I would use as an emergency back up if I ran short on components at some point.
I've played around with the Berger 168's and haven't had much success finding something that shoots as good as the HSM.

Any tips or recommendations are appreciated.

Thanks, BGG

 

[drbill]

Hey BGG,

OCW Overview - Dan Newberry's OCW Load Development System

 

[Derek M.]

Last I heard, HSM is using H1000 in those boxes of ammo you are using which was my #2 choice. Unfortunately, what you are trying to achieve takes a LOT of steps and meticulous brass prep is one of them.

To answer some of your questions, naturally I want to start with a bullet, then figure out what powder. My brass and primers are usually set at whatever I have available or the best brass I can get for that caliber.

For my 7RMs I have a ton of Nosler brass on hand, no shortage of Winchester, and I'd like to buy some Norma. I use Federal 215M primers. I also had excellent luck with Retumbo and the 168 Berger VLD with 73.0 grains. That load is Win brass.

If you really want excellent accuracy, you know to do thorough brass prep, AND weight sort it, AND check the bearing surface length of your bullets and sort those, AND weigh each powder charge.

First thing I do is load up a trial of ammo increasing my powder by 1/2 gr increments and find out what my rifle can handle. Then I take the top 4 powder charges and start working from there. Ideally, a ladder test should be done buy my range is only to 200 yards so I don't do it and thus far, haven't needed to.

I will try up to 4 powders if necessary. If no satisfaction, the bullet gets replaced.

 

[bill123]

Hey BGG,

OCW Overview - Dan Newberry's OCW Load Development System

+1 on Dan Newberrys system. Also for $45 be will consult with you, giving you a bullet, brass, primer, powder combination that's already proven. He will also shortcut for you a lot of the lower charge weights so you can start from a powder weight that's close to what you will end up using. The savings in powder and bullets is worth the price alone.

 

[Mikecr]

In contrast, you don't need to weigh brass, or measure bullets, and there is no such thing as a proven load out there for YOUR barrel..

Pick a mid load for fireforming of your brass to your chamber. While fireforming, run Berger's seating depth testing.
With best seating from this, and fully fireformed cases, start any traditional incremental load development. This can be an OCW approach, 3sht grouping, or 300yd ladder.
Then, if promising, a final tweak of seating to shape grouping. If not promising, fix any problem and/or go to another powder. Don't overlook a possibility of bad primer striking for brand.

 

[BillyGoatGruff]

Thanks guy's for the info and tips.

drbill,
The Dan Newberry technique is interesting. I might give that a try.

I did a seating depth test today and had some good results on the load that I have already been working on.
I may take those results and do a OCW test.

To what extent does neck tension have? With my current brass and bushing I'm getting .003". Should I get a different bushing and try to get .002"?

Thanks again,
BBG

 

[Mikecr]

You don't have .003" of tension, you have .003" of interference fit. There is a difference.
Tension is springback, and yes it does affect a load. Causing a big interference fit = overworking necks = changing springback. A big interference fit also means higher seating forces = higher seating variance.
Ideally you would take it ~2thou under cal, then mandrel pre-expand to ~1thou under cal(after springback), prior to seating.
This helps keeps tension variance and runout low, while allowing very accurate seating.

 

[jsthntn247]

Here's how you do it in less than 30 rounds.

1. Find your max coal to the ogive of the bullet

2. Pick a powder that gives good case volume 95-100% (Retumbo is great for the 168 - 180)

3. Load powder from 2 grains under book max to 1 grain over max in .5 grain increments 3 shots each ( 7 - 3 shot groups for 21 total)

4. Seat bullets with .002 - .003 neck tension and a .010 jam

5. Shoot and OCW test with those rounds at 100 yards round robin

6. Pick your OCW group and load 3 shots at a .010 jam, just touching lands, and .o10 off lands. 9 Rounds total

If your gun is worth a squat you will have at least a .5" grouping gun- capable of shoot stuff a long waays off.

Take 30 bullets and do this and post results.