New Reloading Method for me

[nksmfamjp]

I was an OCW guy, but it uses a lot of rounds, doesn't allow me to focus through each group. Velocity data is a bit hard to collect too.

I didn't really get how to do ladders, but I'm getting better. I have a method now. I used to loose track of the shots.

So my new method:

Run a ladder of my lowest acceptable velocity thru a couple grains over max. I use about 0.8% increments. Use some logical OAL....SAMMI, book, mag length, lands minus 0.030". I shoot until I get excessive bolt lift, case head expansion or other issues....I record max acceptable charge and min acceptable charge based on velocity. I should also be able to identify something close to a node there.

Then run 5 ocw groups centered at that node. 3 shot groups. Vary charge weight. Use the same OAL. Shoot low to high.

Then run 5 ocw groups vary oal. Berger method. 5 shot groups from here on...

Then run 5 ocw groups vary charge weight at 1/2 last increment.

When charge increments are 0.1gr, stop adjusting charge weight, but continue with oal. Until You get your best group that repeats.

Then try another primer, if accuracy seems off. This becomes a bit of a start over when you switch primers.

Sometimes at the beginning, it maybe worth running the ladders with multiple powders and bullets to see which pair work together.

To be clear i'm not doing this yet...

Am I missing something key here? Is there a faster way?

i'm just looking for feedback or shortcuts you know.

 

[Mikecr]

Am I missing something key here?

Yes. Neither seating nor primers are a part of 'tuning', but they can wreck havoc on your tuning decisions.
#1 you're pulling seating out of your butt, so potentially ladder testing at the worst/bad CBTO.
#2 you're testing primers from a tuning node, which is merely taking you in/out of that node instead of telling you the best primer for the powder.

OCW is about finding most forgiving load. This, amounting purely to a powder node -instead of a barrel node.
But you're going for most accurate, so you shouldn't refer to any of this as OCW.
You didn't mention conditon of brass (fire-formed or not, how sizing).

 

[rsmithsr]

still shooting way too much before finding a tunable load.

 

[nksmfamjp]

#1 you're pulling seating out of your butt, so potentially ladder testing at the worst/bad CBTO.
#2 you're testing primers from a tuning node, which is merely taking you in/out of that node instead of telling you the best primer for the powder.

#1 So, can you school me up? How do I pick a better CBTO? Maybe I'm not fully understanding your comment.

#2 How does someone determine the best powder/primer combo

still shooting way too much before finding a tunable load.

I agree. How can I more directly find best bullet, best charge, best primer??

 

[Mikecr]

How do I pick a better CBTO?

Search topic seating testing.

How does someone determine the best powder/primer combo

Search topic primers.

This would be more helpful.

 

[Tiny Tim]

Run a ladder of my lowest acceptable velocity thru a couple grains over max. I use about 0.8% increments. Use some logical OAL....SAMMI, book, mag length, lands minus 0.030". I shoot until I get excessive bolt lift, case head expansion or other issues....

I understand loading over max "book" as many rifles allow for this but, the max criteria you state sounds a bit extreme.

 

[nksmfamjp]

I understand loading over max "book" as many rifles allow for this but, the max criteria you state sounds a bit extreme.

I agree and leave rounds un fired every time. My goal is to find max, not shoot every round loaded.

 

[Tiny Tim]

I agree and leave rounds un fired every time. My goal is to find max, not shoot every round loaded.

Thanks for the clarification. We dont always know what others mean by their statements.

 

[Plinker147]

Use to do somewhat similar to what you describe but no OCW. Shooter ladder for nodes, then shot groups and adjust seating depth with in the node.

Now I shoot seating depth test first, then ladders, then groups with in the node. This works better and less chasing ??. With new barrels you need to shoot 50-100 rds before load development but you can use the the break in to establish seating depth with multiple bullets. Your seating depth isn't going to change as barrel breaks in. There is no short cut method, your going to shoot a lot of rds to establish a good consistent load.

 

[User4302021]

This is my MUCH abbreviated process based on years of trying all the methods (OCW, Audette ladder, various chrono methods...etc)

Find max charge by looking at velocity, base expansion...etc. The rifle system you are using may be more or less efficient than the pressure barrel used at the lab, but all else being equal, pressure = velocity. Adjust your target velocity for barrel length.

Once found, back off from that max and run 4 loads...max-2.5%, max-2%, max-1.5%, max-1%.

Ex: If 45grains was determined to be max...you would test 43.8gr, 44.1gr, 44.3gr, 44.5gr.

One of these should be satisfactory. If you run higher than this, then you run the risk of being in over max pressure territory if shooting in higher temps. You may find an accurate load below this, it will just be slow.

I look for the load striking with the highest POI at 200 yards (5 round groups at least). Ideally, I want the barrel to be at the top of it's travel, rather than at the bottom (look up "positive compensation"). So far, this has proven fairly easy to discern.

There is often a really tight shooting seating depth around 0.010"-0.020" off the lands...but it can be finicky in the same way running high pressure often is.

I prefer to start at 0.040" off the lands and test back from there. It is my experience that bullets, with a little room to run, engrave into the lands much more consistently without the weird, finicky pressure spiking. Of course, all bullets have thier own characteristics.

In the past I've used 0.005" increments, but I've recently decided to use 0.010" increments to cover more ground quickly.

If I can't find a good shooting seating depth at 0.040", 0.050", or 0.060" off the lands, then I abandon this combination and start over.

As an example, I just developed a load with 155 grain SMK's in a 16" suppressed 308. I used LC brass, and IMR4895. This load wasn't anything special at 100 yards. It held under 1.25moa at 100 yards for 10 rounds (groups were round with no stringing).

However, it held that same <1.25moa dispersion at 910 yards! I think I'll keep it.

 

[nksmfamjp]

Interesting article that sums up all I've read: LINK

and the more recent trends I've read quite a bit about...LINK

 

[User4302021]

Interesting article that sums up all I've read: LINK

and the more recent trends I've read quite a bit about...LINK

I read those articles a few weeks ago and found them very illuminating. That series of articles put actual data to some trends that I had noticed anecdotally over the years.

 

[nicholasjohn]

How are you guys measuring case head expansion ?

 

[nksmfamjp]

How are you guys measuring case head expansion ?

Bolt lift

or I do it by the Hodgdon method...LINK
I find their max to be a bit conservative...