I was just wondering how many rounds most people here make up, per different load for development.

Batches of 3? 5? 10? more?

Express

Assuming your rifle is free of any bedding issues, I use 3 shot groups for a hunting rifle.

For bigger bores I start off with a series of 3 shot loads with say up to 5 loads of 1 grain increments in the main chosen propellant.

Then using those results if the groups seem consistent ie getting more accurate and then less accurate etc, I will select 2 or 3 loads and load up another 6 rounds for each. Or if the propellant is not up to it - eg velocity and accuracy desired - then I start again with another powder.

For smaller bores - eg .30 and below I load up 9 rounds straight away and shoot 3x3 shot groups and then let the barrel cool before the next one. Sometimes starting off with a clean barrel for each 3x3 group.

For smaller bores I will go to 1/2 grain increments when narrowing the field down.

Shooting say 50 rounds of .30-06 from the bench is nicer on the shoulder than 50 rounds of a big bore.

Another tip is to space the big bore with shooting a smaller bore in between loads.

Some people claim you need to shoot 5 shot and 10 shot groups to expose bedding issues but I think this is not necessary with a hunting rifle where the first shot is always the most important.

I shoot 4 round groups.

That is a one saving over a 5 shot group.

After 3 or 4 shots, the barrel is too hot anyway.

I use four shot groups working up loads with the chosen bullet and powder in half grain increments over a 2 grain span. (e.g. 58-60).

Bob257

Think I just figured out way it takes me two(2) years for load development!!

Starting with a "new" barrel, I'll load 10 strings of 5 shells with grn. increments starting at a listed minimum for which bullet and powder I start with up to maximum.

Then taking the "best group" of 5 and documenting the results.

After this (using the same grain bullet) all powders for that caliber will be tested the same way.

Now, hopefully by this point we have a stand out powder! Process is repeated for different weight, different manufacture's bullets until a "standout" is found.

Now we have a powder/bullet combination that is superior to all the others tested - now we'll try different primers.

Primer selection is made - now let's fine tune the load: weighing cases for capacity, weighing bullets for consistency, setting seating depth for the given barrel.

Then comes the field test: how does this combo work on the intended game? If you get zero expansion like I had this past whitetail season in PA. - you go back to the drawing board. Luckily, I know where I went wrong on this one - wrong bullet for a handgun (rifle bullets are not constructed for handgun velocities - but they sure do shoot awesome!).

Is this too much work - probably for the average shooter/hunter. I do love to shoot/handload, and I have no questions when I'm done!

Wait a minute, did I ever answer your question? That would be 5 shot strings.

I use ten round groupings for load testing. This all pre-supposes that the primer pockets have been uniformed and the flash hole trues up.
I'll move up the powder weight scale in 1/2 grain increments until I get close to the accuracy I'm looking for. Then I'll switch to one or two tenths grain increments.
Then I'll tinker with uniforming the neck wall thickness, varying length, etc., again in ten round lots.
Once I've determined that I've found the load I'll load up dozens, to hundreds of the same load.
Jim

Pressure testing, I use 3 shot groups in 1/2gr increments. After the 3 shot groups are fired and I've found the load range for that rifle with that powder. The groups are analyzed for which load looked promissing. Then I'll go back and load 10 in that best group 10 more a 1/2gr under and 10 more a 1/2gr over. After that it's back to the range. Ammo is shot in 3 round groups (3 groups per powder weight batch) with one fouling shot from a clean barrel before each 3 group set in that load. after that I feel like I've either found the best load for that combo and I'm satisfied and it's time for fine tuning or it's time to move on to another powder and maybe another bullet (sometimes a new rifle). Terry

[ 01-24-2003, 18:24: Message edited by: TC1 ]

Take a look at my OCW load development method, at this site: http://home.earthlink.net/~dannewberry/index.html

If you choose your powder carefully, you can develop an extremely resilient load with as few as 20 shots fired, counting foulers...

Dan

Dan,

I read your page. Thanks for providing it.

I'm a bit dense, so please indulge in what may be a question with an obvious answer.

In your description on picking a load, after shooting in a round robin through your load increments you say:

quote:

---

I look for the three groups of the five that come the closest to hitting the target in the same position.

---

How is this measured? Is it from some common point on all five targets, like the "point of aim"?

Sorry if this is clear to everyone but me. But then again I should be used to that

Thanks!

-Steve

You're right, Steve... And you're not dense, I just need to make the text a little more clear. I'll work on it...

On each target, I use a small black square, *just* large enough to be quartered by the crosshairs in the scope. Draw the square with a thick black marker, and experiment with size until you know the correct size to make the crosshairs a tight fit in the square. This will allow for a repeatable sight picture. A 3/4" interior square works well with most 9X scopes. The higher the scope power, the smaller the square should be, and vice versa.

Of course you put the square (or bullseye--whatever you use) in the same location on each target, and the targets should all be as level as possible.

Triangulate the three shot groups (provided there are no called flyers--in this case you may want to discount that shot, or replace it with another shot of the same charge weight). By triangulating, I mean to plot the point at the center of the triangle formed by the three shots. This is the POI, or point of impact. The POI's relation to the center of the bullseye is what you're looking for.

Decide which three consecutive groups share a common POI (same distance and direction from the bullseye), and choose the charge weight from the center group of those three as your OCW for that application.

Tuning for supreme accuracy, as well as "flier control" can be done with seating depth variations.

Even if the center charge weight did not shoot the tightest group, it is still very likely the best charge to use, since it can accomodate pressure drops and increases without changing POI significantly. The target shown on page 1 of my site is a three shot group fired at 300 yards with three different powder charges--all in the same group. This is the kind of load you want to develop, and if your favorite load won't pass this test, it's likely redevelopment using my method would be a good idea.

Thanks for the interest,

Dan Newberry
green 788

[ 01-24-2003, 20:36: Message edited by: green 788 ]