Procedure for working up a load

[tracker13]

I'm going to make up some whitetail hunting loads, and I'm looking for some advice on a procedure for working up a load.

I'm loading for a .270 Win. I've picked the 140 gr Nosler Accubond for the bullet and IMR 4831 for the powder, but I'm open to suggestions if anyone else has a better starting point.

What's your procedure?

How many of each load do you make up and shoot?

How much do you vary the charge by?

Do you clean the barrel between groups?

Hw long do you wait for the barrel to cool between groups?

What kind of improvement do you expect to see between loads?

Thanks for any advice.

[Rocky Raab]

First, welcome to HuntChat.

There are many ways to work up loads, most of them good.

Those are excellent bullet and powder choices, so you should have very little trouble finding a load your rifle likes.

Start by getting Nosler load data. It's important to use data from the bullet company, because it's the bullet that causes the most differences in pressure and velocity.

Definitely start loading at the book's recommended "Start" loads. You never know if your rifle might produce high pressure.

I like to work up in powder increments of 2%. That usually gives me five load levels between start and max.

Load five rounds at each level. Fewer than that doesn't give you a good idea of how that load might actually perform.

Shoot them at 100 yards, using the best benchrest techniques you can (solid rest up front, sand bags at the rear, careful trigger squeeze, good weather, one minute between shots and cool the gun between groups.)

If you have a chronograph, record the velocity of every shot.

Clean every ten shots and fire one fouling shot (use practice or cheap factory ammo) before you fire test laods again.

If you notice any signs of high pressure (flat or cratered primers, hard bolt lift, extra recoil, or a sudden spike of velocity) stop shooting immediately.

Back at home, measure all the test groups and record the chrono data.

You may see one group that's much better, or you might see the point where the same extra powder amount stops adding velocity. That's usually at or near your rifle's best load.

You might want to try another group with that same charge, plus two others just a tad on either side of it just to confirm or fine-tune things.

There can be a lot more to it if you were trying several bullets and/or powders, but that should get you a good workable load with the two you've chosen.

One final thing: accuracy is MUCH more important than velocity. Fast but inaccurate bullets miss or wound.

[Catfish]

Let me also welcome you aboard Tracker.
If you do what Rocky suggested you won`t go wrong. I would suggest you forget calulating the the 2% and just increase your load by 1 gn. each time you step it up. That is very close to 2% but it`s easier, and real close. ;) I`ve burnt alot of 4831 powder through a .270. I used to buy it for $ 1 a lb., but that was acouple years back.

[12GA guy]

Good advice for sure.

I try to choose a powder that the case will be close to full, or a slight compression load. You have to do some study to figure out which powder may do that best, for the calibre your shooting, and the velocitys you want. IMR4831 is a popular powder, as is IMR4064 and H4350. I currently use RL-22 for the -06, 7mm rem mag, and .300win mag. It may be a bit slow for the .270

I usually do loads right up to the max listed, for the bullet, primer, and powder, but as I get closer to max, I will step up the loads in .5 grain increments, always watching for pressure signs. As mentioned, in some loads, velocity will actually stall. This may have more to do with your particular rifle then the load itself.

For some reason I have found that groupings for my particular rifle, seem to get best usually a grain, or .5 grain, less then max.

Nothing was mentioned about bullet seating for maximum accuracy, but this can also effect how well your loads group. You may want to look into this aspect of reloading for accuracy. Basically it's tweeking the cartridge o.a.l. for your particular rifle.

Half the fun of rolling your own, is trying different loads, bullets, powders, and even primers. Stick with published load data, be safe, and have fun!:)

[Rocky Raab]

The reason I always say 2% load increments is because that works with any and all cartridges. One whole grain might be a wee bit excessive if you happen to be working with a Hornet or Fireball or 357 Magnum!

If you examine loading manuals, you'll soon discover that the start loads are about 10% less than the maximum loads - no matter what cartridge or charge weight. If the "percentage of maximum charge weight" system is good enough for the professional ballisticians, it's good enough for me.

[gordon baxter]

i use imr 435o in my 270 with 140 gr partion seems to shot good and it is loaded at 52.1 gr with mag primers and bullets at max length.Would 4831 make any difference if gun likes 4350

[12GA guy]

Gordon it really shouldn't make any difference, as far as advantages, if your groupings and velocity is good. H4350 is a good powder for the .270, and the 30-06., as is IMR4831. So many factors come into play with loads. Barrel harmonics, twist rate, weight of bullet, etc.

I am suprised that you use mag primers. Do you hunt in fairly cold temp's? I know they can be an advantage in sub-zero temps.

[gordon baxter]

here in northern alberta in the late season it can get down to -20 to - 40 and some of us still go out hunting. My old model 78 rem seems to like this load it shoots around 1" wich is good enough for any hunting rifle.