Developing new loads

[sniper3]

Hi all . when you guys are developing a new load , what is your process for powder weight , up or down ? If your starting at 4.0 grains for instance , do you go to 4.2, then 4.4 , then 4.6 ? Then test fire for functionality or chrono. Or 4.0, 4.1, 4.2 etc. Or higher , 4.0 , 4.3, 4.6 . Just need a little feedback as to what works best for you

Thanks

[blairmckenzie1]

I usually go in .2 grain increments and always work up from a safe starting load. Use a chrono to see where your velocity is at and check primers for pressure signs. Adjust your length for feeding or to fit the mags. I usually load at least 10 to chrono.

[Hi-Power Jack]

I usually go in .2 grain increments. Use a chrono and check primers . Adjust your length for feeding or to fit the mags. I usually load at least 10 to chrono.

Very similar, but I usually load 5 of each for initial chrono testing.

Once I get in the velocity range I want, I'll load up 20 at a time

for chrono & accuracy work.

[sniper3]

Good info guys , thanks . I'll go with the .2 grains and test

[ttolliver]

Yup, all great advice.

I too pick a likely range I want to test by .2 increments, but there are always exceptions. Titegroup, for instance, is one of those powders with such a small range of application that you are forced to go .1 increments.

My personal approach is to do enough research across different manuals (and here for competition loads) to figure out the powder level that's likely to be best. Then I'll go above that by one increment and below it by 2 or 3 increments. So if research suggests 5.0gr is the likely winner, I would probably load up 20 each of 4.4, 4.6, 4.8, 5.0, and 5.2.

I know that seems like a pretty wide range if I'm already half convinced I'll see 5.0 as the winner. But I like to see an established trend in both the velocity and the group size. And sometimes you get surprised this way. Last, but not least, it is a nod to the wisdom of starting low and monitoring closely.

I go 20 each so that I have 10 to put across the chrono and enough to shoot two 5-round groups to get a general idea of accuracy. I'm not worried too much about accuracy on the first trip, but I do like a general idea.

What I do next depends on the results I get the first time out. In the simplest example, say 5.0 is indeed the leading round for velocity and accuracy. I'll go back with another batch of 100 (30 at 4.9, 40 at 5.0, and 30 at 5.1) for another round across the chrono and careful accuracy testing immediately around that 5.0. Of course I've had times when 5.0 might give me the competition velocity, but accuracy was better somewhere else in the range. When that happens I play with COAL and take another batch like the first. That's the only time I tend to tinker with COAL. Otherwise I use published/recommended COAL from start to finish. And I almost never have to play with COAL.

I should also say that if I get pressure signs I won't bother to shoot the top end rounds. I'll just pull them and remanufacture them into practice rounds later.

Good luck!

[Flatland Shooter]

I pretty much do it the same as the previous posters but with the addition of a target down range. Sometimes the fastest and the slowest are not the most accurate.

My goals are 1st achieve power factor, 2nd get good accuracy, and 3rd excellent reliability.

Hopefully one of my loads will hit that sweet spot and make all three goals.

Bill

Edited December 2, 2014 by Flatland Shooter

[R.Elliott]

Most of the powders (not Clays) are pretty much linear within their range of efficiency, so l'll generally load my first test rounds light and extrapolate once I have base-line chrono data.

Target power factor/actual power factor X charge weight in grains = charge weight to make target power factor.

Most of the time this will put you right on the money.

[R.Elliott]

Delete. Multiple post, sorry.

I hate cell phones.

Edited December 2, 2014 by R.Elliott

[R.Elliott]

Delete

Edited December 2, 2014 by R.Elliott

[dauntedfuture]

I cant say that I have ever loaded pistol ammo for my 9mm or .40 that did not shoot well in my pistols so accuracy has not been a problem. I will pick a powder and based on what the book numbers are for velocity, ill pick a load in the middle and go up and down .2g. The alternative is if I read another guys load, and the book says its safe ill try it and +/- .2g and chronograph velocity. My goal is to load to 130 or 170 PF. I will assess function, smoke and perceived recoil. I load 147g FMJ in 9mm and 180 coated lead in .40 so bullet selection is not much of an issue. The OAL for the 9mm has to fit and run in a 2011 and M&P and the OAL for the .40 is for an STI so its a little long.

Provided I make PF, perceived recoil and smoke are my paramount issues.

[njl]

When I was just starting out with pistol reloading, I'd bracket by about .2gr and take 10-20 of each to the range to chronograph. Lately, I just try to research the heck out of the loads I'm going to try, pick a charge weight, load ~20, and test them. This weekend, I'm testing some .38spl loads, each is one charge weight, but I'm testing 4 different bullets in 2 different weights. I loaded 24 of each, figuring on doing 2 cylinders through 2 revolvers of each.

[kneelingatlas]

I too like to extrapolate, I like to have a baseline for each gun with each load so I can pretty much nail it where I want to me by the second time out.

As a hopeless experimenter I have tons of data so I can estimate correlations between guns, powder, bullets even calibers.

[Hi-Power Jack]

I extrapolate, have a baseline for each load so I can nail it where I want to be the second time out.

But, I'm sure you meant to add "by working up the extrapolation with a chrono",

just to be sure. :bow: