how small a grain increment

First things first - know your gear. Most common reloading equipment can’t actually resolve smaller than +/-0.1grn, so loading by 0.2 grn increments risks loading exactly the same load for 2 adjacent targets.

Beyond that, for rifle, short action, I use 0.2grn increments (having gear which resolves to +/-0.015grn), long action and magnums, I use 0.3, occasionally 0.4 in the first cut. Usually I know a relatively narrow window where I want to load so I don’t need to make a lot of increments, 10 charges at 0.3 or 0.4 covers a lot of ground.

Why are you using such coarse increments for pistol? For some powders, it would only take 3 or 4, or less increments to cover an entire book range from start to max with 0.7grn increments, some only one!

I use 1% changes or the best I can measure. So for 308 that's mostly .3 or .4 grains. I do .2 for pistol because what else can you do....

completely depends on the range of the load data listed. smaller cartrdige smaller charge, smaller increments ... .1, .2 grains is what I've done. haven't done much rifle or larger cartridges, but - same theory, maybe that stretches out to a bit bigger change between steps, but can't say I've actually make it there yet, just theorized a bit on it.

.3 grains for me. When I get accuracy at 37.7 grains, better accuracy at 38.0 grains, diminishing accuracy at 38.3 grains, I repeat it. If it is consistent, I go to 200, dial the scope, then shoot it out to either 500, or 600.

Seems to work for me, .22-250, .243, 7-08, .280, 7mm RM, .338 WM.

conan32120 said:

when building a new powder/bullet/brass ect reload ladder how small a change in powder grain weights do you use? ... 0.7gr for pistol

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0.7 gr will not work for many popular pistol powders that have around 0.5 gr Start-to-Max charge ranges.

For 9mm 124 gr bullet, W231/HP-38, Bullseye, Sport Pistol, AutoComp show 0.5 gr Start/Max charge ranges - https://reloadingdata.speer.com/downloads/speer/reloading-pdfs/handgun/9mm_Luger__124_rev1.pdf

Titegroup has Start/Max charge range of 0.4 gr and Unique, BE-86, CFE Pistol, have Start/Max charge range of 0.6 gr.

For my load development with powders that have around 0.5 gr Start/Max charge ranges, I will use 0.1 gr increments. For powders that have around 1.0 gr Start/Max charge ranges, I will use .2-.3 gr increments to get me in the ballpark then use .1 gr increments to identify the most accurate load that produces smallest groups on multiple range trips.

I try to go by capacity or predicted burn rates. For small capacity cases like .223 i go with .1-.2 increments, and .5 for '06 to magnum rifle. If I find a promising area I will try to work smaller increments on either side, or I'll adjust seating depth. For handgun I go with .1 or .2 .

Like @LiveLife mentioned, the min to max range for pistol is quite small. I use .2 for pistol. For rifle, 3-.5 depending where I am in the process. .5 to find my desired velocity node, then .3 to fine tune to load.

It depends on the range for the load according to the book my .38 special might be .25 of a grain. 7mm Remington I will go up a couple of grains per test batch.

nick22 said:

It depends on the range for the load according to the book

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Yup. I’ll add an s to book and say it depends on the range for the powders and projectile I’m looking at using, the strength of weakest gun the finished load will be used in, and the intended purpose of the finished load. I take the lowest start, the highest maximum I’m willing to go to, divide the difference by the number of increments I can test reasonably accurately, and then load the bottom third for accuracy assessment. If I find an acceptable load there, I stop. I shoot the lowest power that will achieve my desired goals.

The honorable “it depends” answer fits. I don’t even consider loading a ladder until I load a test group at the start charge if I’ve never loaded the powder/bullet/caliber before. If there’s an end goal of minimum velocity that also plays into the answer. OCW workups have a different min max ladder, not just a set increment.

I usually do .2 gr in handgun. But I still haven't started on 9mm. Stating that. I don't shoot the difference .1 gr makes.
In rifle I divide the charge range into 10 charges. If it's something I've played with a lot I jump to just below the charge weight I expect to get accuracy from.
There again in no match winner.

I use 1% of the maximum load rounded up, so 0.3 grains for 223, 0.4 or 0.5 for 308 and 30-30. For pistols I use 0.2 grain increments. I’d use 1% for pistols but that’s too small for my scale to measure.

With a smartphone or computer in hand it's not hard to calculate 10 steps from starting to max load. Load that ladder and focus on nodes within that range refining as needed if all shoot well when testing. I get that these days lack of primers may enter into your decision but safely working up a load is on you. To me a blanket statment of X grains each step is not wise as all case volumes and propellant densities are different.

In general, the 1% increment strategy only works for short action rifle cartridges, which yield .3-.5 grn per increment. Get up into magnum cartridges when 1% is .8-.9, or even >1grn per increment, and you’ll never see nodes. Same for going into pistol loads - we simply don’t benefit by loading to the 0.04-0.06grn increment, and most folks cannot do so even if they wanted to.

Dividing the book data by 10 - it really only works for smaller short action rifle cartridges where the book range is going to be around 5-6grns. A big magnum might have 7-10 grns spread, yielding .7-1.0grn increments, and a pistol with only .5grn book spread kicks us back to 0.05grn increments.

So if we’re living by a rule of thumb (which we don’t have to do), then 0.2-0.3grn for smaller rifle cases and pistol cases, acknowledging our limitations of our gear, and 0.4-0.5 for big case magnums makes more sense for more cartridges than either 1% or divide the book by 10.

45acp & 9mm:

I only use published data and hand dip within the published min/max—one .1gr at a time. When hand dipping this is simple & easy.

That sounds like I dip one tenth grain at a time—no, I change loads by one tenth.

Varminterror said:

So if we’re living by a rule of thumb (which we don’t have to do), then 0.2-0.3grn for smaller rifle cases and pistol cases,

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Agree, limited by scale resolution and powder measure consistency.
A friend has a better scale and tests in small increments and then loads dead nuts, but he is prepping for Long Range.

AJC1 said:

I use 1% changes or the best I can measure. So for 308 that's mostly .3 or .4 grains. I do .2 for pistol because what else can you do....

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I follow the same rule, 1% rounded down

Pistol, I just go .1gr, load 5, shoot them over the chrono. Generally best ES/SD will be the most accurate load, or accurate enough for a mediocre pistol shooter like me.

Rifle, 1% rounded down. 223 has roughly a max cap of 25gr, so 1% is .25gr, rounded down to .2gr. Short action stuff like 308, the Creedmores, etc, roughly 45gr of powder max, which would yield about a .4gr rounded down. Magnums like 300 PRC, 75ish gr max, so .7gr.

If really good precision is really desired for rifle though, you will need smaller nodes. So my short actions I may drop to a .2 or .3gr jump, and magnum stuff I go to .3 or .5gr. This give me room to tune a little bit up or down as I see fit.

Kaldor said:

I follow the same rule, 1% rounded down

Pistol, I just go .1gr, load 5, shoot them over the chrono. Generally best ES/SD will be the most accurate load, or accurate enough for a mediocre pistol shooter like me.

Rifle, 1% rounded down. 223 has roughly a max cap of 25gr, so 1% is .25gr, rounded down to .2gr. Short action stuff like 308, the Creedmores, etc, roughly 45gr of powder max, which would yield about a .4gr rounded down. Magnums like 300 PRC, 75ish gr max, so .7gr.

If really good precision is really desired for rifle though, you will need smaller nodes. So my short actions I may drop to a .2 or .3gr jump, and magnum stuff I go to .3 or .5gr. This give me room to tune a little bit up or down as I see fit.

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The .2 in pistol embraces the fact that my measurement accuracy is really no better than that. That applies equally to any loading so that's why my process is not further refined. If I had a .02 grain accuracy scale my process would adjust to take that into account. I also adjust tables by .1 grain to get even numbers for testing. If the table says .7 I'll load a .6 and a .8. I don't deal with loads or calibers with charge weights less than 4 grains.

Don't remember where I saw it, so can't reference the quote, but suggested increment was 0.6% of Max load. That seems to fall out about right for calibers I'm working with.

It depends. When working up rifle loads, I generally use between 0.3 and 0.5 grain increments. For long-action cartridges like .270 and .30-06, I usually vary my initial charge weights in 0.5 grain increments. If I find something I like, I may stop there, but usually I'll go back and tinker around a charge weight or two in 0.3 grain increments and see how consistently they behave. For short action cartridges like 6.5 Creedmoor, I usually start with 0.3 grain increments and then tinker with 0.1 - 0.2 grain increments around a particular charge weight when trying to "prove" a velocity node.

In light of Varminterror 's point about most scales (including mine) not measuring more accurately than +/- 0.1 grains, resulting for example in the possibility that two charges which measure 40.0 and 40.2 actually in fact both weigh 40.1 grains, I may do some testing/review my notes to see if I shouldn't just stop using anything less than 0.3 grain increments altogether. There may still be validity to using the smaller increments to prove a velocity node, but that's worth me thinking about.

I haven't worked up a new load in a pistol caliber in several years. My recollection is that I just pick a charge weight in the middle of the book range, test it, and then use that if it works.

For rifles, I work up in 0.3 gr intervals typically but sometimes I'll go 0.5 gr. My latest ladder test for rifle is 0.3 and I'm starting slightly below Hodgdon's recommended start load. For handguns, I just find something that functions well and seems to put the bullets close together. I'm unable to obsessively evaluate a ladder test for pistols at my local indoor range so if it's reliable and it's putting a smile on my face, it's good enough for me and becomes my load and since I mostly load for semi-autos anymore, I stay well away from max loads. I'm much more obsessive compulsive with my rifle loads however-magnetospeed and SD and ESs and all that.

conan32120 said:

when building a new powder/bullet/brass ect reload ladder how small a change in powder grain weights do you use? I've been using 0.5gr steps in rifle loads and 0.7gr for pistol. whatcha think?

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I think it could get one into trouble thinking .7 gn for pistol across the board is ok.



Gather your data and study it before making a decision. If .2 gn exists between maximum and minimum, don’t make such a big step…

I do five steps by dividing the difference between min load to max load rounded off to the nearest .1gr.