Acceptable Tolerances

[locknloader]

When you guys reload a round and pick your target figures for OAL and powder charge, are you trying to get that EXACT number every single round or do you have an acceptable tolerance range?

For reference, i am using a hornady LNL doing mostly 9/40 but will be trying 223 soon.

My powder charges are very consistent. Usually i hit my target weight, but i will sometimes see a .1 and rare .2 variance high or low. I don't load max loads, i stay low or in the middle of suggested range to play it safe.

For bullet seating, not so consistent. Seeing variance of about +/- 0.010 but most of them are around the same and i get the odd ball every few rounds.

Can i shoot for a tolerance range on the seating? I know powder charge is critical and i want that was exact as possible but i can live with .1 off for how i am loading right now.

[hounddawg]

If you are down to .1 error and are not using a high end lab grade scale or accurized beam that is about as good as you will get anyway. many a match will be won this weekend using charges weighed on scales that are plus or minus .1 in accuracy

[mikejonestkd]

For most pistol cartridges when loading in the middle of the range for plinking ammo a .2 gr variance is nothing to worry about.

Just for an example let's say your target charge is 5.0 gr. a .2 grain variance is only 4% off the expected charge weight. Not enough to notice or worry about.

If you are working with very small charges/ small cases, or max loads then it can be enough to cause pressure issues, but for middle of the road loads it is not an issue.

[Unclenick]

I've pulled down a number of rounds of Federal Gold Medal .308 Win Match loads with the 168 grain SMK, and found it ±0.2 grains, or about ±0.5% of the average charge weight (a 1% span). That ammunition is excellent to 600 yards. The guys worrying about the last hundredth of a grain are all shooting long range 1000 targets for which a small velocity difference can string you out of a scoring ring. So, before you get concerned about the last hundredth of a grain, decide what range you will need to shoot at.

At the other extreme, I've pulled .30-06 and 7.62 ball ammo that had ±0.6 grain charge variation and still functioned just fine to military requirements (about a 3% span).

For up to 600 yards, you want to find a tuned load sweet spot where the exact load is not critical, then allow that to handle the small charge weight errors. Look at Dan Newberry's OCW method as a starting point.

[F. Guffey]

https://www.outdoorhub.com/stories/2...ngfield-rifle/

He shows up without a rifle and starts shooting a loaner, and then (one of those moments), they take him to an armory to select a rifle from racks of rifles.

He did not ask to load his own ammo, he was someone that could shoot if he had a rifle that would/could shoot.

I like Newberry's train songs., always in the pursuit of the perfect country song.

F. Guffey

[hounddawg]

https://www.outdoorhub.com/stories/2...ngfield-rifle/

He shows up without a rifle and starts shooting a loaner, and then (one of those moments), they take him to an armory to select a rifle from racks of rifles.

He did not ask to load his own ammo, he was someone that could shoot if he had a rifle that would/could shoot.

F. Guffey

I have always loved that story. I remember a club match I shot in in several years back where one guy showed up for a F class 800 yard match with a shiny new Savage FP 10 with a 300 dollar scope and shot a 594 aggregate. He won against guys whose optics alone cost 4 times what he had in his entire rig

I have started to measure my long range match loads down to the kernel. Does it help ? Maybe maybe not but it does make me feel better and sometimes a little confidence boost is really helpful

[RC20]

For a rifle, a tenth is nothing percentage wise.

For a 9mm that's close to max, it can push you over the edge.

Don't worry about it. I use electronics scales, when I group load with known good loads, I am in the middle or a node as best I can determine and it takes a lot more than that to get me out of it.

[hdwhit]

locknloader wrote:
When you guys reload a round and pick your target figures for OAL and powder charge, are you trying to get that EXACT number every single round or do you have an acceptable tolerance range?

To give you a meaningful answer to your question, what kind of shooter are you? Are you a precision shooter looking to shoot five shots at 600 yards and end up with one hole? Or are you punching paper on the weekends at a commercial 100 yard range just trying to get five shots into a 1.07 inch circle?

It makes a difference because for the first type shooter, a tolerance of 0.1 or 0.2 grains might be too much.

My powder charges are very consistent. Usually i hit my target weight, but i will sometimes see a .1 and rare .2 variance high or low.

This will be exceptionally good if you can get your measure to hold that variation when you start throwing 20 to 25 grain loads.

I load on a single stage press. I want my powder charges to be exact, so I throw them light from the measure and then trickle up to the exact desired weight.

I don't load max loads, i stay low or in the middle of suggested range to play it safe.

I read that sentence to say you picked a load in the middle of the published range. Is that correct? If not, go on to the next quote, otherwise recognize proper load development is to begin with the Starting load and then increase charge incrementally until 1) desired velocity and accuracy are reached, 2) you see pressure signs, or 3) you reach Maximum load.

For bullet seating, not so consistent. Seeing variance of about +/- 0.010 but most of them are around the same and i get the odd ball every few rounds.

10/1000 is a fairly big range, but nothing to worry about unless you're not part of the "five shot, one hole" crowd.

Still, you might want to investigate whether the variation is caused by your equipment or variably in the length or profile of your bullets. Cheap bullets often have considerable dimensional variation (some expensive ones do, too) and that could explain the variation.

Can i shoot for a tolerance range on the seating? I know powder charge is critical and i want that was exact as possible but i can live with .1 off for how i am loading right now.

Again, if you're a precision shooter, each variable you have in the round is a potential source of inaccuracy. If you are not a precision shooter, recognize that the degree of inaccuracy caused by each of these variables is tiny.

When I got started loading 223 in 1979, I would wipe my brass off with a shop towel, lube it, run it through the sizer (which also decapped and expanded), didn't bother to measure, trim, chamfer debur, debut the flash hole, uniform the primer pocket, just resorted to priming on the press, threw powder out of a repurposed Lee Load All, dropped it in the case and seated a bullet on top. The process sends shivers down my spine now, but it still all went bang and to within about an inch of where I had aimed it.

I still don't debur flash holes or uniform primer pockets, but my process is much more delibertate, careful, uniform and consistent than it was 38 years ago. But, the accuracy of the ammunition has not changed during that time; it is still capable of accuracy better than I can coax out of the gun.

[jugornot]

What type personality are you? My wife calls me a perfectionist. She's wrong of course. But I do have very high standards. Standards that some will call excessive. Others will call loose. I do the best possible considering budget. Measurable tolerances are + or - .001" on length width and diameter. On weight I am turning my world upside down because my scale is more accurate in grams than grains and I hold + or - .002 gram. Joe Bob is going to show up and say .1 or .2 grain is good enough. And it is good enough ... for him.

[44 AMP]

For reference, i am using a hornady LNL doing mostly 9/40 but will be trying 223 soon.

Am I correct in assuming you are shooting 9mm & .40 out of the common tilt barrel lockup service grade semi auto pistols??

because if you are, the guns themselves won't notice the tiny variations you are talking about, and neither will most .223s.

[locknloader]

Yeah I’m not trying to win a sharp shooter competition, just want safe ammo that’s accurate for practice on sillouhette targets. Safety is my main concern and I was not sure what kind of tolerances would keep me in safe range and are acceptable .