Reloading Tolerances

[Guest A10thunderbolt]

How close do you get your Tolerances When reloading? I am relatively new to reloading so I don't know how picky to be with the calipers.

[Trekbike]

I assume you asking about overall length since you mentioned calipers. If so, I usually see a float around a 0.010" tolerance.

Just measure some factory loads and it'll make you feel better.

[Dolomite_supafly]

Are you loading pistol calibers?

If so find a factor loaded round and use it to set the seating depth and crimp. Make sure the bullets are similar, as in if you are loading FMJ bullets then use a factory loaded round with a FMJ bullet. Same with HP's. If you are loading flat points use a HP with a similar sized hole as the flat on the front.

As a matter of fact this is how I set all my dies. I take a factory loaded round and put it in the shell holder. I twist the bullet seater almost all the way out. Then I bottom the press out. I start to screw down the die itself until I feel the resistance then lock the locking ring down. Next I tighten the seater down until it comes to a hard stop then lock it down. If you are using Lee dies do like I do and use some electrical tape to hold the seater in place.

This should get your rounds to a safe dimension. You have to be very mindfull not to overtighten the die itself because it can make the case mouth disappear. And when that happens the bullet will not headspace correctly. As long as there is enough case mouth for your fingernail to catch on it you have enough. You also might need to see the bullet a little deeper depending on how the rounds feed if it is being shot out of a auto.

Dolomite

[Guest A10thunderbolt]

Well I am asking because my lee press isn't giving me very precise results it vary's by about .050 is this ok? I trimmed all my brass. I wouldn't mind knowing about powder tolerances either.

.223 for this result

Edited March 15, 2012 by A10thunderbolt

[Jonnin]

they are "large" tolerances. Gettting started, you want to avoid necked cases that are too long (trim them to a bit below the max trim length from your data) and you want to avoid seating the bullet too deep (total cartridge overall length should be considerably bigger than the minimum.

Take a 115 grain 9mm. The overall length can be roughly between 1.075 and 1.1, so you have 4/100 of an inch to play with. I split the difference, and would seat them at 1.085 (yea its not exact, no calculator atm, but you get the idea). That gives you 2/100 an inch variation and still in spec, and more important, it seats pretty well on a variety of cases that may be of slightly different sizes. If you seated it to the max, 1.1 or longer, and got a short case, it may not stick in there very well!

Then measure your produced ammo. It should mostly be about the same (within a couple thousandths, probably) and that means it would be very well in spec (within 20 or more thousandths of the extremes).

[Jonnin]

Powder is easy. Weigh the powder. Is it between the starter load and the "do not exceed" value? If not, start over and figure out WHY your method was so far off. If so, it is safe (but may suck due to large variations in loads). You want to get to within at least 1/4 a grain to have reasonably consistent loads even for plinkery. If you want better, you need good gear (good scale, good dispenser, etc) and patience to get it right (it just takes time to do it at higher precision). On a 223, 1/2 a grain may be accurate enough for a "case filling" powder charge.

My 223 overall lenghts are pretty wild as well. My bullets have a crimp ring, and now I just seat them to where that ring is at the very edge of the brass (just inside it) and call it good. I would not be alarmed at 0.05 variation in lengths for this round if you are using random brass picked up from somewhere. Yes, even trimmed brass. Maybe an expert chan chime in on this round, but I have tried and tried and am unable to produce consistent length 223 without just sitting there spending 5 min on each round or something.

Edited March 15, 2012 by Jonnin

[Guest A10thunderbolt]

I'm going for match grade accuracy as accurate as is reasonable anyway. I can load safe stuff just never concentrated on precision and consistency. I did load some 79 grain sierra that I got from Wal-Mart (thanks to Dolomite's Info) and it was a tighter group than the PMC I shot before it may have been the grain difference though. (PMC were 55Gr)

Edited March 15, 2012 by A10thunderbolt

[mikegideon]

Well I am asking because my lee press isn't giving me very precise results it vary's by about .050 is this ok? I trimmed all my brass. I wouldn't mind knowing about powder tolerances either.

.223 for this result

With .223, your bullets can be part of it. The distance between the ogive and the point can vary. The seater die doesn't reference to the point. Get a bullet comparator that measures length to the ogive of the bullet.

http://www.midwayusa...-with-6-inserts

Edited March 15, 2012 by mikegideon

[Guest A10thunderbolt]

Thanks, do the .223 bullets always vary or are there certain brands that are better?

[mikegideon]

Thanks, do the .223 bullets always vary or are there certain brands that are better?

Don't know, but I assume so. Sierras are notorious. I just make sure they don't go over mag length if appropriate. A lot of the stuff I load won't fit in a mag anyway. My length to the ogive is always real consistent.

[mikegideon]

BTW... that bulle comparator clamps right on your calipers. It's not fiddly to use.

[Dolomite_supafly]

Bergers tend to be the best as far as bearing lengths. Sierras tend to be good for weight and concentricity but not bearing length.

To get the same results every time you need to seat and measure at the ogive. I made a seater for my die that has a hole that is .222. That was the closest I could get and still have it work for my dies. And when I measure the loaded rounds by the ogive they are a lot more consistent since I started doing this.

What seater die are you using? If it is a Lee PM me your address and I'll make you a new seater stem with a larger hole. The factory I e works great with short bullets but not so well with longer ones.

Dolomite

[mikegideon]

I'm gonna get a Giraud with a meplat lopper. That will fix the ogive/total length issue. Not why I'm doing it, but it will.

[Guest Lester Weevils]

Some folks are very talented with calipers and micrometers, and others not so much. Takes practice as with most stuff, though some folks will just naturally be better at it.

I copy factory ammo as well, or try to get as close possible to dimensions in a factory ammo recipe.

My dillon SDB press with dillon dies will output some variance in OAL which seems worse with some bullets than others. Even making sure to do "full strokes". The variance isn't much but with the pistol seating dies it is puzzling why there would be any at all. With 9mm perhaps it has to do somewhat with different brand brass having different variances on the base of the case, causing different brands of case to ride at slightly different heights in the shell holder?

I usually load mixed brass. Maybe will try separating by brand to see if that really is one factor in OAL variance.