What are normal consistency tolerances for reloaded ammunition? I finally got all my equipment set up and ran 20 rounds of .40 S&W through it.

The instructions with my dies show a starting load of 7.7 grains (0.55 cc) and designates the 0.53 cc autodisk chamber. Hornady specifies a maximum load for a 155 grain HP-XTP (hollowpoint but I assume similar enough) of 8.8 grains of HS-6. So I went with the 0.53 cc (HS-6 VWD is 0.07120, yielding 7.4 grains of powder).

I loaded:
Once-fired Winchester .40 S&W brass
Berry's Preferred Plated 155 grain
Hodgdon HS-6 with the 0.53 auto-disk
Winchester Small Pistol WSP Primer

Then, since I'm just getting started here, I thought it might be prudent to go through and weigh/measure all 20 rounds to make sure I will have both hands after firing this batch. Out of 20 rounds, I came up with an average weight of 233.6 grains total cartridge. The heaviest was 235.1 and the lightest was 229.9.

Should I be concerned about such a significant difference in this batch? I know that some of the variance comes from the components. I figure primers are pretty consistent and negligible. Of the once-fired brass, I tested 20 and came up with a 2.4 grain variation from max to min and the bullets had a 0.7 grain variance.

Thanks for any help or advice you can provide this newbie.

Mate I always check every fifth case for powder accuracy from the powder chuker and always test randomly too

I am a pretty new reloader and I throw every charge and trickle it to weight. I understand handgun is different in the amount of rounds you shoot though. You should be able to look in the case to make sure the amount of powder is the same in each.

In my humble opinion you can't be too cautious.

I weigh every charge with some powders, every fifth with others and on a few I set up the measure and load several hundred. But the way I've learned which powder/measure/cartridge combinations get what treatment is from 30+ years of reloading. You'll learn a lot from watching how the type of powder, the amount in the measure tube and even your technique effect the final amount that ends up in your cartridge.

Weigh them all for a while and then decide what you can trust and what you are suspicious of.

HTH

quote:

Originally posted by CavRecon:

The instructions with my dies show a starting load of 7.7 grains (0.55 cc) and designates the 0.53 cc autodisk chamber. Hornady specifies a maximum load for a 155 grain HP-XTP (hollowpoint but I assume similar enough) of 8.8 grains of HS-6. So I went with the 0.53 cc (HS-6 VWD is 0.07120, yielding 7.4 grains of powder).

Welcome to AR.
Especially as a newby, always err on the side of safety.
I'm not saying that you'll lose your fingers, but using less powder than the recommended starting load can be just as dangerous as using more than the max load. Beware of sticking a bullet in the bore, then pulling the trigger of that semi-auto a second time. Nothing good can come of it; in fact some very freaky things can happen when you have a very small amount of powder that at one time is up against the primer and the next it's at the base of the bullet.

Change something. Either the powder brand or your measuring equipment to get at least up to the starting load. Look in loading manuals. If you don't have any yet, buy some. Look on the web...all the powder manufacturers have free data.

And NEVER assume that a plated lead core practice bullet will be the same as a sturdy jacketed hunting bullet just because they weigh the same.

Worring about weight variations between LOADED cartridges is a usless waste of time and energy.

Your bullets can vary by +/- 2.0gr and your brass by +/-10.0gr, so your not going to be able to sort out even a +/- 0.5gr variance in the powder charge with any degree of reliability.

tg is correct, weighing your finished ammo is almost useless except to possibly varify there actually ispowder (depends on the charge wt.). Just be cautious about the charge wt. you are throwing, stay away from the max. loads & uberfast powders until you have alot more expereience & you'll be fine. FWIW, your load is below the sugg. starting from Hogdon.

Yup, I've learned the error of measuring completed cartridges. Just spent some time at the bench throwing and checking 20 charges in a row and it looks good.

I put in the 0.43cc autodisk and measured 20 charges of HS-6. My expected charge was 6.04gr and my average actual was 5.89 gr.

Also, Hodgdon doesn't have a load for the Berry's 155gr JFP...only a Hdy HP-XTP 155gr JHP.

Is the variance between expected and actual charge (0.149gr) significant?

quote:

Is the variance between expected and actual charge (0.149gr) significant?

Actually a variation of +/- a grain or less from a measure is pretty good with most powders. The ball powders are normally better then flake or stick types for this.
Keep in mind the smaller the load you are shooting for, the more difference a tenth grain variation will make percentage wise. I can`t say I`ve seen a suggested percentage recommended anywhere though.

quote:

Actually a variation of +/- a grain or less from a measure is pretty good with most powders. The ball powders are normally better then flake or stick types for this.

I believe Ol' Joe meant to say "+/- a tenth of a grain "

Pat

Maybe I lack the equipment or nature for this. I'm generally a pretty meticulous guy, but when we're starting to worry about variation of 1/70,000th of a pound being the difference between having all my fingers or not, I start wondering if this is a realistic endeavor.

From Hodgdon Reloading Data Center for 9mm 100 GR. SPR FMJ using Titegroup Start 4.7gr, Max 5.0gr. That is 3 tenth grain difference, between a recommended starting load to the max recommended load, so I would conclude a tenth of a grain may be significant. Most powder scales used measure to 0.1 gr.
Pat

quote:

Originally posted by pdpdad:

quote:

Actually a variation of +/- a grain or less from a measure is pretty good with most powders. The ball powders are normally better then flake or stick types for this.

I believe Ol' Joe meant to say "+/- a tenth of a grain "

Pat

Thanks for catching my error. You`re right, I meant one tenth grain.

I'm in my first year of hand loading and I weigh each charge and then trickle to the exact weight. I also sort my bullets and brass by weight before I load and weigh each completed round.

I am only loading for 10 rifles and usually only 20 rounds at a sitting so being overly cautious isn't a problem for me.

I also had a hot load of factory ammo almost blow apart a Remington 700 and I think that experience makes me lean to the cautious side a bit more.

Robert

cav -

nothing wrong with being careful or cautious. as you get used to it and become more comfortable with the process, you'll know when and where to streamline the process. more importantly, you'll know when and where NOT to cut corners.

keep up the good work, and take it at your own pace. if you have any questions, just ask - it's a good crew here and they won't steer you wrong.

CavRecon,
I agree with others and to ALWAYS err on the side of safety... Also, if you don't already have one, the Lyman Reloading Guide for handgun & rifle calibers is a really good book for "beginners" in reloading. And, it will also give you some good loads & safety ranges (of powder loads) for almost ALL the common calibers, handguns and rifles...

Lyman Manual

That being said, the variation you found in your loaded .40S&W rounds in not that unusual... If you didn't do a lot of match-type brass prep, just inconsistancies in the brass weights ALONE could account for the variations you saw...
Again, err on the safe side for sure, but the small grained pistol type of powders usually meter very well through a good quality powder measure.... As Joe/Pat said above, most measures will easily keep you within .1 grain +/- on pistol powders. The extruded (large grained) rifle powders are a different story though... Those require a bit closer scrutiny from throw to throw...
Get the Lyman book... It's a really good start...

quote:

Originally posted by CavRecon:
Maybe I lack the equipment or nature for this. I'm generally a pretty meticulous guy, but when we're starting to worry about variation of 1/70,000th of a pound being the difference between having all my fingers or not, I start wondering if this is a realistic endeavor.

1. Smokeless gunpowder weight is quantified in the unit grains, or tenths thereof... 7.6gr of HS-6. Not to be confused for grams used in the grocery store. Perhaps you have some sort of scale that weighs to the second decimal point, but reloading doesn't require such accuracy--not even benchrest shooters. Pounds is only used when asking the container size...1 pound, 4 pounds or 8 pounds.

2. Those Berry's plated bullets can, for this discussion, be treated like a cast lead bullet. The very thin copper wash is only to encapsulate the lead, not to act as a jacket.

3. Many of my sources list the HS-6 starting load for 155gr XTP's at 8.0gr., with max of 9.0gr.

4. Start at or just above the starting load until you gain experience. Treat your semi-auto as a single shot until you know that your combination of components is functioning properly...as a matter of fact, you should use your barrel's chamber as a cartridge gauge to check for fit. Then, make sure that your chosen load functions your action adequately and every bullet leaves the bore.

5. Handloading your own ammo should not be a daunting task. However, and correct me if I'm wrong, you're taking on 3 new tasks now. Learning how to use the reloading equipment, learning to use the auto powder measure, and learning how your loads function in a semi-auto handgun. Reduce these to their most simple elements, master each one, then combine them once you feel confident your reloads are similar to factory ammo. Good luck.

I posted befor I read onefunzr2 reply... Good reply!

Now here is mine

I believe you are hard pressed to be “too cautiousâ€. I mainly load rifle cartridges and I am VERY cautious.
I :
• Sort brass by manufacturer
• weigh all my brass & sort into lots with .5 gr spread (within the limits of my scale)
• weigh all bullets and exact weight (within the limits of my scale)
• Weigh all charges to exact weights
• Weigh 5 of the Primers I use and average the weights
• Sum all of the component weights ( for a control)
• Weigh all of the completed cartridges and compare control weights
Perhaps I am being “too cautious†but it’s fun.

On a single stage press I always weigh after every 10 handgun loads and weigh every single rifle load and top up with a dribbler. Lower volume and higher consistence are important to me, especially in rifles.