Acurately measuring small loads

Hi,

I am loading .32 S&W for my Walther GSP. I am using N310 and 98 gr wadcutters.  The powder loads are pretty small, in the 1.4 gr range and I am concerned about the accuracy and repeatability of my scales and powder throwers.  My question is in two parts.

What are people commonly using for scales and how confident are you in there repeatability.  

Same question for powder throwers.

It would seem to me that being inaccurate but repeatable is okay if the load shoots well and there are no signs of overpressure.

Try Hodgdon TiteWAD. It has a similar burn rate to N310 but is fluffier. A one pound can only has 14 ounces in it. It will work better in a powder thrower.

paulmcallister wrote:Hi,



What are people commonly using for scales and how confident are you in there repeatability.  

Same question for powder throwers.

  I use a PACT BBK II and a Dillon RL550B and a Dillon Square Deal B.  With WST and Bullseye, the Standard Deviation of dropped charges is about equal to the Probable Error of the scale, ~0.05 grains, when dropping nominal 4.5 grain charges.

I'm having good luck with an RCBS Uniflow measure with a 50 grain cylinder and an RCBS 505 scale for loading consistency using Titegroup and BE-86 on 9mm.

I'm having great results with a RCBS Little Dandy for my 32WC loads. I modified a #4 rotor to drop 1.7 grs. of Bullseye. I tested it by dropping 10 charges into the scale pan and weighing. Results were right at 17 grs. plus or minus 1 tenth. 

There may be a better way but this is working for me. My 50 yd. result have been very satisfying   with the 32. 

Good luck.

Jim

I'm using a Lyman Micro-Touch 1500 electronic scale. It uses a calibration set up with a 100 gram weight when starting, but since I don't trust anything due to being a mechanic, where things are broke or going to be broke (the two states of existence), I made some check weights out of short lengths of solder in a small fold of tape. The tape allows me to mark the weight with a sharpie, and the check weight lets me check my scale during use to see if it has drifted or is otherwise lying to me. Since I am loading for a 45, my check weight is 3.8gr and has also been checked on my friends scale collection. Since it is a small item, I use tweezers to handle it, which also keeps it from gaining weight from dirt.

The scale reads to tenths of a grain, but to make sure I'm not seeing rounding errors I'll also measure 5 or 10 throws to see if my powder throw is consistent. I'm using Alliant Bullseye powder in a Hornady powder drop that is grounded and usually it is either spot on for ten throws or down a tenth.

a good quick check for a scale is any new us currency bill it will weigh exactly 1 gram, or buy some rcbs check weight set, it has as low as 5 grains.

I use a Dillon 550B and have the micro-adjustable powder measure, which throws small precise powder charges (http://www.uniquetek.com/site/696296/product/T1231).  To weigh the charges, get a powder scale that weighs charges to +or- 0.02 grains. I shoot a 32 ACP for centerfire and the accurate load for my gun calls for 1.2gr TiteWad, which I want to measure as precisely as possible since weighing errors are more likely to have significant effects with small charges.

The same loading principles applies to the 32 S&W L. Good shooting, dipnet

Greetings,

You will have the best results loading for the 32 S&W Long and similar small charge calibers by "throwing" the charge. You do need to choose a powder that is fine grained, such as Bullseye, VV-N310, 231, WST, etc. and the powder thrower needs to be designed for small charges.

Electronic scales "drift" as time goes on. At least the ones that I own do. I do not weigh powder on the electronic scales. I prefer the mechanical RCBS 5-10 or 10-10 in which the beam "floats" up and down before coming to a rest at zero.

I do use the electronic scale for weighing 400 grain bullets since it is faster; but, I find I have to re-zero the scale often; or, turn the scale on the night before the weighing session for the electronics to stabilize.

For setting a charge, throw ten charges as uniformly as you can. Then weigh all ten charges on a mechanical scale where the beam "floats" up and down gently and finishes up at zero. Divide by ten and this is your "average" single charge weight. i.e. ten charges weigh 14.7 grains so a single charge will "average" 1.47 grains.

Repeat the above two or three times. If you are consistent with your process, the ten charges should weigh within 0.1 grains. i.e. 14.6 to 14.7.

The electronic scales sold to the reloader do not have the precision for weighing small charges. You need to buy a laboratory scale, $$$$.

Also, the electronic dispensing scales have another issue. They continually try to zero the unit to compensate for drift. Dribble a few particles of powder on the pan and see if the scale "zeroes" itself again.

The mechanical measure has a fixed cavity and once you develop a cadence, the accuracy is exceptionally good.

With kind regards,

Dave

You can get a better idea of what your measure is throwing by throwing 10 charges and dividing that weight by ten.

Paul..I have loaded many rounds of .32 S&W Long Wadcutters with real good sucess with Hornady Lock and Load Measure SKU:050069 With Pistol Insert SKU:050116. I actually have 2 Hornady pistol inserts that are set slightly different. One of them is set for 1.5 grains WST and the other one is set for 1.5 grains Bullseye. This makes it real easy to switch loads by just dumping the measure and changing the insert by pushing the pin the side of the metering assembly and pulling the insert out and putting the new one right back in. I really don't think the scale is crucial as once you set the insert it really doesn't change as it locks down. I actually take a sharpie and scribe a line on the insert to see if it ever moves but I've loaded several thousand rounds and it's never moved yet. I just use a Lyman electronic scale to set the insert for the first time and start loading. I have however checked the powder drops several times over the last years and they are always spot on. My routine is throw ten charges and weight them and if you finess the handle on the powder measure right every time you will have 15 grains after 10 drops. Don't stress on the scale as you just want CONSISTANT DROPS and they come for a good powder measure. Kinda set it and forget it. mp

Hello everyone,
 
Firstly thank you for all of your replies.  Perhaps it would help if I shared what I am concerned about.
 
I have a Lee 1000 progressive loader and it uses there disk powder measure. Lee are no longer able to supply the Micro Disk for this powder thrower so I machined up an aluminum sleeve for one of the disks and drilled it out with increasing size number drills until it would dispense 1.4 grains.
 
I measured this by throwing 10 charges and measuring it at 14 grains. It is very consistent throwing 10 charges = 14 grains, however I have no way accurate way of telling if each individual charge is 1.4 grains.  It is entirely possible that although the average is correct, each charge may not be.  This is the reason for asking what type of measuring equipment people are using for small loads.
 

Thanks again, Paul

paulmcallister wrote:
 
Lee are no longer able to supply the Micro Disk for this powder thrower

just a FYI
Titan Reloading is 3d printing the micro disk !
http://www.titanreloading.com/powder-handling-equipment/titan-micro-charge

I load 32 S&W Long for a Hammerli 280, I just set aside time to weigh every charge.

paulmcallister wrote:Hello everyone,
 
Firstly thank you for all of your replies.  Perhaps it would help if I shared what I am concerned about.
 
I have a Lee 1000 progressive loader and it uses there disk powder measure. Lee are no longer able to supply the Micro Disk for this powder thrower so I machined up an aluminum sleeve for one of the disks and drilled it out with increasing size number drills until it would dispense 1.4 grains.
 
I measured this by throwing 10 charges and measuring it at 14 grains. It is very consistent throwing 10 charges = 14 grains, however I have no way accurate way of telling if each individual charge is 1.4 grains.  It is entirely possible that although the average is correct, each charge may not be.  This is the reason for asking what type of measuring equipment people are using for small loads.
 

Thanks again, Paul

  I once spent an evening dropping and weighing charges of Bullseye and WST from a Dillon RL550B.  What I learned was the Standard Deviation for both powders was about equal to the Probable Error of my scale, ~0.05 grains.  So I expect ~66% of dropped charges to have an undetectable variation, and 95% to be within +/-0.1 grains of the desired weight.

  So the question becomes. "How much time do you want to spend chasing the 5% that are more than 0.1 grains off?"

Dipnet wrote:I use a Dillon 550B and have the micro-adjustable powder measure, which throws small precise powder charges (http://www.uniquetek.com/site/696296/product/T1231).  To weigh the charges, get a powder scale that weighs charges to +or- 0.02 grains. I shoot a 32 ACP for centerfire and the accurate load for my gun calls for 1.2gr TiteWad, which I want to measure as precisely as possible since weighing errors are more likely to have significant effects with small charges.

The same loading principles applies to the 32 S&W L. Good shooting, dipnet

I have the Dillon setup with the uniquetek powder drop and its great.  I dont have a scale as accurate as +/- .02 so I do a double charge and divide that by 2 to verify its accurate.