Ever get scared testing a new load?

[smurf hunter]

I decided to take my .357mag loading to the next level and experiment with some full house charges.

I decided on H110 for powder as it was very slow burning and might work well with heavy bullets. What's scary about that powder, min charge == max charge for most cast bullets.

I have a 6" GP100, which is one of the tougher revolvers out there. While that's some comfort, in the back of my mind I'm thinking "how light of a charge might squib, and how hot of a charge will explode in my face?".

I have 2 recipes I'm testing out:

1) 180gr LRNFP (BHN 12) 12.5gr H110
2) 125gr Hornady XTP (JHP) 22gr H110

#1 might be a tick light, so I plan to load only one into the cylinder to ensure no squibs. This was not published. Hodgdon lists only a 180gr JHP @ 13.5gr, so I worked down from that, and up from a 170gr cast recipe Lyman had.

#2 did have a charge range of 21-22gr in the Lyman book. Both end up compressing the powder when seating the bullet. This is scary stuff. I'm used to throwing 5gr of Universal for plinking.

I've only loaded 5 of each, but I'm now second guessing my budget Lee safety scale and overall precision of my process.

Any hand loading adventures others want to share?

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[catwithboost]

I have been loading rifle loads for a few years does not bother me. BUT I just started loading for my 45acp and have not tested them yet. Little scared. 200gr 45acp 5.4g Unique powder.

 

[orygun]

#1 H110 is a powder that is not recommended for loading less for lower velocity. Don't stray too far from what the manuals are telling you. I would think you've found a reasonable starting point, though.
#2 Hodgdon does not recommend using H110 for a 125gr bullet, but other sources do. I think your starting load for that bullet is a bit hot. The Hornady book I have shows 20.8gr of H110 max. I'd back that one down a bit.

 

[smurf hunter]

orygun

Appreciate the reply. While I think H110 is primarily for a heavy cast bullet, hodgdon has a recipe for my exact bullet in #2.

Bullet Weight (Gr.) Manufacturer Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
125 GR. HDY XTP Hodgdon H110 .357" 1.590" 21.0 1881 38,400 CUP 22.0 1966 41,400 CUP

The charge range concurs with the Lyman #49 book.

Even still, I realize that any imprecision will be exaggerated when dealing with such a heavy charge. I just hope I really did drop 21.8gr

 

[smurf hunter]

@cat I started with loading for revolvers, so that removed some of the precision about OAL and crimping.
Given you know how to measure powder from rifle loading, if you have a mechanical issue (seating depth, crimp, etc.) that might result in a feeding or extraction malfunction. Neither are really unsafe.

Good luck though.

 

[nubus]

Smurf,

Digital scales are pretty cheap nowadays.
Advantage, you can weigh the charged cartridge.
Actually your Lee may have enough capacity to do it.
Weigh a primer, bullet and case. See if the difference is approx. 21.8gr.
Cases will vary slightly in weight.

BTW, my cheap Lee scale is more accurate than my digital scale.

Be safe!

 

[Rammit]

I have never had an issue loading the max load, always weight them by hand if im near it. I regularly check the accuracy of my digital scale, and recommend a set of checkweights.

 

[smurf hunter]

nubus,

That's an excellent idea to weigh the finished cartridge - problem is I reuse my brass quite a lot and I'm sure I could find .25gr variation across cases depending on how aggressively I clean the primer pocket, etc.

If I sorted my brand/type and weighed prior to loading that could work.

Typically I use my scale to calibrate my powder thrower. I re-check every 10 or so. In this case, it wasn't worth calibrating two items.

 

[catwithboost]

I use a Lyman 1200 DPS III Digital Powder System. I trust it. For my first 40-50 rounds of loading with it I double checked it with a regular digi scale and was right on. Now i just test it with my first load change.

 

[Gunner3456]

BTW, my cheap Lee scale is more accurate than my digital scale.

Be safe!

Beam scales have been proven over and over to be more accurate than digital scales. The Lee scale is a good scale despite the price.

 

[deadshot2]

Beam scales have been proven over and over to be more accurate than digital scales. The Lee scale is a good scale despite the price.

By Whom? A bunch of reloaders who talk about them in forums or actual laboratories. Unless EITHER scale is being checked against a standard (check weight) on a regular basis, NEITHER is considered accurate.

I have both and a set of calibrated check weights as well. Yes, the beam scale is accurate. So's the Digital. The Digital is far easier to read and it doesn't matter what angle I am viewing the digital readout from. It always gives me the SAME readings. Change the angle you read the beam scale balance point and your readings will vary. So now which is more accurate?

 

[Gunner3456]

By Whom? A bunch of reloaders who talk about them in forums or actual laboratories. Unless EITHER scale is being checked against a standard (check weight) on a regular basis, NEITHER is considered accurate.

I have both and a set of calibrated check weights as well. Yes, the beam scale is accurate. So's the Digital. The Digital is far easier to read and it doesn't matter what angle I am viewing the digital readout from. It always gives me the SAME readings. Change the angle you read the beam scale balance point and your readings will vary. So now which is more accurate?

The way you are using yours, you are absolutely correct and I applaud you.

Digital scales were first developed for scientific use and then someone discovered that they could be very handy for weighing powder.

The problem with a lot of reloaders is that they don't know that all of those devices work on what's called a strain gauge which is very sensitive to temperature and humidity. You need to calibrate the scale every time you use it. Another thing they don't know is that it can take as long as 30 minutes for one to fully warm up, depending on where it's stored.

Yes, assuming it's either stored at room temperature where it will be used or left on all the time, or given time to warm up, and assuming it's calibrated before each use, the electronic will be just as accurate and I might add, much faster to use.

 

[smurf hunter]

It would seem easier to zero a digital scale, as well as deadshot2 mentioned - easier to read.

For safety I like to assume some degree of scale error. For argument sake, suppose the scale weighs 10% low at a given charge.

A recipe calls for 4-6gr, I plan to load 5gr. If the scale is wrong and I load 5.5gr, I'm still safely below max. Maybe it won't shoot accurately, but I probably won't notice in a handgun. I can go on for months loading that 10% too hot without any worries.

Now when H110 recipe calls for 21-22gr and I intend to load 21.5 to split the difference, 10% extra powder totals 23.65gr.
Logic tells me a full frame revolver probably won't blow up in my hands with an extra 1.6 grains, but you can appreciate the apprehension.

10% is a ridiculous amount of error, but I wanted an obvious example.

 

[ZigZagZeke]

The way you are using yours, you are absolutely correct and I applaud you.

Digital scales were first developed for scientific use and then someone discovered that they could be very handy for weighing powder.

The problem with a lot of reloaders is that they don't know that all of those devices work on what's called a strain gauge which is very sensitive to temperature and humidity. You need to calibrate the scale every time you use it. Another thing they don't know is that it can take as long as 30 minutes for one to fully warm up, depending on where it's stored.

Yes, assuming it's either stored at room temperature where it will be used or left on all the time, or given time to warm up, and assuming it's calibrated before each use, the electronic will be just as accurate and I might add, much faster to use.

I was an instrument technician for 20 years before I became a desk jockey. Good strain gauge applications are temperature, pressure, and position compensated. If small variations in room temperature cause your strain gauge based scales to wander then you probably don't have a high quality scale. Also, keep in mind that with digital displays, if you have, for example one decimal place you can actually have any amount of powder between 23.90 grains and 23.99 when your scale indicates 23.9. Of course, the more decimal places, the smaller the possible error in this case, but it is an inherent disadvantage of digital compared to analog.

 

[deadshot2]

It would seem easier to zero a digital scale, as well as deadshot2 mentioned - easier to read.

For safety I like to assume some degree of scale error. For argument sake, suppose the scale weighs 10% low at a given charge.

A recipe calls for 4-6gr, I plan to load 5gr. If the scale is wrong and I load 5.5gr, I'm still safely below max. Maybe it won't shoot accurately, but I probably won't notice in a handgun. I can go on for months loading that 10% too hot without any worries.

Now when H110 recipe calls for 21-22gr and I intend to load 21.5 to split the difference, 10% extra powder totals 23.65gr.
Logic tells me a full frame revolver probably won't blow up in my hands with an extra 1.6 grains, but you can appreciate the apprehension.

10% is a ridiculous amount of error, but I wanted an obvious example.

The best way to use ANY scale, because of the possible errors in linearity is to have a set of check weights. To use your second example, if you want to load 21.5 gr of a powder, merely place the check weights totaling the amount you desire on the scale. If the scale shows 21.5 gr then you know it's accurate. The RCBS check weight sets allow for every combination of weight from .5gr to 60.5 gr. This way you aren't assuming that your scale is accurate just because it zeroed but are comparing your load weight against a known weight of equal amount. These check weights may not be of laboratory grade, accurate to the nano-gram but the are definitely accurate to what our reloading scales are capable of measuring.

 

[Gunner3456]

I was an instrument technician for 20 years before I became a desk jockey. Good strain gauge applications are temperature, pressure, and position compensated. If small variations in room temperature cause your strain gauge based scales to wander then you probably don't have a high quality scale. Also, keep in mind that with digital displays, if you have, for example one decimal place you can actually have any amount of powder between 23.90 grains and 23.99 when your scale indicates 23.9. Of course, the more decimal places, the smaller the possible error in this case, but it is an inherent disadvantage of digital compared to analog.

Good points and interesting info. Thanks. When I mentioned temperature, I was thinking of guys who reload in their garage where the temperature and humidity can vary widely from one reloading session to another, and where warm up time can increase.

 

[Grommit327]

I was an instrument technician for 20 years before I became a desk jockey. Good strain gauge applications are temperature, pressure, and position compensated. If small variations in room temperature cause your strain gauge based scales to wander then you probably don't have a high quality scale. Also, keep in mind that with digital displays, if you have, for example one decimal place you can actually have any amount of powder between 23.90 grains and 23.99 when your scale indicates 23.9. Of course, the more decimal places, the smaller the possible error in this case, but it is an inherent disadvantage of digital compared to analog.

The best way I have found to combat this when adjusting a powder bar is to weigh four charges at once and divide by four. Wouldn't help if you were dispensing individual charges though for single stage reloading

 

[deadshot2]

I was an instrument technician for 20 years before I became a desk jockey. Good strain gauge applications are temperature, pressure, and position compensated. If small variations in room temperature cause your strain gauge based scales to wander then you probably don't have a high quality scale. Also, keep in mind that with digital displays, if you have, for example one decimal place you can actually have any amount of powder between 23.90 grains and 23.99 when your scale indicates 23.9.

You are overlooking the round-off feature. A weight of 23.94 would read as 23.9 and 23.96 would read as 24.0. A weight of 23.95 could go either way depending on the round off scheme and the internal resolution of the reading. What you are talking about is a variation of .05 gr. one way or the other and that little amount isn't going to effect any load when even full 1/10th's don't make a difference in speed/pressure.

As for "wander" I leave my Chargemaster turned on 24/7. Check Calibration before I start a session and check weights to verify the accuracy at my load weight.

 

[deadshot2]

The best way I have found to combat this when adjusting a powder bar is to weigh four charges at once and divide by four. Wouldn't help if you were dispensing individual charges though for single stage reloading

Only flaw with this method, and lots of people use it, is that one load could be a full grain too heavy and another a full grain too light yet the "average" would be just right. It's kind of like standing with one foot in a bucket of scalding water with the other in ice water. The "average temperature says you should be "comfortable".

 

[smurf hunter]

Regarding temperature and moisture - I have seen those impact how powder meters. Hopefully weighing will catch it.