Determining the starting charge for a semi-auto?

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.308 Norma

.308 Norma

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In order to avoid any “go buy a manual” instructions, I need to state right up front that I’m not new to handloading – been at it since the late ‘70s. However, I’m green as a good lawn when it comes to handloading for semi-autos.

My question is how do most of you good folks determine what is a good starting point when working up (or possibly down) to the best powder charge for a semi-auto? A few years ago I tried loading for a 9mm that I had. According to my notes, I started with a fairly low charge of Power Pistol, and worked up .1 grains at a time. Also according to my notes, the low charges gave me a lot of failures to eject, and that improved as I got close to the maximum listed charge in my Speer manual. At .1 grains below maximum, I was having no failures of any kind, it seemed fairly accurate, and it didn’t seem to have any more recoil or make any more noise than factory loads.

But now I have a different 9mm semi-auto, at least 500 once-fired 9mm cases I’d like to reload, and I don’t want to completely start over working up a load that will cycle the action without beating up the gun. So can I start in the middle somewhere as far as the listed powder charge goes? What do you folks do when you get a different semi-auto?

Thanks in advance for your help.:)
 
It all depends on the actual gun (the weight of the slide and/or the recoil spring. Also depends on the powder used, as well as the bullet weight and type.

Some guns cycle easier than others

Also depends on what manual you look at. Speer data is different than say Hornady or the powder company for the same weight bullet.

You as the "experienced" reloader have to determine where to start:)
 
If my manuals agree on a charge weight of say 4 grains starting, 6 grains max I will usually start just above the listed starting charge, say 4.5 grains and then load up in .2 or .3 increments. Most of the semi auto handguns I've loaded for the starting charges in the book often will not cycle the gun.

In the above scenario I would load 5 rounds each at 4.5, 4.8, 5.1, 5.4, and 5.7. So that's just 25 rounds. Then I will go out in the yard and shoot them on paper and note how far the brass ejects. If the brass is falling at my feet or hitting my arm then I know I'm at the bottom of what will cycle the gun. I want the brass to be ejecting at least about 4-5 feet, which tells me there is enough power there to reliably cycle the gun. I find that amount and I write that down in my book as the minimum working load. If the gun shoots well I might stop there and leave it like that. If I want some more oumph and the recoil doesn't bother me yet then I can go up from that point looking for accuracy or whatever you want.

Case in point I was working up on my ruger LC9s recently loading 124 gr plated with 700x. Loads in my various sources call for anywhere from 2.9-3.4 grains to as high as 3.7-4.2 grains for various lead and jacketed bullets. I was looking for a low power plinking load so I started at 3.0 grains and worked up by .2 grains. 3.0 would not reliable cycle the gun and resulted in jams and stovepipes. 3.2 would cycle the gun but the brass was landing on my right arm. 3.4 was fine and brass landed 4 feet away. 3.6 would throw them 6 or 8 feet. 3.8 would throw them over 10 feet and recoil was snappy enough in this tiny gun that I couldn't keep my support hand on the gun during recoil and primers were just starting to flatten. At that point you could pick your load and stop. I loaded 3.4 and 3.6 again 25 rounds each to shoot some groups. 3.4 groups an inch better in my hands at 20 yards and the recoil is more manageable. Winner winner chicken dinner!
 
If I develop a load for a given caliber in one pistol and then buy another of the same caliber...
I load the new gun and shoot.
I have had to tailor loads to individual guns but do so only if I must.
At present, my SA 9mm shoots more different loads reliably than my Colt.
My Caspian .45 shoots more different loads reliably than my STI.
When present stocks of ammo and components run short, I will standardize on the Colt and STI ammo, which works in the other guns.
 
You can start anywhere you want, but you are forgetting 2 important things....

1) Published load data is NOT about making an automatic pistol cycle properly. (Remember, there are plenty of revolvers that shoot 9x19 Luger ammo !!) Published load data is derived from measurements of the chamber pressure. And 98% of everything we do in reloading is to manage chamber pressure.

2) Best accuracy may be achieved well before the slide functions "correctly". This because there is absolutely no relationship between accuracy and slide function. In those cases you may need to "re-spring" the pistol to operate with your low power accuracy load. This is common practice among Practical Pistol competitors.

Best practice is to always begin at the Starting Load. It's not always the most fun, but it's always safe !!
 
When I started loading for my first auto, I quickly learned that the minimum loads were not likely to function. I saved lots of trial & error by starting a little below max - maybe 5 to 10%. Of course it depends on your particular gun, age & weight of the recoil spring, slide weight, etc.
 
After determining the working OAL that will reliably feed/chamber from the magazine, I use .2-.3 gr increment charges from published start charge to identify the charge that will reliably cycle the slide and extract/eject the spent cases.

Then I use .1 gr increment charges to identify accuracy node.

For 9mm, if using longer OAL like 1.150"-1.160", I will incrementally decrease the OAL by .005" to determine if accuracy increases with shorter OAL.

With 115 gr bullets, often higher than mid-to-high range load data will start to reliably cycle the slide and produce accuracy, especially when using longer OAL. With 124/147 gr bullets, mid range loads can reliably cycle the slide and produce accuracy.
 
I agree with the others. Start on the higher end of the middle and increase the charge weights by. 2gr to .3 gr. Since you are a reloaded no need to tell you any more, you will find a good load.

Good luck...
 
If I am working with a new gun that I have no history on ... I always start at the lower end of the reloading data, with enough loads to make sure the gun functions as it should ... then I move on up in the data chart to about 2/3 toward the top ... it is that upper third area that I work in until I find a load that works and gives the accuracy I am looking for .... if I find it ... that load becomes "the" load for that bullet and powder.

If I don't find what I am looking for ... I move to another powder and go through the same process ...

Each gun will pretty much require the same process ... although some loads will shoot well across other guns ... those I mark so that I know that they will shoot well in the listed guns ...
 
I start in the middle and work up in -.1gr increments. I've found over the years that most simi-autos will not cycle at the low end. I've also found out that some powders are better than others at make the slide cycle. I tend to shoot the heavier 124gr bullet for this purpose. The extra weight helps operate the slide. Once I find the load I start decreasing the OAL to see if accuracy improves. Some times it does depending on where I started at on OAL.
 
Some sources have some very hot data in there books. I wouldn't start any higher than the middle myself. Especially if I'm not using the exact bullet in the book.
 
I load nothing but plated bullets, Win231/HP-38, and have always just loaded mid-range jacketed per published tables.
 
Thanks for the responses everyone.:)
That's what I'll do - start in the middle and work up, .1grs of powder at a time. I'm trying 124gr Hdy HP-XTPs and Power Pistol to start with. My latest Hornady manual lists 4.3 to 5.7 grs, so I'll start at 5.0 (right in the middle) in my new Smith Shield 9mm, which seem to be sprung pretty "hard" compared to some of the other 9's I've had.
Anyway, thanks! I'm sure I'll have fun - I love handloading, and now that components are once again becoming readily available, I won't mind as much if it takes me a few tries to come up with the "perfect" 9mm load.:)
 
You might want to use the 124gr Hornady HAPs, since they are a bit cheaper and nearly 100% compatible with the XTP without the controlled expansion part. XTPs tend to get expensive really fast especially out of a semi-auto. That's exactly why Hornady developed the HAP.
 
.308 Norma said:
new Smith Shield 9mm, which seem to be sprung pretty "hard" compared to some of the other 9's I've had.
Click to expand...
Congrats! I also ordered the new M&P Shield 9mm (couldn't pass up the $75 rebate) so will be doing load development with you.

I found subcompacts in general have stiffer recoil spring rate and require higher powder charge to reliably cycle the slide compared to full size pistols.
 
bds said:
I found subcompacts in general have stiffer recoil spring rate and require higher powder charge to reliably cycle the slide compared to full size pistols.
Click to expand...
Yep, some of them hate light loads that will cycle full sized pistols.
 
I have to travel some distance to shoot, so if I'm working up a load, I will follow this process:
  • Consult my reloading manuals as well as manufacturer's on-line data and based on the components and gun(s) used in devloping the data, develop a "concensus" regarding a starting load. This may not be the lowest published starting load, but it will be at or near the minimum of the sources consulted.
  • Using that same data, I will also develop a "concensus" maximum load.
  • Depending on how much difference there is between starting and maximum load, determine the incremental increase in powder for each "rung" on my "ladder". As a practical matter, this is usually 0.1 grains for pistol and 0.2 grain for rifle.
  • Load 10 rounds at the starting load and then 10 rounds for each "rung" on the "ladder".
  • Detailed records are kept as these loads are produced.
  • Each 10 round string is put into a numbered plastic ammunition box with the row containing the lightest string nearest the hinge and each subsequent row being the next highest "rung" on the "ladder".
  • I load until I reach the "concensus" maximum. Even though I may have a manual that gives higher loads, I stop at the "concensus" maximum.
  • At the range, I start with the starting load and fire five rounds through the chronograph and five rounds for accuracy, recording the results of each.
  • I inspect the fired cases and if pressure signs are identified, I stop until I can evaluate the cause.
  • If I don't have pressure signs, I identify the load that shot best for me and it becomes the candidate for the "recipe" going forward.
  • As I gain experience with the load, I may "modify" it from time to time, but this is how I get to the load I am going to routinely shoot.
Just a personal note that many reloaders have an almost pathological fixation on reaching "maximum". This should be recognized for the illness it is. For example, in 9mm with 115 grain bullets (which I load) the difference between 4.4 grains of Bullseye and the published (Hornady #8) maximum of 4.6 is 50 fps. That translates into a difference of 28 foot-pounds of energy at the muzzle which will not make a difference in the lethality of the bullet on arrival at the target. But, if realizing that additional 28 foot-pounds comes at the cost of accuracy, the higher energy bullet may never arrive at the target and that has a dramatic effect on lethality. So, my advice is to chase accuracy and consistency, not numbers on a chart.
 
I have been known to load anywhere from 2 to 18 rounds, drive 30 miles, shoot them, log everything, and drive home. I try to include some recreational shooting along with a trip like that, but it doesn't always happen. Start slow, you don't want 40 leftover rounds of crap.
 
jlove1974 said:
You might want to use the 124gr Hornady HAPs, since they are a bit cheaper and nearly 100% compatible with the XTP without the controlled expansion part. XTPs tend to get expensive really fast especially out of a semi-auto. That's exactly why Hornady developed the HAP.
Click to expand...
Thanks. Yeppers, I totally agree - the XTPs were pricey. But in 3 different gun stores they were the only 124gr, 9mm bullets of any kind I found on the shelves. Reloading components are becoming available again, but around these parts (SE Idaho) it's a slow process. I will keep an eye out for the HAPs you recommended though.:)
 
I think this is on the other side of the state, but aren't CCI/SPEER, RMR, and Xtreme aka Howell Machine all based in Lewiston Idaho? Might be worth it for you to order online esp with the free shipping offers out there nowadays. I know RMR has free shipping on all their bullets and they make a 124gr FMJ right there in house for around 8 cents a pop plus the THR discount :D thehighroad5
https://rmrbullets.com/shop/bullets...rmr-full-metal-jacket-bullets/?v=7516fd43adaa
 
Last edited:
hdwhit said:
Just a personal note that many reloaders have an almost pathological fixation on reaching "maximum". This should be recognized for the illness it is. For example, in 9mm with 115 grain bullets (which I load) the difference between 4.4 grains of Bullseye and the published (Hornady #8) maximum of 4.6 is 50 fps. That translates into a difference of 28 foot-pounds of energy at the muzzle which will not make a difference in the lethality of the bullet on arrival at the target. But, if realizing that additional 28 foot-pounds comes at the cost of accuracy, the higher energy bullet may never arrive at the target and that has a dramatic effect on lethality. So, my advice is to chase accuracy and consistency, not numbers on a chart.
Click to expand...

I've tried to get the chronograph to explain to the bullets that they should be more accurate because of there low deviation or whatever but the bullets just don't see it that way. I let the bullets tell me what they want rather than the chrono. I'm happier if I leave the chronograph in the garage until I have found the load I like.
 
Walkalong said:
I have been known to load anywhere from 2 to 18 rounds, drive 30 miles, shoot them, log everything, and drive home. I try to include some recreational shooting along with a trip like that, but it doesn't always happen. Start slow, you don't want 40 leftover rounds of crap.
Click to expand...
Ah, man! That would be the craps! Luckily, our shooting "range" is a county gravel pit a couple of miles south of the house. The only problem we have with shooting there is that we usually come home with a bag of trash. There are slobs around here that don't realize it would take nothing for the County Commissioners to have "No Trespassing" signs posted at that gravel pit because of all the cans, plastic bottles and other makeshift targets left lying around. Let alone the thousands of AK-47 steel cases and plastic shotgun hulls. So we pick up other people's garbage when we go to our "range.":(
 
hdwhit said:
I have to travel some distance to shoot, so if I'm working up a load, I will follow this process:
  • Consult my reloading manuals as well as manufacturer's on-line data and based on the components and gun(s) used in devloping the data, develop a "concensus" regarding a starting load. This may not be the lowest published starting load, but it will be at or near the minimum of the sources consulted.
  • Using that same data, I will also develop a "concensus" maximum load.
  • Depending on how much difference there is between starting and maximum load, determine the incremental increase in powder for each "rung" on my "ladder". As a practical matter, this is usually 0.1 grains for pistol and 0.2 grain for rifle.
  • Load 10 rounds at the starting load and then 10 rounds for each "rung" on the "ladder".
  • Detailed records are kept as these loads are produced.
  • Each 10 round string is put into a numbered plastic ammunition box with the row containing the lightest string nearest the hinge and each subsequent row being the next highest "rung" on the "ladder".
  • I load until I reach the "concensus" maximum. Even though I may have a manual that gives higher loads, I stop at the "concensus" maximum.
  • At the range, I start with the starting load and fire five rounds through the chronograph and five rounds for accuracy, recording the results of each.
  • I inspect the fired cases and if pressure signs are identified, I stop until I can evaluate the cause.
  • If I don't have pressure signs, I identify the load that shot best for me and it becomes the candidate for the "recipe" going forward.
  • As I gain experience with the load, I may "modify" it from time to time, but this is how I get to the load I am going to routinely shoot.
Just a personal note that many reloaders have an almost pathological fixation on reaching "maximum". This should be recognized for the illness it is. For example, in 9mm with 115 grain bullets (which I load) the difference between 4.4 grains of Bullseye and the published (Hornady #8) maximum of 4.6 is 50 fps. That translates into a difference of 28 foot-pounds of energy at the muzzle which will not make a difference in the lethality of the bullet on arrival at the target. But, if realizing that additional 28 foot-pounds comes at the cost of accuracy, the higher energy bullet may never arrive at the target and that has a dramatic effect on lethality. So, my advice is to chase accuracy and consistency, not numbers on a chart.
Click to expand...
Good advice. I find the greatest accuracy is just below max based on bullet weight and shape. I set the OAL to match commercial ammo with same bullet shape. I do not reload "lead" so no comment on that issue.
Since I reload for "practice ammo" only, accuracy and reliability are my only points of interest.
 
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