9mm reloads

[Brad in Idaho]

I purchased a bunch of reloaded 9mm (Luger) ammo (115gr FMJ bullets) at a gun show in Sacramento, CA years ago. It was from a commercial reloading business in the area. The company had a good reputation. I have fired some of this ammo from a Glock 17 with no problems. I now have a S&W M&P Shield, and I want to use this ammo for practice in this pistol.

Out of curiousity, I weighed some of the loaded rounds. There are, of course discrepancies in total weight. What I have weighed so far (15 random samples) varies from 180.5gr to 181.9gr. I'm sure this ammo was loaded on a commercial type reloading machine and I don't expect each round to be the exact same weight. Considering I am weighing finished rounds and that weight of brass, bullets, and primers all may vary (as well as powder charge of course), is this an acceptable variance in weight? Any thoughts from the group is appreciated.
Thx, Brad

[psteinmayer]

Are the variances between rounds loaded in the same brass (i.e. all R-P brass) or is it more varying between brass lots (say R-P as compared to Win, etc.)? Brass can definitely vary in weight, especially between manufacturers! Are they all the same powder, primer, and bullet? All of these can affect the weight.

[p246]

Is it loaded in different brands of brass. Different brands of brass can vary a lot. Been a while for pistol, but it's not uncommon to see around 20 grains difference in Norma and Remington brass in 300 winmag and 12 grains difference in Hornady versus Federal 308 brass for example ( brass cases only)

[Brad in Idaho]

The brass in the samples I weighed was all Winchester. I have no idea where this company got their brass. As far as bullets and powder, all I know is the bullets are supposed to be 115gr, manufacturer unknown, powder unknown. I suppose I could disassemble some of these reloads and weigh individual components. At this point I think I'll fire some of it and see how it performs first.

I did weigh some Winchester Silvertips (9mm factory loads) and found variances in 10 rounds of up to 1.2 grains. Thoughts?

[Hefights]

This is an acceptable variance for both. This is not match rifle ammo, shoot them at 25yd or less, proof is in how they perform. I bet you they shoot just fine. I compute the total difference in wt of 1.4 gr, divided by an average of approx 181 gr gives a 0.77% deviation of 1.4 off of the "average". This is very rough and not real statistics, but close enough in my view not to matter. You can try a larger sample, or weigh all of them and then compute real statistics.

Depending upon type of powder, if all the variation was in powder, it might be a problem. But obviously the variation is in brass, bullets and powder, mostly bullets and brass.

If you really want to know, ask an ammo manufacturer what their tolerance is, but they may not check them by weighing loaded rounds, but the components going in, and then the dimensions of the loaded rounds. They also no doubt chronograph them statistically for velocity and SD and ES etc, you can do same, that would also be more meaningful, IMHO. (But again, for handgun ammo, not really worth it.)

[Hefights]

This post caused me to weigh my reloaded ammo, and the deviation was higher than your sample, but still performs well. It also caused me to notice that a handfull of bullets in any 50 rd batch are wobbly, so I'm getting he Hornady seater die with a sleeve to aid in having better aligned bullets.

[Chris W.]

I guess it all depends on how far back you bought these. The only commercial reloading co in Sacramento I know of was Binders Reloading off of El Camino Bl. ( last known location ) Binders was a class act with a fully automated system. He was retired prison guard and got cases from local and state PD's, sold practice ammo to them as well. He loaded all of his stuff about mid power, noting to hot. Think this many years later, I doubt he is still with us. If it is his work, will be packed in white foam, 50 rounds to a flat, sometimes, his name in ink stamp on the flat. High quality reloads. Could be many others by now, but, at the time 20 years ago, he was the only commercial in town.
Chris

[Sunray]

"...fired some of this ammo from a Glock 17 with no problems..." Works ok in one pistol there's no reason to think it won't in another.
The weight of a loaded round doesn't make any difference. Especially as the difference is only 1.4 grains.