9mm bullet weight - should I be concerned?

[santacruzdave]

Being somewhat new to the reloading game, I figure it's better to ask a question than try to guess.

I just received some 9mm bullets. And like I always do when I get a new projectile, I measure and weigh a few to see how consistent they are and to have a reference when figuring out the COL for my reloads. These bullets are advertized at 122 grains. They are very consistent in diameter and relatively consistent in length. However among the 10 randomly selected samples I found one that weighs 128.5 grains and another the weighs 127.8 grains. The rest were between 121.8 and 124.0. Should I be concerned about overpressure with the 128.5 bullet? Should I weigh all the rest (there are 500 in the batch)? Is the weight discrepancy something I should bring to the attention of the bullet manufacturer?

 

[Hokie_PhD]

I’m fairly new to reloading too, so take my comments with a grain of salt. My comments are just my opinions, use at your own risk.

First how anal retentive are you?
Second, how pressure sensitive is the gun or guns you’ll be shooting with?
How close to make pressure do you load?
Finally what is the ammo for?

If you’re OCD then weigh them all, sort by weight and enjoy the learning experience.
If you’re near max pressure I’d do thistle.
I’d also do it if you’re trying to get every bit of accuracy.

For plinking ammo, I’d load on the lower end of the rangeusing each weight and watch for signs of over pressure.

My gut feeling is you won’t be over pressure unless you’re near max or over. But you should never load using your gut. Be safe, be cautious and work up your loads using proper processes.

Oh and keep good notes!

 

[hdwhit]

Did you also check the diameter of the bullets to see if they were as advertised?

128.5 when 122 was advertised is just over 5% heavy and so may be within the manufacturer's tolerances. It would not hurt to let the manufacturer what you found, but expect them to say the bullets are within specification. Since 124 grain bullets are more common, I expect you will be using 124 grain bullet data and that makes the weight difference less significant. If you don't want to weigh all 500 bullets, I would begin with the Starting load and see what you get. At the starting load, you should be okay even with bullets that are 5% heavy.

 

[hdwhit]

Hokie_PhD wrote:
For plinking ammo, I’d load on the lower end of the range...

santacruzdave wrote:
....when I get a new projectile,...

The OP said the projectiles are new to him. He should treat the load has he would any cartridge when he introduces a new component and follow proper load development procedures and that means beginning at the Starting Load and working up; not picking a load from somewhere on the chart or using a load developed with other components.

 

[Hokie_PhD]

The OP said the projectiles are new to him. He should treat the load has he would any cartridge when he introduces a new component and follow proper load development procedures and that means beginning at the Starting Load and working up; not picking a load from somewhere on the chart or using a load developed with other components.

I fully agree
I didn’t mean to imply that picking a random load is a wise thing.

 

[Dudedog]

Plated, jacket, coated, lubed lead?
If lubed lead sometimes the amount of lube can make a small difference in weight.
As long as you are not loading MAX or close to MAX loads you should be fine.
If you want MAX loads you will need to work up with the heavy ones then weigh them all just to be sure none of them are heavier than the ones you used for the load work up.
(need to do work ups for all loads even if not MAX)
I doubt a couple grains heavy would make a MAX load Kaboom but remember it's the straw that broke the camel's back.

As mentioned I might call whoever made them and let them know.

I 2nd hdwhit's suggestion to measure them to make sure the dia is what you expect and consistent.

 

[wrench459]

Most if not all of the boolits that I bought.
Came within +/- .2gr. adv.
The one odd ball was from a supplier that rated the slugs as 124....turned out they weighed 125.
Even those was +/-.2 from 125.

 

[Walkalong]

However among the 10 randomly selected samples I found one that weighs 128.5 grains and another the weighs 127.8 grains. The rest were between 121.8 and 124.0. Should I be concerned about overpressure with the 128.5 bullet?

No, load for 124/125 Gr bullet weight. But that isn't very good quality control IMHO.

 

[santacruzdave]

Thanks everyone for the input. These are red hi-tek coated lead bullets. Diameter is very consistent at .3565. Average length is .5436 with a standard deviation of .0049; not the best I've seen by a long shot. I have Unique, BE-86, Win 231, and CFE-Pistol and will be working up from the min load in one of those powders, have not decided which one yet. Primary use will be steel challenge.

 

[redbullitt]

That does seem like pretty wonky quality control. Most I have used are much closer than that.

If the weight variance is the only problem then I doubt you would have any serious issues unless you are hotrodding!

Being that these are cast lead, I think you would have even less chance of a problem than with jacketed. Maybe wont win any bullseye shooting, but for steel I would shoot em up no problem.

 

[springer99]

Thanks everyone for the input. These are red hi-tek coated lead bullets. Diameter is very consistent at .3565. Average length is .5436 with a standard deviation of .0049; not the best I've seen by a long shot. I have Unique, BE-86, Win 231, and CFE-Pistol and will be working up from the min load in one of those powders, have not decided which one yet. Primary use will be steel challenge.

Have to agree with redbullitt. At a minimum, I'd call that pretty sloppy QC, but for your purpose will be fine. ps: I'd definitely contact the supplier to discuss b4 I'd consider buying more from them.

 

[Walkalong]

At a minimum, I'd call that pretty sloppy QC, but for your purpose will be fine.

Agreed.

 

[Rule3]

How accurate is your scale? I also think that the weight variance is pretty bad.

I would call or e mail the company you got them from.

 

[RainDodger]

As above, I'd give a call to the manufacturer (if you're confident in your scale). I have never seen a variance like that. If you load them, I would stay on the tame side.

 

[santacruzdave]

"How accurate is your scale? I also think that the weight variance is pretty bad."

I use an RCBS 505 and a little digital scale. Part of my reloading routine is to check my powder charges with the beam scale and verify one or two with the digital. I do the reverse when weighing components. Here is a link to the digital scale review:



I will email the MFG. I have had good luck with their 240 grain 44 cal SWC.

 

[ray15]

Thanks everyone for the input. These are red hi-tek coated lead bullets. Diameter is very consistent at .3565. Average length is .5436 with a standard deviation of .0049; not the best I've seen by a long shot. I have Unique, BE-86, Win 231, and CFE-Pistol and will be working up from the min load in one of those powders, have not decided which one yet. Primary use will be steel challenge.

I've worked up a CFE-Pistol load for the Acme 124gr. Hi-Tek RN. I get best results from CFE-P near maximum, my best load is 5.0gr. which produces about 1100fps in my 4" guns. Sd is low and accuracy high. Not sure you're looking for that warm of a load, if going slower I'd think 231 would be great.

I also agree that's poor QC, plus/minus ~1gr. is about the worst I've had.

 

[Jim Watson]

I don't weigh bulk cast pistol bullets. Too depressing.
There used to be more nominal 122s on the market than I see now. I would treat them like 124s and carry on.

 

[CZ9shooter]

Like some others have suggested, unless I was riding the upper pressure limits, or searching for supreme accuracy, I wouldn't worry too much about it. Load and shoot.

 

[ArchAngelCD]

Thanks everyone for the input. These are red hi-tek coated lead bullets. Diameter is very consistent at .3565. Average length is .5436 with a standard deviation of .0049; not the best I've seen by a long shot. I have Unique, BE-86, Win 231, and CFE-Pistol and will be working up from the min load in one of those powders, have not decided which one yet. Primary use will be steel challenge.

While not the best QC the weight of cast bullets and coated cast bullets can variety more than jacketed bullets. Like said above don't worry too much about the variance, just load them with 124/125gr cast bullet load data. I charge between 4.0gr to 4.4gr W231 with a 124gr coated bullet in the 9mm. 4.4gr works very well for me with an OAL of 1.125". That said, the other powders you have will also work well in the 9mm with Unique being my last choice.

Of the powder you listed you will probably like the results you get with W231. It's a clean powder that meters very well and producers accurate ammo, at least it does for me.

 

[santacruzdave]

Well, I weighed the whole batch of 500. I have 25 that are out of my arbitrary spec of under 120 grains and over 124 grains. Loaded 15 each of 4.5, 4.7 and 4.9 grains of CFE Pistol, cause I have a ton of that leftover from the shortage days when it was about the only powder available. Hodgdon shows 4.4 to 5.0 for a 125 gr. Lead conical nose bullet (LCN). I know it burns kinda dirty at lower power levels but I'm going to use it with these bullets cause I figure they deserve each other. Off to the range to chrono these loads. COL worked out to 1.057, that's the longest that would plunk in the XD that I plan to use for Steel Challenge.

 

[Dudedog]

4.0gr of HP38 with a Acme 124 at 1.10 OAL gave me an average of 995fps out of a 5" 9mm 1911.
Don't have any chrono data but I seem to recall a load of 4gr of Unique with MBC cast 124s made a nice light practice load.
CFE-P in general tends to be happier with heavier charges but I have got some excellent accuracy with start level loads using it with a couple different bullets, might be worth a try at around 4.4gr
BE86 for me tends to be the same as CFE-P happier at the higher end of the charge range. Maybe try about 4.5gr.
If you need to make 125 PF you will probably need to be about .2gr heavier on all of them.

 

[santacruzdave]

Well I got off to the range this afternoon to shoot the new bullets. That was the good part. It was too shady for the chronograph, so no report on velocity. On my second shot I hit one of the rods holding up the front sky screen. Darn, could I really be shooting that bad? So I took down the chrono, bent rod can be straightened so no harm there, and tried some accuracy shots. Well either I had my worst day ever, or those 122 (sic) grain bullets sitting on 4.5 gr of CFE Pistol are the most inaccurate rounds I've ever loaded. At 15 yards I could barely hit a 9" pie plate. Normally I can hold a 3" pattern in the center of the pie plate. The rounds had plenty of recoil, way to much for shooting steel challenge. Also noticed a lot of sparks with each round. No excess pressure signs, and the notoriously dirty shooting CFE powder produced some fairly clean cases. So my guess is the seating the bullets to a 1.057 COL contributed to a higher pressure that one would expect with a tenth of a grain above minimum. No Power Factor requirement so I can down load to the point just maintaining functionality of the rounds - just enough poop to cycle the XD. I think I might try some W231 at minimum to see if the accuracy improves.

I have a boat load of working accurate loads (RMR MPR-HP 124gr over 5.0 gr of BE-86). Those rounds shoot fine and I can hit a 6" plate at 15 to 20 yards 9 times out of 10, so I'm not sweating the upcoming steel challenge in early Dec.
Having fun and learning a lot too!

 

[Jim Watson]

Are these bullets a rather blunt truncated cone?
A guy here struggled with cast 122 gr TCs and got decent accuracy only at very light loads.

 

[ray15]

I wonder if the bullet inconsistency isn't a factor in the accuracy issue. When you get to the pressures where CFEP cleans up, accuracy is generally very good to excellent. I load 5.0gr. with the Acme 124RN at a COL of 1.03", so I don't think your COL is responsible. Too bad the light didn't play ball, it would have been good to know how fast they were flying.

I looked up the chrono results on my load. It's at least as accurate as my best FMJ loads - much better than I am.

Acme 124RN HTC .356"
5.0gr. CFE-Pistol
CCI 500, .FC. brass
1.03" COL
CZ P-10C

Average: 1120.2 FPS
SD: 8.0 FPS
Min: 1110 FPS
Max: 1131 FPS
Spread: 21 FPS

I do think 231 will better support lower velocities. This is full power non +p.

 

[santacruzdave]

These are the bullets I'm using. Acme 122 gr FP-NLG Coated. I'm still hoping to get them to fly right.