Inconsistent 9mm handloads. Enormous groups. Please help.

D

Dundgren

New member
Hi! This is my first post here as I have just gotten started with reloading. Ive made around 150 cartridges so far.

At first I made some using this reloading data: http://www.vihtavuori.com/en/reloading-data/handgun-reloading/9-mm-luger.html 4.7 grains of N320, 100 Grain bullet, COL 27.5mm.

But even though its the same type of bullet (HP HS 100gr) its not exactly the same brand. Also I measured using a caliper without a bullet comparator. These handloads didnt even hit the target at 25 yards.

Then I made another 5 but using the plunk-test to determine the cartridge-length and used 5.1 grains of N320. Also made 5 with the same length and 4.7 grains. These gave the best groups I have ever seen.

Today I made 50 using the same technique. I used the plunk-test but this time I made the just a bit shorter to accommodate for varying bullet-length. These sucked ass. Then I reset my tool using the plunk-test and made 10 more without adjusting a single thing!! I figured this would make them consistent. But this time the first 5 I shot had 2 completely break away from the group and the second 5 had 1 break away greatly.

Why is the accuracy so inconsistent? I know its not me because my groups would never ever become that large shooting manufactured ammo.

Also I would like to point out that the ones that made great groups were crimped after bullet-seating and the ones I reloaded most recently were crimped at the same time as I seated the bullet.

My equipment:

Vihtavouri N320 powder. 5.1 grains.
Murom Small Pistol Primers
H&N 100 grains Hollow Point High Speed.
RCBS Dies
Varying cases (some S&B, some CBC and some others)
 
My only thought is I've never seen anyone using lighter than 115 gun bullets and many prefer 124. Why did you choose those? What was the factory ammo? Could be wrong but I've never seen 9mm with 100 gen bullets.
 
You seem to have two problems.

First is crimping pistol and 9mm specifically.

9mm headspaces (or is supposed to) on the front of the case.

My take (and its just mine) is never seat and crimp in the same operation.

Always keep it separate. More so in pistol but I never crimp either one while seating (and yes I used to 40 years ago)

What you want, if you are going to crimp, is a mild (by feel) taper crimp not a roll crimp. As little crimp as you can get an a light press (RCBS Junior) is better than a RCBS Rockchucker.

The other part is you are operating in a very narrow range, even for 9mm.

Many low loads won't cycle the action, but you don't have much latitude.

HS-6 is a good 9mm powder, others as well.

Also keep in mind, seating too deep with 9mm increases an already dicey pressure situation, 9mm and below are tweezer loads and very tiny factors have big impact.
 
I have no Idea how to reply directly...

I do not think there is an issue with my bullets being 100gr considering I made 10 perfectly accurate handloads using them.

I wont crimp and seat at the same time anymore. This MAY be my culprit but I dont understand why it would be...
 
If my math is correct the OAL is in US measurement 1.0825. I think that's a bit short for 9 mm. I'm loading mine at 1.1220 or 28.50 mm. Just my .02 worth. Try loading the for the max length and still pass the plunk test.
 
How are you dispensing your powder? If you are weighing each charge we can rule this out. If you are using an automatic powder dispenser you may have some powder dropping light on one drop and heavy on the next. With your load having such a narrow range, a +/- .2 Grain change would explain a lot.


Also, in mixed brass, some brands have thinner necks than others. If your crimp is good for a thick neck, it may be weak on a thinner neck and you might be getting bullet set back when the round chambers. That too will cause fliers.
 
Yes, I have a dispenser. I loaded some with 4.8 grains now so I wont go over the limit if it happens to be +. I never even considered the bullet set-back. Great info!

I also started sorting my brass. Thanks.
 
Did you ever do a ladder load, starting low and working your way up to max load. Doing this will help with accuracy issues
 
No, I didn't. I tried 4.7 grains then 5.1 grains. Found out today that my bullets arent actually jacketed, just plated. So I cant use the loading table from VV.
 
One of the great benefits of handloading ...we can load what works in our particular firearm.
We can find the "sweet spot"
It might be your handgun is telling you something.You CAN use your range time and reloading time pursuing a combination that does not work for you...
If that is what you choose.

Generally there is a range of bullet weights that work well for a cartridge.

You might look to what comes as factory loads. For 9mm,that generally is 115 gr to 147 gr. Expect less satisfactory results when you decide to drive in the ditch beside the road.Between the ditches works better.

Be very careful you don't shave that copper ahead of your case mouths. It messes with your headspace/lockup.

Note lighter bullets tend to have shorter cylindrical bearing surfaces.They are harder to load square and straight in the case.Its also harder to get them started in the rifling square and straight. Bullets that go down the barrel sort of tipped over shoot real big groups.

Your soft swaged plated bullets will perform like cast bullets in many ways.One really important factor is bullet fit. You start by slugging your bore to know your groove diameter. Undersize bullets shoot poorly. Groove dia plus .001 is a ballpark good fit.Bullets must all be the same dia,too.

And if your barrel is polygonal vs grooved ... just get jacketed bullets.

Welcome!! I hope that helps.

You said factory loads shoot well for you. OK. Try buying and loading some 124 gr jacketed bullets.If you choose a JHP,I might not start with a real big hollow point for feed reasons.Targets and cans don't mind if you shoot hardball.See how they shoot for you.

You may discover your loading technique is not so bad,you just chose a bullet that does not work for you.
 
Last edited:
Maybe the gun just needs bigger diameter bullets.
Not all 9mms do well with .355.
I had one that was lousy with that size, better with .356 and great with .357.
 
Back in the late 70's when I was new to reloading I had a loading master tell me not to bother with anything but 125gr in 9 mm as that was the weight designed for the 9mm originally.

There is a lot of good info in the other posts. The things I would do to tighten it up would be:
1) slug your barrel so you will know what size bullet to reload
2) sort your brass - use the same headstamp and preferably once-shot or virgin brass to work up a load
3) sort your bullets - I have seen a 2.5 gr deviation on a package of "match" quality bullets
4) crimp just enough to straiten out the flair. Over crimping will cause accuracy problems among other issues
5) load a heavier bullet - 124gr is a lot more forgiving

I have had more problems developing loads on lighter bullets.
 
"...do not think there is an issue with my bullets being 100gr..." Mostly about those being for .380 ACP and 9mm pistols disliking the wee fellows. Tried some cast 86 grain bullets one time(couldn't find anything heavier on short notice) with sad results. Pistol functioned with 'em, but not accurately.
Anyway, you need to work up the load, not just pick a couple and hope. 4.7 is the start load. 5.1 is the max load. You need to load 5 of the 4.7 and go up by .1 of a grain to the 5.1. Plated bullets use cast bullet data too.
"...the plunk-test to determine the cartridge-length..." That's not what plunking is for or does. Plunking is about the loaded round fitting the chamber. Use 1.050" as the OAL for a 100 grainer.
 
Did you ever do a ladder load, starting low and working your way up to max load. Doing this will help with accuracy issues
Click to expand...

First the powder range is so narrow that you have two loads (min and Max)

Secondly, ladder loads are done at 200 yard or even 300 yards to show results and that is for a rifle.
 
I agree that bullet diameter could be a factor here.
None of my 9mms or .380s have ever had .355" or .356" barrels. Everything is, or has been .357" or larger.
Generally, .355/.356 bullets don't/didn't shoot as well as the larger diameters.

And, sometimes, certain pistols just don't like certain bullets.
My preferred load shoots well, or reasonably well, in a variety of Hi-Powers (and copies), Rugers, CZs, and Berettas. But one particular Sig and another Beretta absolutely choked on the load. They were shooting 6" to 8" groups at just 7 yards, and rarely hit a 25 yard target (14"x18").
And that bullet almost never shoots worth a crap in Glocks.

If my math is correct the OAL is in US measurement 1.0825. I think that's a bit short for 9 mm. I'm loading mine at 1.1220 or 28.50 mm. Just my .02 worth. Try loading the for the max length and still pass the plunk test.
Click to expand...
It depends on the load and the bullet style and weight.
100 gr bullets are fairly short, and likely to end up with a shorter COAL.
Even so, the best COAL I found for my preferred 122 gr Conical FP (wider than a TC) is a "short" 1.090". With ogive variations and neck tension variation, seating depth varies from about 1.086" to 1.094". I couldn't really go longer, even if I wanted to, because the bullets would be into the lands in certain chambers.
 
rc20 said:
Secondly, ladder loads are done at 200 yard or even 300 yards to show results and that is for a rifle.
Click to expand...

So all that ladder testing I did with .44 Mag and .357 Mag pistols at 100 yards wasn't really ladder testing!

And all that ladder testing at 100 yards with the M700 for the club 100 yard benchrest match wasn't ladder testing!

Oh the horror, can you tell me what I was actually doing since it wasn't ladder testing? Would you prefer that we call it "Incremental Load Development Method" instead? Next thing you know, you'll be telling me something sacrilegious, like that my Ar15 doesn't use clips!
 
Last edited:
Most pistol shooters, in my years of experience, cant shoot a group small enough to do a ladder or OCW test and get results that mean anything.

My advice to the new reloader is to put the target close enough that you can shoot groups. When the groups shrink to one inch then move the target out a bit further.
A consistent grip and good sight alignment will go a long ways in shrinking your groups. Dry fire practice is the best way to get a consistent grip.
 
So all that ladder testing I did with .44 Mag and .357 Mag pistols at 100 yards wasn't really ladder testing!

And all that ladder testing at 100 yards with the M700 for the club 100 yard benchrest match wasn't ladder testing!

Oh the horror, can you tell me what I was actually doing since it wasn't ladder testing? Would you prefer that we call it "Incremental Load Development Method" instead? Next thing you know, you'll be telling me something sacrilegious, like that my Ar15 doesn't use clips!
Click to expand...
Just load anything you find published--if the gun blows up you know you've found the maximum load for your gun.;)
 
I tried ladder testing once, seemed like a waste of time to me. Really had no idea what I was actually looking for and if I picked the middle shot and loaded up some like that, it wasn't necessarily gonna give me a group I could live with! How if would work on a hand gun, I have no idea. Problem for me is I don't know even one person that could do a ladder test even at 25 yds and get anything good enough to use. Handgun's just aren't all that accurate! I have two 9mm's for carry guns. I've never shot either at more than 10 yds and I've never fired any handgun at target's hoping to find I'm not as poor a shot with a handgun as I think! I'm old now and the eye's really suck sometimes! To remedy that, I taught myself to point and shoot defensive handguns and at 10 yds if the target is the size of a watermelon, it's going down. Could be that the bullet's are to light, not a clue but if I were you. I'd try some heavier bullet's and see what happens.

That you've just started handloading, is handgun's a new area also? I can handle rifle's fine but I leave a lot to be desired with handguns. My DA revolver's I'll plink with out to about 50 yds and actually try to aim. But aiming is a chore and even though, I don't do teat bad, a watermelon at 50yds is in trouble! Maybe your having shooter error? I'm sure there are more trick's to shooting hand guns well that I don't know. The only time I ever would get real serious about handguns is within about 10 yds a a bad guy with an attitude! His chest is bugger than a watermelon!
 
You must log in or register to reply here.
Back
Top