[xTerpx]

Question: Can highly polished/super smooth plated/shiny coating-like bullet surfaces interfere with my 'interference'?




It's been awhile since I posted one of my philosophical rookie questions, but I was getting the press setup to knock out a bunch of rounds in the morning and ran into an issue.

• X-Treme 9mm 124gr HP plated bullets @ .355

I've been churning out ammo like a monster trying to squirrel away plenty for the winter before the frigid temperatures arrive (I am in the garage and still working on a heating solution). This is one that isn't going to be a Plan A or Plan B bullet, so just churning out the rest of them to hose steel.

I've had no problems until tonight. I have everything dialed in ready to go, then the final check...pressing the finished dummy on the flat part of my vise to check for setback issues. Have everything set to perfection and never an issue, but I didn't shortcut it and sure enough...can easily shove the bullet into the case.

Rounds come out of the seating die @ .3790", then get 'crimped' to .3780" and never had a problem, no rings/marks/resizing...sexy ammo...but not these bullets.

As much as I hate messing with a good thing, I reluctantly add a thou of taper crimp...still can push the bullets in (and leaving a faint ring now, soft bullets). Knowing more crimp doesn't add more mouth tension/interference, I add another thou (now at .3760") just to see what's shaking...same issue.

I'm using a 'setup case' and thought maybe I haven't discarded it in awhile, thinking maybe I've worn away some case wall/have build-up in there/lube/whatever. I grab a clean once-fired, size, flare, seat, crimp...same issue.

No matter how much or how little I crimp, I could push the bullet in. Sure, it wasn't BAD at one point (but was very bad at a few points) and I am not shooting .44mag through a revolver, but just couldn't figure out what's going on.

I took some Ballistol and coated a bullet very well, rubbed it around, then gave it a 91% alcohol bath, rubbed it dry, seated, crimped, boom...didn't move at all from the 1.120" at which I seated it. Once does not a trend make, I cleaned another and same results.

Could these super shiny bullets have a coating on them that is 'interfering' with my 'interference'? I am constantly dropping/fumbling with these...that's how slick they are.

(If I had a dry tumbler, I would have thrown a handful in and see if I could fix the issue that way, if the issue is a function of the coating)

 

[xTerpx]

Okay, I found a solution and this makes sense, though it still doesn't explain why I couldn't dial these bullets in using my once-fired "FC" cases during setup.

I first developed the load for these using virgin Starline...no issues.

I've loaded up the majority of my once-fired "FC" cases, so stuffing these bullets into new "A USA" brass in the morning.

Therefore, I grabbed a non-lubed virgin 'A USA' case, worked up a dummy, and as they say in Deutschland, alles klar! Good to go.

This 'A USA' has noticeably thicker case walls and that definitely snugged it up in the case and no more issues.

HOWEVER, despite having thinner walls, the FC brass has worked for everything else...just this bullet is easily pushed into the case after crimping. How is that?

(Also did a spot-check of a dozen or so just now...all bullets sized properly @ .355" on the money.)

PS: Also double-checked that I wasn't caving the HP in when bearing down on the bullet on the vise...pulled bullets same size as before being seated.

 

[SARDG]

Never loaded a plated bullet, but I thought I remember Extreme plated 124s being .356. Are yours .355 as you've said?

 

[xTerpx]

Never loaded a plated bullet, but I thought I remember Extreme plated 124s being .356. Are yours .355 as you've said?

There are a few odd sized ones...had to print out a sheet for my book to keep the Xtremes straight. Will run out and get it, but these are definitely .355", ma'am.

Edit: Yea, their 124gr HP and 135gr HPs are both sized to .355"

...though that shouldn't matter, as no other .355s have given me this issue.

 

[xTerpx]

...and wonder if I'll have issues with the 135gr HPs, which are on deck. Maybe they have a little more mass and making it deeper into the 'taper' of the case and won't be an issue?

I normally run out to test my hypotheses, but this one drained me tonight...throwing in the towel.

 

[SARDG]

I should never question your measurements... looked it up and it's Berry's that are normally a nominal .356 apparently.

You should eventually try to settle on an effective bullet/powder/case combo for your specific mission(s), and make it easier on yourself.

 

[xTerpx]

I should never question your measurements... looked it up and it's Berry's that are normally a nominal .356 apparently.

You should eventually try to settle on an effective bullet/powder/case combo for your specific mission(s), and make it easier on yourself.

That's the goal here...ruled these two bullets out, so just loading the remainder to hose the plate rack.

Not to go off the rails already, but I did load up some Berry's 135gr HBFPs last week (and a box of their 115gr RN that were given to me)...BARELY made PF floor at max charge.

I was going to trickle 10 more @ .1gr over to collect some data, but decided to just load the rest, send them, and move on...

 

[SmokelessPowder]

You don't really crimp 9mm, just remove the bell you added to seat the bullet. Maybe you are adding too much bell and/or not seating deep enough. What OAL are you going with? I've been loading 124gr HP at 1.070 but that might not be correct for your X-Treme's.

In any case, bullet tension should not be an issue in 9mm.

 

[Collo Rosso]

Pull your sizing and belling plugs (or funnel) and make sure you don't have a coating of copper, Hi-Tec, grunge or other nastiness on them and oversizing your brass. Mic the bullets and make sure they're .355". Consider moving to a nicer climate.

 

[F106 Fan]

What is the ID of the sized case mouth before it gets expanded? You already mentioned a thin wall so the ID may be excessive after resizing and the expander is not controlling the ID.

What's the OD of the expander?

I wonder if you can turn down the expander just a bit if it turns out that the sizing die is creating a suitable ID.

You might search Google for 'turn down expander diameter' Something useful might turn up.

Or just trash the brass with the thin wall.

 

[fredj338]

I assume you actually mic the bullets in question. Yes, bullet pull or neck tension is affected by case manuf. Starline is pretty thick compared to FC. New brass also offers more tension than 10x fired. Brass wears out. So many factors can contribute to loss of neck tension. Over crimping is another factor to pay attention to. Fwiw, I run 0.001" larger bullets when using plated or coated lead.

 

[jmorris]

If you don’t have enough neck tension a crimp can’t help you, without a cannelure.

Problem is lead is pretty much dead soft and brass is not. So you add crimp, swage the bullet to an even smaller diameter than it was, then the case springs back away from the lead. Leaving your worse off than you were beforehand.

 

[fredj338]

If you don’t have enough neck tension a crimp can’t help you, without a cannelure.

Problem is lead is pretty much dead soft and brass is not. So you add crimp, swage the bullet to an even smaller diameter than it was, then the case springs back away from the lead. Leaving your worse off than you were beforehand.

This is worse as brass loses its ductilety. Also why plated are diff than jacketed, as you know.

 

[Taterhead]

Switch to thick 9mm brass like RP or CBC and you'll have no problem. I like FC for my .358" cast, though.

What is the diameter of your expander or funnel?

@jmorris nailed it on crimp.

 

[Jim Watson]

Residual polish on a shiny plated bullet? Maybe.
Smaller diameter bullet? For sure.

If you have a lot of those plated bullets or plan to buy more, first mike the expander. It should be well under bullet diameter. If it is, get the undersize sizing die from Lee or EGW (Made for them by Lee but they might get it to you quicker.)

 

[Taterhead]

Residual polish on a shiny plated bullet? Maybe.
Smaller diameter bullet? For sure.

If you have a lot of those plated bullets or plan to buy more, first mike the expander. It should be well under bullet diameter. If it is, get the undersize sizing die from Lee or EGW (Made for them by Lee but they might get it to you quicker.)

The narrower ID from the undersized die might be nullified by an expander diameter that is oversized. Hence the question above.

 

[F106 Fan]

It's all about the numbers!

Calipers are lousy at measuring case wall thickness. That's why they invented these ball micrometers:

https://www.amazon.com/ball-micrometer/s?k=ball+micrometer

I find the micrometer stand to be pretty handy because I don't have a general purpose vise on my bench:

https://www.hollandguns.com/m7/MIC-S-3HR--micrometer-stand-only.html

Holland also has a micrometer and a complete package. Just search the site for 'micrometer'.

 

[jmorris]

Calipers are lousy at measuring case wall thickness. That's why they invented these ball micrometers

I have found times where a ball mic won’t even do the job I need it to. So I threw this together.

 

[Collo Rosso]

I have found times where a ball mic won’t even do the job I need it to. So I threw this together.

I don't know what you do or have done for a living, but you would have loved Grumman aerospace. I worked for them as a airframe mechanic 80'-83' (my Father retired with 28 years) and your stuff would have fit right in. Maybe not polished and pretty as it was never meant for resale, but absolutely functional.