AR: leading on brass after die change?

[Petander]

Hello all,

I got my hands on a 458 Socom and now I've been inspecting possibilities with coated cast bullets. The bullets are fine,I use them with a Marlin 1895. Goes good.

After a couple of weeks with Hornady dies I switched to Redding. Hornady seater is excellent but it gets crowded with oversize boolits. I also got a better M-expander,groups got better and less leading. There still is some.

But I noticed a new leading issue,the brass is collecting lead now...? I see some lead around the case mouth after firing. This wasn't happening with Hornady dies. Pulled bullets look and measure good.

Here I cleaned 20 pcs of brass with brakekleen after shooting,then lube and resize/decap with Redding. After resizing I wipe brass with brakekleen again and that's when I find lead coming off the brass.

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When I used Hornady dies,even with only flaring,I never got this. Now even with a proper expander I find lead...?

Any ideas where this lead is coming from? My loads are medium pressure,brass gets a bit dirty. Is this an AR-thing? Why does this happen with Redding,not Hornady? This happens with both a Lee 405/458 and Applegate 480/4595. They shoot clean in a Marlin,quite a bit faster too. Hi-Tek coated.

First groups 100 meters are ok,soon leading takes over. Bullets do hit the feed ramp and reveal some lead but... I don't know.

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Thank you.

[Smoke4320]

I noticed you are not crimping the loads .. This I would try first as it will do several things for you
1st the socom can easily set back bullets in the mag from recoil.. Crimping eliminates this
2nd crimping can at times give you a better powder burn on slow burning powders. That the burn on the outside of the cases suggest that you have a powder/burn issue.. many times you can also bump up the load to get cleaner cases
3rd the uncrimped sharp case mouth may be scraping lead off the feed ramp then as you resize transferring to your die

you could try a small batch of 10 to 15 rds AFTER thoroughly cleaning your resizing die and see if this helps

YMMV

[Petander]

3rd the uncrimped sharp case mouth may be scraping lead off the feed ramp then as you resize transferring to your die.

YMMV.

I love this forum.

This makes perfect sense - and never occurred to me. I removed the flare just enough to chamber,to avoid damaging the bullet.

Time to measure case mouth after Redding / Hornady seaters.

I will try some crimp next, VV N130 will like it,too.

Thank you very much!

EDIT:

Here are Hornady-loaded VV N130 / 480 grainers from a couple of weeks ago. Clean brass, almost 1500 fps. You can see they are compressed if you look at the bullet tips.

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[Boolit_Head]

You always crimp semi auto rounds to avoid the possibility of catastrophic setback.

[Petander]

You always crimp semi auto rounds to avoid the possibility of catastrophic setback.

Yes I understand that. I relied on neck tension which is very good,based on what I see happening - and how the bullet puller feels. Takes some hammering to get a bullet out.

No crimp yet,just to get rid of one variable,coatings are easily ruined by crimping. A common cause for leading.

This will be interesting. I never thought no-crimp could cause leading. But I never loaded cast for an AR before.

[Boolit_Head]

I have not had any issues with PC bullets in my 300 blk and I've been crimping them. Some of those in the picture don't even look like they have the belled mount of the case closed down. Don't look for something you may not find.

[popper]

First groups 100 meters are ok,soon leading takes over How many coats of HiTek? Pass smash test? IMHO, light load, some leading, any leading in the case gets blown back on the neck and case expands against the chamber so lead is stuck to the case neck. Second possibility is that you get slight shaving when chambering in sharp bore, ring gets blown onto the case neck. Second typically happens in pistol SA. I don't hard crimp in AR10, just remove the bell, no problems in many years.

[Petander]

But why is this happening with Redding dies,not Hornady?

I loaded and fired some 200 rounds using Hornady dies during my first test week. Two bullets,two powders,light loads,hot loads,different primers... never got this brass leading.I didn't crimp them either,just remove flare.

Now with Redding I'm getting this.

[nun2kute]

Is that supposed to be 1449 FPS ? My 470g Accurate GCPC goes about that fast, sized .459 Is that the "NEW" version of their Chrono ? Mine doesn't look anything like that, but I've had it for a bunch of years.

[Petander]

This Chrono must be almost 20 years old.

But yes,about 1450 fps. .4595 is my size here.Three coats of Hi-Tek,bullets are fine coating-wise,they shoot clean and good in a Marlin.

Maybe I'm sizing too much with Redding,got to get back to the bench. Barrel was a real copperfouler,now it's a little better. Shoots very,very well with j-bullets,Hornady 350FN / 100 meters here,loaded with Hornady dies:

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[EDG]

Using cast lead bullets in an autoloader is something of a gray area if you expect no lead on your cases.
I shoot BPCR. Calibers and a few pistol calibers. Having a tight case mouth grip on a lead bullet often damages your bullet shanks.

In addition if your cases are shorter than the chamber more than a few thousandths there will be a step or gap at the front of the case mouth. When fired with soft bullets or heavy loads the bullet shank will expand into the gap stripping off lead that can stick to the case mouths. I have seen that many times. The particles can be small or they can be a full ring or sliver of lead.

[Petander]

Excellent,thank you EDG. Makes sense. Must check my sizing! Redding sizer (expander ball) may also be scraping that lead out better than the slick Hornady. I have larger expanders in the mail , coming from NOE. A case gauge grom Tromix... it really would help here.

I shoot 9mm Hi-Tek coated,all clean. Trying that coating got me back to cast bullets. But now that I'm thinking,the only autos that I've used cast with have been pistols like 45ACP and 10 mm. No cast for autoloader rifles until now.

Sounds like a GC design boolit would be worth trying here. I have a ton of WW/Lino alloy from the past,might as well figure this out... funny how things start snowballing,shooting coated bullets with a Marlin 45-70 got me here... originally I only wanted to try coated heavy 9mm loads with a suppressed carbine... I had like 10 000 cast 358 bullets from the past.

[Petander]

My Hornady sizer was wrong threaded from the beginning, I couldn't open the expander plug by hand for initial cleaning. The pin was loose.

So it gave up at 150 rounds or so,mostly jacketed bullets for smoothing the rough barrel :

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I bought Redding instead and felt it harder to use than Hornady, needs more force,it also sizes smaller. Redding seater is better for oversize cast bullets though.

Redding sizer gave up today,also at 150 rounds:

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I've not broken a die in 30 years,one decapping pin only. Now I buy new dies and they break once a week, feeling like some soft chinese metal substitute?

Lee next.

[Petander]

Still waiting for expanders.

Meanwhile I found out thst I was pushing the shoulder way too much with Redding.

[David2011]

“Soft Chinese “ metal would bend. Hardened steel will break before it bends in the case of decapping pins.

[Petander]

Yeah I don't know what's up with the dies,I have adjusted the decappers correctly. Redding snapped when the case was on its way out.

But this case mouth leading is interesting, could it be that 458S needs a harder alloy than 45-70 for some reason...? Or maybe there's not enough pressure from a tad slow powder... or the bullet plain base just doesn't cut it... Or maybe the bullet itself is just plain wrong...?

I got this same leading with a 459 expanded case, 4595 bullet, with the first round,a clean rifle. I'm sizing as little as possible.

[Petander]

A different bullet solved the problem,it was the big fat nose hitting something during feeding,scraping lead.

RCBS 325 FN worked pretty good 1750 fps. At least no leading mysteries anywhere.

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