I recently experienced flattened primers with using an established .357 load. I was shooting Hy-Tek (home) coated Oregon Laser Cast 158 LSWC with H110. I was starting with a known lesser charge and when extracting the .357 cases I noticed the primers looked flattened. I went to the next higher up load and noticed the same thing. I had not even reached the normal lead load yet. Also the velocities were well below the recorded lead velocities. The coated velocities were 1064 and 1087 from a 6 inch barrel. The lead average velocities using the same charge were 1184 and 1208 from a 4 inch barrel.

I had heard that coated bullets were slower than lead but wasn't expecting that much of a change.
I thought I'd run it by others and see if anyone experienced anything like this.

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Flattened primers may or may not mean something, particularly with regard to handgun loads. It sounds as if the only thing you changed was the coated bullet for the uncoated one and primers, powder, and cases stayed the same. Is that right? What was the diameter of the uncoated bullet and the coated one? Be sure you measure with a micrometer and not a caliper. If you were getting flattened primers with the only change being a coated bullet, you might have high, though not necessarily dangerous pressure. Was there something wrong with these bullets before you coated them (poor accuracy, leading, etc.)?

“Reading primers” is one of the most abused and misunderstood techniques in all of handloading. Most conclusions that folks make with them are random or false.

I believe that the title of this thread appears to be absolutely false. I don’t think you’ve seen anything that suggests high pressure, let alone excessive pressure.

To be clear, read a primer like this if you wish to gain anything whatsoever from the (almost useless) technique of reading primers:

The only primer reading that has value is if you start low, use absolutely the same components (same primers, same primer lot, same powder, same powder lot, same bullets of exactly same construction, weight and sized diameter, same exact gun with testing in the same conditions and here’s the kicker and it’s a big one… same exact brass of the same or similar construction.

If you do all that and you start LOW and work your way higher, then you can hope to notice some trend in the appearance of the primer by comparing the lightest loads to the heavy ones.

If you want better items to look for to notice high/excessive pressure in a revolver, look first to ease of extraction/ejection. Next, look for a chrono data where a heavier powder charge begins to show a LOSS of velocity.

Primer look? If it isn’t pierced, leaking or blown out and the pocket deformed, you really aren’t likely to make an accurate conclusion based on what you see or what you think you see.

Forgot to add… I think those primers look fantastic and absolutely normal.

All else the same and coated bullets were run through a .358 sizer.
Bullets only coated for range rule of no bare lead.

If my primers were doing that I would back off. Even if there were no other high pressure signs.

Extraction was not like before.

Meaning difficult? Or at least extraction with more resistance than when using uncoated bullets?

Yes I've heard for over 40 years to not read primers as an absolute determination.

If everything else is the same except the coating then why is the velocity so much lower?

I already deprimed all the cases but should have taken pictures of the primers in the pockets. They did not look normal which prompted me to remove and observe. Like they were pushed to one side of the pocket.

I’d check the dimension of the bullet with a micrometer to confirm .358 .. I’ve never seen that much pressure difference between my coated, plated and FMJ rounds, loaded at similar ranges, for pistol calibers

Yes much more force required to extract.

Seems like you'd be experiencing higher velocities if your pressure was spiking with coated versus lead. My personal experience with similar bullets from the same manufacturer, lead versus coated, is that I virtually always get higher velocities with the coated projectiles - all else being similar.

I have compared quite a few coated versus lead bullets of similar design, weight, and manufacturer when coated was "kind of new" a few years back. I have never experienced pressure indications with coated bullets that weren't noticed with lead as well - and darn few excessive pressure indications period - as I don't push things too much. Not once have I experienced lower velocities with coated projectiles relative to their lead counterparts. All bullet powder coating, and lubing of the lead bullets, was factory and not done by me.

I would generally agree the primers don't look that unusual to me. You mention extraction was not the same. If extraction is significantly more difficult that, to me, is a better indication of possibly relatively higher pressure.

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Ordnung muss sein
SWHF #789

YOu did measure bullets, coated and uncoated, sized, unsized with a micrometer, right? That's important and a caliper won't work much better than a ruler for a critical measurement.

I read through the thread to this point. I don't have a chrono so can't speak to if I've had a velocity difference between coated and not with the same bullet.

But, you changed a component and just have to work back up, which it seems you were sort of doing anyway. You said difficult extraction, too, so it does seem you're seeing higher pressure.

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Just Say No - To Social Media

I'll just caulk this up to operator error and leave the coating to the experts.

Your primers are in no way “flattened” by high pressure. They look like primers that were not fully seated before firing. Are they CCI primers?

I personally can't tell squat about the primer condition given the photo in post #1. Give us a picture looking down on the case heads.

Now, it's acceptable for the primer face to be flush with the head of the case after firing. What you want to watch is the rounded outer edge of the primer cup. A flattened primer has no rounded edge on the primer cup and often fills the pocket. If you're really pushing the envelope, the firing pin indent won't be as deep and may show upward extrusion (cratering) at the lip of the indent.

Coated & Moly bullets have more friction going down a barrel than lead.

There was a test done on .45 bullets and what surprised me, was that a
plated bullet was higher over a factory JHP design, for the most resistane of all bullets.

Hope things work out for you.

Here are some pics. My grandson showed me how to use my new phone. Sorry I can't hold it steady.

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I have said it before and see this as a time to say it again. All reloaders must own a chronograph. They only cost $100 for a standard model, which is all most reloaders need. Whenever I change bullets or powder, I load 5 and go shoot them. Sometimes I only shoot one and decide unload the others because of high of low velocities. Using a chronograph will eliminate guessing and help a reloader to develop better loads. Those who read the chart or the box would often be surprised at how far off their loads are as compared to "published" data.

Take all worry out of reloading with a chronograph and you will not need to hire a psychic to analyze your primers.

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Gary
SWCA 2515

I don't like the looks of those primers. It's got nothing to do with the para normal. It just looks like they are close to blowing out to me.

If you are talking to me I used the ProChrono DLX (Bluetooth) to get the velocities of both the lead and coated. I never work up a load without it! I posted the FPS data.
First chrono I bought got whacked a few times before being retired a few years back. Besides it had a long cord attached to a remote.
When I first started loading I could go to the Sporting goods store and purchase just about anything in the Speer #10 book in the calibers I had. Chrono's back then were way out of my reach. Now days it's figure it out and thankfully chrono's are affordable.
If you weren't talking to me I consider it good advice.

I disagree with the chronograph and I have one but have not used it in years. I do not hot rod reloads and stick close to the recommended load, never blown up a gun, kill game cleanly shoot flat enough for shots at 300+ yards so what do I need it for other than something else to mess with. Not even sure where mine is.

Decreased friction.

Regarding the primers, you are shooting a revolver so "flattened" is meaningless.

OK, those are flattened primers, one shows slight cratering-unless the firing pin hole on your breech face/recoil shield is worn somewhat oversize.

Looking at primers that have been removed from the case doesn't tell us anything-unless they fell out of the cases when you opened the cylinder. That would tell you you're more than one-or two-tokes over the line on powder charge for that bullet.

[QUOTE=Fla_Sun;141297284]Here are some pics. My grandson showed me how to use my new phone. Sorry I can't hold it steady.[/

Nothing wrong with your plan to coat the bullets, it should work but from the looks of those primers it’s time to go back over everything and see what the problem is. Primers should not look like that. Let us know what you find.

I'm stumped by what I've read here.

The OP wrote about HY-Tek home coated and I don't think that's quite right with my definitions. I've always thought HY-TEK was a proprietary process from one of the bullet manufacturers. I call my home coating Powder Coating. Does anyone know if that's correct?

Someone later about jacketed or plated bullets. Does he think that's what the topic is? What is the topic?

Yes, those primers look to be smacking the recoil shield pretty good. That's what I call flattened, but I have no idea from what. Those indentations from the firing pin look huge and deep as well. Go to the tea leaves to find out what that means.

My personal powder coated bullets leave the barrel much much cleaner and there is almost no smoke. I have read from some folks that the lubrication is much better. I get more velocity out of my bullets with PC than with wax lubes (LabRadar). I see no downsides to PC.

I am in no way convinced that the coated bullets caused the lower velocities or the higher pressures signs.

My money is on the H110 powder charge to get that much difference. I don't see coating being able to both increase pressure and decrease velocity at the same time. That seems impossible!

Hey OP, how much H110?


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If I shot any revolver and the spent rounds had "Flattened" primers...........

I would pull in the reins, big time and yell....''Woah" very loud !

Someting is very WRONG !!

Those primers DO NOT look normal. Who knows if it's a sign of high pressure -- though I'd sure suspect it strongly -- but something is not right. The fired cases show absolutely no rounding at the primer edges, and the ones that have been removed are distinctly riveted and mushroomed at the top, cratering is present, and at least a couple look to have been just a hair away from being pierced. There's four visual possible pressure cues, not just one. Whatever the cause it bears much closer examination.

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Pisgah

Can’t believe some of the comments. Hard extraction and primers like that spell trouble. I would not shoot these in my 627 or 686. Back off on powder and find the problem.

Back to basics, did you check the calibration on the scale before using it? Habit should be to check the scale calibration before each loading session

As mentioned above your primer indentations are not all in the same location. What gun are you using? Maybe it’s out of time.

Hi-Tek is a brand of powder coating. Coated bullets, Powder Coated, are different than plating and either name is fine, AFAIK.

I have trouble seeing how primers obviously riveted as shown would not tie up the revolver.

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Front sight and squeeze

mtgianni,

Thanks for the clarity on that definition of HY-TEK. I have not seen it sold for personal use.

I use Smokes from Castboolits and couldn't be happier after trying several others.

I'm hoping the OP does some more testing and lets us know what the findings were. Going up in pressure, but getting less velocity has me curious.


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Wrong on moly. Can't comment on the generic "coated" since I don't know what the coating is.

When everyone was first using moly, a big surprise was the drop in velocity. Moly reduces pressure. But moly is a mess and few folks use it anymore.

Are you shooting a sw revolver with an in-frame firing pin? If so the convex shape of the firing pin bushing will exagerate the "rivet" look. That and using soft cup primers like Winchester or Federal.

And definitely make sure you are getting primers seated flush.

For those of us without access to a pressure testing ballistics lab we have to go with the few visual interpretations we can make and go from there. As stated previously to my eye those primers look riveted and i see the primer cup exhibiting what looks like it flowing around the firing pin. Does not IMO have one thing to do with flush seated primers or in frame firing pin. I would not be doing that again.
Riveted primers and hard extraction are big red flags in my book. I have never heard of Hy Tek or powder coating causing that effect. I would be looking for an error somewhere else.

I left my revolver, load data, spent cases, primers and loaded bullets with a retired gunsmith friend. He will get back to me with what he finds.
Thank you all for the replies! I'll post the results when I find out.

It's at least a possibility the revolver has too much endshake.

This is another of those "your mileage may vary" posts. Everyone has an opinion. To the OP, if you don't feel comfortable with them then don't reload that loading or use the coated bullets.

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USMC 69-93 Combat Pistol Inst.

...nice answer sir.

I just got the answer from the guy who sold me the gun.
His first question when I dropped it off was how was the accuracy. My answer was it sucked trying to hit 4" plates at 25 yards.

He firmly believes that it was excessive end shake. His explanation was that the revolver being a Dan Wesson has a detent ball bearing holding the cylinder tight forward at lockup. The ball is held in with a spring and set screw. He said the set screw backed out enough to cause the end shake.
He refused to shoot the remainder of my test rounds but did pull all the bullets and said they were exactly as they were described. He said they should not have been above SAAMI maximum for bullet weight, COL and powder charge.

If I had checked the cylinder at lockup I would have discovered it. Lesson learned.

I will load some more of these hard cast home coated bullets and try again.

BTW some of the most accurate 45ACP loads I've ever experienced were with coated bullets.

It is a 4 hour round trip to go get my gun but I consider it worth the time and gas.

Again thank you all for the replies!

[quote=jjrr;141297357]Well said sir!

Thank you sir.

Lesson here. A Dan Wesson isn’t a Smith & Wesson

This experience sure threw me for a loop! After adding up round trip gas and gunsmith diagnostic fee it was an expensive lesson for me.

Since the first range trip and corrected gun function I recently shot some rounds with the same 140 grain bullets but with a different powder that clocked low 1300's FPS. Flattened primers yes, but nothing like before.

1300 FPS with a 140 gr bullet isn’t a hot .357 load unless the different powder you used was Bullseye

As a note on "Flowing primers"............
2 of your 4 in the picture, had "wiggle room".

I just did a test with two medium slow powders in a 5" 9mm with a 124 Jhp.
"X" with 6.0 grs did 1222fps
"y" with 6.1 grs did 1233fps.

The 1222fps cases had flattened, 100% primer hole fill up..........
the 1233fps cases had 50% of the cases with "Wiggle room" to spare.

Plus the primers used were soft federal's and not my normal cci small pistol primers.

I agree on the use of a chrony to help with load pressures but a flat surface primer
is a good sign that you are in the full load area.

If you or a friend have one of the old Lee pound-through sizing dies in .357 or .358, try re-sizing 10 or 12 of the new bullets and see if that improves anything.

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and what his trumpet saith

My best advise would be to recheck your scale. On a beam balance scale it is very easy to bump it 10 grains when resetting the beam back on the scale. 5 grains can suddenly be 15. Don’t ask me how I know this.

In the 45 ACP test;
for the bullets to reach 800 fps they took so much powder.
Below is the results of that test.......

Plated bullet............ 5.9 grs of powder
Moly coated ............ 5.5
Lead bullet .............. 5.3 grs of powder.