Range report: 1st try with 9mm PC bullets - the good, the bad.

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Skyhawk

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The bullet alloy is mixed wheel weights dropped from the Lyman mold #356637 and weigh in at around 157.5 grains each - .358'ish in diameter. The relatively soft alloy bullets are water dropped. The gun is a CZ used for Production IPSC, sprung to shoot minor PF reliably. Normally these go through the Lyman .357 lube-sizer. With 2.8 gr of N320, they just make power factor and shoot very softly and reliably at a minimum of 805 fps. They never caused me leading problems, but I could only use them for outdoor practice because they smoke like crazy and make a dirty mess of my gun. So I thought I'd give PC a try, with the goal of making this my all around competition round.

The PC I decided on was Tool Blue from Emerald Coatings. I used the simple shake n' bake method and got great coverage. So pretty! I knew I was going to have to start this as a new load, even with the same bullet. I tried loading them "as is" without sizing, and to my horror I'd have to seat them so deep in order to chamber (OAL @ 1.025" instead of 1.086"). I gave up on that idea due to pressure concerns. So I tried sizing them to .257 before coating, however after PC they still came out to about .2585, and I'd still have to seat too deep for chambering (about 1.032"). Next I resized after PC, and pushing them through a .357 Lee sizer I was able to chamber these at an OAL of 1.084". The resizing didn't seem to hurt the PC at all. Success?

So off to the range with these loaded up with 2.8 gr, 2.9 gr, and 3.0 gr of N320. I read I could expect some loss of velocity with PC, so I decided my current 2.8 load would be my starting point. @ 2.8 grains only one made it to 800 fps in a 30 shot string. The slowest was 786 fps and ruined my standard deviation, but likely was my reloading fault. To shorten this story, it took a full 3 grains of N320 to reliably get everything in a 30 shot string over 805 fps. Success?

It was still soft shooting, but without the cloud of smoke from my lubed variety. I shot about 300 rounds, and my barrel looked like I hadn't fired a shot after just passing a patch through it. And the inside of my gun wasn't a black mess either! I would be excited about these developments if it were not for the fact that I got 3 keyholes. Some would say that 1 out of 100 isn't bad, but I've shot thousands upon thousands of these bullets just lubed, and never had a single keyhole with this particular bullet. I have a theory about this: Perhaps PC isn't as good as engaging the rifling in the barrel as effectively as lead when sized to the same diameter. Now how to solve this problem? If I make them bigger, like .358, they just wont chamber unless I seat the bullets MUCH deeper than my gut feels is safe.

I'm starting to think I need a new bullet mold with a more forgiving ogive profile. CZs are pretty fussy about length, but not case diameter so much. Can anyone recommend a mold (4-banger would be nice) that produces a minimum 147 grain bullet that's not so stubby in profile and drops to at least .357 with mixed wheel weight alloy? Something I could shoot as caste and PC'd without sizing....
 
Firstly, I would try bumping up the load just a hair. It might give the bullet just a little more stability and still give you a soft shooting load.
I recall reading a few years back that Americans tended to over stabilize the bullet with their faster twist than the Europeans. I read it on the Internet so it may even be true.

I wholeheartedly suggest Accurate Molds if you are getting a new mould. I had the same problem with an oversize bullet. An RCBS 9 mm mould threw bullets at .359 and after adding a thou or two for powder coating, they were too fat to chamber. I found a nice design from AM and ordered one to throw a .355 bullet out of my alloy. Roughly, WW plus 2% tin. This was one with no grease grooves. I ordered it on a Monday and on Wednesday, I had the shipping tracking number. The bullets, with no grease grooves, almost jump out of the mould at a perfect .355 inch. One caveat, the mould blocks need to be heated very hot at the beginning of the casting session, and then things run very smoothly. You don't want to stop.

OTOH, they aren't cheap. That one cost me $204 and the revenues didn't get me for that one. I ordered another a couple of weeks later. All was golden as before, but Justin's thugs got me, and I didn't want to figure out the total.
 
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Ugg... no wonder these were tumbling. Turns out my Lyman was set up to size my bare lead bullets to .358 - not .357 like the Lee push through I was using on the PC bullets. I managed also to get a much thinner coat with a batch of bullets I PC'd yesterday, so I'll size them through the Lyman this time to .358 later today and see how far I need to seat them in order to chamber. If I can keep OAL to a minimum of 1.074", back to the range to chrono Thursday.
 
I am going through the same deal with my 40 cal S&W. Lubed work great and pc'd won't chamber at all unless seated quite deep in the case. I am going to try a lighter coat of pc before I give up on it. Resizing a pc'd bullet will have to wait till I get a .401 resizing die. I usually shoot as cast as well. I haven't done the accuracy comparison yet between the two.
 
I got a thinner more even coat by standing the bullets up on parchment paper for baking, picking them out one at a time wearing blue nitrile gloves. My first batch trying the "bulk" method popular on YouTube turned out a huge mess of sizes, from .360 to .364"! After measuring a random 10 on this new batch and taking 3 measurements on 3 turns of each, my diameter ranges from just over .358 to .361 on the 4 largest, with most being somewhere in the middle.

I was able to seat them at 1.075 to 1.083, while the reloading data for this bullet specifies 1.086. Not too bad, as they all chamber all the way in. I think the variation in seating depth is due to small variations in the thickness of the PC layer around the ogive. My Redding competition die is very sensitive to this, and it seems a variation of .001" there could mean a variation of .005" or more in seating depth. Seating dies work on the presumption that each bullet is consistent in ogive shape and thickness. Shooting each round will be like eating a box of chocolates. I have a feeling that reading my CED M2's standard deviation on a 50 shot string on Friday is going to terrify me.
 
How much powder are you using?

I have been using tool blue for years, and dont place bullets upright, I use a minimal powder (1 teaspoon or less for 50 bullets) so that after tumbling I have very little left.
 
I'm not using much powder, just a bit more than I need for coverage. I'm only doing about 25 at a time in a margarine container. Maybe I could try the airsoft balls next time. You're just using the wire basket for baking?
 
Skyhawk said:
I'm not using much powder, just a bit more than I need for coverage. I'm only doing about 25 at a time in a margarine container. Maybe I could try the airsoft balls next time. You're just using the wire basket for baking?
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for 25 bullets use half teaspoon, you want it so when you dump on to tray (dont use wire basket or airsoft bbs) you have very little extra powder.

I use a non stick baking tray from dollarstorre, holds 100 9mm bullets. I just dump the coated bullets and bake, have a look at the sticky
 
f55 said:
for 25 bullets use half teaspoon, you want it so when you dump on to tray (dont use wire basket or airsoft bbs) you have very little extra powder.

I use a non stick baking tray from dollarstorre, holds 100 9mm bullets. I just dump the coated bullets and bake, have a look at the sticky
Click to expand...


Thanks, I'll give it a try and also read that sticky again more carefully. There were so many ideas and things discussed there that I think I got a bit lost the first time. Do you dump the bullets while hot in cold water so they come apart without sticking?
 
Skyhawk said:
Thanks, I'll give it a try and also read that sticky again more carefully. There were so many ideas and things discussed there that I think I got a bit lost the first time. Do you dump the bullets while hot in cold water so they come apart without sticking?
Click to expand...

Nope, i just dump them after baking on to table (let them cool for 5 minutes) and any that are stuck usually come apart easy.
 
i got out today to shoot some. It was definitely a day my chronograph didn't like - pure sun, snow covered ground, and 8 degrees below zero. I didn't like it much either.

I didn't trust the absolute speed much on the chrono due to conditions, but SD didn't go above 12 in several 20 shot strings which surprised me. I thought it would be MUCH worse! Just for giggles and reference, I shot a couple strings of crappy Remington Golden LR 22 from the Ruger Mark 4 my wife was shooting. SD never clocked under 40-something, with velocity ranging from 812 to just over 1200 fps. Now that is scary.

Obviously I need to do this all over again when spring is really here. I won't coat and load thousands of these PC bullets before then, but it's promising. There were no keyholes this time sized to .358 behind 3.0 grains of N320. Once the weather improves for the comfort of the chrono and I, I'll work this load up further. Meanwhile, I'll just cast more bullets.

I did manage to recover a bunch of the PC coated bullets in the berm. Most were severely deformed due to the rocky frozen soil, so I really can't tell much from them.
 
Casting, then water dropping only increases BNH by one or two points. Pointless really, as drying these water quenched bullets adds one more step. Not economy of motion.
Even using re-melted range lead of various hardness quality will be incredibly improved by powder coating. Think of factory swagged 9mm bullets: driving this swagged bullet over 1000 fps will horribly smear your barrel and give poor accuracy. Powder coat the same bullet and the new hard PC bullet will allow loaders to surpass 1200 FPS easily. Really....
 
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