9mm learning and constructive criticism

[JCSC]

Hey y’all

I have shot lead bullets but new to casting. I started with a venture in 9mm and would like to explain the progression and get any tips.


For a precursor, I am shooting range scrap. I’ve added some tin for better pour and have had no issue making pretty bullets. I am using Lee 355 TC molds, which I have a 2 cavity and 5 cavity ( I think). My foray in powder coating has been successful with the product from smoke and Eastwood. Basically made a bunch of pink, blue and green crayons thus far.

My first attempt was a set of bullets Lee sized at .356. My logical assumption that was the bore size for 9mm is 355, but After slugging bores, I now understand there is a good bit of variance. These 5-9mm pistols range between .357 and .358. I had ehhh accuracy, no leading and about 15% bullets that wanted to yaw and tumble.

With this first batch I had a slight bit of shaving when seating. I use RCBS carbide dies, but i crimp separately with Lee FCD or regular Lee taper crimp. I learned that I need to flare a good bit more.

Next step was to switch over to a .358 stem for my rcbs expander and I worked a batch of rounds with that set up, which now shaved Andy, because you can’t run the full depth of 38 special expander in a 9mm.

This batch of rounds is now basically crap and I am pulling them. Partly due to now over crimping them and concerns with losing proper headspace from excessive headspace.

To summarize, I have zero concerns with my loading practices. I learn every day, but my foundation is solid.

Is this the normal progression for messing with cast bullets.

To recap- mold makes a .356 and I get .359/360 after coating. I’m sizing , which then requires expanding to .358 and then taking my .356 stem to get the proper flare. I haven’t even got to the point where I know if these newly sized pills will fly.

Please give me your thoughts.

[Castaway]

Others will chime in, but I wouldn’t add tin to range scrap. A bell just large enough to hold a bullet easily, but not overly large Will help in shaving bullets while seating. If they chamber without sizing, try that and see how they work. You didn’t say how fast you were pushing them or the powder and charge.

[JCSC]

Others will chime in, but I wouldn’t add tin to range scrap. A bell just large enough to hold a bullet easily, but not overly large Will help in shaving bullets while seating. If they chamber without sizing, try that and see how they work. You didn’t say how fast you were pushing them or the powder and charge.


Castaway- I’m pushing them mid range. Just trying cheap steel ringing ammo.

3.9-4.0 grains of HP38.

[Dusty Bannister]

It sounds like some of the issues is an undersized bullet, but you do not say if they are sized to a specific diameter or what the As Cast diameter is.

Some members of this forum have gone to a lot of effort to put their knowledge into a thread which has been selected to be a "Sticky". I think if you read through the following sticky, a lot of future questions will be answered and things may go a lot better for you.

https://castboolits.gunloads.com/showthread.php?121607-Setting-up-for-boolits-in-a-new-9mm

[Dave W.]

Shaving is an indication of not enough flare on the case. Stick with the 9MM stem to size the case and flare it. Brass is soft, it will expand to the diameter of the bullet. Sizing the case too large will not allow enough "grip" on the bullet and there will be bullet setback.
As far as crimping, in most pistol bullets, a person is not really crimping the case, they are just taking the bell out.
The yaw and tumbling is another indication of under size bullets.
You may have to get another mold that will throw larger bullets.
Continue on, the learning is half the fun.

[Soundguy]

Hey y’all

I have shot lead bullets but new to casting. I started with a venture in 9mm and would like to explain the progression and get any tips.


For a precursor, I am shooting range scrap. I’ve added some tin for better pour and have had no issue making pretty bullets. I am using Lee 355 TC molds, which I have a 2 cavity and 5 cavity ( I think). My foray in powder coating has been successful with the product from smoke and Eastwood. Basically made a bunch of pink, blue and green crayons thus far.

My first attempt was a set of bullets Lee sized at .356. My logical assumption that was the bore size for 9mm is 355, but After slugging bores, I now understand there is a good bit of variance. These 5-9mm pistols range between .357 and .358. I had ehhh accuracy, no leading and about 15% bullets that wanted to yaw and tumble.

With this first batch I had a slight bit of shaving when seating. I use RCBS carbide dies, but i crimp separately with Lee FCD or regular Lee taper crimp. I learned that I need to flare a good bit more.

Next step was to switch over to a .358 stem for my rcbs expander and I worked a batch of rounds with that set up, which now shaved Andy, because you can’t run the full depth of 38 special expander in a 9mm.

This batch of rounds is now basically crap and I am pulling them. Partly due to now over crimping them and concerns with losing proper headspace from excessive headspace.

To summarize, I have zero concerns with my loading practices. I learn every day, but my foundation is solid.

Is this the normal progression for messing with cast bullets.

To recap- mold makes a .356 and I get .359/360 after coating. I’m sizing , which then requires expanding to .358 and then taking my .356 stem to get the proper flare. I haven’t even got to the point where I know if these newly sized pills will fly.

Please give me your thoughts.

Buy a Lee universal expander..be done with it..add a hair of flare..stop shaving..taper crimp and go.

[DougGuy]

Wow lot of variation in groove diameter with 5 barrels. You may want to go ahead and have the barrels throated .3585" and size to .358" after PC rather than have to vary seating depth on a per barrel basis.

[Kosh75287]

I'm not sure of a great many things in this thread, but maybe the facts haven't been fully articulated.
Did the OP get a chance to chrono his loads? According to Hodgdon's the velocities are in or near the trans-sonic range, which can also do odd things to flight characteristics.
GENERALLY when I get tumbling from newly cast projectiles using "middlin" charge weights, MY inclination is to increase the powder charge by 0.1-0.2 gr. The higher pressure may effect better obturation of the bullet to the bore, as well as push it faster, which should better spin-stabilize it for life outside the muzzle. Higher velocity MIGHT also possibly worsen tumbling and accuracy problems, by a mechanism with which I am not fully acquainted.
If higher velocities give you better results, I would not stop looking there. The two results I mention from increasing the powder charge, if present, are probably "compensating" for other problems rather than resolving them.

[Kenstone]

Hey y’all

To recap- mold makes a .356 and I get .359/360 after coating. I’m sizing , which then requires expanding to .358 and then taking my .356 stem to get the proper flare. I haven’t even got to the point where I know if these newly sized pills will fly.
Please give me your thoughts.
I use Lee 9mm dies and a simple swap of the powder thru the expander to the expander from a 38S&W die (Lee #SE1699 PM EXP PLUG), so
only one operation to expand/flare.
I buy 38/357 coated bullets (.358-.360 dia.) and push them thru a Lee sizing die, depending on what size/caliber I need/want.
https://www.titanreloading.com/product/lee-se1699-pm-exp-plug-38-sw/?search=Lee%20SE1699
You would need to buy a Lee 9mm powder thru the expander die to do that though. :(
:oops:
.
Edit:
I found the Lee FCD would further size oversized bullets, so I stopped using it.
Using bigger bullets in combination with thicker cases can result in rounds that will not "plunk" in guns with tight chambers.
Edit II:
Some have removed the carbide ring from the Lee FCD to eliminate the resizing during the crimp operation.
So, there's that too,
just sayin'
.

[243winxb]

Need BHN 15 alloy. https://www.thehighroad.org/index.php?media/albums/taurus-g3c-9mm-luger.317/

[fayettefatts]

Others will chime in, but I wouldn’t add tin to range scrap.

May I ask why?

[gunarea]

Lee factory crimp die will undersize your lead projectile as a finished product. This particular issue has come up in many other calibers utilizing cast lead alloy projectiles. Undersize boolits are inaccurate. Pull a finished round apart and measure the now resized projectile. Just trying to help.
Roy

[Dieselhorses]

Undersized bullets with result in key-holing and also lead BHN being too hard or both. I do taper crimp my 9’s but it’s a very light crimp.


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[Cast10]

I use the Lee 356-120-TC on my Glock 9’s.

I reload with RCBS carbide dies and use a very slight bell; just enough where the base will sit in the brass. I apply a slight crimp whereby the loaded cartridge, when bullet end is pressed hard against the bench, will not set back into the case. COAL 1.080; kerplunk.

Mix is BHN 11.3, no leading, no tumbling. Loads are in the upper end with WSF and yield 1055-1095fps in different barrel lengths.

[lotech]

Shoot the largest diameter bullet that will allow easy chambering and stay within specs; this will usually be .357" or .358", rarely larger. I only shoot a heavy bullet in 9mm, the Lyman #358212 roundnose design of about 150 grs. because of the good accuracy and perfect functioning in several pistols. About any alloy between about 11 and 15 BHN should work fine. I taper crimp minimally. I've never seen a need to powder coat bullets or to use the apparently popular Lee Factory Crimp Die for the 9mm cartridge, but I suppose both will work if done properly.

[JCSC]

Thanks Roy. I measured a seated bullet when I was using the Lee 356 sizer. I ended up with a bullet at .3545 and too small for my guns.

I have since switched to a .358 sizer and working thru the issues associated with brass sizing, expanding etc.

I believe the comment about the Lee universal flaring tool may be a good next step.

[243winxb]

Cast bullets spring back after sizing. But at different rates depending on the alloy used.

The higher the antimony content, more spring back, larger diameter.

The Lee universal flaring tool only opens the case mouth.

[justindad]

I’m concerned your next step is to apply too much of a flare to the case. Apply as little of a flare as is needed so you maintain maximum neck tension. Make sure your expander die is specifically made for lead - the Lyman M die is common, but I use a Redding version. Your RCBS carbide set most likely has an expander for j-word bullets, not lead (unless you have their Cowboy dies).
*
Keep the practice of crimping and seating in separate steps, but the Lee FCD may not be good if you need larger boolits.
*
Go into the powder coat section, and ask them for how much a bullet can be sized up with the coating before problems occur. You might need a mold that casts a larger diameter.

[Soundguy]

The Lee universal neck expander is nice.

[mdi]

I usually mention to new reloaders use as much flare as you need to get good bullets seating, no shaving now, and worry about case life later. Too much flare is when the case will not enter the seating die. Flare is removed with your deflaring tool (aka; taper crimp die) just enough to plunk easily. I have 5, 9mm pistols that have groove diameters from .355" to .358", so I size most bullets to .358" (some .369" for my Tolerev and .356" for my Masada). I have used a lot of range scrap and have had no problems with what I purchased from The Captain.

[Castaway]

fayettefatts, tin does some, but no appreciable hardening. It’s primarily used to allow the lead to flow into the recesses of the mould. Range scrap tends to flow well enough to use as is.

[VariableRecall]

I've had zero lead shaving with an old RCBS Sizer and seater, paired with a Lee Expander/Lee Auto Drum and a Lee Factory Crimp die as the 4th die on my Lee Turret Press. I've put together very consistent ammo in this fashion.
Quick recap of the dies in order:
1: RCBS Sizer
2: Lee Expander/Auto Drum
3: RCBS Seater
4: Lee Factory Crimp Die

Depending on the brass, the amount of force needed to run a completed round through the Lee FCD varies.

Also, my projectiles are sized to .356, and I have yet to have any lead shaving issues at that diameter. Sure, it's a little on the narrow side, but I've never had a single feeding issue at that diameter and all the case mouths are flawless.

[TurnipEaterDown]

One thing not mentioned in this thread to check in diagnosing instability (the noted yaw, and also 'ehh' accuracy) is to check bullet concentricity.

I find it difficult to seat short bearing length bullets in an inadequate flare (the noted shaving) and end up w/ good run out. Long bearing length bullets are generally a different matter, but even there if the neck is under size and the bullet is started poorly, then the bullet can end up w/ poor runout.

Recently I started loading for a 380 Auto w/ cast bullets. My experience before (30 years) was w/ large diameter revolver (44 and up to 50) or rifle (30 cal up to 416) and I never needed a special expanding tool like the M die. Tried doing without on the 380, and had an utter fail.
The bullets on the first 10 were very hard to start the seating properly due to very short bearing length (using a LEE 356-95-RF) and inadequate neck ID, and though I spent a lot of time trying to get those right at least 5 were seated visibly cocked. This was fixed w/ using an M die which I ordered after spending probably 40 minutes w/ those 10.

I shouldn't have to say, but if the cartridge chambers w/ the bullets seated cocked to bore, they will come out the muzzle that way too.

[whisler]

After fighting the common 9mm/cast boolit problems, (short throat in barrel, cases squeezing down the boolit diameter, too soft alloy) I finally sent the barrel to Dougguy to be throated, purchased a Lee 38 S&W powder-thru expander plug for my Lee dies, and went to 13 Bhn alloy. Problems solved.

[higgins]

My first 9mm cast loads were with some .356 dia 124 gr. truncated flat nose bullets someone gave me. They were just awful in my .358 groove 9mm. Berry's 147 gr. plated bullets were equally awful. Then I tried the Lee 358-125-RF, which drops at .359 from my mold. I have shot them unsized coated with LLA and I have also coated with a light coat of LLA, sized .359, and given a second light coat. Results have been good in the upper 900s fps in my gun. Alloy is straight COWW or salvaged cast bullet range scrap metal which would most likely be "hard cast" bullets.

To load these larger diameter bullets I expand and flare the cases with a .38 spl. M-die and seat the bullets with a .38 spl. seating die so that bullets are not squeezed down during the seating process. Crimping is a taper crimp die with a light crimp. I have found that Blazer and Federal 9mm cases may be thinner than most so are better with the oversize bullets. Before you load any quantity of ammo make sure whatever bullet and crimping method you use will easily chamber in your barrel. Good luck

[Bigslug]

JCSC,

Follow the link to the stickied thread in Dusty Bannister's #4 reply to your post. A lot of hard-won knowledge there. The formulae I arrived at for success starts on page 4 or 5.

[Soundguy]

fayettefatts, tin does some, but no appreciable hardening. It’s primarily used to allow the lead to flow into the recesses of the mould. Range scrap tends to flow well enough to use as is.

Well.. Most reputable sources..uh..completely disagree with you.
Lead has a 5 bhn.
20:1 has a 10 bhn.
" no appreciable hardening " really.. You mean like doubling the hardness?
Most range scrap I test is around 10 bhn.

To the OP.. Make sure you do your own research in the 2 great sources that were listed earlier.

Speaking of lead and The Captain... My last 2 casting sessions were with captain's lead ingots.

I have the bullets pan lubing and some aloxing right now. 10 bhn is fine for plenty of handgun rounds.

[JCSC]

JCSC,

Follow the link to the stickied thread in Dusty Bannister'
s #4 reply to your post. I lot of hard-won knowledge there. The formulae I arrived at for success starts on page 4 or 5.

Thanks everyone. I appreciate the comments and have some follow up articles to read.


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[fredj338]

For 9mm I have run 0.356 up to 0.358 in a wide array of pistols. I have settled on 0.357 for everything. They shoot better than I can on most days. I PC & then size 0.357". Yes you want more flare. I like the "M" die style of expander.

[fredj338]

Well.. Most reputable sources..uh..completely disagree with you.
Lead has a 5 bhn.
20:1 has a 10 bhn.
" no appreciable hardening " really.. You mean like doubling the hardness?
Most range scrap I test is around 10 bhn.

To the OP.. Make sure you do your own research in the 2 great sources that were listed earlier.

Speaking of lead and The Captain... My last 2 casting sessions were with captain's lead ingots.

I have the bullets pan lubing and some aloxing right now. 10 bhn is fine for plenty of handgun rounds.

While true for pure lead, adding more tin doesnt give appreciably harder alloy with say range scrap, if that is the goal. You want antimony in the mix & then water drop somewhere in the process. I water drop my PC bullets out of the oven, get ranges scrap running about 12-13bhn.

[Castaway]

Soundguy, if you go 16:1, it’s only BH of 11. If starting from range scrap, that’s no appreciable hardness. Tin’s too valuable to waste on 9mm. Wheel weights are much cheaper and will harden if needed. Save the tin for alloying big heavy bullets propelled by black powder

[Soundguy]

If you go from pure lead it hardens. Plenty
Y. I took terms with your wording that tin doesn't appreciably harden. It does..but tapers off fast past 5-6% concentration... But a jump from 5-10 is dramatic and very statistically significant. Also, as Applegate and Fryxel point out..range scrap can and IS everything and anything. The makeup of range scrap is directly dependent upon what the clients there are shooting for instance there used to be an outdoor range about 35 miles from my house that is now closed unfortunately and I have to go to one that's about 45 miles away the lead scrap that I used to buy from the closed range tested out almost exactly as 5 to 6 bhn and that's because it was predominantly a black powder range and everyone was shooting pure lead , now an indoor range one city up from me that used to sell lead there lead tested around 10 Bhn, and upon having the lead sent for testing it was pretty much just antimonial-lead , no tin hardly at all and while it was hard-lead , adding tin to it would definitely still Harden it almost to the point where you could make Lyman number two alloy out of it so just saying that tin doesn't Harden lead really doesn't help anybody unless you know the exact alloy they're working with because tin added to lead even if it's hard lead can still Harden it because that hard lead could just be lead and antimony and arsenic.

[Castaway]

Yes

[JCSC]

While true for pure lead, adding more tin doesnt give appreciably harder alloy with say range scrap, if that is the goal. You want antimony in the mix & then water drop somewhere in the process. I water drop my PC bullets out of the oven, get ranges scrap running about 12-13bhn.

I’m still messing around with all this, but when I added tin, I did notice a significant different in maybe (surface tension?) of the lead. It poured differently and smoother than my previous batch.

There was no science to my trying this. I had a 5# batch of lead melted and added a couple feet of tin solder I had. It seemed more workable.

Also could have been mold temp or any million factors I know nothing about.


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[David2011]

Others will chime in, but I wouldn’t add tin to range scrap. A bell just large enough to hold a bullet easily, but not overly large Will help in shaving bullets while seating. If they chamber without sizing, try that and see how they work. You didn’t say how fast you were pushing them or the powder and charge.


fayettefatts, tin does some, but no appreciable hardening. It’s primarily used to allow the lead to flow into the recesses of the mould. Range scrap tends to flow well enough to use as is.


Soundguy, if you go 16:1, it’s only BH of 11. If starting from range scrap, that’s no appreciable hardness. Tin’s too valuable to waste on 9mm. Wheel weights are much cheaper and will harden if needed. Save the tin for alloying big heavy bullets propelled by black powder

These are awfully broad comments and assumptions. A better answer would be to ask the composition of the range scrap. I shot at one range where metallic silhouette was the primary game and there was very little in the way of scrap cast bullets. That scrap was mostly presumably pure lead cores. At ranges where there is a lot of action pistol shooting there is often a large amount of cast bullet scrap which would have a good start on the tin and antimony. You also seem to assume that the OP was adding lead for hardness but he said that it was for the pouring characteristics. Since we don’t know the composition of his scrap I’ll give him the benefit of seeing what he’s doing and determining what he needs. Additionally, 9mm is a faster and higher pressure load than many so I fail to see how it is a waste of tin to make good quality boolits.

JCSC, you could make sure you’re not adding excessive tin by reducing the amount until you get poor fill out but do what you’re happy with. Some people would say that my standard mix is a waste of Monotype but I’ve been adding 1/2 pound of it to 20 pounds of clip on wheel weights for a long time and it gives me good boolits. I’ll deviate from that if I have a reason for the deviation but it’s my go-to for my competition boolits in .40 and .45 calibers. The advice to make sure the boolits are filling the bores adequately is spot on.

One other thing. Cast, powder coat and size in fairly short order. If you let boolits sit too long after casting they can age harden, depending on the alloy, and be a whole lot less fun to size.

[Half Dog]

You have many great suggestions. Here’s what I’ve found:
Size to 0.358”
Keep adjusting the flare until the bullet sets in the case without shaving the lead. Measure the diameter of the flare and keep the measurement for later reference.
Seat the bullet then crimp. FCD will resize the bullet if it’s used the way it’s intended.
Measure the case diameter and do a plink test. I wasn’t able to get my round to chamber reliably. I sent the barrel to DougGuy and now it runs smooth.
I tried Titegroup powder and did not get good results.

I hope this helps.

[Soundguy]

Titegroup is my go to powder for virtually all handguns. Yes..you should ladder test it to find best accuracy..many don't take the time to do that. It's an economical powder with lots of case space.. It is not position sensitive..but you can easily double or triple charge a case if you do not pay attention.

If you don't have your barrel out to chamber test, get a chamber test block.. Easy to plunk test multiple calibers/chamberings.
As for range scrap... As has been pointed out..it can be anything... Testing is cheap..used to just cost a pound of lead and a few bucks and postage. Worth it if you are setting on a large quantity.. Much of it could be jacketed bullet core and have virtually no tin..

[Cast10]

Lee 356-120-TC and WSF for all my Glock 9’s.

All slugged to .356. My melt yields .358. After PC and sizing, .357-.3575.

I use SOWW + Hardball to approx. 11.3 BHN. 1% SN, 2.57% SB, 96.4% PB, No Leading in 9mm or 10mm.

Standard RCBS carbide dies with just enough flare to sit the bullet on top. Coal 1.080 and she goes Kerplunk.

[Hickok]

This is my experience with the 9mm and cast boolits. (found out from the good folks on this sight).

For cast, get the Lee Universal expander, then go to NOE and order expander plugs; .359 x.355 (for .356" bullets) and .360 x .356" (for .357-.358" boolits).

Trust me on this, it makes loading 9mm cast and pc'ed boolits so much better.

I shoot Lee 356-120-TC, use 50/50 COWW/ Lead with Smokes PC, chrony'ed at 1140fps. Pretty soft boolit, but with PC, I have absolutely no leading....barrel wipes out clean with a patch, and very accurate.

Glock 19x, Sig M17, and CZ 75b and Shadow 2, all these pistols eat this load. I can tell no difference in accuracy in sizing .356" or .357" in my listed pistols.

I did own a Beretta 92 that liked .358" cast, but I sold it.

[JonB_in_Glencoe]

Please give me your thoughts.


I am shooting range scrap. I’ve added some tin for better pour...

I had ehhh accuracy, no leading and about 15% bullets that wanted to yaw and tumble.
Here is my two cents.

Loading 9mm with your own cast boolits is a bit more advanced than 38spl or 45acp, because 9mm is a high pressure round and as you found out, 9mm guns have chambers that vary, more so than other calibers...you can research that if you want to know why.
I would suggest you start with a low pressure caliber, like I mentioned, the 38 spl or the 45acp.

Since you are as far along in your loading 9mm project, you will not likely put it on the back shelf, so here is a couple helpful hints.

Your alloy is too soft to get good accuracy. You want a BHN of around 15 for loads in that 25Kpsi to 35Kpsi range. Now, if you are just shooting steel plates at 7 yds, the soft alloy will be fine, but if you want better than " ehhh accuracy" and eliminate the "yaw and tumble" you need a harder alloy.


This batch of rounds is now basically crap and I am pulling them. Partly due to now over crimping them and concerns with losing proper headspace from excessive headspace.
In semi-auto pistols, 9mm headspaces off the case mouth. While some people crimp 9mm (which is fine for 9mm revolvers), I do NOT crimp 9mm for semi-auto-pistols. If you cease crimping your 9mm ammo, you will likely solve more than one of your problems.

Here is a real simplified explanation, if you don't understand what I said.
https://www.youtube.com/watch?v=gtgcgcDb4q4

[Soundguy]

Here is my two cents.


In semi-auto pistols, 9mm headspaces off the case mouth. While some people crimp 9mm (which is fine for 9mm revolvers), I do NOT crimp 9mm for semi-auto-pistols. If you cease crimping your 9mm ammo, you will likely solve more than one of your problems.



Keep in mind that many reloading manuals group all 'bullet retention styles' as crimping.
Also remember.. crimping can be roll crimping, collet crimping, and what most people with straight or nearly straight cases see.. TAPER CRIMPING.

I have seen flame wars and arguments about this term.. 'taper crimp'.. Many say that it is just closing the mouth bell.. ok.. sure it is.. and many people that write reloading manuals, sell reloading gear, etc.. call this closing.. a crimp...

So.. saying not to crimp may actually complicate the situation.. imagine a lurker reading this and they think they can flare a case, charge it, hand set a projectile in, seat it and go... and then wonder why their cases won't chamber.... because they have not 'taper crimped' the case.. which.. as the flame warriors like to say... closes the mouth bell.

Plenty of nuances in reloading that many of us grey hair people know.. that many of the younger or newer reloaders have not had the chance to experience.

I remember way back when if you wanted 8mm nambu ammo you ordered it from 2 buys who were making it in their garage.. turning cases like 38spl down ( others ) and swaging lead wire for projectiles. The good old days.

I still have an rcbs kit to convert 30 rem to 8mm nambu.. but heck.. 30 rem is rare-er than 8mm nambu now.. luckilly 6.8 spc's parent case is 30 rem, and you are cutting the case down anyway.. so I can make nambu brass out of 6.8 spc, and then inside neck turn it.

[JonB_in_Glencoe]

Keep in mind that many reloading manuals group all 'bullet retention styles' as crimping.
Also remember.. crimping can be roll crimping, collet crimping, and what most people with straight or nearly straight cases see.. TAPER CRIMPING.

I have seen flame wars and arguments about this term.. 'taper crimp'.. Many say that it is just closing the mouth bell.. ok.. sure it is.. and many people that write reloading manuals, sell reloading gear, etc.. call this closing.. a crimp...

SNIP>>>
Point taken.

I don't recall reading a manual defining crimping as all 'bullet retention styles' ...But I haven't read them all, so I find no reason to question you on that.

To me, crimping is crimping the case mouth into the boolit.
While I de-flare the case mouth on 9mm cast boolit ammo for semi-auto guns, I won't crimp 'em

[JonB_in_Glencoe]

Keep in mind that many reloading manuals group all 'bullet retention styles' as crimping.

SNIP>>>

I have an afterthought, is case neck tension considered a crimp ?

[Soundguy]

Yes.. That's my point.. That's why I said bullet retention. A taper crimp = removing mouth flare.... And that is the case neck tension that retains the projectile on cases that headspace on the mouth.

That was my point.. Some manuals call that a crimp... Even though it's not a roll crimp where you are bending the neck into a cannelure. Similarly a collet style crimp presses the case neck in, but doesn't fold it in... It's still parallel to the projectile.. The FCD in effect just increases the neck tension by swaging the brass.

So yeah... Taper crimp on a 9mm is closing the mouth bell.

It's a big arguing point over semantics on some sites..

[JCSC]

Yes.. That's my point.. That's why I said bullet retention. A taper crimp = removing mouth flare.... And that is the case neck tension that retains the projectile on cases that headspace on the mouth.

That was my point.. Some manuals call that a crimp... Even though it's not a roll crimp where you are bending the neck into a cannelure. Similarly a collet style crimp presses the case neck in, but doesn't fold it in... It's still parallel to the projectile.. The FCD in effect just increases the neck tension by swaging the brass.

So yeah... Taper crimp on a 9mm is closing the mouth bell.

It's a big arguing point over semantics on some sites..

This would be my definition of a crimp in 9mm as well. Removing the flare that you had previously added.


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[David2011]

The SAAMI spec on the taper crimp at the mouth is 0.3799” (9.65mm) or .380” for us mere mortals. I prefer to measure a hair’s breadth (technical term) back from the mouth to be sure I’m not measuring on top of a burr on the mouth. If your taper crimp measures the same, you’re good. Over crimping reduces the boolit diameter and if done vigorously enough, can cause headspacing issues along with the other accuracy and leading problems of undersized boolits.

[sigep1764]

I set my taper crimp a bit different. I take 10 cases and measure the case wall thickness with my caliper. I average this thickness, double it to include both sides and add it to the .358 that I size to. I then seat a boolit and gradually turn the taper crimp die down until the cases with seated boolits meet this measurement. Then just to be sure, I pull the boolits and measure them to ensure they were not sized down. They must remain in the .3575 to .358 size range.

[ioon44]

One thing I do for my 9 mm, is backing the sizing die 1 turn (.080") off the shell holder so it doesn't size the mouth as much.
This way the brass doesn't swag the bullet as much and I taper crimp just enough to remove the bell.

The barrel on my Walther PPQ SF measures .357" so I size to .3595". I mostly shoot an Accurate 140Z bullet from 12 BHN range scrap with Hi-Tek coating, extremely accurate and no leading. This load will not work in all of my 9mm's, always plunk test.
Bullet fit to the barrel is king.

[gwpercle]

I Taper Crimp ... measure nothing ... Press the boolit nose into the edge of the loading bench .

If it holds tight ...Good To Go .

If the boolit slips back into the case ... add more taper crimp until it don't .

Simple folks have simple ways ... sometimes simple beats complicated ...
... Seven Way's To Sunday !
Gary

[Hickok]

Just my experience with taper crimping 9mm and cast boolits, right or wrong, this is what I found.

I have mic'ed the case neck, read the specs in the manuals, run case through a Wilson Max. case gauge, and used a taper crimp die.

Through trial and error, I find that if I expand and flair the 9mm case with the Lee expander die/Noe M-type expander plugs, I can seat my cast boolit, and as the slug seats, the case neck forms around the boolit, the flair/bell disappears and the loaded round is "good to go."
I have proper neck tension, the round passes "plunk test" and is ready to shoot. NO taper crimp needed.

I flair the case neck just enough to start the boolit in the case nice and straight, press the slug in with my fingers for a good friction fit. No shaving the boolit/or powder coat.

Just my way of loading 9mm with cast....works for me....others may not like my methods.

I do not taper crimp my 9mm loads any more. I "plunk-test" every round through my CZ-75b barrel. It is the tightest chambered of all my 9mm pistols. If it fits the CZ chamber, it works in my Glocks, and Sigs.

Mass production of 9mm on a progressive press may be different,...I use my old RCBS press, and load one at a time.