I've starting working on my first test batches of 9mm loads and mostly doing OK. One area I'm not happy with is the seating and bullet crimp. I'm using the Hornady American Series die because I didn't know better when I bought my pistol dies. Now I wish I would have tried the Custom dies instead.
The instructions I've found for proper setup all seem to go with the Custom die which has three parts and the American only has two. It's easy enough to get the COL set to the right number but getting the taper crimp correct is more of a challenge.
I started by measuring the COL for six factory rounds that I consistently shoot which are Federal Am Eagle. Averaged the length of the six rounds which came out to 1.136. I'm using Berry's 115 gr RN and their specs called for 1.13. Loading in the same Federal casings. What I'm finding is every bullet after seating has a full ring indent in the middle of the bullet 3/16" from the end. I backed off on the crimp a bit and those rounds I could push the bullet into the casing and it would drop all the way in. Tweaked the crimp few more time and even though they passed the finger rub test and measure OK by the calipers I could still turn the bullet in the casing.
Anyone run into this? Is it an American Series die issue?

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M&P9, 40, 357, 22, 40 Pro +++

When you were setting the crimp,did you back the seating stem up so that it didn't touch the bullet?

I don't know much about your die set, but I am a firm believer in doing the taper crimp separate from bullet seating in 9 MM. You can pick up a Lee Factory Crimp die for around $18 plus shipping from Midway right now. And Amazon has it for the same price and free shipping if you are an Amazon Prime member.

This statement makes me think you are not sizing correctly or over expanding a lot. Irregardless of crimp the you should not be able to drop a bullet all the way in the case on a properly sized and expanded case. The only time you could do this is in a fired case prior to sizing.

Check your dies and steps prior to the seating and crimping steps. Something else doesn't seem right.

Sounds to me like somewhere along the way you're losing case neck tension. Also, be sure you're only flaring the case mouths just enough to be able to barely start a bullet without shaving. Any more than that and you lose too much case tension. Lastly, too much crimp can buckle cases slightly also resulting in neck tension loss.

I seat/crimp with RCBS dies and don't have that problem. You have to set them up correctly. If you can't (or won't), seat/ crimp separately.

^^^ this is my guess as well. Just set up a new press using the dies I've used for a year, had the same problem. Realized my sizing die wasn't adjusted properly. Screwed it down a few turns, set it right. Problem solved.


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If done properly 9mm needs no crimp. Case tension (squeezing the bullet into the case) is all you need. The crimp die is to just roll the flared case mouth back to a straight. Being able to push the bullet into the case and have it drop in is not good. You might not be sizing correctly or your way over flaring the case mouth. Maybe a combo of both. Read your die instructions again and find some videos on die adjustment on youtube. Would take forever typing it out here.

I had a similar problem when I first started loading 9mm's. After playing around with the sizing die, expander die, and the crimp I finally realized I just wasn't getting the case sized down enough to get good neck tension. Ordered a Lee undersized sizing die and problem solved.

As others have said, crimp does not hold the bullet in place but neck tension does. You might try seating a bullet without crimping and if it still moves you're not getting the case sized down enough. If it does hold then you could be over crimping it which can cause it to lose neck tension.

Seat and crimp in two steps until you get the dies figured out.

To do it in one step, back out the bullet seater so as not to touch the bullet. Then set the crimp depth first and lock it. Lower the seater plug until you get the right depth.

In 9mm some of us have taken to calling crimping "deflaring". In other words, you crimp just enough to take the flare off of the mouth of the casing.

It doesn't sound like the case is being sized down enough initially if the bullets aren't tight. Or maybe another operation is causing it to lose tension. I've noticed that if I try to 'doctor' a round that doesn't quite plunk right, I usually end up just ruining the neck tension.

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"He was kinda funny lookin'"

Get a set of Dillon carbide dies, which includes resizing, seating and taper crimp dies for 9mm. Setup is painfully easy-just follow Dillon's included instructions.

Dillon dies are "standard" dies-they'll fit on any press that uses 7/8x14 thread dies. No lube required, just clean the brass first before reloading.

Couple revelations to my questions.
Some of the cartridges held just fine, other I could rotate the bullet but all the bullets have a ring around the bullet at about the exact midpoint. I good friend at work brought in his 20++ year old Lee dies and we compared dies. The bullet seating stem for the Hornady American has a deep pocket for the bullet and a bevel at the end of the stem. It appears just this bevel is contacting the bullet and that is what is pressing the indented ring in the bullet sides. The Lee seating stem has a VERY shallow bullet pocket and only the flat end of the stem contacts the bullet. No ring on his bullets.
Tested the bell/flare for seating the bullets and had .357 to .358. Could manually lightly push a bullet into the case to test fit and it would hold if I turned the casing upside down.
In testing various cartridges loaded for the test rounds I think I found part of the issue. While initially doing the seating crimping test I had a bunch of cartridges with no primer and no powder. I used the impact bullet puller and dismantled those cartridges and reused them. I think the cartridges where the bullet could turn where probably the ones with bullets I had used before.
Same buddy says he doesn't like to seat and crimp in the same station, prefers to seat and then crimp (taper crimp).
I have a Powder Cop in one of my stations but 6.0 gr of Power Pistol in a 9mm case is pretty ease to see. Think it might make more sense to eliminate the Powder Cop, add a separate crimp die? Or....buy different seating die, use the Hordady to crimp and back off the seating so it's not used?
Part of the evolution.

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M&P9, 40, 357, 22, 40 Pro +++

Go over your die settings and make sure they are set correctly.

After sizing, just the tip of the FMJ style bullet should enter the case.
After belling the case, the base of the bullet should go into the case and stand on its own.

Now try to taper crimp after you rechecked your settings.

If things are not right, just go out and get a new die to finish your loading process.
I would not get a Hornady so you know you are grabbing the correct die to do the job right.

It's not the dies. I have CH4D , Pacific and Lee dies and have had the same problems with all of them ....it's the 9 mm round , it's a stinker. I've reloaded for 40+ years and the 9 mm Luger is the only one to give me these problems and it even made me curse at it.
Die set up is the key , no magic answer. Fully resize cases, flare case as little as possible to get bullet started into case, seat but do not crimp. after seating bullet to proper depth remove the seating stem and start the crimping adjustment process , put case in shell holder and raise ram to top of it's stroke and begin to screw in crimp die until it contacts case, give it a 1/4 turn in, check crimp, keep screwing in and checking the crimp until the bullet is gripped and can't be pushed in with thumb pressure. Too much crimp will bulge the case and loosen the bullet. Get just enough crimp to hold...no more. The seating and crimping can be done in one step after you get the crimp die adjusted , I still like doing it in two separate steps...but that's just me. Keep fighting it !
Gary

The GunStop in Wayzata is a valuable resource for reloading help and supplies. These guys had powder and dies throughout the recent shortages.

You are so right about 9mm. It had me questioning not only my ability to reload but also 35 years of being a mechanic. Didn't matter if Hornady or RCBS even tried a Redding set from a friend. Took a whole lot of loading dummy rounds to finally get a handle on it.
I always loaded all other handgun calibers with one seat/crimp die but use a seat and another for crimping.

I have a Lee 4-Hole Turret press so a separate taper crimp die is a no brainer.
It make life so much easier

Once you get your problems settled, 9mm is an easy cartridge to seat and crimp in the same operation. Reason being is that the crimp only takes the flare off the case mouth, therefore, you aren't seating the bullet with the seating plug while putting the brakes with a roll crimper.

You SHOULD be able to set your crimp and lock the locking ring in place. Then you can vary the seating plug for different bullet depths.

I've has posts lately about Lee dies using an o-ring instead of a locking ring. I prefer a locking ring which most die sets have. You can buy spare lockings from Midway. I like the Forster and Lyman split rings with the cross bolt. i don't care for the RCBS straight in setscrew.

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"He was kinda funny lookin'"

Gee, I haven't had any problems at all loading 9mm. However having learned the "hard way" that trying to combine Seating and Crimping is not worth the hassle I seat and crimp every single caliber I reload using separate stages for these critical steps.

To DIY guy, I have to question a statements in your original post.

This implies that your Hornady American die set only came with 2 dies. Looking on the Net indicates that the Hornady American dies set for the 9mm has a full length Sizing/Decapping die, a Flaring die, and a combined Seat and Taper Crimp die. Along with that you should have also received a shell holder for hte 9mm. Hopefully I am mis interpreting that statement of yours and you actually did receive all of the parts necessary for a complete die set.

Now, typical procedure for a 3 die set is to size and decap in the first operation, then flare the cases in the next operation, and finally seat and crimp in the last operation. As I stated I am NOT a proponent of combined seating and crimping and will tell you that you can use your third die to seat and crimp in separate operations by re-adjusting the die so it just does one operation at a time.

Now a run through on typical setup for these different stages.

First, you have to set up the Sizing/Decapping die. Something that is VERY easy to do for a handgun caliber like the 9mm. Typically you are supposed to bring the die into contact with the shell holder and then back it off by 1/2 to 3/4 turn. The easy way to do this is to place the shell holder in the ram on your press, raise the ram up with the shell holder empty, and then screw in the die until you feel it bind up due to contact with the shell holder. At this point put a dot on your die with a Sharpie pen at the 12 o'clock position. Now lower the ram and rotate that die 180 degrees Counter Clockwise so that dot is now at 6 O'clock. Then hold the die in position and bring the lock nut down and snug it up tight to "lock" the die in place. Then get out your hex key and and tighten the locking screw on the lock nut. At this point you have your sizing die set.

Next step is to adjust the flaring die, a setup that can get a lot of newbies in trouble. The way I like to set up the flaring die is to insert a sized case in the shell holder and then bring the ram all the way up. Then I start screwing down the flare die until I feel it starting to bind in the case. Then put a dot at 12 O'clock on the die with a Sharpie and lower the ram. Now, depending on the brand and the specific design of the flaring die you can typically have something in the range of 3 to 5 full turns of the die before it starts forming at actual flare. So I start turning the die in and counting. I'll go in 1 turn, cycle the ram up and down and then look for a flare. I keep on going in 1 turn at a time until I can actually feel the press working the case and producing a visible flare. Very often a result of this particular coarse adjustment is a very large flare but it allows you to narrow down the actual "working window" for the flaring operation. If the flare is giant, then back off a half turn and see what happens with a fresh case. The goal for your flare is to get the flare to the point where a new bullet will go into the flared case by 1/32 -1/16 inch and NO MORE under simple finger pressure. Once you have your die adjusted to this point draw a line on your die with your Sharpie at the 12 O'Clock position. Then tighten up the lock nut and re-check the flare with a fresh case. Note, many times you'll have to turn the die in just a smidgen because tightening that lock nut will actually draw the die up slightly in the thread of the press due to the clearances between the die and press threads. So if you need to tweak it a bit that's totally normal. BTW, once I have everything cast iron dialed in I use a diamond burr in a dremel to mark the 12 O'clock position of my dies.

Finally setting a Seat/Crimp die for just seating the bullet. What you do here is turn the bullet stem in by 3 or 4 full turns. Doing this will allow you to seat a bullet without the crimp ring ever contacting the die. Note, you will want to make note of the number of turns on the bullet stem you use between stages and be consistent about it. I'll also note that you could purchase a Lee Factory Crimp Die for 9mm and avoid having to re-adjust your seating die. Once you have the bullet stem set and locked in you then need to slowly bring the die down until you have your desired overall length. Then set and lock in the lock nut. At this point a couple of scribe marks on the lock nut and corresponding marks in the thread just above those scribe marks can make finding this position of the lock nut much easier.

Finally setting up to Crimp only. Start by backing out the bullet stem 6 full turns to insure it won't contact your bullet during the crimp operation. Then loosen the lock nut and run it up the threads on the die by 5 or 6 full turns. Take a case with a bullet pressed in place and put it in the shell holder and raise the ram. Then take you now Crimp die and screw it down until you feel it contact the case. After that point it will only take something in the range of 1/2 to 1 turn more to crimp your bullet in place. Note, I use digital mikes right at the very edge of the case to measure the diameter at the crimp. Then I'll take a measurement about 1/8 inch further down. When I set a taper crimp I set it to be 0.002 to 0.003 inches smaller than the diameter of the case where the bullet is sitting. While that doesn't seem like much of a crimp it's always worked perfectly for me.

Finally a note about overall length.

First, use a length that matches the profile and weight of the bullet being used as listed in your load data. DO NOT use something that "matches" a commercal load from a maker such as Federal. Because they will NOT be using the powder you are loading with. Use the length provided by your powder manufacturer, it's a very important detail. However, a deviation of only 0.005 inch is not a big deal, so if your length is within 0.005 inch you really don't have to fuss to get it spot on perfect. Also note that is just 5 thousandths, NOT 50 thousandths. Please, count the zeros because that can be critical.

Second, profiles between brands are typically quite close in overall lengths, so if you are using a Rainier RN bullet it will be within a few thousandths of a Berry's or Extreme RN bullet. However between a 124 grain FP bullet and a 124 grain RN bullet you may find a rather large deviation. Personally because the 9mm has always used a Round Nose bullet profile I've never tried one of the newer Flat Point plated 9mm bullets. Because finding load data for these oddballs can be difficult and I don't have any need for a 9mm FP plated bullet load. However if I did want to try out one of these bullets I would start by purchasing some 9mm Hornady XTP's because those are typically FP profile bullets. Then I would compare the length of the XTP to the length of the plated FP I was considering and adjust my overall length as needed to have the base of the bullet in the same spot as an XTP base would be. Because data for the Hornady XTP is very easy to find. I'll also note that I have found Hornady XTP's to be superbly accurate bullets.

Anyhow, this is how I set my dies up and I haven't had any problems at all doing it this way. I will also note that I have a Lee Factory Crimp die for every caliber I load, Rifle and Handgun. Some don't like the extra sizing ring in the handgun dies but I have never had any of the supposed problems these sizing rings might cause and they do insure every assembled round will chamber properly.

Scooter123: Great, great response! Very thorough!

Regarding the particular dies included with the sets, yes, I did get three dies plus shell holder with the American Series set. Besides the fact that the Custom-Grade sets have a split locking ring and the American have a steel nut and "O" ring, I discovered a noticeable difference in the Crimp/Seater die.
The Amercan Series Crimp/Seater Die (taper crimp) that I'm holding in my hand has two main parts. It has the main die body which screws into the press body bushing and is responsible for the taper crimp. This locks in using a steel nut and "O" ring. The bullet seating stem screws into the main die body and secures using steel nut and "O" ring also. The main die body moves up and down in the press and the bullet seating stem moves up and down within the die body. Two parts excluding the nuts and "O" rings
I'm looking at the sectional cut-away view of the Custom-Grade Crimp/Seater die in the User Guide. There is the main body that screws into the press (bushing), a middle die body that screws into the main die body and a third part, the bullet adjusting stem. Three, threaded, adjustable parts. There appears to be a forth part which looks to be a sliding sleeve inside the main die body that looks like it holds the bullet until it is seated. Plus the "O" rings and lock rings.
This is what I meant by the American has two parts and the Custom-Grade has three. The two dies are completely different.

An internet search found a variety of info and some very good YouTube videos but the ones I found were using the Custom-Grade Crimp/Seater, not the American.

I'm using the Hornady LnL AP press with the following stations and all Hornady parts:
1: Size and deprime
2: Case activated powder drop with PTX
3: Powder Cop
4: Bullet feeder die
5: Crimp/Seater die (American Series)

It's the crimp/seater die that is pressing the ring in the bullet and I'm thinking I may be better served to eliminate the Powder Cop and seat and taper crimp in separate stations. I don't like the current bullet seater as it leaves a ring. Found options for the separate Lee factory crimp OR taper crimp die, haven't found a separate option for the bullet seater without buying a complete set. Because I'm using the PTX I'm not using the expander die at all. If I cant find the seater and crimp as individual dies I may have to "bite the bullet" and pop for the full set of Hornady Custom-Grade.
Does anyone else have the Custom-Grade seater and does it have a problem leaving an indent in the soft bullets such as Berry's?

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M&P9, 40, 357, 22, 40 Pro +++

I've got the Hornady Series II dies for 9mm that I use in my LNL AP and I get a slight ring on the bullet with FMJ's. Not a big deal at all and doesn't effect accuracy best I can tell. The seat/crimp die is similar to the American series where adjusting the amount of crimp requires moving the entire die body up or down. The seating depth is adjusted by a separate knob that screws into the die body. I do like the bullet guide as it lines the bullet up well before it is seated. The split lock rings are really nice too, especially using them with the LNL bushing system. I've bought extras to use on a couple Lee dies I have.

How in the world does a taper crimping die leave a ring on the bullet? That shouldn't happen and I'd think about getting different die.

All a taper crimp is supposed to do is take the flare off the case mouth and push it (with no pressure) against the side of the bullet.

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"He was kinda funny lookin'"

It's the seating stem that's leaving the ring. It doesn't match the shape of the bullet so the edge on the bottom of the stem is what's leaving the ring.

I would venture to guess he is actually crimping (not just removing the flare) while seating so there is a fair amount of pressure while seating and the stem shape doesn't match the shape of the bullet.

I have had this happen when I first started hand loading and was way over crimping while seating, and this was with RCBS dies. Again, if the shape of the seating stem doesn't match the bullet profile it will leave the ring DYI is referring to.

I have to agree that seating and crimping in one step can be done but it's much easier, at least for me, to get a consistent COL in separate steps, especially when starting out.

Thanks for the explanation! I don't always have a good match for the seating stem, either. I hear that you can use sealing wax molded as a temporary fix, but I haven't tried it. i have a special stem for Speer Gold Dots, but you have to be extra careful or it will flatten the nose of the bullet.

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"He was kinda funny lookin'"

I have flattened a few noses myself. I've heard about the wax mold too but I'm not messing with it. I can see if you're loading a good bullet like the Gold Dots you would want a good fit but for target RN and SCW the round and flat stems work good enough.

When I first started reloading the 380 ACP the only die set I could find was the Lee 3 die budget step. While attempting to get the combined seat crimp die set up I found that as soon as the edge of the case started to "bite" into the jacket of the Hornady XTP I was reloading with and at that point the bullet would "stall" and stop moving into the case. The result was either I assemble the ammunition with no crimp at all or I accept that the nose on every round would be "crushed". A temporary solution that worked to get me ammo to shoot for the next range day was to chamfer every case like we do with Rifle cases, a rather tedious thing to do. That evening after putting together 100 rounds I got on Midway's web site and ordered a Lee Factory Crimp Die for the 380 ACP.

DIYguy, I've worked with Titanium Nitride since the mid 80's and can tell you that I am not the least bit of a fan of this particular coating. In part because I've been involved with fabricating stainless steel exhaust and fuel system components for the auto industry and TiN is pretty short lived when used to swage stainless steel. I vastly superior coating is a multilayer coating that finishes with a Titanium Carbide top layer, when used with a Carbide substrate and the correct lube we can swage many many thousands of tubes before we have to re-polish the tool.

Point is, I believe that Carbide is a superior material for sizing dies and consider Titanium Nitride as a bit of a "cheap out". I would suggest that you look for a Lee 4 die set for the 9mm, these aren't terribly expensive (under 50 bucks) and you get a Carbide Sizing Die and the Lee Factory Crimp Die.

BTW, one criticism I do have to the Lee dies is the friction lock for hte de-capping stem in the sizing die. You have to tighten that lock nearly to the point of bending your wrench to keep it from slipping. If you were to look at most of my pistol die sets you would find they are rather mix and match. For me the RCBS Sizing/Decapping dies are first rate. For the Flare die I've have enough problem with the RCBS flaring die that I prefer the Lee Powder thru Flaring die. Then to press the bullets into the case I reach for RCBS again. Finally to crimp anything I reload I use the Lee Factory Crimp Die. A small bit of good news is that you can Purchase RCBS Dies individually so I will typically start out with a Lee Die Set and fill in the Size/DeCap and Bullet Press with RCBS products. I'll also stock up on multiple Bullet Press dies for those calibers where I load a variety of bullet profiles and lengths.

They are way too scarce and way too expensive. SWCs are plenty good enough for me. And they have a nice big meplat that won't get smashed unless you hammer on it.

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"He was kinda funny lookin'"

I recently had a posting about the same thing. The o-ring on the locking nut and trying to keep the decapper from slipping. These are two design features that I wasn't used to and because they are different, they require some different handling. Many people have great success with them and next time I use a set, I'll know more about what to do. And I did the same thing, ordered an RCBS sizing/decapper. One thing I'm going to do is replace the o-ring nut with Lyman cross bolt locking rings.

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"He was kinda funny lookin'"

I have no problem with 9mm crimp. I use RCBS 3 die set in my Dillon 550. The way I set the seat/crimp die is set the crimp by using a sized and expanded case (without any bullet) then adjust my die until I have a .003 less than full OD case measurement on the empty case mouth, (.377"). Then set the OAL to what you want.

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H Richard
SWCA1967 SWHF244

reloading


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Does anybody have a recipe for 158gr 9mm with oal


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Does anybody have a recipe for 158 grain 9 mm projector with Oal


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In all the discussion Im glad H Richard mentioned the correct case mouth dimension, .377. Kudos.
9mm is quite simple. No roll crimp of any kind. Set desired OAL. Adjust taper crimp to .377 at case mouth. It doesnt take much to achieve this.
Jim

OK, are you talking about a ring at the tip of the bulllet? Kinda like a ring around the tip? If so, it's probably the edges of the bullet seating punch. OR, if further down, could be contact with the taper crimp die. If it's that, either you have a bad die or you''re over crimping. Come to think of it, if you're way over length, that might do it.

Contrary to the folks who don't crimp reloads, a proper crimp prevents bullet setback, possible misfeeds and promotes more even powder burn. Really good idea with all semi-auto ammo.

Suggestion: put a factory round in the press and run the ram all the way up. Back off the bullet seating stem and die lock ring. Now, run the die body down to firm contact with the round. Run the lock ring down and lock it. Then, run the seating stem down to contact with the bullet and lightly lock it.

The above gives you a starting point for die adjustments. You may need to do slight changes in crimp and seating depth, but you're in the ball park. Give it a try.

WR Moore, I am Jealous. That procedure of yours for setting up a Seat/Crimp die is about the most efficient and simplest method I've ever seen put forward. If I wasn't totally fed up with trying to use this combined operation I would steal that procedure from you. Consider this a big thumbs up.

WR More: Part of the mystery solved, its the Hornady bullet seating stem. I took the die apart and fit the cartridge with the bullet with ring around it and the ring matched up with the end of the stem. OD of the seating stem measures.3545 and ID measures.214. The edge of the stem is pressing a ring into the soft Berrys bullets. This is using the American Series die.

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M&P9, 40, 357, 22, 40 Pro +++

I don't know if that particular Hornady die offers more than one stem or not. But, many dies do, and some have two reversible ends, or a completely different stem included in the box. Just find one, that doesn't put a ring on the bullet. I went through the same process, once.

edit: I also use lots of Berry's bullets. There will be stems that work great, even if the shape doesn't look like it will.

I crimp in a separate step. I've found the Lee carbide crimp die works real well. It sizes the case and crimps the case. The way it adjusts it is repeatable from session to session.

LFCD. That's what I use on 9 mm, 45 ACP and 357. Never have liked seating and crimping with the same die. I know, it's an extra step, but I can get those crimps just exactly the way I want them. Before I found out about the lee die I just backed my seater plug out and crimped without it. I just got tired of adjusting it so moved on to the LFCD.

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That's just somebody talkin.

Ok, so this confused me a bit, but I'm from S. IL so that might explain that, anyway I digress.

Wouldn't you want to set the crimp and/or take measurements after the bullet is seated because that would change the dimension on the case, just below the case mouth, depending on the size of the bullet and brass thickness?

The RCBS die instructions say to TC to .001-.002 less than the measurement below the case mouth. Per their instructions I set the COL first, back the seating stem out, set the TC, then screw the seating stem back down till it touch's the bullet. (I am working on a SS press)

Bullet dimensions. You mention .377, my reloads (Xtreme 115 RN-HP) measure .375 and a Federal 115 FMJ factory load measures the same. My Bayou 125 SWC coated measure .376. So wouldn't the crimp be set, (.001-.003 depending on what works for you) relative to the case measurement after the bullet is seated?

I may be splitting hairs here and you guys have been at this way longer than me so I'm just trying to understand a new method.

For 9mm taper crimp I take my measurement after seating the bullet.
The .377 at the case mouth is on the loaded cartridge.
I have had very good luck with this.
Start on a test cartridge with the taper crimp die backed out and adjust it downward until you get in spec.
I am assuming you have a dedicated taper crimp die.
Jim

About crimping separately.......I've done that for decades. But, this year I discovered that for some reason in .45 ACP, plated bullets will set back during the feed cycle. Changing to starting the bullet in the initial seating die (leaving it about 0.060 in from final OAL) and finishing the seating in the taper crimp die produced a deeper crimp with a slight ledge preventing bullet setback. [Yes, I tried different depths of neck expansion and other options to prevent bullet setback without success.]

Berry bullets don't cut through the plating with this process and both function and accuracy is very good. The only thing I can think of is that the copper plate has less co-efficient of friction that plan lead and/or possibly gilding metal jackets.

Plated bullets are very slippery. They slide around a lot in the seating process. Never had a problem with coated lead. I've gone over to coated for this reason. About the same price as plated with a few other benefits. If you have problems with plated try coated bullets.

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That's just somebody talkin.

Yes I do have a dedicated TC die. I guess what I'm thinking is the case mouth measurement would vary depending on the bullet diameter used and the brass thickness. On my reloads I am getting measurements of .375 instead of .377 so to crimp .002-.003 less would give a crimp measurement of .373-.372.