How much crimp? Lee FCD guidance sought.

[moe1942]

I am loading .38 SPCL using 158 gr LSWC and 3.4 grains of WST. Bullet is seated to 1.475 and I don't crimp. In a light load as long as the bullet can't be turned there is no need to crimp. I fire these loads in a S&W mod 28 and find them to be very accurate.

With WST and this bullet the max recommended load is 3.7 grains. The only downside is in a revolver this powder is nasty.

 

[Tuckerp229]

OK, here goes. I have reviewed every possible forum rule category that I could find, PM'd a mod and can find no rules governing personal business links. I hope I am not breaking any forum rules.

This area of crimping drove me to distraction for years. How is that after such meticulous processing of brass, careful powder and bullet selection we press our loads through each die step and then the last step...the crimp step is upon us. The instructions are ...drum roll "put a good crimp on it?."
What pray tell is a good crimp and by golly if I score once and make a great crimp, how do I return to this crimp next time or what if I make a die change?

I worked on the idea until it hit me, I needed a way to quantify the input pressure in an accurate and repeatable way. After one and a half years my solution has gone from idea to prototype to production and is now available for sale.
Men, it works. Its simple and when you see it, it makes sense. The proof is in the targets. You see I discovered that the crimp actually affects Accuracy and Precision. One can actually see the bullet groups move around the face of the target, (accuracy), and see the group size shrink and grow, precision, as one changes the crimp pressure. Did you know that Lee Factory Crimp die can have over 30-50 footpounds of variance from open to closed collets? Did you know that almost every footpound step of the way between open and closed collets can affect the point of impact of your shot groups? Did you know that most of that powder and most of those bullets you thought won't shoot out of your weapon actually will perform wonderfully with the right crimp pressure?

My idea was to attach a Micro-Click torque wrench to a single stage press. First I discovered that the standard ratchet head-90 degree torque wrenches some of us own will not work correctly when attached to a press. I also found out that the standard torque wrench was not able to handle the footpound range needed for a wide variety of cartridges. It seems as though the same people that make those tackle box fishing weight scales make torque wrenches. Just as with the fishing weight scales, the torque wrenches seem to be made with footpound ranges that require the purchase of two torque wrenches to cover your working range. I found that some cartridges optimized at 5 footpounds and others at 30 or 50 or more. I own no super calibers but I expect some of them to require quite stiff crimp pressures both to eliminate bullet jump as well as to optimize performance. I then contacted a manufacturer to make specific shaft only torque wrenches that had interchangeable tool heads-so the pull for the torque release would be correct for accurate torque readings and had them make a footpound range that spanned from 5-75 footpounds and that allowed less than 1 footpounds increments. I designed and patented an adapter to mate the Consistent Crimp to the most popular presses to start the business. More adapters are in the works.
Don't be too hard on me for the website.. I am hiking up a steep learning curve. More videos will follow on installation and use of the Consistent Crimp.

Linky: precisionaccuracycompany.com

As a side note I solved another nagging problem while working on the Consistent Crimp. See my Precision Barrel Temperature gauge when you are on the sight.
Thanks for reading.

 

[Mister_P]

hi, got some informations about crimping :

http://www.hn-sport.de/fileadmin/user_upload/pdf/service/crimp-empfehlung.pdf

informations from Haendler & Natermann Sport GmbH website.

 

[BigBob3006]

Lee,

What is a crimp and what isn't is one of the least understood operations things in rereloading. IF your cases aren't the same length, you will never get conistent crimps in all your load. The only cartridges with good crimp were those that were the same length as the cartridge used to set up the crimp. Cartridges that are as much as .005" shorter will also pass muster. Cartridges that are longer IMHO, should either be trimmed or disgarded.

A good bullet puller will be a big help, But this is the way I teach learners in my home. A large bell of the case isn't really necessary, just enough to hold the bullet. I like the way #1 is belled. Now we are going to experiment. First, adjust the seating die so the crimp ring doesn't touch the case,, yet. You want to seat the bullet deep enough in the case so the bottom of the of the cannelure or crimp groove is above the the case. Now you're going to slowly lower the seating stem and seat the bullet again..and again. Until when your holding the case strait on, you don't see the crimp groove or cannelure. Now
screw the seating stem up until you think it's up far enough. Then go up a couple more turns. Raise the cartridge into the seating, and and lower the die until it touches the case. Now things slow down again. You want to lower the crimp until the type of crimp you want is reached. A methodI was taught almost 50 years ago is to hold the cartridge with one hand and too slowly pull a finger from the front half of the bullet to the case. If you do it and don't feel the sharp edge of the case, you're there. now run the case back up into the die and this will hold the die in alignment with the case. Now, lock that die in place. While the case is in the die lower the seating stem snugly against the bullet. Now whenever you work on a case of the same length you will get a nice crimp. If your cases are longer than the setup die, you're really locking the bullet in and only God knows what your pressures are going to be.
More than .005" shorter and you won't have a crimp.

This crimp

 

[BigBob3006]

Lee,
The crimp seems to be the part about reloading that creates the greatest degree of confusion.But no sweat. A friend took pity on me about fifty years ago This is what he taught me. First, belling the mouth of a case to much isn't necessary. Part of the problem is that no one trims pistol cases. Once you have all your dies setup you will only get cases worked the way you want to be if they are all the same length, or very close to it. I like the belling of case #1. All a bell is needed for is to hold the bullet in a case on the way to the seating die. Now comes one of the two cases of problems. Use a case the has been sized and belled. It might be easier to have about four cases that are set up. It helps if the die locking ring can be turned without difficulty. Screw the seating die into the press so the crimping ring doesn't come in contact with the case. With a bullet on the case, move the seating stem to a point high in the die, run the case into the die. Now screw the seating stem into the die and check where the bullet is in the case. Repeat this until the cannelure or crimp ring are just above the case. Now we go slowly. Screw the seating stem in very small steps. What you're looking for is when you look at the case, and it's level with your eye, you can't see the cannelure or crimp groove. The bottom of the bullet above the crimp groove or cannelure should be resting on top of the case. Screw the seating stem well up and out of your way. Screw the die down, with the case up into the die, down until it makes contact with the case. Now it go slow and check time. lower the case a little bit screw the die down A LITTLE BIT, raise the case then take it out and check it again. The point you're trying to reach is when you hold the case in your hand and draw a finger from the middle of the bullet down to the case. Repeat this until when you draw your finger from bullet to case you don't feel the sharp edge of the case mouth. This will handle almost every need for a crimp except those shooting heavy magnum loads then just A LITTLE BIT more crimp is all that is needed. As I said when I started, this will give you the good crimp on only those cases that are the same length as the setup case to perhaps .005" longer. Cases that are longer than the setup case will have too much crimp and may raise your pressures higher than you want them.
Too show you how much I believe this, Friday I received 500 new cases from Starline, that evening I spent measuring them. I kept those that ran from 1.275" to 1.280" I ended up with 372 case. The rest are for trading.

 

[Walkalong]

Heavy Roll Crimp into cannelure on a Mag-Tech 125 Gr bullet in .357 Mag


The roll did not show as clearly as I had hoped. Regular brass does better for crimp pics.

I used a Redding Profile Crimp Die which has a taper leading into the sharp roll crimp ledge. It gives a longer crimp than a standard roll crimp die with a conventional sharp ledge only. Both ways work well.

.

 

[BigBob3006]

Walkalong,

This is just my opinion, but I think the bullet needs to be seated just a little bit deeper. A ring is visible on the case that indicates where the crimp starts and that point is pretty low on the bullet. This may be the start of a bulge of the case. With the bullet deeper in the case, and not much deeper, your crimp would be an even heavier with less stress on the case.

Please let me say that I've known reloaders that would be happy with this crimp. I know that I'm a nit picker. I've had reloaders look at me as if I should never be let out without my keepers when I've suggested they trim pistol cases to the same length as their shortest case if they wanted uniform crimps. I'm convinced from match shooting that it does make a difference.
Thanks for putting up with this old goat.

 

[Walkalong]

A ring is visible on the case that indicates where the crimp starts and that point is pretty low on the bullet. This may be the start of a bulge of the case. With the bullet deeper in the case, and not much deeper, your crimp would be an even heavier with less stress on the case.

As posted, this is from the type of crimp the Redding die makes. It is a long crimp compared to the old standard you are used to. The die has a taper leading to the sharp crimp ledge. This is the type crimp it produces, compared to a more traditional one like I linked to. There is no bulge at the bottom of the crimp in my post above. The case mouth is crimped into the center (deepest point) of the cannelure. AC




Here is a more traditional short crimp.

 

[Walkalong]

My first attempt at reloading .30-30. I finally found some 150 Gr Core-Lokt bullets to load for the Win 94 .30-30 my son has been hunting with. That is what he has been shooting in factory ammo.

I gave the brass just a little more roll crimp than the factory loads had. I bought RCBS dies and this round was seated and crimped in one operation.

Medium Roll Crimp on 150 Gr Core-Lokt in .30-30

 

[Walkalong]

I hope these shoot as good as they look. I have some lead 200 Gr bullets shaped just like these that shoot great in my 696.

Medium Taper Crimp on an X-Treme 200 Gr FP in .44 Spl

 

[Rico567]

I agree with 'rcmodel,' (and possibly others, naturally). The trick is enough crimp, without working the neck brass so much that you get premature cracking. I load .38 Spl (the example given) to moderate velocities with a 158 gr. Rainer plated bullet, and shoot them in revolvers only. Given that, I'm belling the case (using the expander on a Dillon 650) around .004" (that's four thousandths), which is plenty large to avoid shaving the plating. I, too, use the Lee FCD in station 5, and following the included directions (I know, it's not very manly of me, but, oh well....) I bottomed out the die on the shell plate (necessary for the post-sizing operation), backed out the crimp apparatus, ran a case all the way up and screwed the crimper down until it just touched the case mouth. Then, when I loaded a round, I tightened the crimper 1/2 turn and checked:

1. The cartridge drops into the case gauge & the cylinder of my revolver.

2. I cannot budge the bullet with my thumb or by pressing with moderate force on the bench.

3. I conclude that this is enough crimp for these loads.

When I'm loading .45 Colt, I put a crimp more like "C" in the illustration in the OP, because there's a lot more inertia in the 250 gr. bullet to cause setback, and, more importantly, I shoot some of the .45 LC in a rifle with a tubular magazine that holds 13 rds., and I don't want those bullets moving in the magazine by a combination of spring pressure and recoil energy.

NB: For those who may be new to all this, when NOT using a separate crimp die like the Lee, i.e., you're using the standard seat/crimp die that comes with the majority of die sets, getting the die set to seat AND crimp is tricker, because you must allow some "windage" when adjusting the seating, and seat the bullet a bit further out to start. Then, when you crank the die down for the crimp, since you are simultaneously seating the bullet deeper it will come out right.

 

[Grape_Ape]

When I crimp a hair thick brass ring forms on the outside edge of the brass at the crimp. I can feal an edge with my finger nail. I have minimised the flare to seat the bullet. I am using the RCB bullet seater and crimper. I am measuring about .003 less at the crimp I am loading .44 mag 200 grain copper jackets. Trying to establish sufficent crimp to build enough pressure to seal the chamber so I don't get powder burns on the outside of the brass. I am concerned because this will reduce the life of the brass. Any suggestions?

 

[Walkalong]

If you have not deburred and chamfered the brass it is not uncommon to "shave" a very thin ring of brass off when crimping brass the first time, especially with new brass and new dies. It probably won't do it next time.

Some crimp ledges in dies are pretty sharp. A little polishing with a bore mop and flitz etc in a drill will help that. Trimming the brass to the same length, deburring and chamfering will help get rid of the "brass ring" as well.

.003 is not much of a roll crimp. A good crimp is needed on the .44 Mag for a good consistent "burn" of the powder charge in full loads with slow powders. Sure, crimping works brass harder, but it is necessary. Don't worry about it.

Welcome to THR

 

[Funshooter45]

I wish I had read all this stuff back when I first started reloading. The roll crimp was the item that I wondered about the most. I know I probably overdid the roll crimp a bit when I first started because I sure didn't want those bullets backing out of the cases. Over time, I began to reduce the amount of crimp I applied and I didn't have any bad results. I would say that most of my crimps are about the same as what walkalong calls his "medium" crimp. It is plenty. One thing that convinced me that I was applying too much crimp was to look at some factory ammo. I still had a few diferent boxes of factory stuff for .44 mag leftover from my pre-reloading days. I was very surprised to see that even fairly hot ammo from different makers either had NO visible roll or a very light roll crimp. So now, even with hot loads in my .454 Casull, my roll crimps are fairly modest.

I compliment the posters here on their excellent photography skills. I like the comments made by Seismic Sam regarding quantifying the amount of crimp with a set of calipers. Applying a 0.004" or 0.005" crimp is much more meaningful than saying "light" or "heavy".

 

[bushwacker_hock]

newbie question

I'm just beginning to reload and still collecting equipment. getting a rcbs rock chucker and will load 9mm luger, .270 win, 300 win ma, and .223 for my ar15. It seems like after reading this it would be worthwhile to seat and crimp bullets without powder or primers till I get it right. Is that reasonable?

 

[Jesse Heywood]

Excellent way to start. And when you get one perfected save it as a sample. You can use it to set your crimp and sizing die in the future. I keep a sample of every case/bullet combination.

Also, I would start with the 9mm. Easier for the beginner than bottlenecks.

 

[kelbro]

Trimming your pistol brass to length can be a somewhat painful process (did 100 357s yesterday) but it is one process that you usually only have to do once and will ensure uniform crimps. Accuracy follows consistency. I shot several 2" groups today with my Dan Wesson 15-2 at 25 yds. Open sights, resting the heels of my hands on sandbags. Using that trimmed brass and softcast 158gr SWCs from a Lee mold.

 

[Red_Dog_Leader]

Trying for a medium crimp...

Is this an ok crimp for:
MO bullet 158/.38spl
new win brass trimed & deburred and chamfered
3.7 WIN 231 @ 3.7
Lee seater then FCD

Trying for a "medium taper crimp", buddy says I need to really roll it in...I'm thinking just a wee bit more...

Thanks for the critique, T

 

[Trikerider]

Red Dog Leader, that is just what mine look like. I am using the same bullet and seated to about same depth and with same crimp, by looking at yours. I use the Lee FCD on my test loads. I also loaded some with Lee seat and roll crimp in same step. Haven't shot any of either type yet to see how they shoot. trikerider

 

[Walkalong]

A light taper crimp on a .45 ACP. It is .471 at the case mouth & .472 under the crimp mark where the bullet is seated.

 

[Maverick_52]

As I started reloading I always ran several rounds through without powder or primer to gain practice and the right crimp. Once done then I do save a round to use as a guide an example. 9 mm rounds are definitely a good round to practice with. Measurements are essential.

 

[onebigelf]

"C" looks just about perfect. All I'm looking for with crimp, especially on a straight wall revolver case, is consistent neck tension.

John

 

[Walkalong]

Light Taper Crimp on a Berrys .32 Long HBWC Feeds 100% in my Benelli.

 

[Gato Montés]

OK, so I started reloading using swaged lead bullets with no crimp groove. I found that, with a crimp groove, finding the right seating depth was a tad bit frustrating.

First attempt:

[/IMG]

It's kinda deceptive (well, to me anyway) finding out where the crimp will end up until you actually crimp it. These first guys, the case mouth looked just about even with the top of the groove, yet crimped it ends up a bit lower than anticipated.

Here's where I'm at:

[/IMG]

I lightened up on the crimp a bit and seated a bit further in. Mind you I'm not using perfectly trimmed brass. I'm looking for a compromise seating depth and crimp. These are just gonna be plinkers anyway. OAL is 1.462.

Soooo, lookin' good?

 

[Walkalong]

The one on the left looks real good.