First Time Reloading Part 5 - Seating and Crimping

[sirgilligan]

I didn't want to try and learn how to seat and crimp with a case primed and with powder.

So, I took my resized brass and some 55 gn Hornady FMJ-BT bullets and got out the the seating die with roll crimp, and the seating die with taper crimp.

I followed the instructions that came with these RCBS dies.

I didn't realize how much a turn of the screw would change the depth so my first one I got a little too deep.

The second one I got right were I wanted it and then followed the directions for setting the roll crimp. That went well and then I screwed the pin in until it touched the bullet firmly and locked everything down and tried seating and crimping in one step. It didn't seat as far as I thought, so adjust it about 1/2 a turn and everything went just fine.

Did the same all over again with the taper crimp die. The directions are different for a taper crimp so when I got to the crimping setup step I would turn the die down a little, take the case out and measure according to the directions in the RCBS die. Eventually I got it to crimp some, but honestly it is hard to see.

The roll crimp put a nice little curve on the top of the neck, kind of smooth and subtle.

The taper crimp just looks squeezed a bit, no smoothness to it.

I will take these and see if they chamber, etc., in my three rifles sometime soon.

 

[gamestalker]

Honestly, crimping bottle necks is almost always unnecessary. About the only exceptions would be is if you are using them in a tubular magazine, or being shot from a FA weapon. Other wise, it's just not necessary, and has little, if any positive effect for most.

But OTOH, if you've managed to get the crimp process correct, and don't have issues with shoulders collapsing or getting crushed, then you've managed to succeed where numerous others have struggled, and, or failed. In this case, I would now evaluate whether the crimped rounds are any more, or less accurate.

GS

 

[Walkalong]

If you are going to roll crimp .223 you will need cases trimmed to the same length and bullets with a real cannelure, not just roll marks, and cannelures that are placed consistently on the bullet. The taper crimp is much more forgiving. Chances are you have it over done.

I put a light taper "crimp" on 55 Gr FMJ plinking/blasting ammo. Most do not crimp .223 at all.

I loaded some .223 more aimed at accuracy last night (Better sizer, better seater, better bullets), and I put a .063 spacer ring under the taper crimp die so it just barely, barely, BARELY, touched the case mouth. These will shoot very well, or at least they did the last time.

Again, many do not crimp .223 at all.

 

[Potatohead]

Roll crimping 223? Never heard of it. I always just figured I was listening to folks talk about taper crimping in that conversation...Is that what people are meaning when they say they crimp 223?

I guess that makes sense, it wouldnt be a "taper" crimp since the mouth hasnt been expanded..?

 

[Walkalong]

Whether the case mouth has been "expanded" or not has nothing to do with the type of crimp one might use.

 

[moxie]

No crimp needed. Serves no purpose unless firing full auto.

 

[sirgilligan]

Thanks for the advice that crimping is not necessarily needed.

I am just trying to learn how to do these things. I will take some pictures and post them to show you all what the results look like. I will have to get out the camera because the iPhone isn't going be able to get in close enough to show what I am seeing.

 

[sirgilligan]

Here is a photo of the roll crimp. It is so subtle that I have to hold it next to a cartridge with no crimp and then I see the smoothness/radius on the top edge.

 

[sirgilligan]

Guess what, I looked at the taper crimp to see what it looked like and yes, the shoulder is messed up on one of them. It is so slight I didn't notice it until I looked at it with a magnifying glass. I drop it into the case gauge and sure enough the case head is sticking out above the gauge less than 1000th of an inch, but it is still sticking out.

 

[Walkalong]

A little over crimping will buckle a shoulder easily. And it doesn't take much to cause a problem.

All part of why I recommended trimming to the same length and using bullets with good cannelures consistently placed on the bullet.

In your pic the case mouth is too low. It should be rolled into the middle of the cannelure where it should be its deepest.

http://www.thehighroad.org/showpost.php?p=6385988&postcount=75

Here are a couple of pics. As posted earlier, the taper crimp is much more forgiving, unless it is too heavy.

Roll Crimp on a Winchester 55 Gr FMJ in .223.

Taper Crimp on a Winchester 55 Gr FMJ in .223.

 

[sirgilligan]

Thanks for the photos. So, I should have seated the bullet a little deeper? Is that what you mean by the case mouth being a to low?

I got a kinetic bullet puller and I was surprised at how hard I had to smack the cement floor to get it to come out. I put a piece of card board on the floor, I just couldn't bring myself to hitting it on bare concrete.

 

[Walkalong]

Yes, seat a bit lower. Sounds like you have plenty of neck tension, which is good. No amount of crimp can make up for poor neck tension.

 

[Potatohead]

Whether the case mouth has been "expanded" or not has nothing to do with the type of crimp one might use.

Ok. My line of thinking was that putting just a touch of taper crimp on a 9mm case was primarily to tuck the flare back in a bit, from it being belled/flared/expanded. But I guess that is not what is meant when I hear that we "expanded" a case.

Im a bit confused by the lexicon here, well hopefully just the lexicon.
Or "expanded" is what we're doing to pop the mouth back to the right dimension after it's sized down?



Will PM to avoid hijack.



..

 

[Walkalong]

You said:

Roll crimping 223? Never heard of it. I always just figured I was listening to folks talk about taper crimping in that conversation...Is that what people are meaning when they say they crimp 223?

I guess that makes sense, it wouldnt be a "taper" crimp since the mouth hasnt been expanded..?

I said:

Whether the case mouth has been "expanded" or not has nothing to do with the type of crimp one might use.

You can taper crimp a .223 case, irregardless of whether the case has been expanded or flared, or you can roll crimp a .223 case regardless of those things. I do not know anyone who flares .223 cases, but almost everyone expands them with an expander ball during the sizing function. Either that or they use a bushing die, or a sizer with the neck custom reamed. But it doesn't matter how one gets the bullet loaded, you can taper or roll crimp the round.

That better?

 

[Potatohead]

Gotcha. Analysis paralysis again..

 

[moxie]

With (most) straight wall handgun calibers, and a three die set, the second die is the expander die. It does two things. First, it restores the case diameter to just below that of the bullet diameter, so that when the bullet is inserted there will be a tight friction fit, or good case neck tension, as it is called. Second the expander die also "flares" the very end of the case mouth just a tiny bit to accept the base of the bullet, or "get it started."

With most bottle-neck rifle cartridges, the usual is a two die set. The first die sizes the case AND expands it. Given decent de-burring of the case neck, flaring isn't necessary. So the second die seats the bullet and, if desired, crimps the case. If you are using lead bullets, you might need a bit of flare to seat the bullets. In that case you get a 3 die set that essentially functions the same as a handgun 3 die set, with the second die expanding and flaring.

Regarding crimping.
A "taper crimp" really just removes the "flare" and reduces the case mouth OD to permit smooth feeding and doesn't actually crimp at all.

A "roll crimp" turns a bit of the case mouth into a cannelure or crimp groove. It's purpose is NOT to increase case neck tension. In fact, it can reduce/ruin case neck tension.

The roll crimp's main purpose is to prevent bullet "jump" or "creep" OUT of the case, particularly in heavy recoiling revolvers. The crimp can also, some say, ensure even ignition of the powder, especially in cases with large volume. Crimp can prevent bullet movement in rifles with tubular magazines. And ditto in full auto guns.

 

[trixter]

OK so, if you are opening the mouth a little for lead boolits, won't you want to 'taper crimp' it back to the proper diameter?

 

[moxie]

You can with the third die if needed to chamber smoothly. Either taper or roll, squeeze the flare in just enough for good chambering.

If you do intend to load lead bullets, you can get a neck expander die to augment the 2 die set you have already.

 

[Walkalong]

Get a Lyman M Die for lead.

 

[sirgilligan]

So, I started from scratch again. I do this to get a feel for the entire process of seating and crimping.

I seated all of the bullets a little deeper and got the case about 7/8 covering the cannelure.

I kept one cartridge with no crimp and set it aside.

Next I did the roll crimp. I set it so I just barely felt anything on the press arm. Viola, it was done.

Next the taper crimp. Again, just the bare minimum and then I took out the case and measured the diameter of the neck. It had taper the neck .002" at the cannelure. Sweet.

Since I had such success I got out the Lee Factory Crimp die. The directions said to run it in until it touches the empty shell holder and then lower the press and turn it in 1/2 turn more. I did this and when I raised it I watched from the top as it closed the collets and I could tell the resistance was a lot and I wasn't near the camming point, so I redone it and turned it in less than 1/2 a turn and it gently cammed over and put a nice crimp. That was very easy. The easiest of them all in a way because I didn't have to rely solely on feel but I could look in the top and see what was happening too.

I then checked the cartridge over all length against the non crimped cartridge and they are all the same length still. Wooo hoooo!

I will take some pictures of the cartridges.

I am saving these for reference, since it may be a long time before I get to this again.

 

[sirgilligan]

 

[sirgilligan]

The roll and taper crimps look very slight but I can measure the difference to be about .0015" of an inch less than the non taped round.

I guess I could go for a bit more, but I am satisfied for now that I have a basic understanding of what is happening.

 

[edleit]

crimp & flare comments

For my .223 range fodder, I've been using the Lee FCD. SirGilligan, I agree with you, this was by far the easiest way to get a consistent crimp on these rounds. It's also MUCH less sensitive to case trim length.

If I decide to develop an accuracy round, I may need to pay closer attention to uniform trim length and a taper crimp process

As Walkalong suggests, the Lyman M die sounds like an essential tool for when I start developing accuracy loads with lead bullets for the Mosin.

 

[Walkalong]

The taper looks fine (Light, but fine), the roll crimp needs some more, and the FCD crimp looks good.

It's also MUCH less sensitive to case trim length.

It is completely insensitive to it. Unless of course the case is waaaay too long.

 

[edleit]

Your FCD results are far more displaced than any of the rounds I prepared. My crimps were about half that length from the case mouth, as I recall. It will be interesting to hear about your range performance.