9MM lack of neck tension FC brass

[crimsoncomet]

I am coming to you guys again! Now I am having problems with 9mm neck tension. From a previous post, I am working up loads for suppressor use. I have loading these to 1.142". Today I decided to load to 1.120" and work my load back up just for kicks and giggles. I adjusted the seating die and put my calipers on the bullet. The bullet set back in the case from that small amount of pressure! So, I checked my expander and it is fine. It measures right at .351". I then tried sizing several different brands of cases. CBC, GFL, REM, did fine. WIN was hit or miss and seemed to be in the middle. FC and blazer/speer was no go! Like I said, the expander plug is fine. I can pretty much slide every case over the plug by hand. FC slides over super easy. I was not crimping these rounds. Just sizing and expanding.

So, I feel that my findings point to my sizing die not sizing down enough. Its strange that I have never noticed this before. Maybe it is just the MG 147 bullets I am loading. The Precision delta 124's I normally shoot dont seem to have as much of a problem. I have loaded up about 200 rounds with this brass at 1.142" and it seems okay. I could still push it back if I push hard enough. The end of the brass doesnt appear to be close to the O-give.

Should I buy a new die? If so, what brand? Thank you so much in advance for all the help!

 

[918v]

What does your sizer die have stamped on it?

 

[NeuseRvrRat]

do you have the die all the way down against the shell holder?

 

[crimsoncomet]

The sizer die is stamped 9MM LUGER CARB . 8

The die is all the way against the shell holder on my dillon press.

 

[NeuseRvrRat]

9mm cases do have a slight taper to them. if they're cycling with the longer COAL and have sufficient neck tension, why seat shorter?

if it ain't broke....

 

[crimsoncomet]

I agree if it ain't broke don't fix it. But I prefer a lot of neck tension. I still feel that I am on the border of seating a bullet back while feeding.

 

[beatledog7]

Have you measured some bullets to check their diameter? If they are a tad small, that would account for the setback.

 

[crimsoncomet]

Just measuring with calipers they seem right on with xtp's. Guess I need to break the mic out.

 

[918v]

You might be belling the case mouth too much.

 

[crimsoncomet]

I'll try belling less, but I do just bell enOugh for the bullet not to seat crooked or fall off when ramming

 

[atblis]

What dies are you using? Not that it matters really. Pretty much everyone's handgun dies work just fine.

 

[crimsoncomet]

I just tried something. Went to the bench, sized a FC case, did not expand, and partially seated a bullet to about 1.230". I then pressed the bullet with my thumb, nose down, onto my bench. It took a little force, but it popped right into the case and hit the taper. I should not be able to push down with one thumb and push the bullet into the case. I hate to trash all the FC brass I have.

I am using a RCBS sizer, dillon powder die, dillon seated, an rcbs taper crimp die.

 

[atblis]

How are you installing the sizing die?

 

[crimsoncomet]

The sizing die kisses the shell plate. All my bullets measure the same.

 

[918v]

If you can seat a bullet in a sized case by hand, then your sizer is bad. Send it and dome cases back to RCBS and they will replace it.

 

[crimsoncomet]

I guess since it works with some brass but not all brass, it's on the larger side of the specification. Has anyone ever used a lee u die?

 

[Fisherdave10]

I think you have a sizer issue. All of my FC brass (probably the majority of my brass stash) works wonderfully. Talk to RCBS about your die and they'll probably take care of you. If not, I like my new Hornady 9mm die set. With the rebate, you'll get free bullets with the set too.

You might want to look into getting a Lee Factory Crimp Die for 9mm. I bought one just last week and I am really impressed by it so far. The taper crimp the die applies would be a safe and effective way of increasing neck tension instead of needlessly shortening your OAL. All of my loads are at, or longer than 1.15"-ish.

 

[918v]

A U die is going to make U happy.

 

[rcmodel]

The taper crimp the die applies would be a safe and effective way of increasing neck tension

Actually it wouldn't.

If you have insufficient case neck tension to start with, more taper crimp will not fix it.

The case is harder brass then the bullet jacket and lead core.

SO when you squish the case into the bullet with more taper crimp?
The case springs back, and the bullet core doesn't.

rc

 

[crimsoncomet]

Thank everyone for the help. I will be ordering a U die today. But, I will be calling RCBS tomorrow and take advantage of that lifetime warranty. I will send them the die, a few cases and a few bullets a suggested. Would a lee FCD be of any assistance. I feel if using a U die, it is probably not needed. Thanks all.

RC, I totally agree with you. A taper crimp is for nothing more than feeding reliability to remove to bell.

 

[918v]

[Clap] Bravo! [\Clap]

 

[atblis]

The FCD isn't needed period.
FCD = (regular old crimp die)+(carbide sizing ring at the bottom)

The carbide sizing ring fixes problems that shouldn't exist. Fix those problems. Don't put a band aid on them. The usual problem is excessive flaring. Reduce the flare. If there is any residual flare, a very light crimp should remove it.
and
It can create problems. Most usually resizing the bullet. Resizing the bullet is no bueno.

All sizing that needs done should be done by the sizing die.

I honestly don't know how it's possible to make 9mm with inadequate tension on the bullet (without having faulty dies, brass, or bullets). The darn case bellies out around the bullet.

 

[CZ9shooter]

I have noticed the exact same problem as the OP. In my single stage press there is a noticable difference in feel when seating bullets into FC brass compared to most other brands. I have seen it a bit with Blazer too, but not so much. When dealing with mixed headstamps I would get inconsistancy with seating depth (OAL) as well. Blazer and FC tend to seat a little deaper.

And the ring around the base of the bullet, or belly as was mentioned above, I have never seen on a FC case. Other brands yes, FC no. FC cases with jacketed bullets will setback fairly easily in my experience.

My theory is that the wall thickness on these must be a tiny bit thinner than with other brands. The resizer die will make the OD on any headstamp nearly identicle. The ID will then vary with brass thickness.

I have found a solution though... lead bullets! These looser fitting cases work wonderfully. The extra bullet diameter is just enough to prevent setback. The "looser" fit may also prevent swaging the lead bullet down too. It's perfect.

 

[beatledog7]

Different brands of brass allow the same bullet to seat deeper? With the seating die adjusted the same? I don't get the simple physics of that.

 

[918v]

My theory is that the wall thickness on these must be a tiny bit thinner than with other brands. The resizer die will make the OD on any headstamp nearly identicle. The ID will then vary with brass thickness.

It depends on the vintage. Old production FC, with large and deep lettering, and the sandblasted casehead, is soft and thin. The new "dot FC dot" and subsequent small lettering "FC" is thicker and harder, much like RP and WIN.