9mm bullet setback

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Jan 9, 2013
Started loading 9 mm today and I'm having issues with setback. Using Hornady 115 XTP and Hornady dies on a LNL. I just can't seem to get the taper crimp right.
I tried the die expander and it seems to bell case too much so went with the PTX expander and it works much better and just enough for bullet to stay in place before indexing to crimp seat die.

Have tried every possible setting on the crimp from none to buckling the case. When putting dummy loaded rounds into my 9mm 1911 and racking slide I'm getting anywhere from .005 to .020 plus setback.
They all fit the Lyman case gauge and drop into the barrel fine. Bullet is seated to 1.075 as per Hornady 9th load data.
Am I missing something here as I have no issues with any roll crimp calibers or the rifle ones I load?
These are first time shot federal brass that have been ss pin tumbled.
Make sure the brass is fully resized (bottom of resizing die barely kissing the top of shell plate). If I see daylight while resizing, I will adjust the die until I don't.

Since case wall thickness average .011", I usually add .022" to the diameter of the bullet to determine my taper crimp. So for .355" sized bullets, I use .377" taper crimp.
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No amount of taper "crimp" will fix poor neck tension. The taper "crimp" is for removing the bell and maybe a hair more. Adjust it so the shortest cases will have the bell removed, which means the longest ones will get a hair of inward "crimp". Maybe .001 to .002. More will not help and since the case headspaces on the case mouth could even cause misfires.
Make sure the brass is fully resized (bottom of resizing die barely kissing the top of shell plate). If I see daylight while resizing, I will adjust the die until I don't.
Yep, important here since the case is tapered.
As others have noted, in 9mm bullet resistance to setback comes from brass sizing, not crimping. There's the first place to look.
do you have another source of brass to try and compare ?
the reason I ask I had a issue once with XTP set back I could push the bullet in with my thumb, It turned out the brass was bad if I used the Hornady die I got set back, with a LEE U die no set back ?
I tossed that lot of brass never had another issue.
Did you fire this brass your self to know its 1x fired or ?
It is my Federal American Eagle once fired brass. I even tried some Winchester brass from a commercial reloader that I shot and they do the same.
Sizer, expander and seat/ crimp die are all adjusted as they should be.
Brass at mouth is .386 to .387. After sizing it is .372 to .373. After expanding it is .373 to .374. I did these measurements after several case. I'm expanding about .001 just enough to barely set the bullet in the case.
After seating and crimping its about .376.
I will try to take some picture when I get home. I checked some commercial reloads I have and the bullets do setback .003 to .005" and Factory Federal American don't after thumbing slide lock.

I've never reloaded 9mm as they have been pretty reasonably priced for the amount I shoot but thought I would use these came from buying the LNL a few years ago.
I've never had this issue with any of my revolver rounds or rifle.
Don't know if this is a die issue or not as they are the only 9mm die set I have.
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You might want to read through this thread. I had a problem with setback in certain brands of brass. The Lee undersized die solved my issues in 9mm.

That is exactly whats happening to me with Federal brass. I found some other used Winchester and S&B and they did not set back hardly at all and the S&B even after 3 times through my gun moved only .003".
I don't think the sizer die is the issue as inside measurement after sizing is..349"
The Federal brass and a couple Blazer brass I had both set back 5, 10. 15 or so thousand.
Have you tried using cast bullets sized .356 or .357? Myself I use cast bullets for the most part. Have to admit I've never had a problem with set back in my loading of 9 mm. Curious as to whose dies that the OP uses.
No amount of taper "crimp" will fix poor neck tension.

This is pretty important to understand.

With no cannelure you are not "crimping" as much as just removing the bell/flare you put in place to seat the bullet.

If, after completing loading, you can pull the bullet and it's diameter has been reduced, you have found your problem and no amount of additional crimp is going to help, it will just make it worse.

The fact that you are at .376 after seating and crimping tells me that you are swaging the bullet down. The XTP is .355, subtract that from .376 and you get .021, divide that by two and would leave .0105 for case wall thickness and they are likely .012-.013" thick. So instead of .376" OD after seat and crimp you need to be closer to .380".

Why does crimping more hurt? Because, brass is somewhat "springy" and lead is not. So, you squeeze the bullet down with the case and it stays there but the case springs back. Also why more crimp at this point won't help.

I really try and seat then crimp in two steps to simplify setup (if you could you would notice that you have sufficient neck tension after seating, even with the flare, then it goes away after you crimp) and subsequent adjustments but you can do it at the same time too. Looks like you may be using a "dropper" style bullet feeder if so and you are using any sort of powder check on an LNL you are stuck with seating and crimping in #5.

Back your die out and back the seat plug out too, now lower the die just enough to remove the bell so the case fits the casegauge or your barrel without dragging, that will be your "crimp", now just lower the seater until you get the OAL you want. See what difference that makes.

A quick check would be to pull a bullet, if it looks similar to this, back the crimp off and the bullet is only worth melting at that point. The reduction in bullet diameter would equal the amount that you would want a loaded round measurement over the .376 you have now.

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Good post mr Morris as I will take any advice from you. Though I don't have a bullet die and have tried both the Hornady expander die and a PTX expander. The PTX seems to have a better expansion than the die.
I checked every bullet that I pulled and there were a lot of them and not one has any visible crimp line or any reduction that I could measure with calipers.
I have sizer die in hole 1, expander in hole 2 or powder measure and ptx in hole 2 or in hole 3 if no ptx then seat/ crimp die in hole 5. Will either use a powder cop in hole 4 or put seater/ crimp die there.
I set the die up like you said and now have .0377 to .0378" with bullet seated and crimped. Tried several loaded in mag and after one slide rack the set back is either none or several thousand inch.
I'm going to load some up with either 4.3 grains of Bullseye or 4.3 grains of 231 and see how they work.
I would have zero as my goal but a micrometer might be a better tool for measuring the difference. Also worth noting that the tip of a bullet hitting the feed ramp (or anything else) could take enough of an impact to effect an OAL measurement and not actually move in the case.

That said, at least you have solved the .020" movement problem. I don't know what load they were using but the folks as Speer measured a 34,000 cup increase in pressure by seating a bullet .030" deeper.

Sounds like you need to go back and start over. I'd start with checking whatever I'm measuring with.

Your "Brass at mouth is .386 to .387" is over max saami. You shouldn't be over .385" max.
http://www.saami.org/PubResources/CC_Drawings/Pistol/9mm Luger - 9mm Luger +P.pdf

Your "After sizing it is .372 to .373" is on the small size. I've always gotten .374"/.375" over the decades from several different reloading dies. I'm currently getting .374" from a set of lee dies.

It's the inside diameter of the case after belling that is important. The outside dimension of the case means nothing.

Crimping of the 9mm is 1 of the most mis-understood area's of reloading. It is also 1 of the most important!!!. Typical taper crimp dies are adjusted (depends of mfg) 1/4 turn to 1/2 turn down/deeper into the press after the taper crimp die touches the test case mouth. What 1/4 turn means:
the dies are threaded with 7/8-14 threads. That means that the die is nothing more than a 7/8" in diameter bolt that takes 14 full turns to travel 1".
14 x 4 ='s 56 or it will take 14 full turns or 56 1/4 (quarter) turns to travel 1".
1" - 56 1/4 turns ='s .018" per turn.
That means that the crimp die is only affectin .018" or 18/1000th's of an inch of the top edge of the 9mm case.
1/4 turn ='s .018" (18/1000th's)
1/2 turn ='s .036" (36/1000th's).
The idea is to turn the taper crimp die down enough to get a desired crimp. Myself, I typically use a 3/1000th's crimp on all the semi-auto ammo I reload (9mm/45acp) How many times has someone printed " I use a h&g #68 bullet with xxx powder with a 1.250" oal and a .369/.370 crimp". Countless billions of rounds have been put down range by millions of target shooters over the decades using a 3/1000th's crimp for the 45acp. The 9mm is no different, try measuring 6 or 7 different factory loads. They all end up .377"/.378" for the taper crimp on a 9mm.

Pictures are worth a 1000 words. Here's a picture of 2 of my favorite bullets to use/shoot in the 9mm's. The green bullet was designed for the 9mm. The red bullet was designed in the 1800's for the 38lc. The green bullet is a 125gr hp (hollow point) & the red bullet is a 150gr hb (hollow based). They both are sized to .358". What to look for in this picture:
Look at the walls of the 9mm case. They are smooth and tapered as they should be. You don't see any hourglasses, watermelon stuffed in the case bulge from under expanded brass. You will also see a faint shinny ring at the top of both reloads. That shinny ring is a 30/1000th's long taper crimp that crimped the top of the case mouth down to .377"/.378". When a taper crimp die is setup correctly only the top 20/1000th's to 36/1000th's of the case is affected.

Something else to keep in mind. A 3/1000th's crimp affects only .0015" of the bullet. A bullet has 2 sides, .003" divided by 2 ='s .0015". A typical piece of #20 pound printer paper is typically .0032". Onion skin tracing paper is typically .0018". So if you hold up a piece of onion skin tracing paper and look at the edge of it. That edge is thicker than the depth (crimp ring) left in a bullet from a properly adjusted taper crimp die.

The magic of that .0015" deep taper crimp is that is around 30/1000th's of a inch long. The back edge of a utility knife blade is around 30/1000th's.

Something to think about:
Great you got that coke bottle, watermelon stuffed in the case look thinking WOW "look at all that case neck tension". Don't need no taper crimp here, I'll save on brass wear and tear, better chamber fit and make sure I don't swage the bullet down. So I will only use enough crimp to remove the flare from the bell in the case.

Well as others have already posted different brass has different thickness and couple that with things like brass springback from different types/blends of the grades of brass. Then add the work hardeneing of the different brass from 1x, 5x, ???x times reloaded. The end result is huge differences in brass.

Consistency ='s accuracy
You take that watermelon round and shoot it. It will take different amounts of pressure from the load to expand/seal the chamber of the bbl. The closer you reload to the dimensions of the chamber, the more consistent you ammo will be.
A crimp, not only is it there as an extra measure for bullet setback it is there to aid in consistent ignition. Namely the short start pressure of a reload. You hit the loud bullet, and BANG, everything is off to the races. The fp hits the primer, it in turn ignites and burns the powder. In that millisecond the powder starts to burn the pressure from the primer and the expanding gasses of the burning powder is already starting to push the bullet forward. The crimp gives the bullet that extra hold that is critical to not only get a consistent burn from the powder, it will make for a consistent short start pressure. That in turn allows for a consistent bullet launch.

To much neck tension ='s huge swings in pressure to seal the chambers.
No crimp ='s throwing gas on those huge swings from the differences in neck tension from the different hardness of the brass, thickness of the brass, how much work hardening of the brass/springback. The only thing that is consistent is that your taper crimp will allow your powder to have a more even short start pressure.

Back in the day (decades ago) sihlouette shooters used full house loads in 296 in their 44mags. They found that their loads were more accurate with standard primers compared to the factory recommended (gotta use mag primers to get a good powder burn). The higher pressure from mag primers was starting/moving the bullet quicker than their standard primer counterparts. Which led to inconsistent short start pressure/powder burn which showed up down range with lower scores.

Those same reloads/bullets pictured above. A 10shot test group @50yds with that 150gr hb bullet. Note the fliers. I used mixed range brass for that test. As others have stated, some brass is thicker than others. And rp brass is thinner than most. The base of that long bullet was being swaged down when being seated so deep in the thicker cases. I swithed to using nothing but rp brass with this loadd and it cut down on the fliers.

A 10-shot group @50ft with those 125gr hp's.

The op really should start over and take some time to go through every aspect of reloading the 9mm. Start with sizing the brass and go from there. Ask others what their measurements/#'s are for all the different areas of reloading the 9mm. As it stands right now.
Your used brass # is too big.
Your sized brass # is too small.
You # for belling means nothing.

Just something to think about.
I agree that you have a case sizing problem. I would borrow a sizing die from a friend and try it. You might have a loose sizer.

One other thing I would advise is to replace the taper crimp die with a Lee factory crimp die.

As a general rule, I don't use Lee equipment, but that FCD is the greatest thing to happen to reloading in the last 50 years.:thumbup:
Well I think I have this issue of setback under control now. Forest I guess trifocals didn't work well as after re checking outside case dimension they are .385 ish.
I took a factory and a commercial reloaded round and set the crimp die to it on the press. Also I'm putting almost no bell on the case and thanks to the Hornady seat die guide bullets are seating and crimping good.
Also the sizer die was about the thickness of a piece of paper or two shy of where it is now. Don't know if that would make much of a difference or not.
Have no set back unless I rack slide on the same bullet several times then it moves .005 to .008".
Also talked to several who reload and they have had the same issues with Hornady XTP bullets. A couple of these guys only load 9mm, 40 and 45.
So now will load some up over the next few days and get to the range and see how it goes.
Thanks to all for help and will update after range visit.
Sounds like you are good to go. Do be sure to check some with your thinnest brass.

Up here Lee isn't really stocked much. I was going to try and find a FCD for 9mm but no one had one or a set of Lee 9mm dies with it. So I bought a set of RCBS carbide dies which are a $110.00. So I'm using RCBS sizer as I found it smoother than the Hornady one, Hornady expander, Hornady seat die and using the RCBS seat/crimp die as a crimp die only.
I only used the Federal brass that has been shot one time since new that is .012" and after seat and crimp its now is at .378" Which i will take.
Picture isn't the greatest.

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So how is the bullet setback?

I can push on it against the bench and really have to put my 210 lbs into it to get it to move. Slammed slide several times on same one and moved .005 to .008".
Big test will come after getting them primed, powdered and pull the trigger.
Glad to hear you have it sorted out.

I've pencil whipped myself often enough to know the chalk board's need cleaned every now and then.o_O
I can push on it against the bench and really have to put my 210 lbs into it to get it to move. Slammed slide several times on same one and moved .005 to .008".
I now use the bullet feeding/chambering from the magazine to test neck tension as pushing on the bench top does not reproduce the forces involved when the bullet nose slams on the feed ramp.

You only need to measure the initial bullet setback as deformation of bullet nose may not accurately reproduce on subsequent feeding. I am OK with bullet setback of a few thousandths and up to .005" but not significantly beyond that.
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