Bullet Setback for 9mm...

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gcleff11

gcleff11

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Apologies if this question has been asked before. I did scan for info in this forum, and didn't find any. I'm new to reloading (totally cool hobby, by the way), and recently received an order from RMR for 9mm Luger BrightFired Brass Cases #1, at a 1000 count. The first hundred I reloaded are having several bullet setbacks, even when there is hardly any pressure on the bullet nose. The cases are clearly 9mm, and yes there are a few non-9mm in the mix, but that was to be expected. Case expanding was almost too easy (my first red flag); and basically needed barely any to comfortably seat the bullet. I'm using 115g bullets. Wait for it. Here they come. The newbie dumb questions of the day...

Is there some correlation between the weight of the bullet and the available case used to seat it? Would a higher weight bullet have alleviated the issue?

I'm at the point where I'm apprehensive to even shoot one of the darned things. All other reloading I've done recently with 9mm were with cases not purchased from RMR, and they all worked like a champ. Any info from the masters of this craft is greatly appreciated. Thanks to all...
 
A higher weight bullet would have more shank of the bullet to add to neck tension than a shorter one but the case produces the neck tension, not the bullet length or the crimp.
We have to figure out why you have no tension in your case.
question 1
Is your resizing die screwed down against the shell plate and touching it? 9mm cases are tapered and if the resizing die isn't touching the shell plate you won't get all the neck tension you should have. If your using a single stage press it only needs to touch, if your running a progressive then the die should contact the shell plate a little harder to compensate for flexing.

question 2 This is mixed brass, are all the loose ones the same brand or are they mixed?

question 3 Did you look at the carbide bushing to see if the bushing is cracked?

question 4 Are you using a 9mm neck sizing die or a .38spl.

I wouldn't shoot them until you get it figured out. I have had brass that for no apparent reason wouldn't have neck tension. Brass will harden up from being shot and will resist keeping it's shape when resized. I have had to just throw them away.

Lee makes an undersized neck sizing die for 9mm that may help you if your cases won't respond to being resized. It's the only alternative to this problem I know of.
 
What sizer are you using?
What is the diameter of the expander?
What is the diameter of the bullets?
 
Bullet weight should not be an issue. As posted above the 9MM case is tapered and it is important that the die is screwed down far enough. That means it barely touches the shell holder or plate when actually sizing a case. Not just running the ram up empty.
 
You did resize these, right? It sounds to me like you're seating bullets in brass that hasn't been resized.

Unless the brass that you bought is specifically described as being fully processed, all that has been done to it is that it's been cleaned to make it look pretty.
 
What brand die are you using to expand? I've noticed hornady nickle plated seats way easier than brass. I've mixed the brass and nickel, and bullets will seat deeper into the nickle. So I have began to separate them from the brass. Sometimes bullets will seat easier in dfferent brass, but as long as the COL checks out and Lee post crimp I haven't had any problems.
 
Did you buy the dies new? There should be instructions to show you how to set the dies up. If not, try a Google search for your brand of dies. This would be a great starting point, but it's only that, you must tweak the set up from there.

It could be that the resizer die is not down all the way, as many have said. I think it might be the bullet seater/ crimp die, due to my own experiences. If you have a three die set, you should have a resizer/decapper die, and expander die, and a bullet seater/crimp die. The last stage of many presses is that the bullet gets seated to a certain depth, AND the same die "crimps" the case around the bullet, removing the enlargement required to get the bullet in the case.

My issue at first was that I was "belling" or expanding too much and then if the seater/crimp die wasn't set correctly, you wouldn't get any pressure on the case mouth to stop the setback. The crimp action of the die is set by screwing the die into the press to thr correct depth. The seater adjustment is the screw adjustment on the top.

Follow the instructions that you find for your brand of dies. I say this not to be a jerk, but to potentially remedy your own mistake. I'm fairly new at reloading myself and I continue to learn stuff on every new caliber I start to reload. It's definitely a process.

Edit.. realized that I needed to space between paragraphs..
 
Omigoodness, thanks for all the responses. I will address specific questions, because many of them may lead me to the issue. But in the interim, I will provide this info:

All equipment on the workbench is new RCBS -- just starting out I wanted all the equipment to be one brand
Dies were all cleaned/inspected before first usage (per instruction recommendation), and fully functioning correctly
As mentioned before, all brass that I have reloaded--with shells that were not the RMR stock I'm having the issue with--have been perfectly functional
I believe I am doing everything correctly, evidenced by the many reloads that have been shot/cleaned/primed/etc with the cases that are not the RMR ones

I will be replying to specific questions, but if I do not reply to your post please know that I thank you for your thoughts and insights. The end game is to continue to shop RMR products. At face value, the problem seems to be what they sent me from their third party vendors. I hope it's me and not them. Ya just want things to work as they should. Thanks to all...
 
The one question that has been asked several times and not yet answered is : Did you resize these cases before you started loading them?

This might be the aha moment. The cases came unprimed, and are supposedly ready to go. I trusted info from online reviews of the product that they were load ready. I will start from square one, and treat them like I just picked them off the ground after shooting--sans cleaning. I will certainly let folks know in here on this thread. I really hope I didn't waste all your time. I sincerely do appreciate the help...
 
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Eh, lesson learned. BTW, "ready to go" usually means that they are prepared for loading and when loading, the first step is to always run them through a resizing die, whether they are processed or brand new. I load on a progressive press so resizing just sort of happens anyway.

The only time I've ever loaded without first sizing them just to make sure is when I bought brass that came primed.
 
gcleff11 said:
The cases came unprimed, and are supposedly ready to go. I trusted info from online reviews of the product that they were load ready.
Click to expand...
"Ready to go" and "Load ready" doesn't commonly mean that they don't need to be run through a Sizing die. Even brand new factory brass that you might purchase needs to be initially sized
 
index.php

gcleff11 said:
RMR ... 9mm Luger BrightFired Brass Cases #1, at a 1000 count.

115g bullets ... having several bullet setbacks, even when there is hardly any pressure on the bullet nose
Click to expand...
I have been using several thousand RMR 9mm BrightFired brass (see above picture) along with several thousand "once fired" range brass from member ljnowell and 5 gallon bucket of brass I have collected in recent years. I have not experienced neck tension issue you are having with various .355"-.356" sized bullets.

If you are having neck tension issues with full-length resized brass, you may be expanding/flaring the case mouth too much, which could enlarge the resized case neck. When adjusting the expander/flare die, since longer cases will expand more, I usually measure several sample resized brass lengths and use middle average length to set my flare amount. I use just enough flare to barely set the bullet base barely inside of case mouth. More than that, you could risk enlarging the resized case neck, which would reduce neck tension.

And make sure you are not using too much taper crimp as too much crimp can reduce the bullet diameter and brass spring back can reduce neck tension. You just want to return flare back flat on the bullet. Since case wall thickness averages .011", I usually add .022" to the diameter of the bullet for taper crimp amount. So for .355" sized bullet, .377" taper crimp. And for .3555"-.356" sized bullets, .378" taper crimp.

Also, try using 1.130" OAL with 115 gr FMJ/RN bullets as I have found using shorter than 1.100" OAL will start to decrease neck tension as 9mm is a tapered case.

These are actual bullet setback I have measured using various headstamp brass and different .354" to .356" sized bullets which ranged from none to .001"-.003" - https://www.thehighroad.org/index.p...neck-tension-and-bullet-setback.830072/page-4
 
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LiveLife said:
index.php


I have been using several thousand RMR 9mm BrightFired brass (see above picture) along with several thousand "once fired" range brass from member ljnowell and 5 gallon bucket of brass I have collected in recent years. I have not experienced neck tension issue you are having with various .355"-.356" sized bullets.

If you are having neck tension issues with full-length resized brass, you may be expanding/flaring the case mouth too much, which could enlarge the resized case neck. When adjusting the expander/flare die, since longer cases will expand more, I usually measure several sample resized brass lengths and use middle average length to set my flare amount. I use just enough flare to barely set the bullet base barely inside of case mouth. More than that, you could risk enlarging the resized case neck, which would reduce neck tension.

And make sure you are not using too much taper crimp as too much crimp can reduce the bullet diameter and brass spring back can reduce neck tension. You just want to return flare back flat on the bullet. Since case wall thickness averages .011", I usually add .022" to the diameter of the bullet for taper crimp amount. So for .355" sized bullet, .377" taper crimp. And for .3555"-.356" sized bullets, .378" taper crimp.

Also, try using 1.130" OAL with 115 gr FMJ/RN bullets as I have found using shorter than 1.100" OAL will start to decrease neck tension as 9mm is a tapered case.

These are actual bullet setback I have measured using various headstamp brass and different .354" to .356" sized bullets which ranged from none to .001"-.003" - https://www.thehighroad.org/index.p...neck-tension-and-bullet-setback.830072/page-4
Click to expand...


The OP didn't size the brass.
 
If you can hold your loaded rounds to the light and see the bulge in the case at the base of the bullet you're probably good, if you have followed the excellent advise from all of the above folks you should be able to see that. A case with good neck tension typically exhibits a nice "waist" under the bullet.
 
We are good...! Got all the bullets pulled safely (what a kitten that RCBS puller die is); cleaned and processed 25 rounds of previously used cases; resized and processed 25 rounds of the clean RMR cases, and measured all. Specs were right on Nodor numbers. Went to the range close by, and all worked like a champ. Big relief on my part, having just purchased 1000 rounds of the RMR stock...

Tremendous thanks, again, for all your help. This will never be a mistake I make again. Stay healthy, all...!
 
Hate to be a bother to RMR, but I after all the issues I had above, the batch of one-offs from RMR have had more than an ordinary amount of throw away cases. We're cool, because we've found a ton of range cases in BLM property, but damn...I wanted a thousand of cases that worked. Trust me, even as a novice, I know how to make a cartridge. Some of the RMR cases (after sizing/expanding/seating) looked like they were pregnant, and Tinkerbelle could have hit them with a tiny wand and sent them down to the bottom of the case. I haven't had a problem with the 45 acp range cases from RMR, yet; but I'm watching, kiddos... I'm watching.

And thanks to Shimitup... I know I have a good cartridge when I see the skirt right below the bottom of the bullet on the case after taper crimp. Some may not see it, but I do. It makes me feel like the Mohican when I load up... ;)
 
RMR has great customer service, did you talk to them? Those "throw away cases", what was wrong with them?
 
I read the descriptions for both fully processed and unprocessed brightfire cases. Shame on me for wanting to save a couple of bucks, and have the resizing die do what it is supposed to. And judging from some of the comments on this thread, there are those who would bang the 'fully processed' cases through the resizing die, regardless...

@Walkalong... Pull the setback bullet; reclaim the powder; carefully deprime the live primer while resizing the case; expand as usual (meaning just enough); load the powder; seat the bullet to proper OACL; et viola'! Bullet setback again! I have tons of time for this hobby, but not enough for rework--give it another go--try yet again--on the same dozen or so cases, just to have the outcome be the same...

I also have 1000 RMR brightfire one-offs in 45 ACP, and have had no setback issues with any one of them...
 
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