Chamfer 9mm: Too Little, Too Much Or Just Right

[ArrowJ]

After much research I find that you should not bother using a chamfer and debur tool on 9mm brass...unless you should which lots of other guys suggest.

Reading about it is one thing, but seeing it is another so I searched The Youtubes and find that you just need to run the tool around the inside and outside as if your goal is to barely touch the brass with the tool...unless you are supposed to press super hard on your bench prep tool until you have five pounds of brass shavings after doing ten pounds of cases.

Anyone care to make this less clear for me? It would have been prudent to get at this before I performed the operation on 1,300 cases, but then I would appear smarter than I am.

A sample of my work.

http://uploads.tapatalk-cdn.com/20160310/3f61f9ab27597623bcaed91d24420579.jpg

[merlin101]

From what I can see, it looks like you went quite a bit farther than I ever do. It might be a problem as the 9mm headspaces of the neck of the case and you might have to crimp those cases 'to much' for it to properly headspace on. I'd load up a few and after passing the plunk test take them out and fire them, any 'short' cases will probably misfire and look like a light primer hit.
Remember! You only have to chamfer ONCE! and just a little goes a loooong way.

[lightman]

I can't really tell by looking at the picture. You just want to break the edge and leave the mouth flat. Its easy to cut too much with a new tool thats sharp and fresh. Those should shoot fine.

[aap2]

Unless you are trimming the cases it's not necessary to deburr/chamfer them IMHO. Straight-wall pistol cases rarely if ever need trimming in my experience; and short/fat cases like 45 ACP actually get shorter with repeated reloading and every new 45 ACP case that I have ever measured was shorter than the SAAMI specs so there is nothing to trim. I'm guessing that 9mm brass is pretty much the same and I have never trimmed a single one. When I reload the thousands of mixed 9mm range brass that we process,each case mouth gets expanded and slightly belled by the powder thru die so chamfer isn't needed but a very light cut to break any sharp edge certainly can't hurt anything (IMHO it's unnecesary).

[ArrowJ]

Those should shoot fine.

I am going to pretend that was the only reply :)

Thanks guys. The next batch will be very light. So since I am not trimming at all do I need to debur as well, or can I skip that?

[aap2]

IMHO you can skip the deburr as well since you aren't trimming. The cases that you have done so far (in the photo) are absolutely fine to use.

[bangerjim]

I have never trimmed, deburred, or chamfered any 9mm cases. Or 40's. Or 38's. Or 44's. Or 45's. Not worth the time, and is not really required in my book.

Only bottleneck rifle cases get the full treatment....when needed!

But - do what you feel is necessary.

banger

[wawoodwa]

Everyone has their process. I don't trim 9mm as the case will start splitting before it elongates. As a straight wall cartridge, there isn't any shoulder for the gas to push against that could stretch the case. All the pressure goes behind the bullet, except for what is expanding the case outwardly. My cases are lost (or split) before there is a chance that I will need to trim it.

That said, reloading is a personal experience, and if you want to trim, chamfer, and debur, go for it! Your cases look good btw!

[ArrowJ]

I am not going to trim, heck I am not sure if any of them would be long enough as most are actually shorter than spec.

Several guys on another forum were saying they chamfered for lead bullets, but then a bunch that said it did nothing. I suspect it does very little.

I have not even started making the bullets yet. If you think I am asking a lot of questions now! My father in law has cedar saw dust for me, but I will not have it for another two weeks and then it is my understanding I need to let it dry. I am chomping at the bit, but I think I will wait for the saw dust rather than use store bought flux.

[bangerjim]

I am not going to trim, heck I am not sure if any of them would be long enough as most are actually shorter than spec.

Several guys on another forum were saying they chamfered for lead bullets, but then a bunch that said it did nothing. I suspect it does very little.

I have not even started making the bullets yet. If you think I am asking a lot of questions now! My father in law has cedar saw dust for me, but I will not have it for another two weeks and then it is my understanding I need to let it dry. I am chomping at the bit, but I think I will wait for the saw dust rather than use store bought flux.

Pine sawdust is the standard. Cedar (aromatic) puts off oils when burned that can irritate your lungs and eyes. I do NOT use cedar. Or walnut. Or oak. All of which I have ample supplies of from my wood shop. I only use pine and alder sawdust. Buy a pine 2x4 at the big box and cut on it to make your sawdust. Or have your FIL cut it for you and collect it.

Or...........Get pine pet bedding in a big bag at Walmart. It will last you for a looooooooooong time for only a few dollars.

banger

[Le Loup Solitaire]

A slight amount of chamfer is ok, but as already indicated....if carried too far it will interfere with the taper crimp that is needed to keep the loaded round able to seat on the case mouth. Your cases in the photo may be a bit too far so I would recommend going a little lighter on the chamfering just to be safe/sure. LLS

[captain-03]

I have never trimmed, deburred, or chamfered any 9mm cases. Or 40's. Or 38's. Or 44's. Or 45's. Not worth the time, and is not really required in my book.

Only bottleneck rifle cases get the full treatment....when needed!

But - do what you feel is necessary.

banger

I have always been in this camp!

[funnyjim014]

I have never trimmed a pistol case....now that I think about it I don't think I have even measured one lol

[osteodoc08]

I have never trimmed, deburred, or chamfered any 9mm cases. Or 40's. Or 38's. Or 44's. Or 45's. Not worth the time, and is not really required in my book.

Only bottleneck rifle cases get the full treatment....when needed!

But - do what you feel is necessary.

banger

Same here

[Don Fischer]

After much research I find that you should not bother using a chamfer and debur tool on 9mm brass...unless you should which lots of other guys suggest.

Reading about it is one thing, but seeing it is another so I searched The Youtubes and find that you just need to run the tool around the inside and outside as if your goal is to barely touch the brass with the tool...unless you are supposed to press super hard on your bench prep tool until you have five pounds of brass shavings after doing ten pounds of cases.

Anyone care to make this less clear for me? It would have been prudent to get at this before I performed the operation on 1,300 cases, but then I would appear smarter than I am.

A sample of my work.

http://uploads.tapatalk-cdn.com/20160310/3f61f9ab27597623bcaed91d24420579.jpg

I have never chamfered any straight wall pistol case. I'm fairly new to 9mm and read recently that the 9mm headspaces on the case mouth. In the photo of the ones you've done, that sharp edge seem's to me will be prone to splitting, I'd watch for that. I don't know if it's a good idea or not but you might trim them back a bit and remove that edge.

[Don Fischer]

After much research I find that you should not bother using a chamfer and debur tool on 9mm brass...unless you should which lots of other guys suggest.

Reading about it is one thing, but seeing it is another so I searched The Youtubes and find that you just need to run the tool around the inside and outside as if your goal is to barely touch the brass with the tool...unless you are supposed to press super hard on your bench prep tool until you have five pounds of brass shavings after doing ten pounds of cases.

Anyone care to make this less clear for me? It would have been prudent to get at this before I performed the operation on 1,300 cases, but then I would appear smarter than I am.

A sample of my work.

http://uploads.tapatalk-cdn.com/20160310/3f61f9ab27597623bcaed91d24420579.jpg

I have never chamfered any straight wall pistol case. I'm fairly new to 9mm and read recently that the 9mm headspaces on the case mouth. In the photo of the ones you've done, that sharp edge seem's to me will be prone to splitting, I'd watch for that. I don't know if it's a good idea or not but you might trim them back a bit and remove that edge. In fact, I found out the hard way about that with rifle ammo, split necks! Chamfering is done lightly to remove the burr's after trimming.

[ArrowJ]

I am a little confused. If 9mm cases are almost always short how do they headspace on the case mouth? If it does not reach the ledge cut in the chamber would it not be headspacing on something else by default?

Also, if I trim them would I not make this situation worse? I do not have a trimmer and do not plan on getting one right now anyway. With any luck I have rendered 1,300 cases useless...the biggest lot of the same headstamp I had naturally. So very frustrated with myself. I have never cast before and I thought it would be a good idea to throw another variable into the mix.

[wawoodwa]

ArrowJ, I wouldn't worry about it too much. I'd load 50 up and give it a whirl. That may help put your mind at ease. There are some people who chamfer 9mm. Most others deprime, size, prime, bell, charge, seat, and crimp.

Good luck ArrowJ. Let us know how it goes.

[aap2]

ArrowJ-your question "If 9mm cases are almost always short how do they headspace on the case mouth?" is a valid one. I have never measured nor trimmed any straight-walled pistol case since I measured a bunch of new 45 ACP brass from many different high-quality makers and found that these new cases were shorter than SAAMI specs. Firing these cases until they wore out (until primer pockets were loose or until the necks split) did not result in any of the cases growing any longer and most got very slightly shorter. So to answer your question about cases headspacing on the case mouth: at least for 45 ACP (and I strongly suspect for 9mm also)..most do NOT headspace on the case mouth and rely on the extractor to keep the base of the case tight against the breechface not the case mouth. This is not of any significance in straight-wall cases; IMHO measuring them for length for possible trimming is a waste of time (as is chamfering or deburring). Your cases look fine; I would shoot them until they wear out or until you lose them.

[ArrowJ]

I am certainly going to try to use them. I do not have any bullets cast yet, but as soon as I do I will see what happens. Your experience seems to be the norm with the cases short and even shrinking. I wonder if it wears out the extractor prematurely, but that is another discussion.

[ArrowJ]

I bought some Berry's plated and loaded them up in these cases. While not the same as cast they worked great. Incidentally the first time I have shot my new gun...or any gun in almost ten years. My hand loads performed better than the factory ones and it was incredible. Also found about 50 223 cases...hmm.