Weird "burr" on spent reloaded case

[mr5parkle]

Mr. Sparkle,

In the first picture it appears that the case not only has a burr, but is flattened.  Is that correct or are my eyes deceiving me?

Second, does the width of the burr equal to the width of the barrel hood?

Is the underside of the hood smooth, especially the back "corner"?

By any chance are the cases overlength?

I'm not sure if anyone has mentioned this, but I suggest you mark some of your cases with a Sharpie and load them manually indexed so you can determine where on the barrel the burr is coming from?  E.G. bottom might indicate the feed ramp, top might indicate hood.


As others have suggested, I'd try a bit more crimp first.

In the first picture it appears that the case not only has a burr, but is flattened.  Is that correct or are my eyes deceiving me? I'd say that particular example, it's just a burr with no flattening. However, today at the range, I think there are a few that may appear a bit flattened. I'll post pics soon

Second, does the width of the burr equal to the width of the barrel hood?Not sure, but I'll check tonight


Is the underside of the hood smooth, especially the back "corner"? The entire barrel looks smooth other than some machine marks from manufacturing

By any chance are the cases overlength? They are around 1.1375"

I'm not sure if anyone has mentioned this, but I suggest you mark some of your cases with a Sharpie and load them manually indexed so you can determine where on the barrel the burr is coming from?  E.G. bottom might indicate the feed ramp, top might indicate hood.I cycled 2 dummy rounds several times from magazine to ejection and cannot reproduce the burr. I think for the burr to occur, I need the violent action of an actual firing

[Boris_LA]

It seems to me that such a minor flattening of the case mouth would get fire-formed out when the cartridge was fired.   That suggests this is happening after the cartridge is fired, either during ejection, or after it hits the deck and someone steps on it. 

It actually possibility to get scratch on the concrete bay partition on the range, but then it will be noticeable on all the ammo included factory, not just a selected reloads.

[IDescribe]

It actually possibility to get scratch on the concrete bay partition on the range, but then it will be noticeable on all the ammo included factory, not just a selected reloads.

I'm not sure if you read the whole thread, but he isn't sure if it's his reloads only.  It may be factory loads, as well.  He needs to verify.

[Boris_LA]

I've followed the thread from the beginning and have an impression that burr noticed on reloads unless I missed something, but more verification is needed. Will wait for more data.

[mr5parkle]

It seems to me that such a minor flattening of the case mouth would get fire-formed out when the cartridge was fired.   That suggests this is happening after the cartridge is fired, either during ejection, or after it hits the deck and someone steps on it. 

Yea, I'm starting to wonder if it's because the case is just smacking the floor and getting roughed up. Maybe I was so hung up on evaluating my reloads for over pressure in the past that I never took the time to carefully look at the factory and made a biased judgement. In any case, I think I was more critical of my reloads than looking at factory rounds so I don't think I'm going to sweat these cosmetic defects in the future.

The pics below are from today's trip to the range. None were stepped on, and reload ejection appeared normal. I can't tell how far it could eject as I'm in a stall, but the spent case did his the partition to the right of me. I can say the factory spent cases ejected with much greater force as it bounced off the partition and hit me in the head a few times  This may be another unscientific observation, but withe higher powder charge of 4.3gr (vs. 4.2gr), the burr doesn't look as bad or wide:

Method of loading and firing:
- loaded 2 OEM CZ 10 round magazines with only 5 cartridges with Uplula pistol loader
- shot 10 rounds with the two magazines
- picked up whatever brass I could find in safe proximity

Reloads Berry's Plated 124gr RN HP38 4.3gr 1.14" OAL 0.380" crimp: Shot 100, recovered 64, 12 exhibited the burr













Factory Fiocchi 9mm 115gr RN: Shot 50, recovered 30, 6 exhibited the burr

[mr5parkle]

I've followed the thread from the beginning and have an impression that burr noticed on reloads unless I missed something, but more verification is needed. Will wait for more data.

Looks like I made a pre-mature observation and this happens with reload or factory 

[Boris_LA]

All right, so it is a "Post-mortem" symptom not reload related. Safe to ignore.

[1SOW]

As said above,  check the bbl hood, and check the ejection port for impact marks.  Also check it for roughness or any type of roughness where it may be being hit by the ejected cases.  This would be intermittent and some small differences between case types.

.3775 shouldn't be marking the BRY 124 bullet.  As an experiment,  size a case but do not flare the case mouth.  Seat a bullet to the your OAL.  Measure the case mouth right at the edge.  This is a perfect size to taper crimp or maybe just .ooo5  more crimp.  😃. 

You're responding well to a barrage of suggestions.
 
 

[mr5parkle]

As said above,  check the bbl hood, and check the ejection port for impact marks.  Also check it for roughness or any type of roughness where it may be being hit by the ejected cases.  This would be intermittent and some small differences between case types.

.3775 shouldn't be marking the BRY 124 bullet.  As an experiment,  size a case but do not flare the case mouth.  Seat a bullet to the your OAL.  Measure the case mouth right at the edge.  This is a perfect size to taper crimp or maybe just .ooo5  more crimp.  😃. 

You're responding well to a barrage of suggestions.
 

Took a few more pics of the barrel and slide hoping to confirm that all looks normal. I routinely manually rub gun oil all over the barrel after a cleaning and never noticed any rough or sharp spots. I hope the pics could help show what I am seeing.

Will do on the [resize -> seat sans flare] experiment. I've did do the measurement and math on what the theoretical diameter ought to be (0.01" thickness x 2 + 0.356" = 0.376") but for whatever reason, when I crimp anything less than 0.3785", it leaves a witness mark. I'll snap some pics when I try out the experiment, and make/pull some proper dummy rounds with my last reload configuration to show the witness mark. Maybe it's so slight that I could afford to crimp a bit more???

I'm very new to reloading (maybe 3 months now?) so I'm very open to any advice you guys give. You all have been very great and I thank you all for the advice. Plus, the more I post and respond, I hope future amateur reloaders will find this useful and suffer less by learning from my mistakes... or I'm simply suffering from OCD and can't stand the superficial burrs 

[Boris_LA]

I'm simply suffering from OCD and can't stand the superficial burrs 

Suffering? Enjoy it instead!

[mr5parkle]

I'm simply suffering from OCD and can't stand the superficial burrs 

Suffering? Enjoy it instead!

Haha I guess you're right. If I'm OCD-like, then I should be better at catching my mess ups.

[mr5parkle]

As said above,  check the bbl hood, and check the ejection port for impact marks.  Also check it for roughness or any type of roughness where it may be being hit by the ejected cases.  This would be intermittent and some small differences between case types.

.3775 shouldn't be marking the BRY 124 bullet.  As an experiment,  size a case but do not flare the case mouth.  Seat a bullet to the your OAL.  Measure the case mouth right at the edge.  This is a perfect size to taper crimp or maybe just .ooo5  more crimp.  😃. 

You're responding well to a barrage of suggestions.
 

Below is how I measure case mouth and thickness. I hope I'm doing it right:



So I made a round with a seated bullet with no flare and no crimp. After, I pulled the bullet. There's some vertical marks from forcefully seating the bullet without flare, but no horizontal marks:
bullet diameter: 0.356"
case thickness: 0.0115"
case mouth diameter before resize: 0.3765"
case mouth diameter AFTER resize: 0.3735"
case mouth diameter with a seated bullet: 0.3785"
OAL: 1.1445"


Then, ran the same process with NO flare, but did crimp at the end. As you can see from the photo, this crimp left a witness mark:
bullet diameter: 0.356"
case thickness: 0.0115"
case mouth diameter before resize: 0.3760"
case mouth diameter AFTER resize: 0.3730"
case mouth diameter with a seated bullet: 0.3780"
case mouth after crimp: 0.3770"
OAL: 1.1430"



Same routine as the second round - ran the same process with NO flare, but did crimp at the end. As you can see from the photo, this crimp left a witness mark:
bullet diameter: 0.356"
case thickness: 0.0110"
case mouth diameter before resize: 0.3740"
case mouth diameter AFTER resize: 0.3735"
case mouth diameter with a seated bullet: 0.3770"
case mouth after crimp: 0.3765"
OAL: 1.1410"


On a side note, I did make a few dummy rounds that were resized, flared, seated, and crimped. There, the final OD of the mouth was 0.3785-0.3800", which also left horizontal witness marks similar to the severity shown in the pics above. I'm beginning to think any level of crimping with the SDB on plated bullets will leave a mark.

[1SOW]

I've loaded many many boxes of 1000 Bry 124 hbrn TP .377-.3775 and never showed any effect on accuracy using Win, R&P, F.C., Speer and in the past PPU cases.  These run from fairly thin to fairly thick brass..
Your choice,  just trying to minimize any effect from the larger case mouth diameter.

Interesting  discussions make me curious.   

[mr5parkle]

I've loaded many many boxes of 1000 Bry 124 hbrn TP .377-.3775 and never showed any effect on accuracy using Win, R&P, F.C., Speer and in the past PPU cases.  These run from fairly thin to fairly thick brass..
Your choice,  just trying to minimize any effect from the larger case mouth diameter.

Interesting  discussions make me curious.   

Thanks for the advice. It's just puzzling how my bullets get crimp impressions even at max SAAMI specs 

In any case, looks like there's not much else I can do to improve the aesthetics of my cartridges. Just gotta shoot more to improve my shooting 

[1SOW]

I just tested one of my BRY 124 HBRN-TP bullets seating it in a sized case.  Mine read .378 when I was right on the R&P case mouth.
Adding .0005"-.001" for the taper crimp is adding half or a full dia. of a human hair to the TP.

PS  My R&P brass measured about the same: some checks .011 some .0115  My digital caliper is the Harbour Freight special.