First try 9mm flat primers, why?

[DukeInFlorida]

Actually, what that looks like to me is that he didn't properly taper crimp the brass after installing the bullet. Which is maybe a good thing. That lowered the internal pressure (safety relief valve kinda thing). If he had tightened up the crimp, who knows what would have happened.

My advice, as a really really really experienced Reloading Instructor, is that this fellow stop willy nilly reloading based on advice. And, do some more reading, specifically for the subject of internal pressures, and how to control them. That is to say, the importance of choosing the right bullet, and how best to use it. There is a safe load for that bullet. He sure didn't seek it out, or use good judgement.

Here's a good suggestion: If you can't find good safe reloading data for a very specific bullet, commercially cast or otherwise....... CALL your powder manufacturer, and tell them what powder you are using, and what bullet. Ask them for safe powder weights, and most importantly, safe load lengths. They will give you GOOD advice, and they have an obligation to keep you safe.

Upon loading the first round/die adjustment you should have caught this and pulled/tossed the round.

[mike in co]

+1 on lowering by 10% AND working up loads..... I'm kind of surprised that no-one mentioned the fact that the OP is using military brass..... Usually if you switch to mil brass you have to reduce load by 10% as well.


Dan

i still have not seen a length posted on the boolit!!!

that is not a good rule of thumb.
it came from WWII where lots of mil brass was on the market and varied large amounts from commercial brass in the same calibers.
it aint true with all mil brass used TODAY.
in the case of 9mm...doubt you can tell the difference.
in the case of 223/5.56 brass...there is more variation by maker than there is by mil headstamp.
in the unigue case of 7.62x51/308 win in lake city match brass( 852)...4% reduction was ideal for 168 match loads.

the botom line is always work up..and reduce if components are not a 100% match to the listed data.

rocky....in this case it is infact an overpressure casuing flat primers......

mike in co

[Rocky Raab]

Thanks, mike. That's entirely possible with the 9 - and why I posted only a general truth about primer behavior.

Having said that, if you look at an enlarged view of the photo with the fired primer, there is clear evidence of firing pin drag. The lines in the primer and on the headstamping run parallel to the direction of that drag, which indicates they are NOT breechface imprints but drag marks created during barrel unlock. Whether that translates to high or low pressure in this round, I cannot say.

[DetForMe]

Upon loading the first round/die adjustment you should have caught this and pulled/tossed the round.

I'm not sure exactly what you're talking about here..


I haven't been home the last few days, so I haven't been able to measure a boolit yet. I'll post that as soon as I return home.

Duke, how is the taper crimp done properly? As I understood it, the 9mm headspaces off the case and that the crimp should be just enough to reverse the flare put on the case by the flaring die. Is this incorrect? I agree that one can never read enough literature, especially in the context of safety. That being said, one has to start somewhere. It's not as if I eyeballed some random powder into a case and smashed some random bullet into it. I went to a friends house who has experience loading several kinds of cartridges, for good number of years, because I knew I was inexperienced and had much to learn. We went to a notable manual for load data and found the components most like what we had to start with.

[mike in co]

Thanks, mike. That's entirely possible with the 9 - and why I posted only a general truth about primer behavior.

Having said that, if you look at an enlarged view of the photo with the fired primer, there is clear evidence of firing pin drag. The lines in the primer and on the headstamping run parallel to the direction of that drag, which indicates they are NOT breechface imprints but drag marks created during barrel unlock. Whether that translates to high or low pressure in this round, I cannot say.

naw...i disagree...there is a small disturbance at the firing pin srtike, but there are machine mark imprints across the brass and the primer face...that is a machine mark imprint not a drag.

a drag mark from the firing pin would be somewhere in line with the firing pin strike..

the brass and primer face have several marks in parrallel in the same general direction which implies machine mark transfer from the breech face......

but since we don't have the gun....we cannot tell , so i will leave it at that..just an opinion.

i do agree that primers come in different physical strengths and can be flattened by lower pressures...
there does not appear to be an extrussion at the fireing pin hole, but it is flat to the edge of the primer hole...no real radius left in the primer.



mike in co

[Rocky Raab]

We may see those marks differently, but there's no way to be sure. I'll leave this to the experts.

[DetForMe]

The marks in the case match the breach if that helps.

[DetForMe]

Boolit length is 0.668"

[mike in co]

well that boolit length, the pressure is around 46kpsi....................

that is a tad over max of 34kpsi...which just might flatten a primer.....

ohhh and shows as 135% case filling ,so a tad compressed.....
some how i doubt there were 1.061 when the trigger was pulled


thanks to qucikload software......


mike in co

[220swiftfn]

Mike, to be honest, my experience with military brass is indeed with larger rifle brass, so I will defer in regards to pistol brass.

One other question to the OP. Where was the brass landing? Might not mean much, but if factory loads are usually five feet away, and your reloads are spitting the brass to ten, maybe the load's too hot. If they're dribbling out at two, you're under powered. (trying to think of supporting evidence to the "coining" marks from high pressure or a low pressure backing out the primer and slamming the case back over it......)


Dan

[220swiftfn]

Just caught Mike's last post....... nevermind....


Dan

[fredj338]

+1 on lowering by 10% AND working up loads..... I'm kind of surprised that no-one mentioned the fact that the OP is using military brass..... Usually if you switch to mil brass you have to reduce load by 10% as well.


Dan

I have to agree. The charge wt isn't out of line for commercial brass & a 147gr bullet @ that OAL in most guns. Milspec brass can have not only smaller volumn but thicker brass, which means less expansion to release the bullet, also raising pressure. Everything affects pressures in high pressure/small volumn cases. That load will be probably be fine if reduced 0.1gr-0.2gr or if you increase your OAL another 0.03" or so. The load as is may also be fine in another gun, but in your, certainly appears over pressure.

[GabbyM]

The MBC bullet is from a magma mould. I have that mould.
Even in my S&W pistol a 1.145” COL fits. S&W has the tightest barrels I’ve encountered.

with the long 147gr bullets most 9mm expander plugs do not reach far enough into the case to free up deep seated space for the 147's or the 124 TC. then you swag down the bullet with that thick case wall. Accuracy and leading issues result.

that said load the 147 FP to 1.140" after checking for fit in your barrel. a slow powder is my personal fave.

See linked thread for discussion on 9mm expander plugs. I think at least a Lyman M die or better a longer plug for the 147’s would be best.

http://castboolits.gunloads.com/showthread.php?t=95269

[NVScouter]

[QUOTE=DetForMe;1121798]I'm not sure exactly what you're talking about here..


I haven't been home the last few days, so I haven't been able to measure a boolit yet. I'll post that as soon as I return home.

QUOTE]

OAL depends on many things but just for the boolit portion: Measure where the front start to taper this is max depth it can be loaded. Then measure how far out it can be loaded and used in your chamber/mag this is minimum. If the minimum compresses your powder compared to a similar book load you can be over pressure fast.

In your picture it looks like the boolit is seated too deep and the brass is well over the boolits bearing surface and into the taper. Try seating the boolit out more for die adjustment.

[918v]

Any resolution to this issue?

Alliant now lists 5grs of PP under a 147 JHP seated to 1.130" OAL.

4.5 grains with an OAL this short is prolly max, and the breech face marking the case head is a good physical evidence of that.

FYI, I just pulled apart a few UMC 147s and they were loaded to 1.090" OAL using 4.5grs of something that looks like PP. The RP 147gr FMJ measures .635" and is the shortest 147 on the market. This particular round pierces primers in my SIG.

So did you increase OAL and retest?

[MT Gianni]

Probably not, he last visited the board on 1/13/11 per his profile.

[Bwana]

Hi, this is my first attempt at reloading. I had the help of a good friend that has some experience with reloading, and is also the member of this forum, so I won't mention any names since he's stumped too. We followed the Lyman 49th edition reloading manual for data, went .1 grain above minimum load. Shot about 40 rounds through my Kahr CW9 and everything seemed to cycle fine. I didn't notice any excessive recoil, although I'm not sure that means much. I didn't notice the problem until I read The ABCs of reloading. It looks like I have flat primers and breach machining marks on the head of the case.
Load data is as follows, 4.2 grains Alliant Power Pistol, 147 grain FPBT cast lead boolit (Missouri Bullet Company "sub-sonic" grinell 15), Brass Length prior to firing 0.743" -+0.001 (supposedly once fired same headstamp), OAL 1.061", CCI small pistol primers.
Brass length after firing 0.739" -+0.002.
All this seems to say hot load, the thing thats really confusing us is that we both triple checked the scale for the right weight. Could it be compressed powder somehow?

Since no one else has mentioned it, let me. Just because a reloading manual states something, that does not make it so. They do make mistakes in their data and sometimes the printer puts that into the book and sometimes the printer fouls up the data and that gets printed. Proofreaders are not foolproof. They don't catch everything. Just look at the obvious errors in the novels you read. I find them all the time. So, don't go with just one or even two sources for your load data.

[FirstBrit]

Hi, this is my first attempt at reloading. I had the help of a good friend that has some experience with reloading, and is also the member of this forum, so I won't mention any names since he's stumped too. We followed the Lyman 49th edition reloading manual for data, went .1 grain above minimum load. Shot about 40 rounds through my Kahr CW9 and everything seemed to cycle fine. I didn't notice any excessive recoil, although I'm not sure that means much. I didn't notice the problem until I read The ABCs of reloading. It looks like I have flat primers and breach machining marks on the head of the case.

Load data is as follows, 4.2 grains Alliant Power Pistol, 147 grain FPBT cast lead boolit (Missouri Bullet Company "sub-sonic" grinell 15), Brass Length prior to firing 0.743" -+0.001 (supposedly once fired same headstamp), OAL 1.061", CCI small pistol primers.

Brass length after firing 0.739" -+0.002.

All this seems to say hot load, the thing thats really confusing us is that we both triple checked the scale for the right weight. Could it be compressed powder somehow?

Hi, Out of curiosity I ran your data through my QuickLoad ballistic programme. Assuming your bullet from MBC was made with the Magma mould ( bullet length 0.670") then on a standard case volume the pressure would be running at about 45 k. psi !!!!! Way too high. Of course if the case volume of your cases is higher than the 13,3 gr. H²O standard this will reduce the pressure somewhat. But, your load is definitely compressed with your OAL and even so the powder burn is not so terrific - only about 80% with a 6" barrel.

If you increase the OAL to 1.138" then P max. drops down to 22 k psi. Just goes to show how critical seating depth can be on small volume cases like the 9 mm Para. Of course powder burn will be inherently worse. I have very good results accuracy wise with either Hodgdon Longshot or VV 3N37 somewhere between 4,0 and 4,2 gr. I use either PMC or Win. brass where case volumes are slightly over standard at 14,0 and 13,8 gr. H²O respectively.

Best regards,

Adrian, Germany.

[popper]

Compressed load? Drop a pencil or something into a charged case, use your mic to measure depth and then measure seated depth and bullet length. The flash hole can be enlarged to reduce primer setback for light loads, those cases need to be marked so they aren't used for normal loads. Get more info before doing this on 9mm. I don't use PP, but the powders I do use, 5 gn. pretty much fills the case. Email MBC a with your question, they have good responses, very helpful.