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Posted: 1/4/2013 2:39:52 PM EDT
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Fired the following load recently and it is severely under pressured. To the point it wouldn't cycle the slide on my SW 915 and was very quite when fired. I thought the first shot was a squib, so I tore the gun apart and found a lot of unburnt powder in the barrel. I couldn't find any solid data for the load so I used what appeared to be a good starting point based on available info. I'm wondering if the c.o.l. is too long? Or maybe the powder charge is too weak?
124g hornady fmj - no crimp 5g HP38 powder new winchester brass cci primers C.O.L. 1.130" Dissecting the loads show the powder charge to be spot on in every round tested. Thanks in advance for your help. 
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Quoted:
Brother I highly doubt length is a factor here. Improper ignition is listed above. That would be my first look. What does the primers look like? Is there soot around the casing after firing? An improper burn is a first guess.... i would agree something with the ignition. you found unburnt powder so, bad primer, bad powder, or....wet powder, wet primer....sounds as though some burned just not all of it. so to me that rules out primer. |
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Quoted: Fired the following load recently and it is severely under pressured. To the point it wouldn't cycle the slide on my SW 915 and was very quite when fired. I thought the first shot was a squib, so I tore the gun apart and found a lot of unburnt powder in the barrel. I couldn't find any solid data for the load so I used what appeared to be a good starting point based on available info. I'm wondering if the c.o.l. is too long? Or maybe the powder charge is too weak? 124g hornady fmj - no crimp 5g HP38 powder new winchester brass cci primers C.O.L. 1.130" Dissecting the loads show the powder charge to be spot on in every round tested. Thanks in advance for your help. I'm wondering about the no crimp part. How is your bullet tension? Could be that because the bullet isn't crimped the powder is not burning properly.
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Hornady manual also says no crimp on 9mm luger, tho you do have to reset the flare, at bullet seat time.
This is because 9mm headspaces on the MOUTH of the cartridge, not the base. Looking at hodgdon, hornady and other data 5gr should be good to go.(actually they show 4.8gr max) hodgdon load data shows COL from 1.125(124gr lead) to 1.090(125gr fmj) You didn't lube the cases with an oil did you? Handle primers with oily fingers? Normal cci small pistol primers? not magnums? This seems strange... |
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Quoted:
Hornady manual also says no crimp on 9mm luger, tho you do have to reset the flare, at bullet seat time. This is because 9mm headspaces on the MOUTH of the cartridge, not the base. Looking at hodgdon, hornady and other data 5gr should be good to go.(actually they show 4.8gr max) hodgdon load data shows COL from 1.125(124gr lead) to 1.090(125gr fmj) You didn't lube the cases with an oil did you? Handle primers with oily fingers? Normal cci small pistol primers? not magnums? This seems strange... I used a dry lube on the cases and was very conservative, and normal small pistol primers. Below are a few pics of what I'm working with. 
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Looks OK to me. Try to see if you can move the bullet in the case buy pushing it against something like your bench. It seems to me I'm used to seeing a little more case bulge where the bullet is in the case.
Zero crimp is usually OK. I know what you mean. (All mouth flair removed.) Measure some of your bullets too and make sure they are the correct diameter. They should be .355/.356 If the bullet is not being held tight in the case it could move forward from just the primer ignition and cause what you describe. |
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All bullets are .355 dia. I know its dangerous but I tried to move the bullet in the case with a pair of pliers and they are definitely tight. Even when pulling the bullets they seem nice and snug. Really think its an ignition problem as stated above, so I will replace the powder and keep everything else the same.
I have used the same lot of primers in other 9mm rounds with different powder and they work fine, although I suppose it's possible to have bad primers within the same lot. One thing I am uncertain of is how long the HP38 was on the shelf before I purchased it. The gun shop I picked it up from uses an old refrigerator with a worn out seal to store their powder. I recall a lot of dust on the lid of the powder when I brought it home but didn't really give it much thought at the time. 
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Quoted:
All bullets are .355 dia. I know its dangerous but I tried to move the bullet in the case with a pair of pliers and they are definitely tight. Even when pulling the bullets they seem nice and snug. Really think its an ignition problem as stated above, so I will replace the powder and keep everything else the same. I have used the same lot of primers in other 9mm rounds with different powder and they work fine, although I suppose it's possible to have bad primers within the same lot. One thing I am uncertain of is how long the HP38 was on the shelf before I purchased it. The gun shop I picked it up from uses an old refrigerator with a worn out seal to store their powder. I recall a lot of dust on the lid of the powder when I brought it home but didn't really give it much thought at the time. Well I would not rule out that you got some bad powder but it would be a first for me coming from a new unopened container. What is the container made of? I have gotten some old IMR powder that came in the steel can and found rust dust mixed through the powder. One pound of 4891 was so bad it had to be scraped. The outside of the can looked good. This was not a new sealed can though but was nearly full. |
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Just guessing but here are a couple of thoughts:
1. No crimp- Maybe the pressure isn't building enough before the bullet starts moving, causing the powder to not burn completely. I think that you want a light crimp at least. 2. Is HP38 temperature sensitive? Was it cold? |
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Double check your scale for accuracy.
Did you resize the new cases or just tried seating the bullets as is? All straight-walled pistol cases must be resized prior to belling the mouth to accept a bullet. This is true even when new. Otherwise you'll end up with very little neck tension. |
The container the powder came in is plastic and I was shooting at an indoor range, temp was about 110 though. At least it felt that way lol. Lost 5 lbs in the hour I was there. 
My scale is calibrated and accurate and tested prior to each loading session. I belled the case mouth after resizing and I have my die set right on the edge of zero crimp. I have always been told not to crimp bullets without a cannelure. But the bullets are definitely tight. If it isn't the powder I will try to seat the bullets a little deeper, but that too is within spec.
I have only been reloading for about two years but this is a first for me. The bullets do go down range, albeit very slowly. |
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Quoted:
I belled the case mouth after resizing and I have my die set right on the edge of zero crimp. I have always been told not to crimp bullets without a cannelure. I used to misunderstand the purpose of crimping pistol cases when I started reloading them about a year ago. Crimping straight-wall pistol cases is for straightening out the flare/bell, not so much for holding the bullet. Neck tension from the sizing holds the bullet (further back in the case behind the flare). The neck of a measured round should simply be equal to the bullet diameter plus 2 times the brass thickness at the mouth. Example: 0.355"(9mm diameter) + 0.020" (0.010" on each side of the neck) = 0.375". I think crimping for these kinds of cases should be called deflaring, or as Motopic said above, resetting the flare. |
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It looks like there's a terminology problem going on here. The manual apparently wants the loader to NOT apply a roll crimp or a significant taper crimp, but for most of us, the "crimp" part of the process includes "de-flare" of the case mouth, removing the bell needed to seat the bullet. The pictures posted show rounds that are definitely de-flared, so there is some "crimp" going on, but not a significant taper crimp.
That still begs the question about mouth tension: how secure are those bullets in the cases? Most pistol powder requires a tight seal within the case to burn efficiently, and if the initial ignition of the powder causes the bullet to move into the barrel, that can easily prevent the rest of the powder from igniting (it gets spread out by the expanding gas and never lights). |
I have never crimped a round of 9mm. 
I have loaded and shot thousands of them, with bullets of 90, 100, 115, 124/125, 147, a 158 grains. Plated, lead, jacketed, and sintered. Many different powders. Never crimped even one. My Lee dies size the case down enough that I get a nice coke-bottle effect and PLENTY of pull on the bullet. All I've ever done is remove any remaining flare (usually not really any left after I seat the bullet anyway). They shoot out of many pistols of many different designs as well as subguns and carbines just fine. Can't really measure setback after chambering in an open bolt subgun, but never had one set back in a pistol. Always make a dummy round to check. Anyway... Crimp has nothing to do with this. OP, your loaded rounds LOOK fine. Why did you use a "dry lube"? Are you using carbide dies? No need to lube with carbide dies. My guess is you've either got a bad batch of powder or bad primers. Either by manufacture or through mishandling / contamination. By the way, you are over max at 5 grains under a 124gr bullet. Hodgdon says 4.8 max, HOWEVER that is at an OAL of 1.09" which would considerably raise pressures over your 1.13". My very first 9mm load was a 124gr FMJ-RN over W231 (same powder as HP-38) at 1.15" OAL. At 4.8 grains I had primers starting to flatten. Velocity was anemic, it was dirtier than factory ammo, and accuracy was nothing special. I didn't like HP-38/W231 in 9mm. |
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I have shot that same load a few times in testing so I would expect a normal boom. I agree with everyone else about it being some sort of ignition issue which points me to contaminated powder.
Concerning this crimp debate... what is the outside diameter of your loaded round at the top of the brass? .375 to .380? |
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If you measure a factory round at the edge of the case mouth, you will find that the 'crimp' will be about .372". Removing the flare for seating to only .376" is just not quite enough, although this is the number I use for my cast bullet loads (.356 sized LRN). I think bullet tension is one thing, but a high pressure load in 9mm runs about 32k psi +, requiring the taper tension as applied to factory fodder to accomplish the desired internal ballistics. I reload this stuff as stated by the thousands and the only problem encountered will be the lack of the correct tension applied, or 'crimp'. Dropping a loaded round in your pistols chamber(barrel removed) may also indicate some resistance to fully seat(without pressing on case). It should 'drop' in and head space on the case mouth. Have fun:)
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