Just wondering when reloading 9mm what the minimal case length acceptable would be?My manual states the case should be .754”
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Just wondering when reloading 9mm what the minimal case length acceptable would be?My manual states the case should be .754”
That is SAAMI Spec
Yes,so I was just wondering the acceptable minimum case length.
Most semi-auto pistols feed the case up under the extractor from underneath during the feeding cycle. The extractor holds the case against the breechface and the chamber mouth serves as a secondary stop for the cartridge.
With this system, you can use cases of varying length and the pistol will still function as it should. I have even tried using 380 auto cases with the boolit seated out to normal 9mm OAL and they work fine.
For best accuracy, it is more important that cases are all the same length than what that measurement actually is.
Personally, I don't check case length on 9mm cases any more. I am not a good enough shot to make use of any possible increase in accuracy due to absolutely matched cases.
If you need a specific dimension for case length for best accuracy in your pistol, you would need to test a number of different length cases and see which length groups the best.
Each pistol makes it's own rules in this regard.
Thanks tazman.Thanks for the great insight.Just wanted to make sure that a case measuring say.744 wouldn’t put me in any danger due to the pressures being increased with the shorter than normal cases I have since they are.010 smaller.I would naturally go with recommendations for starting loads.
I don't know what manual you are using, but most that I have will list a "maximum case length" and a "recommended trim length", which is usually anywhere from 0.004" 0.010" shorter than the recommended max. So long as you maintain a consistent O.A.L. on your loaded cartridges, one that will pass the "plunk test" and the equally important "magazine test", the shorter 0.010" in length of your cases will not cause you any problems.
Ok.I use the Lyman.Thanks!
I can't remember the last time I even bothered to check the case length of a 9mm casing.
The saami max is .754 The trim length is .749. I usually discard anything shorter than .745, but I am extremely anal.
FWIW; the OAL is from the case head to the bullet tip. When you seat a bullet you are seating to a depth as measured from the case head, so case length won't affect case capacity when a bullet is seated. You can get the same OAL with any case from minimum to maximum case dimensions...
Some 9mm guns will reliably shoot 380s with the case head spacing on the extractor. Some will fire 380s intermittently, some probably wont fire 380s at all.
The 9mm is intended to head space on the case mouth. If your cases are too short, you are heading in the direction of potential FTFs (depending on your gun).
I check the length on my 9MM brass and cull brass longer than .752 and shorter than .748 simply because if I set my Lyman M die (or Lee expansion die or NOE expansion plug) to adequately expand (short) brass which is .742~.740 in length so that no lead is shaved when the boolit is seated, that same expansion die setting will make .754 long brass look like a tuba.
I'd be a bit concerned about shooting 380 ACP in a 9mm weapon -
9mm rim diameter 0.392 in (9.96 mm)
380 auto rim diameter 0.374 in (9.50 mm)
Bit of a difference.
Yet people fire 9mm using a 40S&W slide which has an even larger difference(.030) regularly by using just a different barrel.
9mm ---.394
40S&W ---.424
GONRA sez - most (all)? of us can pick up Range Brass, Reload and Blast Away Just Fine.
(Clean dirt off, weed out Berdan primed / tiny flash hole Boxer brass FIRST!)
Yer air compressor is yer Friend on his stuff.....
I check the length on my 9mm brass and I go with the min. of .744 and anything below that I load a different data I made and shoot them in my 9mm wheel gun that have a moon clip. I get more use out of the brass and I shorten the brass more that way I can pick them out when I tumble them with other brass.
The slop of a 380 case is the problem in a 9mm chamber but low pressure may let you get away with it. And probably will. The area of greatest discrepancy is where the case is thickest.
Shooting a 9mm barrel on a 40 slide using 9mm ammo is not the same thing, because you are using 9mm ammo in a 9mm chamber. The 40 slide offers no difference in case support versus a 9mm slide when in battery. The barrel offers the case support, and there are no slop issues shooting 9mm in 9mm barrels on a 40 slide when the cartridge is fired.
My understanding is the same as others posted above, that, given a specific type of case and bullet, the internal ballistics of your load depend more on the internal case volume where the powder burns, which changes with COAL, not case length. A longer or shorter case might affect the tension holding the bullet, but it's my guess that it's only a minor factor.
I'd also guess that using multiple headstamps and brass that varies in the times fired previously would change how the load behaves, not necessarily from differing case lengths but because of different thicknesses in the case heads changing case volume and of work hardening changing sizing and neck tension (is it still called neck tension if the cartridge isn't necked?).
ETA: I've never checked case length in 9mm, but I do sort by headstamp and times fired for ammo intended for major matches: I find ammo loaded with that brass to have more consistent velocity and to group better.
Just yesterday, I checked the length of 30 pieces of 9mm brass. Fifteen of PMC headstamp and fifteen of CCI Blazer. Not much difference between the two brands. Both had variable lengths from .744 to .749, and everything in between. Even though, I sort my brass by headstamps, I'm not about to uniformly trim them.
Winelover
Load shoot repeat😁
I have never checked the length of the 9mm's that I buy once fired from police ranges, all the same headstamp.
I can tell you for a fact that varying the Cartridge OAL in .005 can make tremendous differences in accuracy as long as taper crimp stays constant with the same powder charge and primer.
It is never a bad idea to take the barrel off the 9mm and use it as a go gauge for your ammo and cases as most of the chambers are cut a tad long.
Here is my method ... use an empty 50 round plastic 45 ACP tray that comes with factory ammo. Hold the tray with one hand with holes facing up, then drop CLEAN 9mm brass over the tray with your other hand. Do this over a bucket or shoe box and most brass will fall into the tray head first. Then hold the full tray at eye level and you can easily scan across the case mouths to see if you have any that are long or short and .380’s are easily seen this way too. Then look into the brass and pull any stepped or cracked brass out. If you want to sort by head stamp you can flip this tray over into another empty tray to see the head stamps.
Haha... I tried for years to describe this method of counting/sorting pistol brass in messages on forums. A few years back I videoed myself sorting/counting 9mm brass and put it on YouTube. Here’s a link to my video: https://youtu.be/BpkUnUqMo8U
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A Pilot "Precise" V5 or V7 pen fits the mouth of a 9mm case perfectly, or just use a bit of dowel to make something to pull them out (I've been counting 9mm brass out today, long story.) Sometimes the darn things fall in head first and I want them all showing head stamps; Fingers are too large to grab 'em easily in the block I'm using so I do that.
LOL, Same method I use too fish and thx for sharing your well done video. Only difference is that I sort my brass ahead of time using those slotted plastic trays that fit inside each other over a 5 gallon bucket. It easily sorts 40 from 45 but 380 and 38 super still get mixed into the 9s and require height sorting like you demonstrated. One other thing I do different is when I invert mine to check the head stamps I invert into an empty 45 tray instead of on a small piece of wood which keeps my clumsy hands from knocking a bunch over with shaky hands and tweezers.
I also use the white plastic trays to inspect and sort 9 mm brass, but find that after flipping the cases into another white tray to get the head stamps up, they're too deep in the second tray to pull out. It turns out that there are black plastic ammo trays that are those same size as the white ones, but thinner. They need a piece of cardboard fit into the bottom to keep 9mm cases from falling through, but the cases stand up by about a quarter inch, making it much easier to pick out a case for sorting.
Attachment 245463Attachment 245464
Hope I'm not hijacking too much, maybe you fellows can help me. Using a 9mm lee loader and Ht coated truncated cone 125 gr flat base boolits. I am shaving some of the coating off when seating the bullets, some don't align perfectly when dropped. Will chamfering the case mouth a bit do or will I need a expander die for lee hand press? Thx.
Try chamfering the case mouth a bit, &/or adjust your exp. die down to make just a little larger flare to the case mouth, ( or both) first. Either one might stop the issue.
If you are not using an expander die with a plug that is oversize for the diameter lead alloy boolits you are seating, you may be also swaging the boolits as well when ya seat them. The NOE plugs in a Lee Univ. Exp. die, or the appropriate M die from Lyman will do the job if ya don't use them already. Usually the "factory dies sets come with Jacketed bullet exp. dies and they are the size of the caliber & not oversize to account for the .001" -.002" cast lead alloy boolits we use to get a good fit in the bbl. to keep from leading/obturation issues. Sometimes you can find a exp. plug that fits your die that is of another caliber but works, like a 38S&W exp. plug(.360") for 38/357M boolits that are .359" or .360", instead of the .358" that normally comes with those factory dies for jacketed bullets at .357, etc.. Being you are talking about a 9mm, perhaps, if you have the same dies & have the 38/357M exp plug, you could maybe try using that to see if it works first. ( Personally, I just bought the NOE plugs & Lee Univ. Exp. dies for almost all my calibers & don't have to worry about which ones are which anymore. Your choice on what ya want to do though...)
{ Funny, I just mentioned the same info in another topic. Coincidence perhaps? Haha. ;) }
Anyway, that is stuff that I would consider, if I were seeing the same things you mentioned.
:)
G'Luck!
:)
The only time I remember checking 9mmX19 case length was for my Ruger NM Blackhawk Convertible. And since some one was nice enough to steal the 9mm cylinder off the shooting bench before I got to try it. I haven't felt the need to do it again.
Hogtamer, I load HiTek coated 147's sized to .357". One of my favorite boolits shaved badly until I had Lathesmith turn me the equivalent of an M die for my SDB. The factory die, bot,h mine and another Dillon owner, wouldn't expand the case ID over .350". I guess that works for jacketed and for some cast, but it didn't for me.
In 10s of 1000s of reloaded 9mm I have never measured nor trimmed a case. As noted, the case really ends up head spacing on the extractor. Semi cases rarely if ever stretch, so load shoot repeat.
.
Just curious why would anyone want to shoot 380s out of a 9 mm? That is something I would never do that and I would never recommend that being done. In all my years of shooting I have never heard of anyone suggesting that . How would you have a loaded magazine made for 9 mm with 380s . Neither would I attempt to fire Makarov 9 by18 out of my 9 mm even if I could get them to chamber which you can’t . Well maybe you could but it probably gets stuck in the chamber. I’m certainly not trying to be rude or anything there’s many but no more than me but I have never heard of such a thing .If you could explain the reasoning behind us I would be greatly appreciated thank you.
As it happened, I was loading some 9mm and a 380 case slipped into the mix. For whatever reason, I wasn't paying enough attention and that case made it all the way through and got a boolit seated into it.
I noticed that the boolit was seated farther out of the case than the others and checked it. That is when I realized it was a 380 case.
I put it in a box with other 9mm ammo in a position so I would know when I put it in the magazine.
That case fed and fired just like the rest of the ammo in that box. No difference as far as impact point or anything I noticed.
I would not deliberately try to load 380 cases for 9mm. That said, if you load them to 9mm specs, they will function in the gun.