UGH! - pistol case run-out!!!

[Grey_Lion]

So I swage my own .40 S&W JHP out of 9mm brass w/ lead cores ( BT Sniper swaging die in a walnut hill press ) and the die maker says just keep the jacket case whole.... ( see attachment )

Well - I started having the occasional case that the bullet would literally fall into..... Didn't think anything about it until I hit 3 in a row..... OH boy - what's going on.....

Well - I had gotten to the bottom of my primed brass bucket and that's where there's a block of brass that came off of the range after I'd fired a bunch of my swaged JHP's.....

Best as I can figure, the longer pistol rounds are stretching the brass beyond usable tolerances. :-( Typical .40 range brass - the mouth specs out from .392 to .398 - no problem..... but the swaged JHP brass is specing out at .400 to .407 :-( So now I'm going through by primed bucket and pulling out all the ruined brass.

On another note - I'm working up a jig to cut my swaged projectiles to remove the 9mm ejection ring which I hope will prevent the reloads from wrecking the brass after I put a small taper on the cut edge to ease the project's path into clean brass.

 

[T. O'Heir]

This is .400" bullets you're making using 9mm cases as jackets? I'd bet the 9mm jackets are too thick. That'd be a very big WHAG though.
"...the bullet would literally fall into..." Cases aren't sized or more likely crimped correctly.
Range brass of any kind isn't a good idea. You have no idea what has been done to it. Or how many times it has been done.

 

[Grey_Lion]

the 9mm case is first annealed to soften the brass. Then a lead core is pushed into the shell. Then this assembly is pushed into a creasing die to crease the top of the brass case - then this is placed into a forming die to form the ogive as well as the actual hollow point and compressing the lead core to fill out the case. This step also expands the 9mm shell to between .400 and .401. What you end up with is a long thick walled JHP. the OAL of the projectile is typically 2.5 to 3mm longer/deeper than your typical .40 projectile - and that's what's causing the problem - I believe.

 

[oley55]

Grey_Lion, have you visited this site/forum? There is even a sticky with 13 pages for the 40 call/9mm.

http://castboolits.gunloads.com/forumdisplay.php?41-Swaging

 

[Unclenick]

Grey Lion,

I looked at the SAAMI chamber dimensions and what you are finding is perfectly possible if the pressures are high enough to stretch the case beyond its normal ability to spring back to shape. I would be concerned the deep seating bullet is making the powder space so small your peak pressures are significantly higher than they would otherwise be with that bullet weight.

 

[Grey_Lion]

Yeah Nick - I agree w/ you which is why I'm marching down the road to trim the ejection ring off the swaged round. While the reduced powder space is a factor, I more-so suspect that the projectile is seating so deep that it's expanding the brass. I evidence this by the curious ring that shows up in the loaded round at the depth of the ejector ring - marked in the attachment.

 

[Grey_Lion]

Oley55- The die maker is Brian - a.k.a. BT Sniper - the guy that pretty much runs & comments that forum thread. His dies have a consistent following. It's a good setup. I've been using the die since June 2017 pretty routinely.

 

[Unclenick]

Sorry I didn't look at the photo more closely before. The curious ring is what is called mirroring of the bottom of the bullet. All semi-auto brass that is designed with a slight taper to its sides but is then resized straight by a carbide sizing die ring will be smaller than bullet diameter all the way to where the die stops just before the head, and that means the bullet will enlarge the case diameter during seating and show at least some amount of mirroring at the base.

The additional problem, and the one you appear to have here, is that semi-auto cartridge cases are also designed for barrels that don't support them perfectly, for which they compensate by making the case brass thicker on the inside below a certain distance from the mouth of the case. If you seat the bullet so deeply that it reaches that thicker place, the addition of that thicker brass around the bullet makes the case wider than the chamber taper at some point along the way to a
fully seated position. It is then unable to pass a plunk test as it wedges that wide spot into the chamber before the case mouth reaches the end of it. That wedging is what shined that line and made it so clear.

I ran into this problem in designing a 300-grain bullet for the .45 Auto cartridge. The solution was to put a short 5° boattail on the bullet that slipped inside the thickening portion of the case.

The illustration shows the taper in the case. I located it by taking a handful of resized cases and putting the widest pin gauge I had that would enter the case mouth in and measuring where it was stopped by the thickening taper. You just measure the length of the case and the length of the pin gauge and sum them and then subtract the length you get measuring them together with the pin inserted (the COL of the case and pin). The result is how deeply the full diameter of a bullet may be seated before trouble starts. In new Starline .45 Auto cases, it starts at 0.40" of seating depth, but I've run into other headstamp cases where it was about 0.35". Less than a caliber deep.

 

[Grey_Lion]

I'm EXTREMELY curious what job you had in mind when you developed the need for a 300 grain .45 round - do tell?!?!!??!!!?!?!?!!!?!?!?!?! .45 is already a considerable stopping round - what what you've made there seems to be a knock into next week round. - But seriously - I'd love to hear the story.

 

[Unclenick]

Actually, what got me thinking about it was an article in Handloader in which a 300-grain half-jacketed RN bullet that got up to about 700 fps was tested for penetration and out-penetrated hardball. So I figured, why not throw away the extra penetration with a flat point and inflict more damage, making the 45 Auto a better trail round.

I had Lee make a 6-cavity mold for me and cast a bunch up and they worked most of the time, but I got a few failures to completely feed, despite a 20 lb spring in the 1911 and despite my having been careful to keep the nose profile inside that of a military ball bullet. It did, nonetheless, shoot OK and from a revolver has no problem. I also paper-patched them and launched them from my Marlin 1895 as a target/deer load, and accuracy was pretty fair.

 

[Grey_Lion]

Update - after mulling over half a dozen different schemes, I tried the easiest I came up with and dusted off some .380 auto brass and my lyman brass trimmer. I cut down the .380 brass, cut down the lead plugs, and pressed 5 JHP's with the shortened brass. The results weren't satisfactory. .380 brass OD is .374. 9mm brass OD is .392+ and even after annealing it, the .380 brass just didn't stretch to the needed .401 I want and it also didn't stretch in any way evenly. This attempt wasn't anything I'd ever consider loading. :-( I'm going to try to work up a clean repeatable quick way to cut down the 9mm brass next.

My past failed attempts focused on cutting off the ejector ring after I had formed the JHP in the die and all attempts at this failed - Tried a micro-lathe but the lathe just doesn't have enough material to grab on to hold the round - results were messy & uneven. I made a jig to hold the round on my drill press without deforming it but the drill press bed as well as the drill itself has too much movement - same result as the micro lathe - messy & uneven.
I tried the little harbor freight chop saw but the vise/clamp on it is truly junk and couldn't hold on for dear life - If any of you have the design for a bullet vise for the harbor freight saw, please send me a link to the file or a picture.

I tried making a custom cutting jig with one of my many dremel tools but due to C-19 I couldn't finish 3D printing the jig at our local makerspace yet. This remains a possibility but I can't pursue it until after the shelter in place orders lift.

I've got a couple more things to try with what I have on hand - updates as I work through them - check back.

 

[Unclenick]

To turn something as thin and flimsy as a case on the lathe, you want to turn a steel plug to fit inside to support the case walls against the clamping force. If you have a collet chuck, I would then use a collet to hang onto the outside of it (with the plug inside), but if you don't, wrap a few turns of brass shim stock around the outside so the lathe chuck jaws don't mar the surface. Then you should be able to tighten down on it quite firmly to turn the rim off.

 

[Grey_Lion]

Update 2 -

Valid points Uncle Nick, but I have abandoned the lathe idea - I wasn't trying to turn an empty case, but one with the lead core seated. At the end of the day, the projectile just didn't offer enough surface area for the chuck to have enough grip on it to hold it.

Tried a thingiverse dremel tool attachment that I printed a month ago.https://www.thingiverse.com/thing:2863860 but anything you put near it that you didn't have an iron grip on went shooting across the garage. Tried both the empty cases, and a finished projectile. :-(

And then I tried just a very simple pipe cutter. Used a sheetrock screw in a vice grip through the primer hole to hold the brass, but, as Uncle Nick pointed out on the lathe comment, the pipe cutter did one of two things, it either just crushed & deformed the brass, or it started threading it - which was surprising, but did nothing for me. Thought of using a wood dowel inside the case, but you'd end up cutting the dowel and having it break off after you made it through the brass and end up with the wood chunk being stuck inside the case.

So then I went back to my drill press jig thinking if I used a counter-sink bit, it'd self-center in the brass and just trim it down to where I liked, but no - it only destroyed the piece of brass and mangled the hell out of it.

So at this point, I'm out of ideas to try.

Problem is you just can't hold on to the case tight enough to tool it without deforming the brass.

I think the answer may be back with my Lyman case trimmer which I tried, but it just doesn't do a great smooth job removing a lot of material ( 2.5 mm ) https://www.lymanproducts.com/lyman-universal-trimmer

I may end up inventing a hand tool that can grip a case neck for the purpose of manually sizing down the case. Hm - will have to ponder this..... might be a slotted bolt nut and a modified turned bolt that'd self center on the primer hole of the shell. A slotted wing nut might be best choice if I can find one large enough....

 

[Unclenick]

Hmm. You know, looking at your original post, just to get a fit that won't stretch the brass too much you really only need to get a hundredth of an inch off the rim OD's. That means the lathe really only needs to hang on hard enough to let you take passes of just a couple of thousands at a time with the point of a sharp lathe tool along it's outside edge. You could put a little rosin on the brass shimstock wrap to get a better grip. Another trick is to wrap a turn of toy balloon skin around the bullet first.

 

[Grey_Lion]

I think you've confused your apples and oranges. On the micro lathe, I was attempting to remove the extraction ring & head stamp end of a finished swaged JHP taking down appx 2.5 to 2.8 MM to reduce the over all length of a finished swaged JHP. The lathe chuck couldn't get adequate purchase on the ogive end of the projectile to allow either an end mill bit or a tool mount cutting bit to take down the annealed brass. I'd literally have to re-machine the lathe chuck teeth to the specific bullet diameter to get a solid firm grip on that little material and I'm not prepared to do that.

I have ordered a part for my Lyman case trimmer to allow me to motorize it. I think that the manual crank on the case trimmer is fine for taking off burs and a little off a rifle round neck, but I have proven it definitely isn't ok for removing 2.5 to 2.8 mm off a pistol case. Two factors - case length - the shorter pistol case causes the tool mandrel extension to be extreme which introduces some forces aggravated by manual cranking. And secondly, as you go deeper into a pistol case, the brass thickens ever so slightly. But if I motorize the reaming bit to give me a steady high speed cutting action with a support plug, there's a chance that I'll get smooth even material removal from the neck of the annealed 9mm case.

I found a youtube of a guy who wanted to do a LOT of .223 to 300 blackout conversions so he clamped a modified Lyman case trimmer into a drill press with good results. I'm hoping something similar will work for me. I'll let you know as my efforts proceed.

 

[Unclenick]

I was thinking that if the rim of the case (yeah, I know it's a "rimless" cartridge, but that's still what SAAMI calls it) is narrowed enough you get most of what you are after. The bulge stops on the outside and gas can get around the rim and into the extractor groove space, so you get over half of the volume increase you are after.

 

[Grey_Lion]

Solved bullet OAL issue BTSniper JHPs

I make my own .40 S&W JHP's using a BTSniper one stage JHP die in a Walnut Hill swage press.

I had a problem in that the bullets produced per instruction using the 9mm annealed brass as the jacket with a lead core were too long and essentially ruined the .40 brass - would cause it to expand by .003 to .005 so that the brass could only be cleanly reloaded once - And the round also deformed the brass - See attachment 1. This projectile made to instruction came in at 187 gns and an OAL of the projectile of .688

What didn't work -
I tried to make a jig for my drill press to turn down the butt of the brass with an end mill. I could not create a set of jaws strong enough to hold the projectile in the round and the drill press I have isn't stable enough and the whole mess moved all over the place creating a mangled mess.

I tried printing a "saw table" for my many dremel tools to chop the brass - this sent 2 pieces of brass shooting across the garage at great speed besides mangling the brass. Again - the real problem was holding on to the brass to do a clean cut.

I tried the harbor freight chop saw - but the vice jaws on that are truly pathetic - didn't even turn on the saw.

I bought a micro-lathe on ebay but the 3 tooth chuck on that would have to have been machined to the exact diameter of the brass to get a good grip on it and after 3 valiant attempts to make this work, I gave up.

I tried a Lyman universal case trimmer - but with naught but the supplied hand crank, this gave me an uneven finish, and took a good 7 or 8 minutes removing all the material I needed to remove to reduce the depth of the brass case.

Back to Youtube - and a guy making 300 blackout cases out of .223 had modified his lyman case trimmer and added a drill to it.

Lyman makes a trimmer mandrel already modified for this - I ordered it, came in a couple days ago - BINGO! See attachment 2 - I tried it with an 18 volt Dewalt rechargable, but it didn't have enough lasting power and torque to do the job - but my power drill did.

See the last attachment to see the projectile size difference. - The first is a standard NOE cast powder coated hollow point - .557 long 155 gn- then there's the amended JHP - cut down 9mm junk brass .579 long 147 gn ( smaller lead core ) - and then the original JHP - full size 9mm annealed brass .688 long, 187 gn.

The speed and power of the drill solved the last problem of a smooth powerful cut. Problem solved!

 

[Grey_Lion]

Here's a side view of the projectiles

here is an angled view of the projectiles