She's not only a waste of food, water and shelter. The oxygen she's consumed could have been put to better use by composting animal manure into useful garden nutrients.

I found a couple of pieces of 9MM brass like that described at the local range. When I picked it up, I didn't notice it being any different from the other brass casings. I also didn't detect any difference when sizing the cases. It wasn't until running them through my wet/pin tumbler that it became apparent that they weren't brass. When they came out of the tumbler, most of the brass plating had come off and they had a reddish brown almost rusty appearance.

Handloader magazine had a couple of articles about the .41 Special. Many of the loads were in "full-house" .41 Magnum territory as for velocity and energy. If this one was created back when the .38 and .44 Specials it would probably be as anemic as the factory loadings for the two aforementioned rounds. As it is, this is a bad ass little round that rivals it's slightly larger sibling.

I've read your post and will give it all some consideration, however my problems/issues are not with the Blue Dot powder.  The original issue was what is/was causing the cartridge to increase it's length by as much as .030" when applying the taper crimp. Yes the 9MM does require a crimp after the bullet seating, all pistol cartridges require a crimp, be it a taper crimp on auto pistol cartridges or a roll crimp for revolver cartridges if the bullet configuration allows that to be done.
I thought about powder compression or neck tension causing the loaded rounds to grow as you said, but the loaded rounds have a neck diameter of .3765-.377",  under recommended neck/mouth diameter of a loaded round. The Blazer brass is about .001-.0015"thinner at the mouth than the WCC brass, usually this doesn't create issues when loading ammo. The last variable I can think of is maybe the bullets themselves, there is some length variation by as much .012-.015", but those that I've checked the diameter of all fall between .3558-.3662". I may end up melting all of these down and casting my own from the salvaged lead alloy. So far I haven't had any issues with my home cast bullets.

I have a goodly amount of 147 grain cast TC 9MM bullets and have been trying to work up a load. My Lyman cast bullet book said that Blue Dot gave the highest velocities with this bullet, so that was where I started, then the problems started. The sized cases (all range brass) were given a sufficient case mouth flare to accept the cast bullets without shaving lead, and had no issues in that regard. The loaded rounds had a C.O.A.L. of 1.054-1.058" checked right after seating the bullets, then they were crimped with  a LEE FCD and shot for functionality. The load was 5.5 grains of Blue Dot, right in the middle of the load data and the primers of the fired rounds were completely flat. I tried another 5 rounds using the same load procedures only I cut the load back .2 of a grain (5.3 grains) did the same exact load procedure and I was still getting flat primers. I walk away from the loading bench scratching my head trying to figure out whatinthehell is causing this, and come up with nothing. After a while I go back to load 5 more at the reduced charge, go through the same loading procedures except that I check the C.O.A.L after crimping and the measurements are from .022-.030" longer than what I checked them at after seating the bullets. I now know what is causing the flat primers, the bullets are being forced into the rifling causing the high pressure. I know how, I just don't know why or how the rounds can be increasing their length by simply adding a crimp.
Today I'm back at it with two different taper crimp dies, one is mine a 38/357 taper crimp die and a 9MM taper crimp die that I borrowed from a friend, both of these are Redding. I also changed the seating plug to the type for round nose bullets and the seating depth/OAL lengths became more consistent even though I'm loading truncated cone bullets and the other replaced seating plug was designed for flat nose bullets (?). Now I'm thinking everything is in order to test these new loads, the loading procedures have been double checked for any errors, the C.O.A.L. is 1.052-1.056", crimped with the Redding die and double checked for length, I should be ready to shoot them. I re-checked the C.O.A.L. and a couple  of them have grown in length while sitting in a cartridge block on my loading bench, they have increased their length by .009" and .012" WTF? They are different brass makes, one a WCC mil-spec case and the other a Blazer. One of them, the longer of the two I have re-seated the bullet 4-5 times and it keeps going back to that +.012" length.  Does anyone out there in reloading land have any idea what is or might be causing these foibles?

I started doing the wet/pin tumbling a couple of years back and I really like how it makes even scroungy range brass look as good as new. It does have a down side from what I've been reading at another forum. It cleans the brass so well that it removed the carbon layer in the neck of rifle brass, affecting the bullet pull of some really precision loaded cartridges cause bullet dispersion (larger groups from using this method). I don't notice this shooting hand gun ammo, but if any of my rifles shot groups in the .10s or better, it would definitely be a concern.

LEE doesn't have any of their own original data, it's all reprinted/regurgitated data that they've gotten from someone else.

I've only used a few of their rifle brass, but those that I did gave no problems. From what I'm getting from the original post, it sound to me that it's more of a head space issue than a brass problem. SMLE's are notorious for short brass life. They designed to function under battle conditions with no regard for reloading the brass afterwards. These can be corrected somewhat by swapping the bolt head for one that has the correct dimensions (the SMLE has interchangeable bolt heads to set the proper head space). The sizer die setting (pushing the case shoulder back too far) could also be the cause of the brass separating also, although this case head spaces on the rim, this could still be the cause of the brass separation at ignition.

I used to hang out with a couple of guys that shot at a lot of rifle bench rest matches. They both said to use lacquer thinner to clean bullets, they said you'll be amazed at the amount of crud that comes off even factory 1st line bullets. I did what they suggested, and WOW were they right. I took two metal cans, one that fit inside the other and drilled many holes in the bottom of the smaller can. Put a couple of inches of lacquer thinner in the bigger can, put the bullets in the smaller can and dunk it the larger and shake/slosh it around for a few minutes then take it out and spread the bullets on a paper towel to dry. When I did this the bottom of the larger can had a lot of tiny shiney shards of jacket material and tiny pieces of some kind of black crud on the bottom of the can.

The picture of the case in the original post is from insufficient case mouth belling and/or case mouth chamfering when seating a bullet. When I first started re-loading I did the exact same thing by not having enough belling or chamfer on the case.

I've had two of the LEE hand priming tools, one set up for small primers the other for large. I broke the thumb lever twice on the old style (S), no issues with the new model (L). I also had two of the RCBS hand priming tools, also one set up for small primers the other for large (dedicated). The RCBS models had a tendency to have the primer tray come out while using. I thought, there's got to be a better way to seat primers. After reading several reviews, I got a RCBS Automatic Primer Tool. It came down to that or the Forster Co-Ax Primer Seater. What made my decision was availability and the RCBS primer tubes hold 100 primers, and the Forster holds 55. I wish I'd have gotten one of these years earlier, seating primers is now a pleasure with this tool over the "thumb busters" I had before.

Real name is Paul, I hail from the great (?) state of NOhio. Retired now, I've been shooting rifles for 50+ years,handguns for close to 50 years and rollin' my own ammo for 40+ years, but am new to the 10MM. I found out about this site at a different forum, I've been watching for a couple of weeks and decided to get on board.  The 10 I got is a Ruger SR1911 Target model, now waiting for the weather to improve so I can get it out and stretch it's legs.