Do I really need to Anneal the 9mm brass that I am turning into 40 cal bullets?

This thought popped into my head tonight and I was wondering if we really needed to bother annealing the 9mm cases that we are turning into 40 cal bullets. It is only going up about .012" or so.. we are barely bumping the size up that much.. so I took a tumbled 9mm brass, seated a core, applied a touch of lube and put it on the press and formed the bullet... and it didn't have any more or less resistance than the annealed case 40 cal cases I made from the annealed brass.. so um.. what do you all think? Do you think we need to bother? At this point I'm going to make 50 or so and try them since Barrel steel is still MUCH harder than cartridge brass.. and I don't see that it will be a problem.. anyone else have something to add or say to deter me from trying this? I could effectively remove 1/2 of the steps needed to form bullets from brass.. my steps would be tumble brass, seat cores, form bullets.. done.

The biggest reason for annealing is just to be able to stretch the case to the diamter you need. If you are able to make the bullets without annealing, and you get to the diameter you need without annealing, then IMO, your good to go.

For what it's worth, I do not anneal my 40 brass for swaging 44's one step. The diameter I am getting from the non annealed cases are .429.

Since I need to stretch the 40 case for my 45 acp bullets, those I do anneal as it takes quite a bit to stretch that case..

I have annealed and not and see no real big difference either. That being said my next big project is a keln so I can anneal brass.

Months ago, someone claimed they didn't anneal brass for the 9mm to 40.
If I didn't have the annealing process down, it's so easy in the wood stove then an Acid bath before tumbling, I'd consider it also.
Let us know about accuracy.
Jon

PS Oh measure the base, I imagine the base isn't expanding like an annealed base would.
Not that, that is a bad thing...it'd be like a boat tail.

The base wasn't expanding all the way on annealed cases either.. it was a few thousanths under, so I didn't need flare the case mouth much at all.. saves the brass I am loading with the stress of flaring and then crimping.. As long as there is some "fat" part of the bullet to engage rifling and seal the bullet in, it'll catch rifling, spin, and off to the target. I am getting similar readings annealed or not... so for this process I will test the 50 I made up and if they work the same I will forego the anneal process so I can make them as fast as I can aquire brass and cast cores.. which put the emphasis on casting cores.. :)

If/when I try to size them down for other calibers, that's when I'll anneal the cases to make it easier to do so. Thanks everyone.

It is best to get the base up to the same diameter as well, that's why most of us anneal. This will seal off the powder gases much better and probably shoot better as well.

If yours are not getting up to the correct diameter, your annealed cases may not be soft enough or you are not seating the core harder enough. If you are using the one step method some are using, you will have a hard time getting it there either way.

If they shoot good enough for you not annealed, then by all means go for it. It will not hurt anything unless they are way under sized. Then you might have some powder gases getting between the base of the bullet and the barrel. This could cause some extra wear on the barrel, but in a pistol it probably won't be too bad.

I think the only part of the bullet that would not form all the way will be the rim and a small portion in frount of the extraction grove. The rest of the barring surface of the bullet will make it to .400 no problem. I would bet you will be good to go. I recently tried the 40 to 44 without annealing and it formed just fine except the rim of course.

An annealed case will allow us to swage the brass case a bit more and make a slightly shorter bullet. This is evedent in the smaller extractor grove. So your bullet may be a few thou longer.

Either way I think you will be good to go skipping the step but I am sure more accurate bullets would be made from annealed cases. Accuracy not needed...... go for mass production.

BT

Yeah, I'm only looking for up to 50 yard accuracy anyway.. and even that is a stretch.. I looked at my bbq after running several batches.. the cast iron grates are starting to look stressed a bit. If I can save a bit on propane and wear and tear on my grill well.. :)

I'll see how my initial 50 shoot and report back..

Well, OK go ahead.

I wonder if wear & tear on the dies would be an issue?
Either way case brass is softer than die steel but if more pressure is required,
maybe a small percentage less die life?

I didn't notice any difference anealed or not it felt exactly alike. Without some sort of stress tester (besides my arm/wrist) I can't be absolutely certain.. but I am pretty sure.. and if it stresses the die so that it stretches a little bit over time.. well, slightly oversized from .3995" would mean it opens up to .4000" or .4005".. that would be fine by me. So far I've made... about 4000 of the anealed case bullets.. and 50 of the non-annealed type.. I guess I'll have to see after about 5000 non-annealed if it has affected sizing and then at 10k, 15k, 20k, etc..

I don't imagine the die will give much for quite some time but if it does just let me know. A replacment can be had for like $50 then just swap the internials.

BT