Would would cause this while reloading?

**redturbo0** · July 20th, 2020, 08:18 PM

I'm somewhere between an advanced beginner and a proficient reloader, just a little back story first, but tonight I was just screwing around sizing 300 BLK brass from 223 and 556 cut cases, and I had this 223 case sitting there that was cut too short a long time ago to load 223 back into it. I said screw it, lets see what happens... The case looked like this before I put the 30 cal round into it.

The case is well tarnished from sitting in my dud tray for probably 3 years, but I also didn't use any sizing lube on this case (figured the die would have enough after running 50 through it).

Would that coloring on the neck be from the stretching and it being very tarnished, or would that be because I didn't use sizing lube?

I personally think it happened because it stretched out the tarnished brass and clean brass showed from under it, but I'd like opinions from the pro's.

**Kramer** · July 20th, 2020, 08:38 PM

Case lube is your friend.

**redturbo0** · July 20th, 2020, 08:46 PM

Originally Posted by Kramer

Case lube is your friend.

Of course, I just really didn't care too much about this round to take all the precautions as it will obviously never be fired, unless some one goes ahead and makes a Remington 22300 BLK round.

**SgtRecon** · July 20th, 2020, 09:02 PM

lay off the monster, take your time, clean your dies & use case lube

**Delkal** · July 20th, 2020, 09:06 PM

I never saw a sized case with evenly spaced vertical lines like that at the tip. It is hard to tell from the pictures but is the neck of your "22-300" longer than the neck of a 300 blackout? If it is longer the neck was shoved further into the die than it was designed to go. This could mean the neck rubbed an unfinished section of the die or the neck could have even been squeezed back down in the die and opened up again by the expander plug on the down stroke.

Either way you got lucky. With no lube you could have had a major PITA with a stuck case. When reforming frass you need to have the cases well lubed. Including a little inside the case neck.

**redturbo0** · July 20th, 2020, 09:25 PM

Originally Posted by Delkal

I never saw a sized case with evenly spaced vertical lines like that at the tip. It is hard to tell from the pictures but is the neck of your "22-300" longer than the neck of a 300 blackout? If it is longer the neck was shoved further into the die than it was designed to go. This could mean the neck rubbed an unfinished section of the die or the neck could have even been squeezed back down in the die and opened up again by the expander plug on the down stroke.

Either way you got lucky. With no lube you could have had a major PITA with a stuck case. When reforming frass you need to have the cases well lubed. Including a little inside the case neck.

Yea, it kinda was pushed in further then it was suppose to go, also, keep in mind the case was not trimmed, as it was never intended for use.

That assessment does make quite a bit of sense though, thank you

**Delkal** · July 20th, 2020, 09:40 PM

I never formed a 300 blackout but I assume you trim first to slightly long, size / form, then a final trim to spec? I see no reason you couldn't trim the long case and use it. Those are all surface marks so as long as there are no signs of splits the case is fine.

I do fireform 7mm TCU for my Contender pistol. You run a 223 brass and it necks it up to 7mm then you fireform it to blow out the shoulder. No need to trim. Most cases expand ok but every now and then the neck splits when necking up. Do you get many rejects necking up to 30 cal? If you do you should research using a 7TCU die and neck up in steps.

**redturbo0** · July 20th, 2020, 09:50 PM

Originally Posted by Delkal

I never formed a 300 blackout but I assume you trim first to slightly long, size / form, then a final trim to spec? I see no reason you couldn't trim the long case and use it. Those are all surface marks so as long as there are no signs of splits the case is fine.

I do fireform 7mm TCU for my Contender pistol. You run a 223 brass and it necks it up to 7mm then you fireform it to blow out the shoulder. No need to trim. Most cases expand ok but every now and then the neck splits when necking up. Do you get many rejects necking up to 30 cal? If you do you should research using a 7TCU die and neck up in steps.

Yep, the cases need to be trimmed down before they can be used in a 300 BLK die, and then trimmed to final spec, in this case I didn't, because I wanted to see what would happen. Right about at the start of the neck in the picture is where you would cut it (preferably with a chop saw and a jig), so technically this case is salvageable.

I've never personally had a case that rejected a 30 cal bullet, I had one that was a bit lose, but another run through the sizing die fixed that.

**Delkal** · July 20th, 2020, 10:02 PM

I just looked up how you formed a blackout case. I didn't realize you had to cut the whole neck off but that is the reason you don't get any split cases when forming. With a 7TCU you expand the 223 neck to 7mm (thats when it splits). For a 300 blackout all you are doing is necking the shortened case down a little. You shouldn't get reject doing that.

**redturbo0** · July 20th, 2020, 10:32 PM

Originally Posted by Delkal

I just looked up how you formed a blackout case. I didn't realize you had to cut the whole neck off but that is the reason you don't get any split cases when forming. With a 7TCU you expand the 223 neck to 7mm (thats when it splits). For a 300 blackout all you are doing is necking the shortened case down a little. You shouldn't get reject doing that.

True, because it's a much thicker less abused case wall