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Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 9:23 am
by 760405reloader
Hi everyone im new to the forum. I was just wondering why it seems all the .223 brass i convert to 300 blk doesnt get that nice sharp look at the shoulder mine look round and bubbly if that makes any sense. It seems i can barely tell they even have shoulders

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 11:27 am
by rlandry6
It is hard to tell because there is so little material on which to form a shoulder. That said, the shoulder is going to be somewhat rounded.
If you are going to be doing a lot of brass conversion, I would recommend that you get the Sheridan slotted gauge. It will show if the shoulder is bumped/formed correctly, and if you rotate the case in 90 degree increments, it will tell you all you need to know.

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 12:26 pm
by dellet
I will try to find the original post for this photo that has each case identified, the photo was dated the first week of Nov. 2016. It's a mix of factory new, commercial converted, converted by me and fire formed. You can see how much variation there is.

The quality of the die in combination with the hardness of the brass and forming process will determine the quality of the shoulder. Forster and Redding probably have the best off the shelf dies, unless you step up to a Wilson or Whidden.

Remington double strikes their brass and that also helps.

Image

It will get better after it is fired once.

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 3:00 pm
by 760405reloader
My cases dont look like any of those. They look almost like a marshmallow at the shoulder. How do i attach a pic on here?

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 3:00 pm
by plant.one
what dies are you using?

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 3:01 pm
by 760405reloader
And thank you for the quick replies. Where might i find this sheridian gauge

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 3:01 pm
by 760405reloader
And thank you for the quick replies. Where might i find this sheridian gauge

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 3:02 pm
by 760405reloader
Hornady dies 300aac/300whisper red box

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 3:02 pm
by 760405reloader
Hornady dies 300aac/300whisper red box

Re: Forming 300 blackout shoulder problem

Posted: Sat Jan 12, 2019 3:55 pm
by bangbangping
760405reloader wrote: How do i attach a pic on here?
You have to upload to a hosting site like imgur or tinypic and paste the [img ] tag in your post.