Forming 300 Blackout, shoulder location problem

[Rich22]

So I ran my first case through my Hornady sizer to try to form the case. Cut on a trim saw to about 1.41, know it is a bit long but working on fixing that, the shoulder location when compared to a factory piece of brass is not even in the ballpark. I am sure mine is off but what do I do to correct it? Looks like it needs to move down the case towards the case head about 1/10 of an inch or so. I have the sizer adjusted to just touch the shellplate when at full ram travel. Factory on the left and mine on the right.

Thank you

[HATCH]

Youk might need to file the bottom of the sizing die so it sits farther down.

[BK7saum]

Before you trim the die. Try screwing the die in an eigth or quarter turn so that the press cams over. If you don't a lack of lube or oversize case can cause the press to flex as well as taking all slack out of the linkage.

Check the cases in your chamber. You don't want to size them too far or you might have ignition problems from too much headspace.

[r1kk1]

I would get a case gauge and do as BK7saum said. Once the piece of brass fits into the case gauge, lock the ring. When I used to form 7 TCU, I discovered two things: commercial brass reduced the number of split necks compared to military brass (without annealing in this instance) when forming cases and I got my best cases from new brass not once fired when forming.

Take care

r1kk1

[cavalrymedic]

trim your cases a bit shorter, to 1.355, then size. you may be running out of room in your sizer die and the case can not get in any farther. when you size the brass, it lengthens past the 1.41 inches you have been trimming to.

[Rich22]

trim your cases a bit shorter, to 1.355, then size. you may be running out of room in your sizer die and the case can not get in any farther. when you size the brass, it lengthens past the 1.41 inches you have been trimming to.

Now that I did not think of, having to remill a slot on my trim jig, will hopefully have that up and running tomorrow and can at least get it much shorter. Then I will give it a shot, My goal length is 1.358, should I still trim to a length shorter than that prior to sizing?

[casca]

Greetings,
I am not any kind of expert on 300 blk. but I do have the trimming blisters.
May want to try and get your case a little more square on the cut . if by chance that you maybe measuring the low side when you measure. i also run mine thru the RCBS trim master stations after cutting . I use the WFT trimmer that measures the trim from the shoulder.

casca

[Rich22]

trim your cases a bit shorter, to 1.355, then size. you may be running out of room in your sizer die and the case can not get in any farther. when you size the brass, it lengthens past the 1.41 inches you have been trimming to.

Now that I did not think of, having to remill a slot on my trim jig, will hopefully have that up and running tomorrow and can at least get it much shorter. Then I will give it a shot, My goal length is 1.358, should I still trim to a length shorter than that prior to sizing?

[KinkBreaker]

you sure there aint somethin labeled 300 whisper in the mix there?

[lmfd20]

you sure there aint somethin labeled 300 whisper in the mix there?

Even if he had whisper dies, the shoulder would not be out of spec like the pic. I'm more inclined to believe the brass is running out of room in the die as stated above.

[Jupiter7]

I assume you've resized factory brass? If so, I believe that would rule out your die or shellholder being outta spec.
In the pic you can clearly see that the brass you formed did not bottom out in the die. I've cut them longer with no ill effect. Make sure you deburr and chamfer before resizing/forming and after trimming. Also lube whole case and inside neck, not alot just everywhere.

I've formed a couple thousand, with hornady dies. Also the whisper is only different in neck length. 1.340 for whisper, shoulder is in the same place.

[Steve E]

I'll second cavalrymedic's notion about the length being too long.

Steve E...........

[Evilbetty]

Found this thread on a Google search.

I'm having this exact same problem. Mine look exactly like yours. I lowered the die another 1/8 of a turn with no change.

The factory brass sits 0.001" inside the case gauge. The reformed brass sticks out about 0.035" from the case gauge.

Did you come up with a solution?

[blikseme300]

What press are you using? There have been reports of some case holders being too thick and not allowing the die sufficient travel.

If it is suspected that there is insufficient length in the die cut a case shorter, form and check in a case gage.

BTW I use a Hornady Whisper/300blk die in a Hornady Pro7 to form 300blk brass and the die can be set too deep causing too short brass. I use a Wilson gage to check.

[Evilbetty]

What press are you using? There have been reports of some case holders being too thick and not allowing the die sufficient travel.

If it is suspected that there is insufficient length in the die cut a case shorter, form and check in a case gage.

BTW I use a Hornady Whisper/300blk die in a Hornady Pro7 to form 300blk brass and the die can be set too deep causing too short brass. I use a Wilson gage to check.

Hornady L&L AP and Hornady Dies

[john hayslip]

Redding has a trim die for the 300 Blackout that was unlisted when I got mine. You put the 223 case through it and cut off what comes out the top with a fine tooth hacksaw blade and then do a very light trim of a thou or so and chamfer. It was about $80 and they paid the shipping. It makes the forming job simple. The shoulder comes out in the correct place on mine.

[blikseme300]

Hornady L&L AP and Hornady Dies

Hmm, this is weird. I will do a test on one of my newest LnL AP press using the #16 plate and Hornady die and report back the results. I prefer the use of the Pro7 for just forming as it allows the other presses to stay set up for loading only. (My wife says I'm a capitalist pig as I run 4 AP's on my main bench.)

[Evilbetty]

Hmm, this is weird. I will do a test on one of my newest LnL AP press using the #16 plate and Hornady die and report back the results. I prefer the use of the Pro7 for just forming as it allows the other presses to stay set up for loading only. (My wife says I'm a capitalist pig as I run 4 AP's on my main bench.)

Well it turned out I just needed to snug it down a lot more. I had to tighten it down so much I thought the press wouldn't cam over but it's working fine and now my brass is within spec and matches the factory brass.

I need to get me a AP or two

[Rich22]

I think I have the setting down. Pawl broke on my lnl ap so once that is fixed I think I will be good. Many thanks to Grumpa for a major league assist

[sparky45]

The most efficient method I have found (not my own design) for trimming .223/5.56 brass to make 300 BO is this: A) have the right size forming Dies; B) Buy this setup and watch a video (again not mine) such as http://www.youtube.com/watch?v=ZAAlT...e_gdata_player ; C) Cut the brass. At this stage, after the brass has been de-capped and swaged, I run all cut brass through a tumble cycle with SS pins which acts to not only clean the brass but also de-burr the cut edge. Some lube (Hornady One Shot for me) then into the case feeder on my 650 to size. On to my WFT 300BO trimmer for final trim and chamfer. Then a final media tumble in Walnut media with polish. Brass is ready for loading. Seem complicated? Not really, I'm just a bit anal about the 300 and have LOTS of time since retirement.