300 blackout reloding issues.

[Camo]

Been a novice part time reloader for awhile now. Just standard 270, 223, and 308. Always use RCBS dies. Recently got a 300 blackout and got some dies for Christmas .

Dies are RCBS 300acc blackout sb t/c set. (small base /taper crimp)

Clean dies as I should with new dies. resizing/depriming goes great. Start to seat/crimp and I crush the neck. Sure I am doing something wrong with these dies. Anyone know of a tutorial for using them or anyone near Yukon Oklahoma want to teach a fellow what he is doing wrong? I use singe stage rock chucker press so noting fancy.

Thanks in advance.

 

[dlbleak]

Quick little vid that explains why shorter cases often crush if the expander isn’t set properly

 

[Defcon Shooter]

Time for boat tails and factory crimp die

 

[Camo]

This is happening during the seating /crimp process. No issues during resizing.

I am using 125 grain nosler boat tail ammo. This ides is different than all my other standard full length sets, so I am certain its something I am doing wrong.

 

[swampratt]

I can come by and check out the set up and process if ya want.

 

[DRC458]

I'm surprised you're having this issue with boattail bullets. Still, several possibilities. What's the origin of your brass? Case neck thickness could be one issue. Are you chamfering inside the case mouths before seating? I highly recommend you take swampratt up on his offer! Nothing like hands-on to figure things out.

 

[NikatKimber]

My guess is the crimp portion of the operation. I did this with some .243 rounds because the seat/crimp die was set a little too far in.

 

[NightShade]

Agree, back the crimp way off and see how it does. Don't need a huge crimp on it if the sizing die is right. The bullet will pretty well sit down in there and be held. Just use the crimp to ensure nothing is snagging on the way in the chamber. If it is happening during seating then you likely have neck walls that are too thick and the rounds will likely not chamber properly either.

 

[Camo]

Thanks everyone , I am still working this out.. I know its an issue with the crimp part of the process. Going to reset and try again tonight.

Hoping to get it figured out without having to put someone out to come help, but may have to take you up on that swampratt. Very generous offer.

 

[swampratt]

A seat and crimp die in one .
I would raise the ram all the way with shell holder and the brass in it.
Twist the bullet seating portion all the way out.
Twist the die in until it contacts the brass case and then lower the ram.
Give the die another 1/8 turn and lock the lock ring down or less than 1/8 turn for less crimp.

Now you adjust the seating portion.
I never could wrap my head around that seat and crimp die as it is not crimped all the way until the ram is all the way up and as you are moving the ram up you are still seating the bullet deeper and deeper..This is fine if it has a crimp groove as the bullet and case crimp will not touch until the very last.

But if no crimp groove is there you skid the bullet for a bit against the case mouth during crimpint.

Now when I did crimp I did so with very little crimp I could measure it at .001"
The crimp was .001" smaller OD than just below the crimp. Basically ironing out the flare.
If you are getting .005" I feel you went too far.

1/8 turn may be way too much.
And then all cases need to be spot on in length.. you get one .007" longer you may get the crinkle.

I actually developed a feel when crimping and never brought the ram all the way up on some cases.
I could feel the crimp happening.. Like the winter time crappie nibbling on a jig 20 feet below the surface.

Now I also tested bullet pull with a gauge and bullet seating forces with a gauge and it is usually 20 lbs minimum.
.001" neck tension and winchester NON annealed cases .308.
Annealed would be 40 psi to pull or seat the bullet.
Lapua cases were in the 80 psi area.

I sort my cases by neck ID and neck OD after sizing..all cases are annealed each time.
Consistent bullet pull that way and improved accuracy.
No crimp.

Is there a reason you are crimping?