300 black out chambering issues with RCBS SB taper crimp

[nikdanja]

I new to loading this round and using RCBS SB taper crimp die.

Im following the directions to the T and I’m still getting issues gauging and chambering.

When I load to 2.260 it is just barely out of spec in my gauge and when.I chamber it, it gets stuck. I have to slam the butt stock on the ground to get the bullet out.

BUT if I keep seating the bullet farther in the case, it gauges and chambers fine. 2.240 is the sweet spot where it functions fine in my gun and gauge. WTF I’m pulling my hair out trying to figure out what’s going on. I’m using a 220 grain bullet and there’s zero difference on tbe bullet taper between these 2 depths.

This is a 2 die set and the second die Seats and also puts a taper crimp on the bullet.

I load for 7 different calibers and nothing is as much of a pain in the ass as 300 black out.

 

[ShtrRdy]

I would go off of what the loaded cartridge is telling you. Load to a length that chambers without interference.

 

[Bullspotter]

What kind of brass? Sounds like from the info you give, you are jamming into the lands. 2.260 coal gets stuck, and 2.240 dose not. OR you are not getting the shoulder bumped back far enough, and when you are seating and crimping at the same time, you may be pressing the shoulder back a tiny bit. Have seen a lot of guys talking about crimping rounds and deforming, or moving necks.

Make dummy rounds with no powder or primers to test, Also can color with a marker and chamber, look to find marks on brass and bullets.

Need to measure everything and find the True problem causing the hangup.

What is the Shoulder to base measurement of a fired un sized case?

What is the Shoulder to base measurement of a case that Jams?

What is the Shoulder to base measurement of the round after you seat the projectile to 2.240? the same as the 2.260?

What is the out side neck Dia of a loaded round that jams? and what is the outside neck Dia of a case un sized, fired from the rifle?

 

[Hoser]

Load to 2.240 and go with it. Easy.

If you are using jacketed bullets, dont crimp. If you are using coated cast, crimp in a separate step from seating.

 

[Shoots 700's]

You are probably jamming the 220’s in the lands. My 220’s are seated to 2.089. Ymmv

 

[nikdanja]

I’m finding out 2 things that are going on…1 case head stamp matters cause this IWI shit sucks but lake city is awesome.

if I load to 2.230-2.220, it chambers and I’m good

 

[Rippey715]

It’s possible it’s your crimp. If it’s crimping too early it will over crimp before seating and possibly bulge the case shoulder as it seats the bullet. You need to set it up so that your seating is correct and then adjust for crimp. Reset up your seating die and try again. A guy on another forum literally had this problem for the last 12 hours and it was the crimp. Hope this idea helps.

 

[NCHillbilly]

If you really want to crimp your rounds, set your RCBS seater to ONLY seat, not crimp, get a lee factory crimp die, and crimp them in a separate step. I use RCBS sb dies to form and load and have zero issues. I would also stick with lake city brass, as others may be too thick.