.300 blackout reloading with hornady dies??

Coach Z · December 12, 2013, 12:51 PM

I've fully caught the reloading bug and I'm thinking about getting a .300 upper for one of my AR SBR's My question is Hornady calls their dies 300 whisper and says that they're compatible with .300 AAC blackout rifles???

Is this a .223 5.56 situation? I love the rebate hornaday is currently offering for free bullets with the die purchases but I have no experience with the caliber and was hoping someone here could shed some light on the situation.

Thanks in advance

Roughedge · December 12, 2013, 06:16 PM

My first set was hornady and they done good but when Lee started making them I got a set just because I like the Lee dies better.The whisper and the BO are so close I've shot whisper in my BO upper once.

rg1 · December 12, 2013, 08:04 PM

I have the Hornady 300 Whisper/300 Blackout die set. Works great, no problems. Hornady says the Whisper/Blackout dies are identical. Also they say the only difference in the chambers of the two are that the 300 Blackout throat is .015" longer than the Whisper. Whisper loads are ok in Blackout. I also have the RCBS set also and I'd recommend either. Since the headspace on factory Blackout ammo is minimum to work in all rifles and it seems AR15 chambers are a little long that I'd highly recommend a case gauge such as Hornady's Headspace Gauge set that works with your calipers to adjust your dies for headspace. Use the 350B insert on Hornady's Gauge. With the 350 insert factory case headspace measures approximately 1.068" to 1.069" and a lot of posts say fired cases measure around 1.075". Mine do also and my bolt will close on a case measured at 1.076" Or you can just check cases in your upper until they will just chamber and reduce around .003-.004" My Hornady sizing die will size back to factory lengths if adjusted for firm contact with the shellholder, which is too much for my chamber. It's fun to reload and shoot the Blackout.

December 12, 2013, 12:51 PM	#1
Coach Z Senior Member Join Date: February 18, 2011 Location: RI Posts: 795	.300 blackout reloading with hornady dies?? I've fully caught the reloading bug and I'm thinking about getting a .300 upper for one of my AR SBR's My question is Hornady calls their dies 300 whisper and says that they're compatible with .300 AAC blackout rifles??? Is this a .223 5.56 situation? I love the rebate hornaday is currently offering for free bullets with the die purchases but I have no experience with the caliber and was hoping someone here could shed some light on the situation. Thanks in advance __________________ Love my guns

December 12, 2013, 06:16 PM	#2
Roughedge Senior Member Join Date: January 24, 2011 Location: Monroe,NC Posts: 669	My first set was hornady and they done good but when Lee started making them I got a set just because I like the Lee dies better.The whisper and the BO are so close I've shot whisper in my BO upper once. __________________ The man that die's with the most stuff win's!

December 12, 2013, 08:04 PM	#3
rg1 Senior Member Join Date: November 6, 2001 Posts: 1,125	I have the Hornady 300 Whisper/300 Blackout die set. Works great, no problems. Hornady says the Whisper/Blackout dies are identical. Also they say the only difference in the chambers of the two are that the 300 Blackout throat is .015" longer than the Whisper. Whisper loads are ok in Blackout. I also have the RCBS set also and I'd recommend either. Since the headspace on factory Blackout ammo is minimum to work in all rifles and it seems AR15 chambers are a little long that I'd highly recommend a case gauge such as Hornady's Headspace Gauge set that works with your calipers to adjust your dies for headspace. Use the 350B insert on Hornady's Gauge. With the 350 insert factory case headspace measures approximately 1.068" to 1.069" and a lot of posts say fired cases measure around 1.075". Mine do also and my bolt will close on a case measured at 1.076" Or you can just check cases in your upper until they will just chamber and reduce around .003-.004" My Hornady sizing die will size back to factory lengths if adjusted for firm contact with the shellholder, which is too much for my chamber. It's fun to reload and shoot the Blackout. Last edited by rg1; December 12, 2013 at 08:16 PM.