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300 Blackout SBR, AAC vs Daniel Defense

eddiemac

Sargent
Full Member
Minuteman
Nov 18, 2012
277
15
South Carolina
I intended to get a AAC 9" upper in 300 BLK, then saw that Daniel Defense has a new 10" 300 BLK SBR in their catalog. Does anyone have any recommendations on the DD upper (is it any better than the AAC upper?) or better yet experience with both SBRs. I will be using an AAC SDN-6 suppressor.
 
AAC is a 7 twist barrel, DD uses an 8 twist. There will be negligible ballistics differences in 1" of barrel length. Both utilize the same coatings on the barrel. I cant find the post on 300blktalk.com that talks about AAC's barrel construction. I think its 4150 button rifled where as DD is a 4150 CHF barrel. AAC BCG is nickle boron coated where as I believe DD is straight mil spec parkerized.

I prefer the 7 twist barrels over the 8 twist and it seems that is where most people are going or have already gone. I suspect DD will make the switch at some point when they run out of barrels and have to re-set their hammer forging equipment.

I believe that is really the main difference between them. If you like one hand guard over the other would be the other thing I would look at.
 
AAC is a 7 twist barrel, DD uses an 8 twist. There will be negligible ballistics differences in 1" of barrel length. Both utilize the same coatings on the barrel. I cant find the post on 300blktalk.com that talks about AAC's barrel construction. I think its 4150 button rifled where as DD is a 4150 CHF barrel. AAC BCG is nickle boron coated where as I believe DD is straight mil spec parkerized.

I prefer the 7 twist barrels over the 8 twist and it seems that is where most people are going or have already gone. I suspect DD will make the switch at some point when they run out of barrels and have to re-set their hammer forging equipment.

I believe that is really the main difference between them. If you like one hand guard over the other would be the other thing I would look at.

I appreciate the information and will check out the 300blk site. What is the advantage of a 7 twist for 220 grain bullets? Funny you mention the handguard, I like the AAC version and the DD modular free float handguard, which would be special order.
 
The 7 twist will stabilize pretty much everything you could put through it: 240g SMK, 225g Hornady OTM, 245g cast, 230g Berger, etc... The 8 twist may not stabilize the 240g stuff, will be just fine with the 220g SMK's and could have issues with the others depending on length.

I am falling out of love with quad rails, but I really like the KAC URX III on the AAC stuff.
 
I will probably go with the AAC, I found one about $300 cheaper than the DD option and I should have it next week. From what you said, it looks like I'll have more flexibility with different types of ammo with the AAC for suppressed shooting.
 
I ordered an AAC 9" 300 BLK upper, it shipped out today. Thanks again for the advice, this forum is very helpful.
 
I have had both the 8 twist and 7 twist AAC 9" uppers. AAC replaced the 8 twist when I could not get decent accuracy. The 7 twist was markedly better, but 2 MOA was the best I could get it to do. I bought a 10.3 DD upper off Gunbroker last month and preliminary testing has shown it to be 100% reliable and I have seen .75 MOA groups with handloaded Barnes 110 blacktips. UMC 115 grain is 1.5 MOA. I like the shorter AAC barrel and the Knight's handguard, but the lack of accuracy kept gnawing at me. I use the SDN-6 on all of them. All of the uppers ate damn near anything I fed them.

YMMV.

-J
 
I have had both the 8 twist and 7 twist AAC 9" uppers. AAC replaced the 8 twist when I could not get decent accuracy. The 7 twist was markedly better, but 2 MOA was the best I could get it to do. I bought a 10.3 DD upper off Gunbroker last month and preliminary testing has shown it to be 100% reliable and I have seen .75 MOA groups with handloaded Barnes 110 blacktips. UMC 115 grain is 1.5 MOA. I like the shorter AAC barrel and the Knight's handguard, but the lack of accuracy kept gnawing at me. I use the SDN-6 on all of them. All of the uppers ate damn near anything I fed them.

YMMV.

-J

Good to know, I am not looking for great accuracy from this upper, I will probably shoot it more for fun. However, if I am not happy with the AAC I will definitely go with the DD upper.
 
This is a 5 round group a local guy shot with handload 208g AMAX out of a 7 twist AAC upper.

E84355AE-EF00-40AC-84E8-3B63325D8FA6-9632-0000011EF88099D6.jpg
 
Good to know, I am not looking for great accuracy from this upper, I will probably shoot it more for fun. However, if I am not happy with the AAC I will definitely go with the DD upper.

If you dont like the AAC upper I would look at Noveske WAY before I would look at DD. That barrel twist, to me, can make a huge difference. If DD would switch to 7 twist it would be a 3 way tie.
 
If my AAC upper shoots similar to the target you posted, I won't be looking at all. I will only shoot 208-220 grain bullets which might help out in the accuracy department. On a side note, I have not seen any Noveske SBR uppers for sale recently, but had no trouble finding the AAC upper.
 
The 208g AMAX seems to be the ticket. My AAC shoots it great and so does my buddy as posted above. I dont have an optic on my gun yet so my groups are nothing to write home about. I think he shot this at 100 with a USO 1-8.
 
Does anyone sell 208 grain 300 BLK ammo? I can't even find 220 grain stuff at a reasonable price (may have to break down and start reloading).
 
Hornady makes 208g AMAX Whisper ammo. Will run in the BLK chamber.

If I didnt reload I would have NEVER gotten into 300blk.