*300 AAC Blackout Conversion*

brickhouseblues · July 12, 2013, 12:52 PM

After reading an article from "book of the AR-15" last month about Daniel Defense DDM4 ISR-300, my curiosity was piqued and I wanted to run out and get me one of those beauties... After looking at the 3200 retail price, not including the 200 tax stamp, I had to slam on the brakes!

Fear not, I figured and been researching the 300 AAC and came up with an alternative. I found a DSA DM4 16" 1:8 chrome molly 300BLK upper receiver for a reasonable price. Which brings me to my question or questions I guess; I have a S&W M&P 15 lower fully assembled with a chrome bolt carrier group with only 40 rounds of 5.56 ammo through it. Is this a safe and effective marrying of the two?

velillen · July 12, 2013, 12:57 PM

Yes take takedown pins out and switch uppers. Use same bolt and charging handle and shoot. Switch uppers depending on ammo used.

The only difference in the two is the barrel. Everything else is the same including most mags

Palmetto-Pride · July 12, 2013, 03:11 PM

Hope you reload because if you don't good luck finding ammo right now for the 300BLK.

brickhouseblues · July 12, 2013, 08:25 PM

I can get some by me, just expensive!

dean1818 · July 13, 2013, 05:25 PM

The promised cheap ammo is like a unicorn

If you are a reloader its can be a good choice.....
(maybe the cheap ammo will hit in the future, but its not here today)

It also seems to do well supressed

If you are a hunter, and could possibly shoot to 250 to 300 yards there are better choices

Palmetto-Pride · July 13, 2013, 06:52 PM

Before the meltdown you could get this Remington UMC 115gr 300 BLK for around $11.00-$12.00 which really wasn't to bad for a non standard round, now its $15.29 which still isn't that bad if you can find it in stock anywhere.

http://www.midwayusa.com/product/547...base-box-of-20

dean1818 · July 13, 2013, 08:32 PM

It being touted as readily available on the main site at 11 bucks......still

Which it isnt

I considered it, and may at some point get one to run suppressed, but if I
Would have jumped on the bandwagon in 2012 and didnt reload, i would be highly upset, based on the constant promises of ample supply by an individual (300 blk developer) that Goes on EVERY gun board in the usa and starts arguements about the caliber.

The style of this individual didnt sit right with me

The other rounds are coming around for a few months....... This one is much slower to come

Its has more energy than a 223 within 200 meters, and nearly 20 percent more than a 7.62x39, but falls significantly short of a 6.8 and 6.5 at all distances...

For hunting purposes, the best bullet I could find in the 300 blk dropped below 1000ft lbs at 128 yards. The bullet I hunt with, the 6.8 120 SST, drops below 1000 ft lbs at 278 yards........ Double the distance for that energy

Many people use 1000 ft lbs as a minimum hunting energy

The 300 has an advantage that if you reload, you can use common 30 cal bullets and common 223 cut down brass...... A great cheap plinking option

Another advantage is that it uses the same bolts and a barrel swap from 223 is possible.

I do think the hype of swapping barrels is more of a theory..... The people seem to always buy a dedicated 300blk upper anyway, and I havent read where someone swaps their 223 and 300 blk back and forth.

And....... If you use the 300 blk and the 223 in the same magazine, you can have a major accident and load the wrong round in the wrong upper.......
Its already been reported to have happened

It has its place, but I get frustrated by people that try to make it something more than it is

brickhouseblues · July 13, 2013, 08:56 PM

On second thought. I may need to do some more research. I do like that caliber suppressed as well, just that its just so darn expensive! I think I'll stick with my trusty 5.56!

July 12, 2013, 12:52 PM	#1
brickhouseblues Member Join Date: March 3, 2013 Location: Tulsa Oklahoma Posts: 27	*300 AAC Blackout Conversion* After reading an article from "book of the AR-15" last month about Daniel Defense DDM4 ISR-300, my curiosity was piqued and I wanted to run out and get me one of those beauties... After looking at the 3200 retail price, not including the 200 tax stamp, I had to slam on the brakes! Fear not, I figured and been researching the 300 AAC and came up with an alternative. I found a DSA DM4 16" 1:8 chrome molly 300BLK upper receiver for a reasonable price. Which brings me to my question or questions I guess; I have a S&W M&P 15 lower fully assembled with a chrome bolt carrier group with only 40 rounds of 5.56 ammo through it. Is this a safe and effective marrying of the two? __________________ "I'll give you my gun when you take it from my cold dead hands!" ~Charlton Heston~

July 12, 2013, 12:57 PM	#2
velillen Member Join Date: October 20, 2012 Posts: 93	Re: 300 AAC Blackout Conversion Yes take takedown pins out and switch uppers. Use same bolt and charging handle and shoot. Switch uppers depending on ammo used. The only difference in the two is the barrel. Everything else is the same including most mags

July 12, 2013, 03:11 PM	#3
Palmetto-Pride Senior Member Join Date: May 31, 2009 Location: Charleston, SC Posts: 2,071	Hope you reload because if you don't good luck finding ammo right now for the 300BLK. __________________ “The problem with socialism is that you eventually run out of other people's money.” -Margaret Thatcher-

July 12, 2013, 08:25 PM	#4
brickhouseblues Member Join Date: March 3, 2013 Location: Tulsa Oklahoma Posts: 27	I can get some by me, just expensive! __________________ "I'll give you my gun when you take it from my cold dead hands!" ~Charlton Heston~

July 13, 2013, 05:25 PM	#5
dean1818 Senior Member Join Date: December 5, 2009 Location: Frisco Texas Posts: 844	The promised cheap ammo is like a unicorn If you are a reloader its can be a good choice..... (maybe the cheap ammo will hit in the future, but its not here today) It also seems to do well supressed If you are a hunter, and could possibly shoot to 250 to 300 yards there are better choices __________________ An imperfect servant of my Lord and Saviour, Jesus Buying American made, wherever I still can

July 13, 2013, 06:52 PM	#6
Palmetto-Pride Senior Member Join Date: May 31, 2009 Location: Charleston, SC Posts: 2,071	Before the meltdown you could get this Remington UMC 115gr 300 BLK for around $11.00-$12.00 which really wasn't to bad for a non standard round, now its $15.29 which still isn't that bad if you can find it in stock anywhere. http://www.midwayusa.com/product/547...base-box-of-20 __________________ “The problem with socialism is that you eventually run out of other people's money.” -Margaret Thatcher-

July 13, 2013, 08:32 PM	#7
dean1818 Senior Member Join Date: December 5, 2009 Location: Frisco Texas Posts: 844	It being touted as readily available on the main site at 11 bucks......still Which it isnt I considered it, and may at some point get one to run suppressed, but if I Would have jumped on the bandwagon in 2012 and didnt reload, i would be highly upset, based on the constant promises of ample supply by an individual (300 blk developer) that Goes on EVERY gun board in the usa and starts arguements about the caliber. The style of this individual didnt sit right with me The other rounds are coming around for a few months....... This one is much slower to come Its has more energy than a 223 within 200 meters, and nearly 20 percent more than a 7.62x39, but falls significantly short of a 6.8 and 6.5 at all distances... For hunting purposes, the best bullet I could find in the 300 blk dropped below 1000ft lbs at 128 yards. The bullet I hunt with, the 6.8 120 SST, drops below 1000 ft lbs at 278 yards........ Double the distance for that energy Many people use 1000 ft lbs as a minimum hunting energy The 300 has an advantage that if you reload, you can use common 30 cal bullets and common 223 cut down brass...... A great cheap plinking option Another advantage is that it uses the same bolts and a barrel swap from 223 is possible. I do think the hype of swapping barrels is more of a theory..... The people seem to always buy a dedicated 300blk upper anyway, and I havent read where someone swaps their 223 and 300 blk back and forth. And....... If you use the 300 blk and the 223 in the same magazine, you can have a major accident and load the wrong round in the wrong upper....... Its already been reported to have happened It has its place, but I get frustrated by people that try to make it something more than it is __________________ An imperfect servant of my Lord and Saviour, Jesus Buying American made, wherever I still can Last edited by dean1818; July 13, 2013 at 09:36 PM.

July 13, 2013, 08:56 PM	#8
brickhouseblues Member Join Date: March 3, 2013 Location: Tulsa Oklahoma Posts: 27	On second thought. I may need to do some more research. I do like that caliber suppressed as well, just that its just so darn expensive! I think I'll stick with my trusty 5.56! __________________ "I'll give you my gun when you take it from my cold dead hands!" ~Charlton Heston~