Smith And Wesson Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Ive never built an AR so im a bit uneducated in what can and cant be done.
I have a stock M&P 15 5.56 which shoots just fine. How would i go about converting this to a 300 AAC Blackout? Do i just buy a new upper. Ive read the 300 is built along the same dimensions as the 5.56 cartridge. Its just shorter with a larger piece of lead. If thats so i wouldnt even need a new bolt, it would just be the barrel that was diffrent wouldnt it? Can i just buy a new barrel and change it out and be done with the conversion? Or does a new upper come with a new bolt, barrel and all? Oh and what about the magazine? Will my lower work with a magazine for the 300? If i do need a new upper what brand should i use? Money is a consideration for me so ultra high priced parts isnt an option.
See theres alot I dont know yet. I bet some of you are going please Lord someone take this guys guns from him, lol. Hey yall had to ask questions in the beginning also.
 

·
Registered
Joined
·
74 Posts
If you have never built an AR it might be better for you to just get a complete upper assembly for 300 AAC. If you want to try to change your 5.56 to 300 all you will need to do is just change barrels. However, changing barrels requires a couple special tools if you want to make the job easier so there would be an investment in buying the tools. The magazines will work for both 5.56 and 300. The bolt is the same too.

I would stick with a brand name if you do buy a complete upper.

Good luck which ever way you decide to go.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #3
If you have never built an AR it might be better for you to just get a complete upper assembly for 300 AAC. If you want to try to change your 5.56 to 300 all you will need to do is just change barrels. However, changing barrels requires a couple special tools if you want to make the job easier so there would be an investment in buying the tools. The magazines will work for both 5.56 and 300. The bolt is the same too.

I would stick with a brand name if you do buy a complete upper.

Good luck which ever way you decide to go.
Bubba you gave me the exact info that i needed. Thank You!!
I have a pretty wide assortment of tools all ready. I dont have the reciever vice block, the bolt insert piece to keep the upper from being crushed nor do i yet have an AR wrench. I do have the ability to build a pretty decent barrel vice clamp though. Ill look into the specialty tools a bit more before i buy anything at all. Im sure i didnt list all the gun smith tools ill need for this job.
I have to admit im a sucker when it comes to buying tools though. I just cant help myself when i see a tool that i want/need.
Anyway have a good day Bubba and thanks again for the information you gave me.
 
1 - 3 of 3 Posts
Top