I want to build an SBR out of my DDM4. Basically I want to change out my 16" barrel for a 11.5" BCM barrel. Here is a picture of what it would look like if I did this and kept the current fore grip (poor photoshop job). Is there a problem with the flash hider partially in the fore grip? I would like to ultimately get a silencer for this build as well.
Anyhow yall get the drift. I plan on getting an upper vice block to strip my upper. Is there something else I need to know? I have never assembled an upper so I am a little worried about doing this, however I plan to do more research as this project is a few months out from happening. IS there a good book yall recommend?
My ultimate plan is to have a 18” SPR build, a 16” 5.45x39 upper, and a 11.5” SBR build. However I will keep my 16” DD barrel so that I can change it out with the 11.5 barrel if ever desired.
Most suppressors will not be able to mount on the barrel as you have it configured because of where the rail ends. I ended up with a BCM 11.5" upper and a 9" DD AR15 rail.
Blast, that is going to be a problem. Thanks for the help. Perhaps I would be best suited to build an SBR lower from scratch or pick up a complete upper from BCM or G&R.
The better idea would be other uppers. Not sure if you have changed barrels before but it isn’t something you want to be doing on a continuous basis. Use one lower for the SBR and then get a second lower for the Recce/ 5.45 gun.
Possibly- you may encounter issues due to the differences in gas ports, etc… Take a look at my set up in the NFA picture thread and see if it appeals to you. My set up was a happy compromise between what was really possible and what I envisioned.
Well after more reading, I am really tempted to get a 11.5" barrel and new quad rail hand guard and install it on my DD upper. Then put my 12.0 omega rail on a S&W 5.45x39 upper.
This would be the most cost effective way for me to get both of the guns. Use my DD card for a 10" quad rail and buy a 11.5 barrel from BCM. Then I would just need to buy a S&W M&P15r gun…am i missing something?
I’ve got a 10.5" LWRC and unless I was going to build a piston 10.5", I’d definitely go 11.5" for reliability reasons.
A lot of 10.5" DI guns don’t run 100% because the gas port is too close to the end of the barrel (~3.5"). 11.5" gives you another inch of barrel and higher velocity to boot.
I have a local smith that will cut my barrel down, recrown it, and thread it for 50 bucks. Cash is tight so being able to only spend 50 bucks to have a SBR verse by a new bbl and foregrip is a big plus for me. I would like to build an 18" upper one day, so I think that at 12 and 18 inch upper would have me covered pretty well.
After more reading about silencers I really question if I will ever put one on anything bigger then a 22 lr so if that the case I may want to cut the barrel down to 11.5" which would put it back to the orginal picture I posted. What are yalls opinions?
This is what it would look like. If i did it it would be about a 12.5" bbl so that a suppressor would be an option down the road.
No, not really. And till’ you get a suppressor, any thoughts on a KX3? It’d look and work pretty badass on that upper. I don’t REALLY like the rail, but it looks like its function is worthy and something I’d use.
What do you know about your local smith? We have seen enough horror stories of personnel taking their weapons to the local guy and they end up screwing it up. I am guessing that there will also need to be a change in the gas port size as well.
If it were me, I wouldn’t do it. I would wait until I could do it correctly.
