Gas Block DDM4-V2 - size and what other parts

AR/M4 AR Technical Discussion
1

New to the AR platform. Picked up a DDM4-V2 the other day and I would like to install fold down sites. I picked up a Troy Micro Tritium M4 Front & DOA Rear Set for a great price (used).

Don’t know much at all about the AR platform but I think I need to locate a low profile gas block for the gun to install the Troy front site. DD has two sizes a .625 and .750. Which size would I need to get? Are they sized to the fatter part of the barrel and the next down section? I would be installing the gas block on the larger diameter of the barrel.

Is removing the stock front site easy to do on this gun? It looks like there are two pins on the underside of the site mount/barrel that need to be removed and then it would slide off?

The gas tube I assume will just slide out (after removing the grub screw) and a new low profile gas block will just slide on over the barrel / gas tube and then locked down.

Any other parts I would need?

Your help is much appreciated

Thank you,

2

You need to do research on removing an FSB (front sight base). A fixed A2 front sight is the most reliable front sight there is. Why do you need to remove it and install a fold down? Your Troy rear sight will work with the fixed front.

Removing a FSB can be a trying experience if you don’t know what you are doing.

3

Cut it down don’t remove it. Many “how to” threads and videos

4

Since youre new to ARs, id hold off on doing anything drastic. Keep the sights you bought and Shoot it as is first. Learn it, evolve, and only then decide which route is for you (fixed or folding) based on needs you discover from experience.

5

I agree. I would leave the front sight alone and pick up a DD fixed rear. The Troy micro is not made for that rail I believe. You would need the regular Troy flip ups not the micro versions.

6

Thanks for all the feedback I will hold off up grading until I can locate a local gunsmith.

7

Great decision on the DD, but a small mistake on the Troy micros.

On my V2, I removed the FSB and installed a DD LPGB (.750), 13" Troy TRX and Troy BUS. It’s now back in it’s original configuration. In my opinion I wouldn’t change anything. Sell the Troy micros and spend your money on ammo and training.

The only thing I am now contemplating is changing the 7" rail to a 9.5" or 12.5" FSP. But that’s really low on my priority list.

8

Do more than just contact a gunsmith before making these changes. Go out & shoot the rifle as is as Col_Crocs advised.

Do more research on what you want. Many 'smiths do not really know what works on an AR and have put together many- er, interesting configurations

9

Thanks again. I will keep researching and planning what I may do. Will definitely shoot before changing.

10

I bought a DDM4 V1 during the panic the week before christmas(did alright on the price for the timeframe $1550) at my LGS because I wanted a higher end rifle and was not sure if I would be able to get one in the future so I made the impulse buy. Anyways, the point of my post is that I was sure I wanted a rifle with a low profile gas block and rail with flip up sights, but “settled” for the V1 with FSP integrated in the 12" rail which I love the flexibility of. I also bought an aimpoint PRO and now that I have been to the range a few times I would not change a thing. The optic is a little higher than the iron sights(1/3 cowitness I believe) allowing me to align all three if I want through the iron sights or look over the sights at the red dot level at just the red dot. Seems perfect to me and I would not change a thing. I can choose my sight picture on the fly and it is super accurate. It took me like 9 rounds to sight in the optic and another 8 for the iron sights. Try it by putting some serious rounds down range before making any changes to your rifle. My .02