DPMS Oracle Handguard Change

[treillw]

I would like to change the forearm on my DPMS Oracle, so I can attach a vertical grip to the front of it. I might also like to put some flip up iron sights on it as well. I don't want to put a heavy forearm back on the gun - want it light as possible.

Do I need to change the gas block to install a new forearm? The gas block is not level with the top of the upper, so my iron sights will not be even - I think I would need a new gas block if I want to install iron sights. Does anybody make a spaces of some sort or sights for this application?

I am a fairly handy person and can do the work myself if I have instructions. From looking at a couple of videos, it looks like I will need to install a new barrel nut to install a new forearm. Do you have to set the head space on an AR similar to the way you set it for a Ruger Precision Rifle?

Just wondering how far down the rabbit hole I will have to go with buying tools. It might be better to take it somewhere. I honestly am not sure of what I need to do, but I know I can figure it out with some help!

Thoughts?

Thanks!

 

[Screwball48]

You can buy a front sight that is “gas block” height. As for the handguard Look at the Magpul MOE line. It would allow you to mount a vertical grip. Just note that it would not free float the barrel.

 

[hlee]

If you're going down the rabbit hole, might as well go all the way down. Get a low profile gas block (perhaps adjustable), so that you can get a longer rail that will completely cover it. This will give you more real estate to grasp, allow for a longer sight radius with your iron sights, and let you put a bipod further towards the muzzle (if you wish to attach a bipod).

 

[MNhunter1]

Yep, I'd swap out the gas block with a low profile one which can be had for a bit over $20 and throw on a free float with top rail to give yourself a longer sight picture as well. You can find a free float tube that leverages the existing barrel nut (would need to cut off the delta ring) if you don't want to mess with removing the barrel nut. Many other options available if you've got the tools and desire to monkey with barrel nut removal.

Beware...the rabbit hole can get pretty deep and before you know it you'll be building new rifles because you have a spare part laying around. Seems like once I obtained the right tools, I kept finding excuses to use them.

 

[ShooterwithNoName]

I recommend a full rail covering the gas block too. It also helps keeping your gas block from being knocked around if not pinned. I do recommend getting a quality gas block though, cheap ones don't seal, have overbored gas pin holes, etc. You'll want to measure the outside diameter of the barrel where your gas block rests to determine the size you'll need. Will be most likely 0.750" or 0.625". You don't have to get a super high dollar gas block, but I wouldn't skimp here. The Geiselle Super Gas Block is my personal favorite:

https://geissele.com/super-gas-block.html

It's $60 and worth every penny. Hope this helps you out some bud.

Fixed my original post, lol, you can use any AR handguard seeing it's NOT a 308, lol...

 

[MNhunter1]

The pic posted looks like an AR15 Oracle, not the LR308 version, but I don't think the AR15 version had a target crown??. I believe the rail height issue only applies to the LR308 versions, but yes, an important thing to consider if it is indeed the LR308 version.

 

[ShooterwithNoName]

The pic posted looks like an AR15 Oracle, not the LR308 version, but I don't think the AR15 version had a target crown??. I believe the rail height issue only applies to the LR308 versions, but yes, an important thing to consider if it is indeed the LR308 version.

Crap, lol, I don't why I thought it was a 308...

My bad OP, fixed my post above to make sense...

 

[treillw]

Yep, I'd swap out the gas block with a low profile one which can be had for a bit over $20 and throw on a free float with top rail to give yourself a longer sight picture as well. You can find a free float tube that leverages the existing barrel nut (would need to cut off the delta ring) if you don't want to mess with removing the barrel nut. Many other options available if you've got the tools and desire to monkey with barrel nut removal.

Beware...the rabbit hole can get pretty deep and before you know it you'll be building new rifles because you have a spare part laying around. Seems like once I obtained the right tools, I kept finding excuses to use them.

Cutting off the delta ring would be doable. Having a partial system installed there wouldn't hurt anything? What holds the ring in place? What tubes would work with the existing barrel nut/how do I figure that out?

Thanks!

 

[treillw]

Can I use a free floated tube with my current barrel nut?

 

[treillw]

The pic posted looks like an AR15 Oracle, not the LR308 version, but I don't think the AR15 version had a target crown??. I believe the rail height issue only applies to the LR308 versions, but yes, an important thing to consider if it is indeed the LR308 version.

It is the 5.56.

 

[ShooterwithNoName]

You may also want to consider a "drop-in" rail or quad rail system? I have multiple KAC RAS systems that drop right in place of hand guards and give you what your looking for without cutting the delta ring.

The time you spend cutting that delta ring off, plus the risk of damaging the upper/barrel nut, in my opinion you would be better off just buying a barrel nut wrench and break it loose. It's really not too hard to do, may be worth investing in the tools. A barrel nut wrench can be had for little $$.

You have a carbine length gas system so that's the size drop in you would want if you choose to go that route. Also known as 7" length rail.

Here's some of my recommendations for a drop in rail:

Troy Industries 7 Enhanced Drop-In Battle Rail 2-Piece Quad Rail

The Troy Enhanced Drop-In Rail is a non free-floating direct replacement for M4/AR15 plastic handguards. The Troy patented clamping design ensures a...

www.midwayusa.com

Midwest Industries Gen2 Two-Piece Drop-In Handguard Up to 21% Off — Free 2 Day Shipping w/ code 2DAYAIR — 3 models

Shop Midwest Industries Gen2 Two-Piece Drop-In Handguard | Up to 21% Off 4.8 Star Rating on 55 Reviews for Midwest Industries Gen2 Two-Piece Drop-In Handguard Free 2 Day Shipping + Free Shipping over...

www.opticsplanet.com

The best I've used:

Daniel Defense | Omega Rail, AR Rifles, 2 Piece Drop-In Free Float Rail System, Black

Get grips, pads, stocks, and accessories for every gun in your arsenal at CharlieCoopers.com! The best products at the best prices!

www.charliecoopers.com

My KAC M4 RAS is also one of the best drop ins I've used. If you dig around on eBay or maybe post a WTB ad here or just watch for one they can be had for a decent price. I would give something like these a hard look before cutting the delta ring off.

If your not comfortable taking the barrel nut loose to install a full "free float" rail, then check or ask around on here. I'm sure there's someone on here that lives close enough to you that would be willing to help you do it on a weekend or something. If you want to go free float, the barrel nut will have to be pulled.

There's a few rails, I know Midwest Industries makes one and I have a Centurion Arms M4 quad rail that clamps over an existing standard barrel nut with delta ring/spring removed. I can dig around and recommend a few of those if you want?

If you want more than 7" of rail space then you will have to swap to a low profile gas block. You want picatinny "quadrail" or something like Keymod or M-Lok let's you put different lengths of rail sections where you like.

The options are pretty much endless... But I would definitely try to do the best job possible installing it. I've found many barrel nuts clocked off a little bit from the factory. I've found them loose, etc. This will cause you problems even if your able to cut the Delta ring off. The barrel nut wrench also gives you the ability to ensure proper torque and alignment of the barrel nut.

 

[chevy_man]

I like the Magpul ar wrench.

Push the collar back on the reciever side of the hand guards and take the glacier guards off.
Put the barrel in a vise and spin the flash hider off.
Take the set screws loose on the gas block, slide the gas block and tube off.
Spin the barrel nut off.

New barrel nut on (will come with any decent free float guard).
Slide new gas block on (can transfer the gas tube over, just need a 1/16" punch to drive the pin out/in) and set the screws with the gas block aligned with the gas port. Should have a gap where the delta ring was.

Slide new handguard on and attach.

Takes 15-20 minutes and the barrel extension is indexed to the reciever via a pin. No worries about headspace or misalignment.


You will notice if you do a few mag dumps how effective the glacier guards are. I had to do a fore grip after I realized how damn hot the aluminum rails get.