How to Attach Flat T-Slot Rail to Round Handguard?

[Phil3]

I have a 2.00" diameter JP Rifles round handguard on an AR-15. I quite like it, and want to use it with a Mystic Precision MPOD (bipod). The MPOS attaches to a T-Slot rail, which Mystic Precision sells. See pics below. Any ideas on how I can attach the T-Slot rail (flat mounting surface) to the round handguard? I contacted JP Rifles, but they have no solutions. Until I sold my lathe and mill, I could have made an adapter out of black Delrin. Argh! Thanks. Phil

 

[Twdmar]

What does the handguard look like? Is the a space to attach accessories with mounting holes? Get some hardware and nuts to inside the handguard like the rail sections that normally go on. Bed the rail to the handguard with a release again to give a little support.

 

[Dusty Stevens]

Bed it

 

[Phil3]

Cannot bed since T-slot rail is mounted to an AR handguard. See pic of guard below. The slots go around the entirety of the round guard. I can screw the rail to the handguard using screws and backing nuts, but the rail would be sitting on a thin line of contact, and only in places where there is no guard slot. I do not see how one could make an a clean looking arrangement using bedding material.

Since my original post, I thought I would see if someone could 3D print it. I can easily make a drawing of what I need. Along with screws, it would solid.

 

[coldboreshot]

I have a 2.00" diameter JP Rifles round handguard on an AR-15. I quite like it, and want to use it with a Mystic Precision MPOD (bipod). The MPOS attaches to a T-Slot rail, which Mystic Precision sells. See pics below. Any ideas on how I can attach the T-Slot rail (flat mounting surface) to the round handguard? I contacted JP Rifles, but they have no solutions. Until I sold my lathe and mill, I could have made an adapter out of black Delrin. Argh! Thanks. Phil

View attachment 1231715

View attachment 1231716

I'm thinking, no matter what type of adapter, the issue seems to be mounting to that particular forend. I am curious because I am not completely familiar with JPE products but can that forend be indexed to where anyone of the slots can be positioned at the bottom 6 o'clock? If that's possible then you can mount the t-rail to one of the slots directly without drilling holes but inevitably, your looking at a direct mount. You would have the option though of mounting that rail in any of the slots in that line to adjust where you want the bipod to fall. The direct mount should be stable enough and at the end of the day with the bipod removed, all you'll have is a small rail mounted to the bottom of the forend. Or, you may end up having to look toward a Harris or similar mounting bipod. Even if you sought out a picatinny rail or even an Mlok forend, you still need to search for a mount to adapt that t-rail. Now, your just stacking up components to use that bipod. The lower profile of that t-rail as a direct mount may not be so intrusive at that point. Good luck with your project.

 

[shootermeb]

I had a similar issue where I wanted an Anschutz/UIT rail so I could use a handstop for high power position shooting, and I wanted to add the rail to a M-lok handguard on an AR. I have a bunch of Anschutz accessories so having the same rail on an AR was appealing.

My solution was to 3D print an interface to accept a Freeland Shooting Supply UIT rail. The M-lok screws went through the rail, through my 3D print, and through the handguard. The primary purpose of the 3D printed piece is to have something that can be held comfortably in the hand. Also, with this solution, there is no permanent modification to the handguard.

One solution could have been machining the rail into the handguard, and not buying or building any extra pieces, but where's the fun in that?

I do not have any pics readily available of what this looks like in real life, but it has held up over years of use. The interface is 3d printed and coped to the diameter of the handguard. I have included a rendering of the object for reference in case you are looking to do something similar.



UIT Rail: https://freelandssports.com/product/anschutz-blank-rail-section-15/

 

[akajun]

My match rifle handguards are simply slotted for the t nut. No need for an adapter
If you have a mill it’s easy to do

 

[Fast14riot]

My match rifle handguards are simply slotted for the t nut. No need for an adapter
If you have a mill it’s easy to do

This is the best way.

 

[Phil3]

My match rifle handguards are simply slotted for the t nut. No need for an adapter
If you have a mill it’s easy to do

What handguard are you using that already has a T-Slot?

 

[Phil3]

I'm thinking, no matter what type of adapter, the issue seems to be mounting to that particular forend. I am curious because I am not completely familiar with JPE products but can that forend be indexed to where anyone of the slots can be positioned at the bottom 6 o'clock? If that's possible then you can mount the t-rail to one of the slots directly without drilling holes but inevitably, your looking at a direct mount. You would have the option though of mounting that rail in any of the slots in that line to adjust where you want the bipod to fall. The direct mount should be stable enough and at the end of the day with the bipod removed, all you'll have is a small rail mounted to the bottom of the forend. Or, you may end up having to look toward a Harris or similar mounting bipod. Even if you sought out a picatinny rail or even an Mlok forend, you still need to search for a mount to adapt that t-rail. Now, your just stacking up components to use that bipod. The lower profile of that t-rail as a direct mount may not be so intrusive at that point. Good luck with your project.

Because of the mounting design, the handguard can only be turned 180 degrees. That means two long open slots now on the bottom are on top, and the line of screw holes on the top, are now on the bottom. At present, there are two long slots in the bottom. I am using one JP curved back nut to secure a swivel point for a bipod (Harris). I can certainly use two curved back nuts to secure the T-Slot rail (UIT or Anschutz) to toe JO handguard, but this mounting a FLAT rail against a ROUND tube. It might be somewhat secure if tightened down hard enough, but clearly, not ideal. This is my only issue. I would much prefer the rail and the handguard to have more direct contact with one another than what is available now.

I have a Harris bipod and that works, but much prefer the other bipod previously mentioned. You are right, I do not want to stack up components. I am trying to get the rifle to sit in the bipod and the stacking would reduce that.

I may order the T-Slot rail and see how it fits and what I can do to improve handguard to rail contact at the mounting point. I do not wish to change handguards (I have no need for all the Picatinny rails). I may have to see if anyone can print me a 3D adapter, or find a machine shop to make it.

 

[Phil3]

I had a similar issue where I wanted an Anschutz/UIT rail so I could use a handstop for high power position shooting, and I wanted to add the rail to a M-lok handguard on an AR. I have a bunch of Anschutz accessories so having the same rail on an AR was appealing.

My solution was to 3D print an interface to accept a Freeland Shooting Supply UIT rail. The M-lok screws went through the rail, through my 3D print, and through the handguard. The primary purpose of the 3D printed piece is to have something that can be held comfortably in the hand. Also, with this solution, there is no permanent modification to the handguard.

One solution could have been machining the rail into the handguard, and not buying or building any extra pieces, but where's the fun in that?

I do not have any pics readily available of what this looks like in real life, but it has held up over years of use. The interface is 3d printed and coped to the diameter of the handguard. I have included a rendering of the object for reference in case you are looking to do something similar.



UIT Rail: https://freelandssports.com/product/anschutz-blank-rail-section-15/

I saw the photo of the T-Slot rails for sale, but not a rendering of what you made. I would like to see that. Thanks.

 

[Walt Krafft]

I think you are over thinking it. Screw your rail to the handguard using backing nuts and go shoot. Lots of sling hooks have less attachment than that using only a single screw and they work fine. JMO

 

[coldboreshot]

Because of the mounting design, the handguard can only be turned 180 degrees. That means two long open slots now on the bottom are on top, and the line of screw holes on the top, are now on the bottom. At present, there are two long slots in the bottom. I am using one JP curved back nut to secure a swivel point for a bipod (Harris). I can certainly use two curved back nuts to secure the T-Slot rail (UIT or Anschutz) to toe JO handguard, but this mounting a FLAT rail against a ROUND tube. It might be somewhat secure if tightened down hard enough, but clearly, not ideal. This is my only issue. I would much prefer the rail and the handguard to have more direct contact with one another than what is available now.

I have a Harris bipod and that works, but much prefer the other bipod previously mentioned. You are right, I do not want to stack up components. I am trying to get the rifle to sit in the bipod and the stacking would reduce that.

I may order the T-Slot rail and see how it fits and what I can do to improve handguard to rail contact at the mounting point. I do not wish to change handguards (I have no need for all the Picatinny rails). I may have to see if anyone can print me a 3D adapter, or find a machine shop to make it.

I understand your concerns. What I should have included in my offering was, at one time, I had the same type of Anschutz rail section mounted directly to the bottom of a slotted, round forend with 2 fasteners to utilize my handstop and prone sling attachment. The pressure I exuded on the handstop certainly out-weighed the force you would ever need to ever preload that bipod on an AR15 platform. My mount was solid. So in a sense, I have to agree with @Walt Krafft's contribution here. You will be fine. And yes, the rail mounted of the bottom of the curved forend may not be the most attractive, but it will certainly get the job done.

 

[coldboreshot]

I have a 2.00" diameter JP Rifles round handguard on an AR-15. I quite like it, and want to use it with a Mystic Precision MPOD (bipod). The MPOS attaches to a T-Slot rail, which Mystic Precision sells. See pics below. Any ideas on how I can attach the T-Slot rail (flat mounting surface) to the round handguard? I contacted JP Rifles, but they have no solutions. Until I sold my lathe and mill, I could have made an adapter out of black Delrin. Argh! Thanks. Phil

View attachment 1231715

View attachment 1231716

Additionally, if you ever decide to change direction with the forend, talk to Gary Eliseo at Competition Machine, Inc. If I'm not mistaken, he makes a slotted tubular forend with the Anschutz rail incorporated into the forend, for an AR 15 platform.

 

[boltfluter]

Just thinking out loud here, but what if you cut a shallow groove down the center of the adaptor, for two points of contact on the round forearm. Simple enough on a mill.

Paul

 

[MislMan]

Take a piece of your delrin and sand a curved groove in it. Use a wooden dowel or a deep-well socket and wrap sandpaper around the dowel/socket. Do a internet search for “ar15 benchrest” and you will find examples of these.

 

[LVLAaron]

That's an m-lock rail right? Use some m-lock hardware and attach your rail?

 

[akajun]

What handguard are you using that already has a T-Slot?

White oak, compass lake, my first match rifle was simply a RRA varminter that I slotted the handguArd myself in a mill.

 

[Phil3]

I could easily accomplish what I want with a mill OR lathe, but do not have these tools, nor do I have access to them. The idea of using a 2" diameter dowel with sandpaper could work on Delrin, but not exactly accurate and could lead to a cocked rail. I am going to try mounting the rail using standard JP backing nuts (curved to fit inside of round handguard) and see how secure it is. I don't like the arrangement but it might be sturdy enough. The mounting system for rails and such is not M-Lok. See the first part of this video to see the guard I have and how attachments work.

This is an older handguard like I have. My rifle is older!

Thank you,

Phil

 

[LVLAaron]

@Phil3 - it'll be plenty strong. You could bed the gap with a 2oz marine tex kit if you wanted to get fancy