Modern Sporter - Build Discussions

[Wayne W]

Ideally, I'm gonna build my rifle from :

10″ Colt Canada IUR upper
Surefire FH556-216A flash hider
Standard Colt Canada mag catch
Colt Canada ambi charging handle
Magpul CTR Stock
Ergo grip 4011
Geissele SSA trigger

Still waiting for the upper, hopefully I can source one soon, fingers crossed

[rally guy]

How much length does the law folder add?

1.2" noob, use the search function chump!

[Ryang5177]

1.2" noob, use the search function chump!

haha, at least you caught it.

[Canadian-Sniper]

Has anyone used a Daniel Defense MFR XL rail? If so, I would love to see pics.

My goal is to achieve a BCM mcmr style rail, but it has to fit and function over a .936 gas block. The KAC URX 4 is almost perfect for this, except for the crazy install design. Any other suggestions are also welcome.

[Canadian-Sniper]

I had an IBI barrel w/0.936 block, their low profile gas block and a BCM MCMR handguard. The clearance was nil along the bottom. Even after shaving the Allen screws to be flush with the gas block. It would work with some dremel work, but I had no interest in butchering a HG.
With an ALG EMR v2 there was ~1/16“ clearance under the rail and 1/8" clearance on the bottom. IIRC it was a PITA to time the barrel nut on the ALG, but it was solid.

Was the gas block touching the handguard? Do you think there are smaller profile gas blocks that might work better?

[Clvland]

I’m planning to build mine with a KAC urx4 next week when my receiver comes in. I don’t think the installation will be all that difficult but I’ll post results.

Has anyone used a Daniel Defense MFR XL rail? If so, I would love to see pics.

My goal is to achieve a BCM mcmr style rail, but it has to fit and function over a .936 gas block. The KAC URX 4 is almost perfect for this, except for the crazy install design. Any other suggestions are also welcome.

[PinaKaleada]

I’m planning to build mine with a KAC urx4 next week when my receiver comes in. I don’t think the installation will be all that difficult but I’ll post results.

I'd be excited to see how this turns out. I've been debating between a KAC Mk12 handguard or the URX4 for my next one.

I'm curious, why no love for the Geissele rail though? To take apart the URX4 you might have to do all that shimming and timing if you ever need to change out gas blocks or gas tubes, for fun.

[Canadian-Sniper]

I’m planning to build mine with a KAC urx4 next week when my receiver comes in. I don’t think the installation will be all that difficult but I’ll post results.

Much appreciated!

[PinaKaleada]

Has anyone used a Daniel Defense MFR XL rail? If so, I would love to see pics.

My goal is to achieve a BCM mcmr style rail, but it has to fit and function over a .936 gas block. The KAC URX 4 is almost perfect for this, except for the crazy install design. Any other suggestions are also welcome.

Due to the geometry of the ATRS upper, you may not be able to get those 4 screws to fit without damaging the upper itself. It's not a matter of modifying, the screws might simply not fit. I'm basing this on dd lite rail 2, I could be wrong though. Older RIS II and LITE 1 rails could still fit except for the 3,9 o clock screws.

[biologic]

Ideally, I'm gonna build my rifle from :

10″ Colt Canada IUR upper
Surefire FH556-216A flash hider
Standard Colt Canada mag catch
Colt Canada ambi charging handle
Magpul CTR Stock
Ergo grip 4011
Geissele SSA trigger

Still waiting for the upper, hopefully I can source one soon, fingers crossed

Sorry i have to ask, whats the point of building from the colt canada IUR ? youll still need a rail.. you know that right?

its a good barrel indeed. but not very cost efficient (and it will be restricted)