Modern Sporter - Build Discussions

[robab]

Attachment 345229

I just bought the kit used (from a reputable CGNer), but just realized it doesn't fit in my AR mag well either.

I checked my cmmg mags. Mine doesn’t have the bumps quiet as large as those ones. You can pm me I’ll send u pics. My cmmg kit works perfect in my MS. Try filing down those tabs.

[ATRS Shaun]

Attachment 345229

I just bought the kit used (from a reputable CGNer), but just realized it doesn't fit in my AR mag well either.

Interesting! I have not seen those before... If I was to guess however, I would think they are an attempt to align the feeding path better. Some mags have a bit of wiggle in any receiver be it AR or otherwise, and in the 22lr ones it can lead to misfeeds if the angle of the ammunition changes from one round to another. I've used a dot of 5 minute epoxy on the back of magazines to correct this same thing, and just sanded until they are a snug fit.

I'd also suggest sanding/filing the tabs down, BUT I'd go at it slowly and evenly to sand them down only the minimum amount necessary as I'm virtually positive those little tabs are there to snug up your magazine.

Very cool, and let us know how it goes!

[Sluggo_m14]

Will any Barrel Torque tool and vice block work with these receivers?
Will the Magpul Bev block work?

Thanks

[PinaKaleada]

Will any Barrel Torque tool and vice block work with these receivers?
Will the Magpul Bev block work?

Thanks

In my experience barrel torque tool that locks into the barrel extension works the best. You wont worry about applying undue stress on the upper.

[Brodie720]

Can u please explain why you think a barrel torque tool puts less stress on a on a upper I have been trying to wrap my head around it. The way I think of it is, the barrel extension pin slides into the slot on the upper and the barrel nut is not putting any force on to the barrel to make it want to twist, the force is on the upper making it want to turn with the barrel nut. soo by using a barrel torque tool it’s just holding the barrel from turning, all the force that there is would be is on the pin on the barrel extension because tighting the barrel nut will make the upper want to twist with it. I totally understand for putting on a flash hider or muzzle brake i would use barrel torque tool. Sorry fairly new to building.
Thanks
Brodie

[PinaKaleada]

Can u please explain why you think a barrel torque tool puts less stress on a on a upper I have been trying to wrap my head around it. The way I think of it is, the barrel extension pin slides into the slot on the upper and the barrel nut is not putting any force on to the barrel to make it want to twist, the force is on the upper making it want to turn with the barrel nut. soo by using a barrel torque tool it’s just holding the barrel from turning, all the force that there is would be is on the pin on the barrel extension because tighting the barrel nut will make the upper want to twist with it. I totally understand for putting on a flash hider or muzzle brake i would use barrel torque tool. Sorry fairly new to building.
Thanks
Brodie

That was my first thought as well. But I've found out that is not the case. Firstly, if you degrease the barrel extension flange and the front face of the receiver, this allows the friction between the barrel flange and the front of the receiver to hold the barrel nut and receiver in place when the majority of torque is applied. As a result the pin shouldn't put much force into the slot, as majority of the resistence is from the friction between barrel flange and receiver front. Thats what I read, I verified that even though I've put a lot of torque(higher than recommended), the index pin doesn't cause any deformation inside the slot.

[langfordbc]

..............

[Dennisan]

has anyone tried the new Cross Industries Mags in their modern sporter yet? How is the fit?

I found that my hera mags were pretty tight.

[Brodie720]

That was my first thought as well. But I've found out that is not the case. Firstly, if you degrease the barrel extension flange and the front face of the receiver, this allows the friction between the barrel flange and the front of the receiver to hold the barrel nut and receiver in place when the majority of torque is applied. As a result the pin shouldn't put much force into the slot, as majority of the resistence is from the friction between barrel flange and receiver front. Thats what I read, I verified that even though I've put a lot of torque(higher than recommended), the index pin doesn't cause any deformation inside the slot.

Thanks for your reply. Really appreciate it.

[Sluggo_m14]

In my experience barrel torque tool that locks into the barrel extension works the best. You wont worry about applying undue stress on the upper.

the Bev block does lock in into the extension;
Will any Barrel Torque tool and vice block work with these receivers?
Will the Magpul Bev block work with these receivers?

Thanks