Marring in upper receiver on Radian Model 1 builders kit rifle

[Nickeljk]

I have a friend who built himself an AR using a radian model 1 builders kit as the base. He put a 16” .223 wylde proof carbon fiber barrel with a superlative arms adjustable gas block on it. It is using a jp bcg and bolt. The buffer is a jp spring and weight. Not scs. The bcg is clearly hitting the edges of the one spot in the upper receiver and I know that I’m not smart enough to give him a good answer about why it’s happening so I’m hoping someone here can give us some insight. Thank you in advance

 

[bfoosh006]

Consider trying a "Domed" cam pin.

By chance is it a LtWt, BCG ?

https://www.lantac-usa.com/product-page/cp-r360-cam-pin

 

[Nickeljk]

I’ll ask him! Thank you!

 

[Nickeljk]

Full mass

 

[TonyAngel]

It's kind of hard to tell if there's something wrong without being able to inspect the upper, but wear of that sort is normal and it will typically get to a point where it will stop wearing.

Those roller cam pins are neat, but they're expensive and cam pins are a wear item. Also, the ones I've seen require the use of a proprietary gas key to allow for installation and removal of the pin.

 

[Shoreglide]

Rubber City Armory BCG’s with adjustable gas key are GTG for the roller pins. Haven’t tried it with their standard gas key. I picked up a few from POF on sale over the holidays for about $20/each.

 

[owtlaw]

I've seen that on a lot of AR's. I don't think it's anything to worry about.

 

[Nickeljk]

It's kind of hard to tell if there's something wrong without being able to inspect the upper, but wear of that sort is normal and it will typically get to a point where it will stop wearing.

Those roller cam pins are neat, but they're expensive and cam pins are a wear item. Also, the ones I've seen require the use of a proprietary gas key to allow for installation and removal of the pin.

Radian told him it was normal wear if that means anything.