All

If you didn't know about Mark's feed insert for the shrike I would highly recommend it.

I had to send my receiver back after it was damaged for a new feed tray, which wouldn't run 55gr ammo.

Since I got the new feed insert, it works with anything I have tried 55gr-77 FMJs or SPs.

Highly recommend it. Got it from Mark Genovese in Hi for 110 bucks

mauiarmsATmauiDOTnet

Best investment I've made, I don't feel worried about damaging the receiver now.

thanks for sharing!

Is he not making them out of yellow polymer anymore?

I also bought one of the new "dark" colored one Mark said  that he changed the geometry and will last a lifetime. Have not been to the range yet, but may go today.


The yellow one was from his earlier batch.

mine looks like a urethane resin, it has a dark "shell coat" of black with a semi clear body.


Its not milled as its too smooth, but its tough and heavyish for the size, feels like resin to me

I have not had any receiver hits since I put the insert in. It does seem to be doing the job well! Certainly for the money... it worth the chance it will make things better.

Ok , so what does this do?  And how does it help?  Is it used when the rifle is shooting linked ammo or only with the magazine?
thanks
Gary

This plastic insert guides the tip of the bullet more directly into the chamber. Without it, the tip of the bullet will hit the aluminum part of the receiver just above the barrel bullet guide, causing a divot which can catch the bullet tip and jamming the gun.

People who have a ruined upper can either buy a new upper or use this guide to salvage it.

I think it only affects the upper with the belt feed, since the usual M4 bullet guides are used with the magazine.

This photo is of the upper from the underside showing the wear in the aluminum where the bullet tip wears without the guide in place...