Factory upper issues-gunsmith needed

[Kev_lar]

So I finally had a chance to shoot my new .450 upper for the first time this weekend. I loaded up a mag with factory Hornandy ammo, chambered a round and *click*. Nothing. I go the eject the round and it won't budge. I put some real oomph into it and the casing goes flying along with a shower of glitter in the air. As I inspect the casing I notice a very light primer strike. When I look at the opened action I see I burnt powder everywhere. As I inspect the chamber I see the slug still in the chamber.

Since I didn't have a rod handy, I disassembled the rifle and took it to Randy's in Bad Axe. The fellas there were able to remove the projectile. The checked it with a set of go/no go gauges and said the action properly went into battery as intended. However on a live round, it got stuck again. They think that the chamber was not reamed properly at the factory.

I called Bushmaster to have it services and they stated they don't do any work on unserialized parts and I should just return it to Midway. Midway won't take it back because I had the handguard replaced and it is no longer in its factory original configuration. Sadly I parted with the mag light flashlight style handguard so swapping them back is no longer an option.

Are there any gunsmiths here on the forum that have a chamber reamer that can check this out to see if it is really the case? At this point I am kinda stuck. I don't really want to drop $150 on a chamber reamer for something I have (1) never done and (2) will only use once.

Thoughts?

[Al in Mi]

try this thunk test.

pull your BCG, clean the chamber/barrel, then drop a factory round in the chamber and listen to hear if it thunks, meaning in bottomed out on it's headspace in the chamber.

[Bmt85]

Well sounds like headspace is fine. I would do a thunk test and mic the ammo. Kind of weird you saw burnt powder everywhere with a squib. Could be chamber is fine but ended up with too much freebore, maybe? Just guessing right now.

[Avenger10]

Kev_lar-

Give us an update the suspense is killing me...

If you haven't made any progress you can send it to us and we'll give it a goin over for you. We fix other manufactures 450's all the time.

-Bartt