Did I just mess up my barrel?

[steelholder]

Hello everyone, I recently put my upper receiver on the vice to install a free float tube. Im all done and was putting everything back together and Im having some fitting issues.

The bolt face that goes into the barrel makes contact and doesnt go in/out smoothly, I have to give the CH a good tug to open it up. Im sure its not the gas tube making any contact. I used a different bcg than the original and that one slides in perfect without much resistance. I didnt have this issue with the original bcg before I viced the upper though (sigh). Worst case scenario Ill need a new barrel, what say you calguns? Is it debris or crap on the bolt face/ barrel entry point or did I fuhg it up?

[CoopsDad]

Does the old bolt still slide in easily? If yes, the new bolt just needs to wear in. If no, then you buggered the gas tube alignment. You didn't ruin tbe barrel. Unless you use a 4 foot breaker bar and all the weight that FiPi lost, you COULDN'T ruin the barrel.

Mighta jacked the upper receiver, but not the barrel.

[TripleThreat]

Photos?

[baih777]

Depends on how you put the upper in the vise.

Before you assembled the upper did you happen to check if the bolt fit into the barrel?

[steelholder]

Does the old bolt still slide in easily? If yes, the new bolt just needs to wear in. If no, then you buggered the gas tube alignment. You didn't ruin tbe barrel. Unless you use a 4 foot breaker bar and all the weight that FiPi lost, you COULDN'T ruin the barrel.

Mighta jacked the upper receiver, but not the barrel.

The old (original to the rifle) BCG is the one that has issues sliding in and out.
A different BCG from another rifle fits perfectly and did not give any resistance.

[steelholder]

Depends on how you put the upper in the vise.

Before you assembled the upper did you happen to check if the bolt fit into the barrel?

I did and it did not do this.

[baih777]

And there is a great teacher in van Nuys that can help you out for a small fee.

[steelholder]

Depends on how you put the upper in the vise.

Before you assembled the upper did you happen to check if the bolt fit into the barrel?

And there is a great teacher in van Nuys that can help you out for a small fee.

Thanks but Ive done this a few times before. I was unable to find my upper vice and resorted to wrapping it in an old pair of jeans.

[bajadan]

Try a different BCG.

[LeadFarmer74]

The old (original to the rifle) BCG is the one that has issues sliding in and out.
A different BCG from another rifle fits perfectly and did not give any resistance.

[baih777]

The resistance might just be the lugs on the bolt. If you look at your old one. I. Bet the edges have a radius. There could be a burr somewhere.

[steelholder]

Pardon any confusions guys Ill try again.

BCG#1 is the one that came with the rifle that "might" have the damaged barrel. When inserting this BCG into the rifle it makes contact with the barrel entry point(w.e. thast's called). This did not happen before I viced the upper.

BCG#2 has nothing to do with the potentially damaged gun. I just used it to see how it would fit in the potentially damaged rifle and it fit fine. Unlike BCG #1.

[steelholder]

The resistance might just be the lugs on the bolt. If you look at your old one. I. Bet the edges have a radius. There could be a burr somewhere.

I doubt the BCG is the culprit as it wasnt inside the upper when I viced it.

To clear up this issue further, I dont think my BCG is damaged. I think the fact it's giving resistance (when it didnt before) might mean I bent something.

[Chapped Hide]

I was unable to find my upper vice and resorted to wrapping it in an old pair of jeans.

[UclaPeon44]

Check to see if the m4 feed ramps line up with feed lip of chamber extension. If not,. You warped the upper receiver