Barreled Receiver will not pass tilt test

[RichieRich3902]

How hard is it rubbing? Can you relieve the ferrell to allow it to pass?

[krdomingue]

Originally Posted by dnmccoy

Have you tried other barrel bands?

Yes

Originally Posted by RichieRich3902

How hard is it rubbing? Can you relieve the ferrell to allow it to pass?

It would have to be what I feel is a significant amount. Not so much that it would invalidate the integrity of the band, but enough that I feel it shouldn't be done. The band is the symptom, no the problem. I would rather be sure of the cause and fix that.

[Rock]

Have you checked op rod function with the rifle fully assembled? If you have, does it bind or drag at a particular point along its travel?

[Mark1]

As Rock stated, assembly the rifle, but put chalk on the op rod. This will transfer to any area rubbing.

[sparx]

Was proper barrel indexing ever established?


Sparx

[krdomingue]

Originally Posted by sparx

Was proper barrel indexing ever established?


Sparx

It is properly indexed.

[TSimonetti]

Please continue to define what you mean by "failing". Does it move part way and then stop? Does it fail to move at all? Is it just sluggish rather than smooth and easy as you expect?

Did you apply grease everywhere necessary?

In my few conversations with CMP armorers, they didn't seem to place a lot of finality to failing a tilt test. Their response to me usually was along the lines of "See how it shoots". Perhaps you should consider doing this?

Is it possible that you can simply file away the area that is rubbing? I know this subject was addressed already, and I know you feel that it should not be done, but it doesn't seem like chasing this rabbit further down the hole to solve the mystery will be beneficial short of replacing the barrel, which you don't want to do.

Relieving the rub area of the band is what I would do at this point. I've seen several lower bands and ferrules worked over in this manner.

[sparx]

If barrel is properly indexed then has to be a problematic barrel, as Larry pointed out early in this thread.


What are the barrel markings?



Also, I do tilt test without grease.


As Tsimonetti, asked I am curious as to how much resistance there is? Not very easy to explain this I understand.


I would fire the rifle if not already been done, be interesting to know if it shoots to (or close) the point of aim since the barrel may be bent. Also curious to know if excessive sight adjustment is required to get it on paper at 50- 100 yards.



sparx

[johnpick]

When you are dealing with mil spec parts you can get a rifle with a barrel at one end of the spectrum and a op rod and ferule at different ends and it just doesn't quite meet up. That is what you are probably dealing with and I would work over the ferule and see how it shoots and operates.

[krdomingue]

Originally Posted by Mark1

As Rock stated, assembly the rifle, but put chalk on the op rod. This will transfer to any area rubbing.

I don't need chalk, I already know where it is rubbing. It starts to rub when the oprod is halfway back and continues to get worse as the bolt is pulled back.

Originally Posted by Rock

Have you checked op rod function with the rifle fully assembled? If you have, does it bind or drag at a particular point along its travel?

I have tried it in everyway possible. See above answer to where it is rubbing.

Originally Posted by johnpick

When you are dealing with mil spec parts you can get a rifle with a barrel at one end of the spectrum and a op rod and ferule at different ends and it just doesn't quite meet up. That is what you are probably dealing with and I would work over the ferule and see how it shoots and operates.

True there is some variation from part to part. Particularly when dealing with used parts but that is why I went through a progression of parts to see if it was any particular part that was the problem. I am fairly certain that it isn't the lower band that is out of spec. I am reluctant to file medal off of it when it isn't the real problem. It might solve the immediate issue, but could leave me with a subpar barrel.

When I have the time I will attempt to check if the barrel is straight or not. If not, then I am not sure what I will do. I started this project back in 2015, because I wanted an HRA in my collection and I thought it would be fun to build out a barrel receiver. I have since acquired a better HRA example for my collection. I could replace the barrel, but I built a great shooter at the AMC course and don't need another one. It would be a good experience to replace the barrel, but then I would end up with a rifle that cost more than it is worth. Breaking back down for parts, might be the final answer.

Thanks