Anyone know how to fix this op rod problem

[chalkriver]

I indexed a barrel for a guy today and when putting it back together I noticed the op rod is contacting the barrel just before the receiver .
The barrel is indexed correctly and the gas system and the op rod and guide all line up correctly . The op rod runs straight and no binding in the receiver channel .
The tube is contacting the larger diameter section of the barrel where it meets the receiver. Out of spec op rod I assume.
It wouldn't take much to get it to clear the barrel but I don't know how to fix this .
I am tempted to remove a tiny bit of material from the barrel to get the clearance as I don't think trying to bend the op rod a bit is a good idea and the op rod is already thin where it contacts the barrel.

 

[supernova]

I would run some 240/320 emery cloth over the offending area. Doesn't look like it needs much.

 

[chalkriver]

Thanks .. my thoughts too.

 

[45ACPKING]

Use grease base lapping compound applied with a q-tip
G96 bluing paste and some clp when done
very common fitting procedure when building a lot of these rifles.
emory will work too but lapping compound will better mate the parts.

 

[chalkriver]

Thanks Thomas

 

[weasel1]

If you need some lapping compound, let me know. I'm not far away.

 

[sigrunes]

I had this exact problem on an older polytech I owned. I emery clothed the barrel contact point a bit, then the op rod contact point a bit but alot less than barrel area. Then applied a good dab of grease to that area and never had noticeable issues after. I did almost a years worth of shooting before I did complete strip again and it was still all good there with just the slightest bit of clearance, all it needs I guess.

 

[Odd Shot]

duplicate post

 

[Odd Shot]

Where does one buy lapping compound?
And what grit should be used for lapping parts on the M305?
Could the same grit used in this case be used on the trigger hooks?

 

[45ACPKING]

Where does one buy lapping compound?
And what grit should be used for lapping parts on the M305?
Could the same grit used in this case be used on the trigger hooks?

automotive supply.... grease based lapping compound and in some cases jewellers supply
but NO , absolutely not for the trigger group.

 

[rascal1]

Where does one buy lapping compound?
And what grit should be used for lapping parts on the M305?
Could the same grit used in this case be used on the trigger hooks?

Auto supply, valve lapping compounds come in various grit.

 

[Odd Shot]

What grit would be suitable?

 

[45ACPKING]

permatex no. 474G will suffice
for lapping oprods at track and saddle and for lapping in bolt lugs.
not for use in trigger groups

 

[Odd Shot]

permatex no. 474G will suffice
for lapping oprods at track and saddle and for lapping in bolt lugs.
not for use in trigger groups

Thanks!