Terminus Apollo Action & Proof Research Barrel Headspace

[Miklary]

Hey all, looking for some help. I picked up a Terminus Apollo action with a Proof Research Prefit Barrel in .223 for a trainer build. I have a short action customs barrel vise and ordered up an action wrench from Joel at Terminus, I have torqued the action to the recommended 65 ft lbs but this action is eating a no-go gauge. I asked Joel and he pointed out that proof suggests adding a piece of tape to the no go gauge and checking for headspace, which I will try tonight.

But has anyone else seen something like this before by chance? Or have any recommendations please. Any help would be appreciated.

 

[_Windrider_]

Hey all, looking for some help. I picked up a Terminus Apollo action with a Proof Research Prefit Barrel in .223 for a trainer build. I have a short action customs barrel vise and ordered up an action wrench from Joel at Terminus, I have torqued the action to the recommended 65 ft lbs but this action is eating a no-go gauge. I asked Joel and he pointed out that proof suggests adding a piece of tape to the no go gauge and checking for headspace, which I will try tonight.

But has anyone else seen something like this before by chance? Or have any recommendations please. Any help would be appreciated.

I think you are confused. The trick is add a piece of scotch tape, which is 2 thou thick to a go gauge to make a no go gauge. If it’s closing on a no go go, there’s a problem somewhere.

 

[wade2big]

Is there any resistance when closing the bolt?

 

[BurtG]

I had a terminus 223 that wouldn’t shoot worth crap till the bolt was changed out

Ended up trying different
Stock
Scope
Barrel
Suppressor


First barrel maker figured it out

Cluster f for sure

 

[wade2big]

I had a terminus 223 that wouldn’t shoot worth crap till the bolt was changed out

Ended up trying different
Stock
Scope
Barrel
Suppressor


First barrel maker figured it out

Cluster f for sure

What was the defect with the bolt that caused the rifle to shoot badly?

 

[srt-4_uk]

There is no standard for headspace gauges.
Forster no go gauge is 1.467
PTG no go gauge is 1.4696
Max SAAMI spec is 1.4736

The point of adding tape to the no go gauge is to see if you are out of SAAMI spec.

 

[BurtG]

What was the defect with the bolt that caused the rifle to shoot badly?

Don’t know

Someone speculated poor / uneven lug contact ?

 

[Miklary]

I think you are confused. The trick is add a piece of scotch tape, which is 2 thou thick to a go gauge to make a no go gauge. If it’s closing on a no go go, there’s a problem somewhere.

Confirmed a no-go gauge, confirmed that with terminus and proof research.

 

[Miklary]

Is there any resistance when closing the bolt?

None, closes with no resistance.

 

[Miklary]

Update: Below is what I got from Terminus and confirmed by support at Proof Research.

Disassembled, cleaned everything thoroughly and reassembled, per specifications and followed the below procedure and could not get a no-go gauge to close with one layer of cellophane tape.

Test firing and will post an update after in case it helps anyone else.

 

[DeathBeforeDismount]

This is how a young boy learns about proof prefits and why certain smiths will not even touch their blanks.

And FYI I have 2 proof barrels including a .223 prefit.

caveat emptor

 

[Miklary]

Forgot to update this thread. All is right with the world. First five shot group after sighting in.