Defiance Pre-fits

[7MMMAG]

On proof's website it says they sell pre-fits for the ruckus but doesn't mention anything about any of the other models. Does that mean they are all compatible with the proof ruckus pre-fit?

 

[Kimber7man]

You can spin a proof prefit on an anTiX with no issues.

 

[7MMMAG]

Not for shouldered prefits. Many of defiance’s actions will need a gunsmith to measure. After that the smith can spin up prefits for your specific action. I believe the tenacity and anti will take “off the shelf” prefits.

Hmm, I wonder why proof has their off the shelf pre fits listed under ruckus

 

[7MMMAG]

Ruckus will take proof’s prefit. I have a ruckus, with a proof prefit. I believe anti and maybe tenacity will too. Deviant and deviant elite won’t, and I don’t think rebels will.

So with these “pre-fits” can I just use the action wrench barrel vise and the go/no go gauges or is there something special a smith needs to do?

 

[762 ULTRAMAGA]

So with these “pre-fits” can I just use the action wrench barrel vise and the go/no go gauges or is there something special a smith needs to do?

Yep
You don't even need the gauges for a shouldered prefit though, just spin it on and torque to spec

 

[Sevens]

Ruckus, Anti and Tenacity all have the same specs. Any of the prefits for the Ruckus will fit the other two.

 

[HandgunHTR]

Yep
You don't even need the gauges for a shouldered prefit though, just spin it on and torque to spec

You should be just fine, but it never hurts to check it. Better safe than sorry. Manufacturing mishaps happen.

 

[vonb]

You should be just fine, but it never hurts to check it. Better safe than sorry. Manufacturing mishaps happen.

Absolutely! Don’t forget your face is next to high pressure combustion. I don’t care how good the reputation of a smith, everyone can make a mistake. I always check shouldered pre-fits with gauges. A well known 3 lettered smith had a come to Jesus moment a few years back when test firing a barrel.

 

[762 ULTRAMAGA]

Absolutely! Don’t forget your face is next to high pressure combustion. I don’t care how good the reputation of a smith, everyone can make a mistake. I always check shouldered pre-fits with gauges. A well known 3 lettered smith had a come to Jesus moment a few years back when test firing a barrel.

Hows that?
If the headspace is to tight the bolt won't close without force, if it's excessive the worst thing that'll happen is you won't get a primer strike.
I've had a barrel headspaced so out of spec that the primer barely got a dent, occasionally it fired but mostly it didn't.
Pretty easy to diagnose and send back, it wasn't even a prefit just a poor chambering job.
I always measure my case shoulder length pre and post firing, over .008 growth is excessive.

 

[vonb]

Hows that?
If the headspace is to tight the bolt won't close without force, if it's excessive the worst thing that'll happen is you won't get a primer strike.
I've had a barrel headspaced so out of spec that the primer barely got a dent, occasionally it fired but mostly it didn't.
Pretty easy to diagnose and send back, it wasn't even a prefit just a poor chambering job.
I always measure my case shoulder length pre and post firing, over .008 growth is excessive.

Case head separation. You nailed the issue...Brass stretching. You might can get away with excessive headspace here and there but why take the chance.

 

[762 ULTRAMAGA]

Case head separation.

You'll know if that's going to be a problem if you measured the shoulder before fire forming, it's not going to happen on the first firing.
With the amount of case stretch that would be required for virgin case head separation the primer literally wouldn't be struck.

 

[HandgunHTR]

You'll know if that's going to be a problem if you measured the shoulder before fire forming, it's not going to happen on the first firing.
With the amount of case stretch that would be required for virgin case head separation the primer literally wouldn't be struck.

Actually, it can happen on the first firing. You get lucky if you only have a light primer strike, but I have seen two bolt guns and one AR have case head separation upon first firing due to excessive headspace.
If your method is working for you, so be it, but as I tell my crews, when it comes to Safety, you are always fine, until you aren’t, so be vigilant and take the time to do it right.

 

[vonb]

You'll know if that's going to be a problem if you measured the shoulder before fire forming, it's not going to happen on the first firing.
With the amount of case stretch that would be required for virgin case head separation the primer literally wouldn't be struck.

Hey guy, you do you. I'm not trying to start an academic debate on whether it will or won't happen or the best methodology. Do what works for you. I know what I'm going to do.

 

[762 ULTRAMAGA]

Actually, it can happen on the first firing. You get lucky if you only have a light primer strike, but I have seen two bolt guns and one AR have case head separation upon first firing due to excessive headspace.
If your method is working for you, so be it, but as I tell my crews, when it comes to Safety, you are always fine, until you aren’t, so be vigilant and take the time to do it right.

Interesting I've had several experiences firing bolt guns that had extremely excessive headspace.
How much were the cases stretching? Something isn't adding up..
Autos are a different beast, and not enough headspace is actually the dangerous part.
I was a machine gunner and I saw ruptures after swapping barrels that were screwed in to tight on the fly.

I had a saum with so much headspace that the case moved forward to the point it wouldn't fire, the faint dimple on the primer was the first clue.
Some fired and they were fine, I was new to this at the time and took it to a smith who walked me through what was happening.

My second experience was with peterson 338 norma mag brass that was way out of spec.
I had similar light primer strikes and intermittent failures to fire, I got some shoulder gauges and discovered the brass was headspaced .020 short!
Standard headspace is around .003-.005, and .010 is where 2nd or 3rd round case head separation typically starts.

Head space is extremely important, which is why on a new barrel or batch of brass I Always Always Always measure virgin shoulder length before and after firing.
Most people don't realize that they've likely fired cases with super excessive headspace due to brass that's out of spec, especially with the belted mags.
You all do what makes you feel good, but I won't be buying gauges for bolt gun shouldered prefits.

 

[JakeSCH]

I just installed a proof defiance prefit on my AnTi action. I rented go / no go gauges from reamer rentals $27 ($7 rental, $20 for shipping).

It is worth renting the gauges for peace of mind, all though mine was in spec when installed.

 

[Mountainrancher]

I just installed a proof defiance prefit on my AnTi action. I rented go / no go gauges from reamer rentals $27 ($7 rental, $20 for shipping).

It is worth renting the gauges for peace of mind, all though mine was in spec when installed.

I had never heard of reamer rentals until just now. I was kinda struggling with the idea of buying 80 dollars worth of gauges that I will use once. Thank you

 

[ChrisAU]

I had never heard of reamer rentals until just now. I was kinda struggling with the idea of buying 80 dollars worth of gauges that I will use once. Thank you

Assuming 4D Rentals, I use them every time I build an AR. $20 minimum but it’s worth the peace of mind for sure! If I knew I’d be building a bunch of rifles in one caliber I’d buy gauges, but I like to continuously try new things so they are the bees knees.