The 20 Practical is here ...

[Ironman308]

The gap gives you the cratering. Some rifles have punctured primers and this can be the fix. I would call LRI and discuss it. They are good people.

 

[Bachekermooni]

What primer did you load with?

CCI SR

 

[redrockranger]

My 20 Practical was very similar to what i see here. Remington 700 with PTG bolt. I was using h-4198,22.4 grs.

 

[Cemetery21]

Had a couple of my Remington bolts bushed and it completely solved the cratering problem.

Bolt Bushing Photos

I'm bushing a couple of bolts for a forum member today and thought I'd post a couple of photos. 2 identical bolts allowed a before and after photo in one shot. Cleanup cut on second photo is .0004" so no effect on headspace. --Jerry

forum.accurateshooter.com

 

[Mark M.]

Did you use the M1 bottom metal and 3 shot mag?

 

[Bachekermooni]

Does this look like the firing pin is sticking out too far causing the cratering?

 

[Mark M.]

Does this look like the firing pin is sticking out too far causing the cratering?

What primer are you using

 

[Bachekermooni]

What primer are you using

#22 post above

 

[Mark M.]

#22 post above

Sorry, I guess I couldn't keep up.
On my 20 tactical I had to move up to a match or magnum primer

 

[L.Sherm]

#22 post above

41,400 or 450?

 

[Bachekermooni]

41,400 or 450?

Standard small rifle, not BR or Mag.

 

[L.Sherm]

Try the 450's or 7.5's and you will probably see less flow.

 

[Bachekermooni]

My concern is how far the firing pin is protruding out. It seems excessive. I need to compare with other FAs.

 

[L.Sherm]

Measure it

 

[Bachekermooni]

What should it be?

 

[2dogs]

I have seen that cratering on my primers. I send my bolts to Gre-Tan to have them install a bushing to tighten up the firing pin hole. Problem solved.

 

[L.Sherm]

What should it be?

I'm not 100% but .058 comes to mind.
.050- .058 in that range

 

[Bachekermooni]

I'm not 100% but .058 comes to mind.
.050- .058 in that range

Thanks. My Kimber Montana in 223 is 0.054". The CZ is 0.085+/-0.005

 

[L.Sherm]

Thanks. My Kimber Montana in 223 is 0.054". The CZ is 0.085+/-0.005

.085 is alot

 

[redrockranger]

Heavy bolt lift and stuck cases indicates high pressure ? See post #7.