Primer Help (CCI 450 run back and piercing)

[Walker TR]

This has been happening as of recently in my Dasher with the CCI450 primers and I am puzzled and wanted to see if others are having similar issues. No pressure no flattening of the primers with a mild load of Varget. What usually comes with it is pierced primers as well. See below on the pictures. The center of the primer is sticking up. Running this on an Impact Action.... This has happen in two different types of brass (Lapua and Alpha). Any insight would help as this is a first for me.

 

[mcfred]

Try different primers with a "thick cup" (CCI BR4 or No. 41) and see if it's just that lot of primers. Otherwise it's indicative of an oversized firing pin and pin hole. Typical solution for that phenomenon is to bush the bolt and reduce the FP hole/pin to about .062".

Band-aid solutions are to run less pressure, thicker cupped primers or to increase FP spring weight.

 

[Walker TR]

Try different primers with a "thick cup" (CCI BR4 or No. 41) and see if it's just that lot of primers. Otherwise it's indicative of an oversized firing pin and pin hole. Typical solution for that phenomenon is to bush the bolt and reduce the FP hole/pin to about .062".

Band-aid solutions are to run less pressure, thicker cupped primers or to increase FP spring weight.

Thanks I appreciate it .......bushing is not an option being this is already a small firing pin in an Impact 737 Action.

 

[spife7980]

Bullshit “no pressure”.
You have highly cratered primers and ejector prints.

Primal Rights

Primal Rights

www.primalrights.com

 

[918v]

Clean the shit out of the bore using a lot of bronze brush action. Make the bore and throat pristine. Bet it will stop doing that.

 

[mcfred]

This is already a small firing pin in an Impact 737 Action.

Yeah, then I agree with Spife that you are NOT running low pressure. What's the "mild load" load you're running? How's bolt lift, haha.


Here's 25.25gr of Varget in a SAAMI .223 Remington chamber with CCI 450s and "factory" firing pin hole. It's not low pressure (2920fps 77gr SMK 2.300 OAL) and you still see the round primer corners. Notice the primer cupping?

 

[Walker TR]

Yeah, then I agree with Spife that you are NOT running low pressure. What's the "mild load" load you're running? How's bolt lift, haha.

31.7 Varget with 105s and the bolt lift can be lifted with one finger.

 

[Walker TR]

I have ran much stiffer loads for years in competition and never had any problems. This just popped up recently and am puzzled. Not new to Dasher.

 

[supercorndogs]

Velocity? Did it jump up like when you have a carbon ring? i see a line around the base of your case also. Might want to check for CHS. How many loads on the brass?

 

[Walker TR]

Velocity?

2920

 

[Walker TR]

Bullshit “no pressure”.
You have highly cratered primers and ejector prints.

Primal Rights

Primal Rights

www.primalrights.com

No ejector prints on the brass....and the primer is not flattened and cratered....it is protruding. So not bullshit.

 

[spife7980]

No ejector prints on the brass....and the primer is not flattened and cratered....it is protruding. So not bullshit.

Yes ejector print.

And you’re a cunt hair away from pierced too with all that cratering.

All these signs you’re excusing as not signs are in fact signs. If they weren’t then you wouldn’t have these symptoms to ask about.

 

[supercorndogs]

Its kind of a bad picture, but that sure looks like an ejector mark to me on your brass.

 

[mcfred]

I have ran much stiffer loads for years in competition and never had any problems. This just popped up recently and am puzzled.

Clean it. $50 Teslong bore camera might prove informative if it's a carbon ring.

 

[Walker TR]

Yes ejector print.
View attachment 7309449

And you’re a cunt hair away from pierced too with all that cratering.

All these signs you’re excusing as not signs are in fact signs. If they weren’t then you wouldn’t have these symptoms to ask about.

I appreciate the perspective.....I will back it down even more and see if it goes away.

 

[Walker TR]

Clean it. $50 Teslong bore camera might prove informative if it's a carbon ring.

Yep have one and checked that, clean carbon ring at least every 150-200 rounds......again I appreciate the suggestion.

 

[mcfred]

Well, something's different. Different lot of powder (or some left out and moisture content changed), different lot of primers, different lot of projectiles, something.

Verify scale and caliper calibration/zero?

Do you have an old lot of ammo that was "fine" to compare a new lot to?

 

[Walker TR]

Well, something's different. Different lot of powder (or some left out and moisture content changed), different lot of primers, different lot of projectiles, something.

Verify scale and caliper calibration/zero?

Do you have an old lot of ammo that was "fine" to compare a new lot to?

No I don't.....lol.....it happened before on "Practice Day" at Clay's Cartage match a few months ago in Oklahoma......had to switch to back up ammo and ran fine for the following two days....today 80 rounds ran fine then the last 20 this started happening. Looks like back to square one

 

[PAYDIRT]

Yeah, then I agree with Spife that you are NOT running low pressure. What's the "mild load" load you're running? How's bolt lift, haha.


Here's 25.25gr of Varget in a SAAMI .223 Remington chamber with CCI 450s and "factory" firing pin hole. It's not low pressure (2920fps 77gr SMK 2.300 OAL) and you still see the round primer corners. Notice the primer cupping?

Looks very familiar, I was running same thing but with win primers, finally pierced one and trashed a trigger. Went to 450's and backed powder off a tiny bit, cleaned the f out of it and keep it clean. My primers had rounded edges too.

 

[PatMiles]

As asked above, new jug of Varget?

 

[Seth0351]

Was this ever resolved? I'm running into the exact same issue in my Impact 22BR

 

[Walker TR]

Check primer depth, headspace on your shoulder bump, and then don't run a hotter load. That solved my issues

 

[918v]

So what was the problem in your case? Was it a combination of variables or one in particular?

 

[Walker TR]

No problems with the case at all, it was a combo of multiple variables

 

[918v]

Sorry I meant case as in your situation. What happened exactly?

 

[Walker TR]

it was a combo I believe, running hotter loads(not extreme) backed it down with 105s to 31.7 from 32.0, primer seating depth (was only .001-.002 deep) pushed them to .004-.005, a little too much head space (.004) back it down to .0015-.002.