check out these primer strikes

[IRY]

What is going on here? I'm using CCI 400&450. The 400 we're piercing. I am within max levels. Using RL16 41.7-42.5gr. I didn't shoot all of these at one session because I initially thought it was my seating depth. I was close to the lands and working deeper.. am I going to hot! The strikes seem light? No other signs of over pressure (I.e. bolt lift, cracked brass)!

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[KKG]

From your picture I would say your loads are WAY too Hot! Max loads can be very different from one firearm to the next.

 

[41mag]

put my vote in for WAY TOO hot; you got cratering, flattening, and it looks like actually pierced a few....
are all the other dimensions within spec?

I'd pull a few & re-weigh them. Then make sure the infamous 'headspace' is adequate.

Something ain't right.

 

[Member 34319]

Those are not light primer strikes. That's from overpressure. Your not blowing primers yet, but getting close.

 

[CLT65]

How does the tip of the firing pin look? A damaged firing pin can cause pierced primers also.

 

[Member 34319]

How does the tip of the firing pin look? A damaged firing pin can cause pierced primers also.

If this is overpressure loads it can damage the pin as the primer is essentially blowing off the part deformed by the firing pin strike. It can end up in the firing pin channel of the bolt.

People think it's over penetration of the firing pin, nope it's a blow out at the weakened deformed metal.

 

[Greenbug]

I had the same issue with RL 17 in my Creedmoor. It turned out to be caused by the powder.... After about 50 rounds or so it would develop a carbon ring ahead of the chamber and cause pressure and velocity to increase. Clean the barrel and chamber and re-check your results. My speed went up nearly 100 fps when the carbon ring was present and it began piercing primers. When it was clean there was no pressure signs at all. YMMV...


Edit.
I was experiencing this with only 40.5 grains charge of Reloader 17. Reloader 16 may have some of the same traits...

 

[No_Regerts]

Is the firing pin hole much larger than the pin itself? A warm load can cause primer metal to move into an oversized firing pin hole. This compromises the primer and it can create pierced primers. A gunsmith can fit a bushing in the bolt face to fix this.

 

[IRY]

The firing pin looks good. Ill check the pin hole tomorrow. I keep the rifle very clean, but the chamber could be dirty. This is a fairly new rifle with 185 rounds fired and ironically It has only fired RL16 and RL17. I just loaded some rounds with less powder and will seat them at book specs. I did fire a primer only once tonight to see the strike and it looked normal. The cases pictured are 1.5-2.5gr below book max, but were close to the lands. Someone suggested I seat them lower, but it didn't help. Thank for the reply's everyone!!!

 

[Crohnos01]

I would say, as have others, too hot of a load for the rifle in question, especially if you fired a empty primed case and everything looks ok. Check that chamber and start up from minimum loads with a chrony if you have one available.

 

[snarlingdog]

How are you weighing the charges? Maybe something is off on your scale? I have a scale where a low battery,wind, and even the dryer across the room can make it read wrong.

 

[IRY]

How are you weighing the charges? Maybe something is off on your scale? I have a scale where a low battery,wind, and even the dryer across the room can make it read wrong.

RCBS 505 and I use test weights to check the scale before every charging session.

 

[Capn Jack]

Be careful about setting any bullets too deep in the case as that can cause a spike in chamber pressure
Stay Safe.

 

[P7M13]

Every one that isn't pierced is cratered. Easily 1/3 look like they have flattening.
Obviously, you have volunteered to be the hamster in a chamber pressure failure test.

Are you sure that's RL16? Is it supposed to load with the same powder charges as RL17?
Do you have any chrony measurements? That would give a lot of info.

I would not shoot another one of those, and instead do this:

1. Measure each one for C.O.A.L. and Base to Ogive (B2O) measurement;
   
2. Pull the bullets;
3. Weigh the powder of each cartridge;
4. If you can, measure the chamber B2O with a bullet comparator.

If these are the first loads out of your RL16 container, stop using it, something's wrong.
If not, go back to minimum and start to work up again.
Good luck, please keep us posted.

 

[Member 34319]

Also, did you start with basic recommended Cartridge overall lengths at all? Did you get good results? I'm always hesitant to tell folks about going straight towards loading off lands when the haven't even tried the starter loads first.

 

[Tankjr]

Try a different primer also.

 

[IRY]

Also, did you start with basic recommended Cartridge overall lengths at all? Did you get good results? I'm always hesitant to tell folks about going straight towards loading off lands when the haven't even tried the starter loads first.

To be clear I started loads originally with RL17, but learning about temp sensitivity I wanted to try RL16, so I used my RL17 data obtained combined with 4 other sources to start load development with RL16. One source was from Sierra with their 140-150gr high BC bullets which suggests a max charge of 43.5gr RL16. My max fired was 42.1. Looking back I'm not sure why I kept going. I had a hard time believing that I was over doing(over charging) it, but I guess I was!
As far as seating depth I use a bullet comparator and found my lands at 2.250 and seated starting .020 from there(because the rifle shot good from here with RL17). when I got the cratering I thought I might be to close and sank them deeper firing a few, sink deeper and repeat, until I reached .060 which gave me a COAL of 2.825. 2.80 being book minimum I believe.
My chrono recently quit on me, so I have no Idea about the velocity. I do know that I was pushing it with RL17 and maxed at 2830. My Rifle is a custom Rem. M700 with a 24" barrel. All brass was trimmed to 1.910 and I was using CCI 400 and 450 primers. I wanted to see the difference, if any, between the two primers. The 400's are softer I would say!

 

[IRY]

Here are some I fired this afternoon with large primers and reduced loads.
From the left the first is a primer only strike then 40.4gr, 40.8gr, 41.2gr.
still some cratering. The rifle was clean bore and chamber!

 

[Member 34319]

To be clear I started loads originally with RL17, but learning about temp sensitivity I wanted to try RL16, so I used my RL17 data obtained combined with 4 other sources to start load development with RL16. One source was from Sierra with their 140-150gr high BC bullets which suggests a max charge of 43.5gr RL16. My max fired was 42.1. Looking back I'm not sure why I kept going. I had a hard time believing that I was over doing(over charging) it, but I guess I was!
As far as seating depth I use a bullet comparator and found my lands at 2.250 and seated starting .020 from there(because the rifle shot good from here with RL17). when I got the cratering I thought I might be to close and sank them deeper firing a few, sink deeper and repeat, until I reached .060 which gave me a COAL of 2.825. 2.80 being book minimum I believe.
My chrono recently quit on me, so I have no Idea about the velocity. I do know that I was pushing it with RL17 and maxed at 2830. My Rifle is a custom Rem. M700 with a 24" barrel. All brass was trimmed to 1.910 and I was using CCI 400 and 450 primers. I wanted to see the difference, if any, between the two primers. The 400's are softer I would say!

I ask that question because I think a lot of reloader kind of go overboard when they really don't even need to.

For instance, you switched powders solely on what someone said about temperatures, even though it sounds like you had a good load with that powder.

I'm not trying to come off as condescending, just trying to say don't always do what others say on the internet.

If YOU noticed temperature problems, then I'd say, change powders, otherwise stick with what works.

I feel the same about loading so close to the throat, if you don't have to? Why do it?

Just a few thoughts.

 

[IRY]

Reno, Don't feel bad about your comments!!! I probably need better guidance anyway!
The only thing that was bothering be is that I did a load development in the winter and I want to use this gun on a Antelope hunt in August. Maybe I'm thinking to much into it, but as a hunter I thought consistency in temp extremes would be a good thing. I am just glad I stopped when I did!!! It cost me some bullets and some powder, but live and learn I guess.