223 cratering primers

[KMW1954]

I know this has been discussed before which is why I am reaching out for suggestions or direction.

The gun is a Model 11 receiver and bolt that was originally a 243. I changed the bolt head and baffle with parts from Gun Shack to swap it to a 223. Started working up loads and soon started to see cratering and a few pierced. Seeing this happen with loads that are way below max.

I ran a thread about this on another forum an caught a lot of flack from people certain this was an over pressure issue. To the point of being called names and being flamed. David Hoback responded with the bolt head bushing and also about the firing pin. Someone else reponded it was the CCI400 primers being too soft. So I tried some Remington 7 1/2 and it went away. Though it worked and remedied a problem I feel that is only a band-aide and not a fix.

I can say I have shot these same loads in a Model 10 223 and an Axis 223 with no signs of cratering.

What I can contemplating:
Replace the bolt head and firing pin.
Have the bolt head bushed
Swapping the barrels on two of the guns. The Model 11 has a new Model 12 Varmint that currently has less than 200 rounds, so to remove and place this barrel into my model 10 that I was already looking to replace the barrel with a Shilen

Last question, from the past as I recall this model 11 has the new style firing pin. Measured the pin extension uncocked and get .0556" and recommended in .025" and I don't know about pin radius.

[Dave Hoback]

I’ll say the same here partner. Check your firing pin protrusion (no more than .040”.. I like no more than .035”), and the pin radius. (Not pointy) Also the slop in the bolt head hole. (Which bushing will fix)

[Whynot]

This has probably all been said- but you can be over pressure well below max in the manual.... You can't always make it up to max.

As above- check that out...

And if the other gun is also a short action (and you have a gauge to make sure you are good with headspace) you could try the other bolt and see if it is a ammo/pressure issue or a bolt issue (hopefully without having to adjust barrel- but either way can show you what your have)

[celltech]

If you decide to go the bushing route with Desh I believe he will also grind the non-adjustable pin down to whatever you want. I had him do 2 of my Savage bolts and it stopped all cratering/blanking in my small primer loads...and I use CCI primers as well.

[Dave Hoback]

If you look at the picture, it represents the firing pin in the bolt head hole. The tip radius is represented by how obtuse the round face is. Imagine it was much more pointy. You see how much slop there would be on the sides? The radius should not drop into the hole at full pin protrusion.



You’ve likely seen this, but again this is my bolt with the firing I machined. You can see clearly how the radius does not drop below the bolt face surface. And that is at around .035” or a bit less. That is where it should be, .035”. Not .025”.

[KMW1954]

Thanks guys for the responses.
Dave thanks for the clear picture and no I have not seen it before. Now looking at that picture the pin in this bolt(mine) is protruding much greater that that. Looking at my pin through a magnifying glass the radius looks pretty good. Will have to pull the bolt apart and try to get measurements.

celltech do you recall what his fee was? Turnaround time?

Was supposed to be using this rifle in a winter league come Jan.

Whynot I understand the whole pressure issue and that it can happen with less than max charges and can even happen in very light charges. As stated I fired this load before in my Model 10 and was the load I used last winter in out league.
I do have the go-no go gauges just reluctant to try and swap just the bolt in the receivers because of being "worn-in". I would rather swap barrels. But that is just me and my thinking.