Aarrrggg ! ! ! I etched the bolt face on a new BAT action

[alf]

Bushing the bolt would restore the aesthetics......

 

[ridgeway]

I would send it back to BAT. No one else better to take care of your problem.

 

[gunnermhr]

Amen, I would hesitate to give it to anyone other than BAT. They are great people and do great work. Taking it to anyone else would be like taking a maserati to a volkswagon Dealer, just doesn't make sense

 

[nosualc]

That BAT is junk. I'll take it off your hands for disposal for $200. You'll be time and money ahead.

-nosualc

ps - It has been 4 days since the OP, and nobody else has said this. This is my duty as an internet forum poster.

 

[spclark]

I'm trying to figure out why people are recommending to bush the bolt? He did not pierce a primer with the firing pin, he had/has loose primer pockets in the brass.

Right - the suggestions are for returning the bolt face to its original flatness. You're correct that in this instance there's really no need to improve the firing pin hole to fp condition as a BAT's a very high quality product to begin with.

Perhaps BAT could do something for the OP also, hopefully short of suggesting a complete new bolt? Worth asking about.

Nothing can inprove too-small primers; even with in-spec, high quality brass the cups will still allow gas leakage even with moderate loads.

Yes, the Tula brand is essentially the same as Wolf, atleast from what I've learned. I started using the Russian Murom-plant LR primers several years ago, then the same product under the PMC logo, now Wolf. They've been a great value & exceptionally consistent performers for my long- and mid-range shooting. If there were a competitive, comparable US-sourced product available I'd switch.

Against that statement, maybe a few forum members will offer comment on there being virtually no US-made propellants either? What we buy & use is imported, often in bulk then repackaged here for distribution.

 

[Benjerman08]

I guess what I would like to know is for sure what caused it? Some of the replys elude to out of spec brass, bad primer pockets, hot loads etc. Were there any other previous pressure signs? Have had over pressured, too hot loads expand base of brass, leave ejector marks and cause real sticky bolts. Never heard of the etching before.

 

[gene pool]

I guess what I would like to know is for sure what caused it? Some of the replys elude to out of spec brass, bad primer pockets, hot loads etc. Were there any other previous pressure signs? Have had over pressured, too hot loads expand base of brass, leave ejector marks and cause real sticky bolts. Never heard of the etching before.

Dear Benjerman08,

There were zero pressure signs. In the OP photo I showed the piece of brass which made the largest of the etches. Click on the photo to enlarge it and take a look at the primer. It looks like it's just inserted in the case except with a firing pin mark and smoke around the edge. I would think that if there was enough pressure to "blow a primer," that blown primer would show at least one sign of pressure. This one shows none. And the previous two reloadings of the case were minimum loads too.

I still suspect the brass or the primer as the problem.

Gene

 

[jo191145]

I saw mention of soft primers.
Personally with mild loads I might be expecting hard primers coupled with loose fit may be a cause.
Perhaps the primer is leaking (not sealing)at the beginning of the burn instead of leaking at higher pressure.

I imagine we've all seen what happens with mild loads in largish factory chambers and hardened well used brass. Blowby.
Maybe you've stumbled upon the perfect storm of scenarios that allows the primer to blowby under light pressures. Just thinkin.

 

[Benjerman08]

I guess that takes us back to an age old question...how loose is too loose for primers and pockets. I think most of us here are using some type of hand primer and we all know some pockets get loose and it is notibly felt. I have been told that if at least "some" pressure is felt while seating, it is ok. Maybe once they get to that point, they should not be used (?).

 

[spclark]

I have been told that if at least "some" pressure is felt while seating, it is ok. Maybe once they get to that point, they should not be used (?).

Two separate but related issues:

1) Primer to primer pocket fit - if fired case head(s) have deformed to the point primers will not stay seated, IMHO those cases are tossed. If primers seat easily but can't be unseated by tapping the case rim on a hard surface they're probably OK to use again but perhaps not in auto-loaders.

2) Out-of-spec primers - if you find yourself seating a new batch of primers with the usual amount of force required in new or known-good brass but then see evidence of leakage from reasonable loads, that batch of primers ought to be suspect. Uneven cup metal thickness and / or hardness could cause issues with uneven sealing, or burrs on the cups' rim that hold them away from the pocket wall.

With manufactured products there's always a chance a company QC program is flawed & may result in distribution of product that otherwise should have been scrapped.

Lacking solid info, do you have the means to measure and compare the batch evidencing leakage to a known-good batch of primers? I'd be looking at cup diameter uniformity first while cup thickness demands a leap of faith unless you have unusually uncommon access to proper instruments.

 

[expiper]

Gene,,have you measured your brass above the belt (at .200 line) and compared to new unfired brass...it will tell you (and us) if the chamber is too large or brass over stressed,,,Im still thinkin it is loose primer pokets and not bad primers...and an out of spec. chamber/reamer can cause this,,it doesnt matter how good and strait the gunsmithing is,,if thngs dont fit you got problems,,i have run into this with chambers/reamers that are spec. for lapua and then shooters try and use Win. brass ....nothing wrong with WW brass but in .284 and .22/250 the Lapua is .002-.003 larger at .200 line,and that is enuff to cause case swelling at normal operating pressure and primer lekage like you are seeing,,,the chamber should be no more than .004 (preferably .0025-.003) larger than the new unfired brass......please let us know what you find,,,,...Roger

 

[ab_bentley]

If it's bad primers call the manufacturer and tell them. I have had friends that had a batch of Remington Small Rifle primers that ended up recalling a whole lot of primers and replacing a few rifles due to their lack of QC. If the primers are truely bad and out of spec you may get the problem fixed without you paying for it.


Adam

 

[boltfluter]

Based on the etching pattern. I would consider that the primer hole in the case is egg shaped, thus will not seal. I would get a different brand of brass at least for a test. Just a thought. Good luck.

www.boltfluting.com

Regards, Paul

 

[25AI260]

sorry the etching happened . i have one like that its just deep enough you'll see it in the fired primer .. i found it doesn't really hurt the performance an think your will either..

i mite have the head space check before brushing the bolt < if you were to, the chamber an case relation is that there needs to have enough room for expansion an relaxation of the brass.. the fire pin when released actually moves the brass forward , when fired expands the case an forces it back against the bolt face .. at that time the prime can an mite back out an get pushed back In slightly all in an istant which could possibly leek a little at that point.. the brass Should now be totally expanded..

not loosing focus on that point what i see in your picture is you mite be under loading your powder..

i see No creator around you firing pin on the primer it looks nice an round.. the primer is No where near flatted.. so the same thing can happed as explained as a over sized chamber... Just Guessing other Possibilities...
then a question also arises... Do you set the depth of your pockets.. do clean the pockets well... do you set the primer square in each pc of brass... ?
Ok... i know i'll really get beat on this one, BUT..... ?

 

[gene pool]

Gene,,have you measured your brass above the belt (at .200 line) and compared to new unfired brass...it will tell you (and us) if the chamber is too large or brass over stressed,,,Im still thinkin it is loose primer pokets and not bad primers...and an out of spec. chamber/reamer can cause this,,it doesnt matter how good and strait the gunsmithing is,,if thngs dont fit you got problems,,i have run into this with chambers/reamers that are spec. for lapua and then shooters try and use Win. brass ....nothing wrong with WW brass but in .284 and .22/250 the Lapua is .002-.003 larger at .200 line,and that is enuff to cause case swelling at normal operating pressure and primer lekage like you are seeing,,,the chamber should be no more than .004 (preferably .0025-.003) larger than the new unfired brass......please let us know what you find,,,,...Roger

Roger,

I did measure and it is .0025 exactly.

To wrap this up, I am ditching the Remington brass and Winchester primers since one or the other is likely the problem. My 300 SAUM Norma brass has arrived and I have CCI magnum primers on hand. I need to work the 300 brass to make 7mm out of it.

Like I said earlier, this batch of Remington 7mm SAUM brass had several pieces that would not fit shell holders--the rims were too large. I wrote (and sent pictures) to Remington but thus far they have acted uninterested.

Regarding the bolt face of my new BAT action, it won't effect the performance of the rifle, I don't think. It just irks me that it happened to such a beautiful piece of equipment.

Anyway, thanks to all for your comments and concerns. Now back to the reloading room.

Gene Pool