So this just happened-- Game over man >.<

[Merovingian]

168gr should be fine, it depends more on the powder you're using if it will be hard on it. A powder around the same burn rate as H4895 should be good and seems to be what most recommend. I use Varget and 168's in mine without issues. The M14 is not as sensitive as a Garand but any semi will cycle better with a powder slightly slow for the projectile weight to keep things cycling smoothly. Check out the service rifle data available, my Hornady manual has a whole section devoted to service rifle loads.

With that few of rounds through it I'm going to say your issue is more just a case of bad luck and getting a bolt that had a flaw in it. Check the EE for a new bolt. Lot's of guys put thousands through their Norinco bolt without failure so I wouldn't get too carried away with an expensive one unless you have bigger plans for the rifle in the future.

One of my M14's has a Fulton Armoury bolt but it also has a Krieger barrel and I bought it already built and probably wouldn't have upgraded it until the original failed. The bolt won't make it shoot any better so big bucks can be spent more effectively if the rifle is going to remain relatively original other than a chassis.

I hadn't planned on spending alot more on this guy. Hopefully just a bolt replacement and some gun smithing work can get it going again.
I'm trying to get on the next Pre-sale for one of the BCL-102's so hopefully fixing this guy doesn't hit the pocket book too hard >.<
Thanks for the load advice, I haven't jumped into reloading but its coming soon.

Appreciate the tips.

 

[teknition]

Pic #2 shows a fine grain structure (proper heat treating up till just after the quench) with instantaneous failure (lack of rust showing that it was cracked for a while). My guess is the bolt was heat treated properly but not tempered back far enough or at all.

 

[Garaldtao]

Something similar happened to me but I caught it before the bolt broke apart. The bolt was begining to contort so I switched to 150 grain. The bolt did not seen to get any worse but in the end I switched that out also. I now save my heavier rounds for my bolt actions.

 

[Merovingian]

Pic #2 shows a fine grain structure (proper heat treating up till just after the quench) with instantaneous failure (lack of rust showing that it was cracked for a while). My guess is the bolt was heat treated properly but not tempered back far enough or at all.

Here is a better pic of the break

 

[Merovingian]

Something similar happened to me but I caught it before the bolt broke apart. The bolt was begining to contort so I switched to 150 grain. The bolt did not seen to get any worse but in the end I switched that out also. I now save my heavier rounds for my bolt actions.

Hmm good to know, I might try some 150's when I get it going again.

 

[maltextract]

Hmmmm I run 180g winchesters and 165s and 168s in my polytech M-14 all the time... never had a problem.

 

[LordEvilPepper]

Welcome to my world, 168 SMK from federal as well.
Case neck was to long, and stubbed out cripping the round causing an over pressure.

but hey don't worry, people here will tell you are a moron and its for sure a reload that blew up your gun.

 

[Bartok5]

Welcome to my world, 168 SMK from federal as well.
Case neck was to long, and stubbed out cripping the round causing an over pressure.

Holy Crap!! Hope you are OK after that one!?!?

 

[Merovingian]

Welcome to my world, 168 SMK from federal as well.
Case neck was to long, and stubbed out cripping the round causing an over pressure.

but hey don't worry, people here will tell you are a moron and its for sure a reload that blew up your gun.

Sweet fancy Jesus! That looks like it hurt. I hope you kept your digits

 

[Odd Shot]

Dude, you have the absolute worst luck when it comes to boomsticks going boom all badly in your hands!

Welcome to my world, 168 SMK from federal as well.
Case neck was to long, and stubbed out cripping the round causing an over pressure.

but hey don't worry, people here will tell you are a moron and its for sure a reload that blew up your gun.

 

[LordEvilPepper]

i'm fine.... whole thread about it here:

https://www.canadiangunnutz.com/forum/showthread.php/1233927-A-quot-lovely-quot-morning-shoot-today-I-do-enjoy-picking-up-pieces-of-my-rifle-Update

suffice to say, I will never ever shoot Federal Ammo again... every ammo related issue i have ever had has been federal ammo.

 

[Sh0ckw4v3]

I have a brand new bolt I'll ship you for $50 to get you going again.

 

[teknition]

Here is a better pic of the break

Grain structure is a little coarser than what I could see in the first pic but still not outrageous. The "skin" around the outside of the fracture looks odd to me, almost like it was case hardened. Also looks like there may have been a flaw in the steel to begin with (lower section of the piece that broke off).

 

[Merovingian]

I have a brand new bolt I'll ship you for $50 to get you going again.

Thanks Shock, I'm currently working with the store I got the rifle from to see if the bolt can be replaced under warranty. Failing that my gunsmith has a USGI bolt he can install, but thanks for the offer.

 

[Merovingian]

Grain structure is a little coarser than what I could see in the first pic but still not outrageous. The "skin" around the outside of the fracture looks odd to me, almost like it was case hardened. Also looks like there may have been a flaw in the steel to begin with (lower section of the piece that broke off).

Lower left on the bolt roller piece, I see that small channel in the steel. The bolt was actually inspected the night before going to the range, I didn't seen any obvious signs of stress or cracking.
The skin around the bolt looked a little strange but i'm no metal expert.

 

[dimeN]

yep, it does look like the grain is large on this ... which will reduce the toughness of your bolt ! go and crack a nicholson file in half, a fine grain structure should look like this !! extremely fine !!

when you case harden, its stuck in a high temp with a carburizing medium ... the C migrates into the steel at the outside perimeter ! pending on the steel alloy and the temp they use, it can lead to some grain growth

fulton armory makes a nice bolt.. abit on the over built side !

 

[alberta tactical rifle]

Was it Federal Gold Medal Match ammo? I am not aware of any other Federal ammo loaded with the 168 SMK.
The Federal GMM ammo is quite hot as it is normally intended for use in a bolt action rifle.
The metallurgy of that bolt does not look right. Having seen more than a few bolts with sheared off lugs the grain is usually very noticeable and does not look dull in color.
I am certainly no expert when it comes to M14 style rifles but my guess is a combination of hot ammo and poor quality metal used to make the bolt.

 

[Sh0ckw4v3]

Thanks Shock, I'm currently working with the store I got the rifle from to see if the bolt can be replaced under warranty. Failing that my gunsmith has a USGI bolt he can install, but thanks for the offer.

I would hope they would replace it! You could have been seriously injured or worse by that failure if the safety lug had failed as well.

My U.S.G.I. bolts have all had magnetic particle inspections, which makes me feel a lot better about using parts made that long ago which saw heavy service use. Make sure if you do go that route you get a bolt with an M mark on its reverse.

 

[Merovingian]

Was it Federal Gold Medal Match ammo? I am not aware of any other Federal ammo loaded with the 168 SMK.
The Federal GMM ammo is quite hot as it is normally intended for use in a bolt action rifle.
The metallurgy of that bolt does not look right. Having seen more than a few bolts with sheared off lugs the grain is usually very noticeable and does not look dull in color.
I am certainly no expert when it comes to M14 style rifles but my guess is a combination of hot ammo and poor quality metal used to make the bolt.

Yes it was Federal ammo. I get mixed opinions on if these are too hot for the M14. When it gets running again I'll start in the 150gr area and pay more attention if a factory load is on the hotter side.

 

[dimeN]

if you look at the bolt... see the area where its just a tad shade darker grey ! and the center is a lighter shade of grey .. I suspect the darker shade is where is was previously cracked to and it has oxidized abit .. and the light shade is the bit that just recently failed !
- so it could be that your bolt has been on the way out for awhile
- oh and what are those small black looking flecks ...are they pores/porosity .. or actual particles ( could be graphite or slag from the melt ) any porosity or non ferrous inclusions will dramatically reduce the strength in these areas