I know this is tech, and I tried searching, but I didn't find anything.

I'm having good accuracy with this round from my 16" SR-25 APC, and my 20" REPR. At a shoot last weekend, the REPR had a 3 shot, 4" group at 500 yards.

I did have a few issues, and I'm not Ammo-savvy enough to know what was going on.

I had two primer blow outs that actually jammed my SR25 up - the primer blew out the back and caused a Failure to Eject, then fell out loosely on the table after clearing the jam.

When cleaning my SR25 and REPR bolts, I found a number of small brass disk like things in the firing pin channel, under the extractors. Also, the firing pins and channels themselves were heavily blackened, and both firing pins look like they were media blasted with black media. The finishes are pockmarked wit h little black dots now that aren't coming off.

Additionally, the REPR's cotter pin was bent laterally.

hmmm not looking to good for IMI ammo right now

The thread right under yours is about blown primers:
http://www.ar15.com/forums/t_3_16/696873_Problems_with_IMI_77_gr_razor_core.html

no kidding, dumping their shit on our shores?

Boy I'm glad I saw this thread.  I literally the exact same things happen to my Fulton Armory 308 a few weeks ago and have been looking for a cause.  Same discs, failure to eject, and the firing pin retainers were just chewed up.  I'll stay away from the IMI 175's but I haven't had any issues with their 77 and 55 grain ammo.

I wonder if this has something to do with the COAL being longer than standard M118LR

Any one have the lot numbers on the 175s in question?   I'm in contact with IMI on the 5.56 77gr blown primers issues and will pass this on to them as well

Lot 00405/F for the 7.62

I had no issues with the previous lot number I bought. I want to say it was 00402/F

Will pass that one on when they get back to me

I emailed SGAmmo.

Sam said that this should not be an issue on the newer (higher) lot numbers of IMI.

Obviously high pressure... That looks like primer blanking - not the normal blown primer (where the whole primer is blown out).
Usually, in a bolt rifle, this happens when the primer flows back into the firing pin hole and the FP spring is overcome by the pressure enough that the primer stretches to the point of metal fatigue... leaving a cookie-cutter hole in the center where the edges of the FP hole cut it. Those bits of metal are probably the remains of the primer and they are what chewed up your internals. Since your bolt doesn't use a spring it may be more susceptible to the initial pressure force.
Check the end of your firing pin for tiny pinholes from the gas cutting- you may need to replace the FP if there are any.





As someone mentioned the bullet OAL may be hitting the lands if you have a short throat (if a match chamber or otherwise) thus driving up pressure astronomically. The others seem to look normal - no obvious craters or top-hats (where the primer has stretched but hasn't blanked yet)



 

Did you measure this? actually curious, not trying to be a prick
I read the letter SGAmmo got in from the IMI Moshe dude and seems like they're made to LR M118 US specs..... i'm asking since i have 6 boxes of the same lot# that blew up, and unfortunately i don't have calipers to measure accurately...
thx

Lot 00405/F is what i have

Yes. They will NOT fit in regular Pmags, but they will fit in the M118LR Pmags, and all of my metal mags.

SGAmmo said the first lots that came in were designed around bolt guns, not semi-autos, but the ammo being made now should have a harder primer and a shorter COAL.

awesome, thanks for the info :)

Someone in the KAC forume mentioned there was a running thread regarding issues with this stuff--IMI 7.62x51 175gr--which is exactly what I was shooting when this happened. Failure to eject and the bolt was stuck in the forward position. Had to mortar the rifle, although I mistakenly failed to collapse the buttstock extension which resulted in what you see, below:



Sucks because I've had great experience with IMI 77gr in my 5.56 guns--which lead me to buy bulk supplies of IMI 7.62x51 175gr

Ouch! I was almost in the same boat, but I found FGMM for the same price as the IMI and I've got three boxes left. Going to give three boxes to s friend with a bolt gun tomorrow and see what he experiences.