A 955 TS first

First time I’ve ever seen it.
Casting flaw maybe?

 

Was that a pre existing crack in the casting?

 

You wouldn’t have seen it if that was indeed a crack.
Would have been inside of the casting.
In any case it’s good to know HP will take care of you.

 

I wonder if anyone else has had the same experience or could it be just a one off failure in WhitewolfK's 995TS.

 

I'd consider that a first in the molding process, considering that even the original(classic) 995 monkey guns are the same carbine made, as today's 995 TS model receivers/bolts/barrel used. So there's millions of combined carbines out there in usage and no problems that have shown this fault. And we all know how fast problems can travel with today's internet and the HP haters.

 

That is certainly the weakest spot in the bolt assembly and combine that with having to push against the recoil spring! Not crazy about the design myself. The spring guide will also add a bit of length to the spring length and compression force. My classic 995 does not use a guide. Are all the springs the same length regardless of guide/ no guide?
Did this carbine have a higher pound rating spring? Are those available? If yes, maybe it's better to let the rear of the bolt hit the stock.

 

Looking at my bolt and stock, the material could have been cast thicker via projected forward or the inside sharp corner cast w/a 45 degree angle or at least a inside curve. Cracks develop easily at inside square corners. Add that the recoil spring pressure is not even inline w/t cross section, but offset which adds leverage pressure at the bottom of the inside corner!

One good thing, assuming the bolt & frame are the same material, is that the material seems to have a little elasticity. I've cut on my frame quite a bit via a bandsaw and when I got to the last of the cut I stopped to break the piece off and it takes quite a bit of bending before it snaps off. Cuts rather easy too vs a hard brittle casting.

Most likely the break is just a fluke. If there were hundreds of broken bolts, HP would probably want to make a new casting design vs a rare replacement cost.
And this being a 9mm, the real test is when the 10mm's get shot a lot.

No, I'm not done!!
Better yet, if you're going to have a full stocked carbine, why not just build a captive recoil spring system and buffer right into the stock? You could have 1 or 2 rat tails like a FAL carrier that push against recoil springs.
Although I personally chose to work w/t HP carbine as I had the option for a folding stock or Bullpup conversion.

 

HP might also ask you this question, but did it have the stock HP plastic recoil spring guide? And have you ever fired the gun without the receiver being in the stock?
It also looks like HP changed the bolt design slightly in that area where it snapped.

 

Hey ratchow, thanks for pointing out the bolt front difference! I didn't look that close to adams pic.
But that also leads to the needed question to adam of IF the bolt he posted a pic of is from a 995 and not a larger cal carbine.
Here is a pic of my 995 classic, Gen 2. It has the stepped down cross bar and the recoil spring lug is .217 thick.

 

Either they put too much belly button lint into the mixture, or not enough

 

Now that's something that hadn't been considered. The BBL mix ratio was incorrect or the BBL shelf life date had expired.

 

could also be that a 380 carbine spring found it's way into a 9mm by some flukie mistake.