[Percevel]

In an attempt to not side track another thread I will ask my questions here.
1. Is it true that receiver that crack are ones where the charging handle is traveling so far back that it strikes and dents the far end of the slot?

2. Are there any receiver that have cracked where the charging handle was not strike the far end of the slot?

3. Is the charging handle striking the back of the slot the cause of the cracked receiver or is it it just indicative of the bolt carrier going too far back?

4. Regardless if it is the charging handle strike the back of the slot or the bolt carrier slamming the back of the receiver why do some Su-16 have this happen and others do not?

5. Aside from painting the charging handle or the bolt carrier is there some part that is out of spec that can be checked before it becomes a problem?

6. Is there a serial number range that is most at risk?

7. Is there a Model type that is at most risk? Alpha? Bravo? Charlie? CA?

I have had no problems with my charlie model at all. I am just trying to figure out if we can make sense of this issue instead of just worry about it.

 

[fortti51]

My A model receiver cracked after about 220 rounds of Federal .223 were fired thru it. The bolt handle slot was deformed at the rear and that is what caused me to cease firing. Cant give you the serial # as the gun and box are now in Kel Tecs facility for a replacement rifle. I can say that although I bought it new, it was "New Old Stock" and had the discontinued front sight on it. So the gun is older than when KT started installing the current sight.

 

[Forrest]

Great questions! I hope to see more answers in the future!

 

[zaitcev]

4. Regardless if it is the charging handle strike the back of the slot or the bolt carrier slamming the back of the receiver why do some Su-16 have this happen and others do not?

This really is the crux of the problem, isn't it? I used to talk with authority about this, but the more I study the problem, the more I see that I don't understand how it happens. In the past, these cases used to be linked to the excessive rearward travel because of the piston rod unscrewing itself. Nowadays, it's never the reason, but the problem keeps happening, just rarely.

I think that something is just not right in the gun from the factory in problem cases. It it were made well, the receiver will not crack even after thousands of rounds.

6. Is there a serial number range that is most at risk?

Nope. It happens even these days, on guns as late as of 2015.

On the upside, it's easy to see signs of the impeding disaster as the bolt carrier starts gouging the back of the receiver before the gun breaks.

 

[Forrest]

When I called Kel-Tec and asked them about the receiver cracking the rep said there is nothing you can do about preventing it from cracking other then only using proper factory loaded ammunition. He also said SU-16 receivers cracking is VERY RARE! But I still see it happen occasionally, he said there is no plan for a recall as the issue is VERY RARE!

 

[Forrest]

2. Are there any receiver that have cracked where the charging handle was not strike the far end of the slot?

Yes, the issue is with the back of the bolt (where the firing pin is) strikes the back of the receiver this is causing the cracked receivers, NOT the operating handle hitting the op handle slot.

3. Is the charging handle striking the back of the slot the cause of the cracked receiver or is it it just indicative of the bolt carrier going too far back?

It is my understanding that the op handle should never contact the rear cutout for the op handle, per the F.A.Q. SU-16 Sticky.

 

[Capnron50]

Su 16 broken receivers

Maybe the gas port hole on some rifles was drilled a little oversize causing excess strain on action. An adjustable gas block would be nice like you can get for a Mini 14.

 

[ramtuckybandit]

Check the rear of your receiver for any indents from the firing pin, bolt, or carrier. Per Kel-Tec, it shouldn't be hitting hard enough to leave any marks.

There was a thread on another forum where someone mentioned that their hitch pin, which was a little larger than the takedown pin, may have strained the receiver enough to cause the issue.

 

[IamScotticus]

there is nothing you can do about preventing it from cracking other then only using proper factory loaded ammunition.

Why Im only running 55gr. .223