I picked up a Winchester 100 carbine in .308 in real nice condition,almost like new. It shoots great with one exception, once in a while it goes auto for 2 shots. I have looked at the trigger group and it looks like new, no dirt, oil,nothing. Any help/ideas would be appreciated,thanks..

Winchester 100's and 88's have a recall on the firing pin. Call Winchester and give them your serial # and they can verify if the firing pin has been upgraded. If it has not been changed you can have a gun smith remove the old pin, send it to Winchester and they will send you a new one and $26 check to cover cost of replacement. Old (original) firing pins can break and cause the round to fire upon closing the action. This may or may not be your issue but I would start there.

Tom, this one has had the recall for the firing pin done. The frustating thing is it does this 2 shot auto fire when it wants to,it shoots normal most of the time.

wondering? are you a rifle shooter and using this off the bench when this happens? does it ever double in the field or hunting? on certain autos if one can really squeeze slowwwwwwly can double. usually happens on bench not when shooting game.

Jay: best to fit this ASAP since BATFE says that posession of a firearm that fires more than one shot with a single pull of the trigger is a machine gun, even if it does this by malfunctioning. knowingly having a gun like will get you into deep sushi. likely due to a worn hammer/sear/discnnedtor.

What he said..

The M100 has been known to have that issue at times.. Get it to a gunsmith PRONTO (one that truly KNOWS the M100) and have him/her correct the issue..

Do NOT send it to NULINE... Just my .02.. IIRC, Midwest Gun Works is quite familiar with the M100.. I don't know where you reside, but do some research on who to send it to..

I have one that I bought brand new in 1964; it has a lot of critters to its credit. The rifle itself is not the problem, it is the operator. In the hanging tag that came with the rifle, there is a note stating the it will "double" if the rifle is not held correctly. It has happened to me at the bench when trying to sight it in with a light grip on it. Your problem will disappear if you concentrate on holding it tighter. I venture to say you did not have the problem when in a hunting situation.

It scared the $hit out of me when it happened the first time; what is happening is the rifle is "bouncing" against your trigger finger from your loose grip.

JK,

That's terrifying.
I had a 10-22 double on me once at the range, and I about crapped my knickers.

Wait'll you have a 12 ga with turkey loads double on ya..

OUCH!!

Good information. I've had this problem with mine and have had it to numerous smiths.

Shoots very well but it scares me. I kind of thought it was my grip.

I'll take it to the range and give it another go with a tighter grip.

Thanks all for youe input.I returned the rifle today as it was making me flinch and I don't want to develope that habit. It is a shame because I liked the rifle,but not worth the problem. In my mind I would always wonder if it was going to double shoot and the second shot is not under control, not a good thing.
jay