Pre-fit Lemmon? What’s your thoughts

[Teekerguy]

I had a few issues with fireforming and split cases. It was corrected by necking up and back down to create the false shoulder with a slight crush fit and jamming into the lands about .010". Also only a mid range load.

You can't tell until you get formed brass. Once he has that, then you will be able to tell accuracy potential. I tried hard to shoot the big pills (250 Bergers) with it, but it really would not let me, had to shoot light and fast.

That what I did with my 280ai but I just think what's confusing me is my 223ai was load, shoot, formed cases no problems at all no false shoulder no jamming the bullet but I had a solid smith spin that up for me

 

[bluedog69]

You don't use the go gauge on an AI chamber unless that is what you asked for, some have the .003"-.004" negative headspace on the go gauge, others do not.

Cheers.

Sorry to bother but I am a learner.
The only AI I have been around was my friends 257 Roberts back when we were in high school.(40 years ago) He would buy factory rounds which chambered pretty hard and shoot them to fire form his brass.
I assume this is what you are implying with negative head space?

 

[Shane Lindsey]

Yup it was a prefit shouldered barrel for tikka actions which to my understanding you cant adjust anyways unless a smith does it. But I did recommend getting the go and no go gauges just to double check but that recommendation was not taken

I would not be next to him when he is doing range sessions with anything he produced...definitely wouldn't shoot anything he rolled...

 

[Teekerguy]

I would not be next to him when he is doing range sessions with anything he produced...definitely wouldn't shoot anything he rolled...

Already ahead of you on that recommendation haha!

 

[Sdvldog1371]

I read...loaded close to book max for fire forming at 0.010 off lands and didn't use headspace gauges. That is 3 no nos in a row. As mentioned either neck up and then neck down until there is a false shoulder created on the neck giving a crush fit. OR, Jam the bullet, preferably with a moderate crimp. Also, mild to moderate first load and depending on the brass manufacturer, it may be wise to anneal prior to first firing so that the brass flows. Seems like a lot of tomfoolery and mongoonish bafoonery afoot.

 

[Teekerguy]

I read...loaded close to book max for fire forming at 0.010 off lands and didn't use headspace gauges. That is 3 no nos in a row. As mentioned either neck up and then neck down until there is a false shoulder created on the neck giving a crush fit. OR, Jam the bullet, preferably with a moderate crimp. Also, mild to moderate first load and depending on the brass manufacturer, it may be wise to anneal prior to first firing so that the brass flows. Seems like a lot of tomfoolery and mongoonish bafoonery afoot.

I completely agree with everything you're saying and I appreciate all the reply's. Just wanted to throw this out there and see what others thought. Just trying to help a buddy out and trying different avenues but I'm with everyone on here there's way to many variables of no nos going on at once