PDA

View Full Version : 223 AI headspace.



243LPR
03-29-2018, 09:37 PM
Slightly confused on headspacing this cartridge due to the different things I've read. I just got confirmation my barrel is headed my way soon and want to do this right. I've read to use a 223 no go as a go(I have both)and use a field as a no go(which I don't have). Why can't I just set the barrel up with a FLS case as a go and use the tape for no go? That was how I set my 6mm AI with no problems. This is my 3rd AI and really like them,look forward to loading this one. Mainly bench and groundhogs.

Whynot
03-29-2018, 10:43 PM
I've personally never found most of the AI cartridges to be worth it- so other than a 280 AI I don't have very much experience with them-- so this is all from what I have read and can't tell you if it is correct. But I believe that an AI chamber is actually a few thousandths shorter than a standard chamber- so that it can safely fire the standard ammo. So I think that your 223 go gauge becomes the no-go gauge. I may be wrong- but if the no go became the correct go-gauge then it wouldn't seem safe to fire form non AI ammunition in it.

Evlshnngns
03-30-2018, 12:26 AM
I used a crush fit on my brass. I want a 223ai, what twist and how much freebore?

GaryB
03-30-2018, 09:03 AM
But I believe that an AI chamber is actually a few thousandths shorter than a standard chamber- so that it can safely fire the standard ammo. So I think that your 223 go gauge becomes the no-go gauge.

This is correct. I rented gauges and they were marked "223AI go" and "223 go(for the 223AI no-go)". I hope that makes sense.

Also, here is some information on the 223/223AI...
http://www.6mmbr.com/223rem.html

mnbogboy2
03-30-2018, 10:52 AM
This is correct. I rented gauges and they were marked "223AI go" and "223 go(for the 223AI no-go)". I hope that makes sense.

Also, here is some information on the 223/223AI...
http://www.6mmbr.com/223rem.html
+1 on above
Understanding the OP is already familiar with A.I.s this post may give insight to those not familiar with them setting up. It is a good thing that the OP questioned using a no-go for the go. This is not right. The go for the AI is shorter not longer. Like Evlshnngns said I use a crush fit with my brass for my AIs (3-.257 Bob AIs & 2-6.5/.257 Bob AIs). Goal obviously is to minimize stretching on the first firing.
Full length sizing a piece of brass .002-.004 short of SAAMI will work as a go gauge. A std size full length sized case then must be forced to close (eliminating any headspace and case stretching).
Good luck,
Randy

243LPR
03-30-2018, 10:58 AM
I have some LC brass all prepped for this,think I'll just set it up with that.

Zero333
03-30-2018, 02:00 PM
Usually you'll want to use the go-gauge as the no-go gauge.

Easiest thing to do on the Savages is to set headspace with the go-gauge and not back out the barrel any after taking out the go-gauge. So once you tighten the nut the HS will shrink a thou or 2 (since you didn't back out the barrel any). This will give you a crush fit with the brass.

I hope I explained it good enough to be understood. It's easier done than said.

mnbogboy2
03-30-2018, 03:56 PM
Usually you'll want to use the go-gauge as the no-go gauge.

Easiest thing to do on the Savages is to set headspace with the go-gauge and not back out the barrel any after taking out the go-gauge. So once you tighten the nut the HS will shrink a thou or 2 (since you didn't back out the barrel any). This will give you a crush fit with the brass.

I hope I explained it good enough to be understood. It's easier done than said.

This makes sense to me I know exactly what you mean. Another method is to fully set headspace snug with the go gauge & final torque, witness mark the nut and barrel with a sharpie, then make a second witness mark on the barrel approximately 1/8" (for a small shank), loosen the nut and turn the barrel in that amount and re-torque. [1/8" of circumfrence on 1 1/6" diameter is just shy of .002" with 1.055x20 thd].
At final torque the nut ends up clocking the same but the barrel will be turned in that little bit more and the sharpie marks will clock accordingly.
Using this method may help to get exactly where you want to end up.
My .02,
Randy