223 AI Headspace

[GaryB]

I have reheadspaced this rifle because of multiple problems and I just want to make sure it is right this time.

Below are two pics of the rifle in the barrel blocks showing the position of the bolt. The first is with the No-Go(223 Go) headspace gauge in place and with bolt closed as far as it will go. Does it look right? Some pictures I have seen it seemed that bolt closed a little further. The second picture is just for reference because of the bad angle.

Thanks for the help!
Gary

[WinnieTheBoom]

I might tighten it up a litttttttle bit so it just barely doesn't close if that makes sense, but it's impossible to tell from the pictures. I do this almost entirely by feel.

[Hotolds442]

It looks to be in about the same location that the bolt handle on my 243AI resides when the 243 Winchester go gauge (243AI no-go) is installed. The center of my bolt handle locates just below the bottom of the serial number.
Since it's an AI chamber, the biggest determination is whether factory 223 ammunition will chamber. Since factory brass needs to be a crush fit before fireforming, you have to have the ability to close the bolt handle fully while still providing that .003"-.004" crush. Tighten the headspace up a bit from where you are now and you may not be able to chamber "all" factory 223 brass. Using once fired brass may be even worse.
I'd tighten it down there, and fireform a few rounds. Full length resize the fired rounds in the 223 AI dies with the sizer screwed all the way down on the shellholder, and then see if they chamber. If they do, add tape to the cartridge base until the bolt handle won't close, and then measure the tape thickness. That will give you a real good idea of where you're at and where you need to be.

[GaryB]

It looks to be in about the same location that the bolt handle on my 243AI resides when the 243 Winchester go gauge (243AI no-go) is installed. The center of my bolt handle locates just below the bottom of the serial number.
Since it's an AI chamber, the biggest determination is whether factory 223 ammunition will chamber. Since factory brass needs to be a crush fit before fireforming, you have to have the ability to close the bolt handle fully while still providing that .003"-.004" crush. Tighten the headspace up a bit from where you are now and you may not be able to chamber "all" factory 223 brass. Using once fired brass may be even worse.
I'd tighten it down there, and fireform a few rounds. Full length resize the fired rounds in the 223 AI dies with the sizer screwed all the way down on the shellholder, and then see if they chamber. If they do, add tape to the cartridge base until the bolt handle won't close, and then measure the tape thickness. That will give you a real good idea of where you're at and where you need to be.

I tried chambering a couple of 223 case that were full length sized and the bolt closes with just a bit more force than a FL sized and fire formed 223 AI brass case. The bolt handle only moves down about 1/4 inch so I am thinking it's good to go. It has to be better than it was before. VERY BAD!!!
The guages I used were a 223AI Go and a 223 Go(223AI No-Go).

Thanks
Gary

[Twostepct]

Where did you 223ai gauge come from? I ordered mine through Brownells and set it a shade tight on it. The result is a very slight resistance clambering factory 223 for the crush fit but it's smooth as silk with fireformed brass.

[adammiddagh]

I have started comparing shoulder measurments between fired and full length sized to see what i have for clearanc when done. Or comparing fired vs measument to headspace gauges. Just to double check. My bigger calibers, i am usually within ancouple thousandths. My last one was a 300 blk. It was about .003 to .004" over compared to a full length sized. I think go and nogo are usually about .004" apart.

[GaryB]

I just rented the gauges from 4D Reamer Rentals. I have not tried a live factory round in the gun as of yet, the weather has been to lousy to get out.
As I stated in the previous post, the full length resized standard 223 cases do close in the gun with some resistance. I suppose that is the "crush" fit referred to here.

Long story short, I originally took this to a gunsmith, who obviously did not know how to headspace an AI chamber, and it was way off! I had two case head separations and ended up putting the rifle away until I had time to try headspacing it myself. I am not mechanically challenged, but am a little apprehensive about doing things like this for the first time.

Tomorrow is supposed to be a nicer day, so I will take the gun out and try a factory round then. I am 99% sure it's OK, but just wanted some input from the members here.

Thanks
GaryB

[GaryB]

It's been a long time I know. Crappy winter here!
Finally got out and fire formed some brass and was very pleased with the results. I fired 100 rounds in about 2.5 hours and had zero problems. No sticky bolt, NO STUCK BOLT, and no backed out primers.

Here are a couple of targets...
100 yds 1" target dots
outside two are Midway 50gr HP DogTown bullets(left-1 1/4" right-5/8")
middle 50gr Hornady V-Max(just over 3/8")

[scooterf79]

Looking good! Seems to have fixed the problem! Look forward to seeing full power loads.
Scooter