Headspace?

So I am trying to get my Axis 300BlackOut headspaced before PA whitetail season on 12/02/13.

I didn't have the time to rent them, or buy a set, so I was going to use what others have recommended on this site. I was going to use a spent piece of brass to set headspace.

Now, the spent case the bolt closes fine. I used two pieces of clear "scotch" tape and that piece of brass and the bolt still closes.

This is the McGowen 1:8 barrel I bought from a vendor from 300BO forum. Before I removed the barrel, I did notice that the barrel is marked 300blackout and it aligned perfectly with the receiver. Should I use that as my reference or does anyone have another idea for me to try? I thought adding two pieces of tape was going to work as my no go gauge.

If I cannot get this resolved in the next day, all is not lost as I have another Savage in 308 that I can use to hunt. I prefer to use the Axis as it's much lighter then the 308 rifle.

1. Was the spent case you are using fired in the chamber you are headspaceing?

2. You don't have much shoulder on that case to work with. Meaning, it doesn't take much pressure to force that case further into the chamber than it should be.

3. If I were doing this, I would set the headspace just snug, lock it down, then go to a safe place and make sure your loaded rounds chamber
easily, then go to the range and see how it shoots. All should be well, and you can forget about the scotch tape.

4. Bring it on, beat me up if you like, but "headspace", on a Savage system, is almost a "no brainer". To little, and you can't chamber a round. And I think anyone with basic mechanical skills would have to work at it to get "too much". jMHO ;-)

Good Luck- Good Shooting.......Jim

Well.... I am just not 100% on what you are trying to accomplish here.

If the barrel is already installed, and you are head spacing from a spent cartridge, you won't accomplish anything (in my mind). I believe you are swapping barrels but I'm unclear about you comments regarding the "Before I removed the barrel, I did notice that the barrel is marked 300blackout and it aligned perfectly with the receiver. Should I use that as my reference or does anyone have another idea for me to try?" So... again, it sounds like the (new?) McGowen is already installed?

I'll assume that your spent brass [sic] is from the factory barrel, and you are using that to headspace - correct?

[1] The chamber cut isn't likely to be cut identical between the 2 barrels - so this would be a problem (using a spent cartridge) unless you've measured that cartridge (brass) to ensure it's of proper dimensions.
[2] What are you trying to accomplish with the head spacing? SAMI specs? Tighter tolerances with your dies (hand loads)?

I have no problem with using expended brass (sized with your dies) to headspace with, but that would ONLY be if you shoot it exclusively with those hand loads and you are not going to shoot factory loads. My real caution is with performing head spacing without full knowledge of why (and how that is important). Personally, I use gauges; and set my dies to give me acceptable bump (I FL size as I'm of the camp that this gives me the greatest consistency and I anneal every firing). That is not to say that is the best way (for you). Just make sure you fully understand what (and why) you are doing it.


PS - this is not to be taken as a flame in any way (please).... just something to think about.

Of course the cases were fired from my chamber. 300BO isn't exactly as common as say 223/308. Cases were formed and annealed. I have 20 fired cases prior to having my ejector/stuck case issue, which is why I had to loosen the barrel nut.

First time I rented the head space gauges. I thought this would be a one time process, so I didn't purchase the gauges. I'm pressed for time, so I thought of using a fired case to get the rifle running again.

Once the gauges are available for sale, I'll be purchasing a set, but this does not help my immediate issue of trying to use this rifle come December 2nd. I don't mind having 221fireball/300bo gauges, but I don't have the time to wait for them as I need the rifle to function in two days.

I'm going to load up some more 300BO rounds and try what the first poster suggested.

When you say spent case, do you mean fired and resized or just fired? Several on here headspace off resized cases. I have used a go gage as an extra measure of safety, but I am sure the sized case method will work.

Pull the firing pin and use a new round. Then use a .004 shim behind the case head for no go. A beer or soft drink can could be used, cut to the case head size with mommas scissors and use it between the case and the bolt to check. When you get the gauges check for posterity. As always point the sb in a safe direction not at your wife or kids....or the neighbors constantly barking dog.