Head Space Question

I'm re-barreling a Model 11 from .223 to 25x45 with a barrel from Black Hole Weaponry. This is my first barrel swap and Black Hole advised to use .223 gauges so I ordered a go & no-go Foster gauges. With the barrel clamped down in the barrel vise and the go gauge inserted I screwed on the action and bolt (extractor and ejector removed) until it stopped. When I opened the bolt it was very stiff so I figured I needed to back off a little but before I did it I tried a dummy round and the bolt closed easily. I thought this was odd I expected it to be stiff like it was with the go gauge, so I tried a fired non-sized 223 round and the bolt open and closed with no resistance. When I tried the no-go gauge it would not allow me to close the bolt at all. Should the dummy 25x45 and fired 223 brass be easy to close the bolt when the go gauge is hard to close? From what I read the bolt should close with slight resistance with the go gauge and not close more then half way with the no-go gauge.

There's .005" difference between go and no-go. If your dummy rounds fall within that .005" range, then the bolt should close easily. You should be able to proceed to loaded rounds now and be confident that you're in spec.

Remember that the new cases/ammunition have a shoulder that is back far enough to run in any chamber for the cartidge. I've measured new PMC that was 0.010 below SAAMI minimum. It has to run all the time in all the guns. On your fired case it may have in a short in-spec chamber. Also not all HS gauges are the same. BHW uses PTG gauges if you have a Forster it will be a tad different. Any SAAMI spec gauge will get you in the safe range.

That being said remeber that once you shoot the ammuntion you have your own specific chambers. You won't be far enough out to cause and issue anyway. You'll have to set your die up + or - regardless if you want the good fit. If you choose to neck size only then that will even be a moot point. The bugger is that when you pull and reinstall the barrel a variation will be induced if things are not exactly the same.

I'm going to pick up a 25X45 BHW barrel in the near future. I have chatted with them but have some others already in the pipeline. Hopefully I'll have one in my paws by JUne or July after I evalute the other ones. I just prurchased another rifle so I won't have to break down my match gun every time I want to play and experiment. Mind of like a three piece suit vs a pair of blue jeans.

Greg

I'm very pleased with the BHW barrel I have. It's chambered in 22x6.8 and that 3 groove polygonal rifling is amazing.

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Originally Posted by Hotolds442

I'm very pleased with the BHW barrel I have. It's chambered in 22x6.8 and that 3 groove polygonal rifling is amazing.

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Well there are some other variants out there from BHW. Like potato chips you can't have just one, or two or...

Greg

Thanks for the help I'll get her finished tonight.

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Originally Posted by Hotolds442

I'm very pleased with the BHW barrel I have. It's chambered in 22x6.8 and that 3 groove polygonal rifling is amazing.

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Sounds like an interesting caliber. Is it easier to find 6.8 brass now?

6.8 barss is pretty well available if you want Hornady. Also Federal, the best going right now IMHO, is often avaiable as 1X or bull down primed cases. SSA was purchased by Nosler and they are selling brass through the Pro Shop.

The 22X6.8 is a PD killing machine. I'm running it in an AR and it is devastaing on the litle ones. 50's at 3750 seem to work well. I have a 267" Savage on order that should be in soon as I just purcahsed another donor rifle. Case forming is only a matter of a couple bushings and a 6.8 die.

Greg

Greg