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Headspace |
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DarioPirovano 
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Joined: May 20 2023 Location: Italy Status: Offline Points: 219 |
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 Topic: HeadspacePosted: January 21 2024 at 11:42am |
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he!!o guys, my long branch started to push out primers from the case a little bit, previously I had installed a 1 bolt head which measured .628” I found another 1 bolt head that measure .630”
So after install I decided to measure headspace, but i haven’t got any gage to control it. So i tryed this, stripped the bolt and removed extractor claw and spring from the bolt head and with a new cartridge with a rim thickness of 1,45mm , started to close bolt with a feeler gage placed between the back of the cartridge and the bolt head face, the 0,20mm leaf moved freely, the 0,25mm leaf fit perfectly snug with no bolt resistance in closing, and the 0,30mm leaf didn’t allow the bolt to close completely. Meaning that 1,45 + 0,25 = 1,70mm = 0,0669” headspace. What do you think of this method? I think that it might work very well without spending money on gages that I will use once in a lifetime.  
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britrifles
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Joined: February 03 2018 Location: Georgia, USA Status: Offline Points: 8404 |
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Posted: January 21 2024 at 12:06pm |
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I’ve used this method before, to estimate an actual headspace dimension. I started with a 0.064 headspace gage though, cartridge rim thickness varies around the rim and it may not be 90 degrees true to the bore axis. But this gives you a fairly close estimate, call it 0.070.
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DarioPirovano
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Joined: May 20 2023 Location: Italy Status: Offline Points: 219 |
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Posted: January 21 2024 at 12:10pm |
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Thank you for reply Geoff, i measured the rim in 8 different points with a star like pattern and was spot on 1,45mm
.070 is still a good result in your opinion? Otherwise I’m going to seek another longer bolt head |
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Shamu
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Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 20510 |
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Posted: January 21 2024 at 12:22pm |
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You can also use the rear face of the visible locking lug to do the same thing as a substitute measurement.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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DarioPirovano
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Posted: January 21 2024 at 12:29pm |
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Exactly Shamu
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britrifles
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Joined: February 03 2018 Location: Georgia, USA Status: Offline Points: 8404 |
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Posted: January 21 2024 at 12:29pm |
Yes, 0.070 is perfectly acceptable. But, if you want longer brass life, try to find a longer bolt head. Most commercial brass has fairly thin rims which exacerbates this issue with case web stretching and thinning. I think the tighter headspace also promotes a more consistent case position in the chamber which is good for accuracy, as does sizing the case to get it to headspace on the shoulder rather than the rim (hold the case back against the bolt head).
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Shamu
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Posted: January 21 2024 at 12:41pm |
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^^^^ This! Particularly with "Remchester"  US made brass.Greek HXP & Prvi Partizan PPU (or nny Cyrillic) headstamped is usually much better.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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DarioPirovano wrote: