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Rifles, Reloading, Optics, Equipment
Reloading
Should I be worried?
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<blockquote data-quote="Bob Wright" data-source="post: 1934164" data-attributes="member: 104363"><p>If you are loading under book minimum, it can be disastrous. "Bridging" or simultaneous combustion of most of the powder is a massive spike in pressure.</p><p>Just stay above by a grain and work up to max.</p><p>Head separation is usually head space errors. Belted mags when new, headspace off the belt. Once!</p><p>After a few firings, each brass should stretch to the shoulder datum of your chamber. The shoulder datum should be checked on each brass before reloading. If they vary more than .003, you're not there yet. Anneal them at the neck/ shoulder, full length size without bumping the shoulder (measure!). Check for fit.</p><p>Those should now give you a final headspace number after firing within .001 of each other. My 7RM cases stretch .019 on first firing at the shoulder datum. It's normal.</p><p>This cartridge family, yours/mine were dangerous game designs where each cartridge is guaranteed to chamber and eject by basing the headspace of the belt first.</p><p>Start measuring, look for bright rings above the belt, use the paper clip feeler internally to feel "under cuts" and/or start over with new brass.</p></blockquote><p></p>
[QUOTE="Bob Wright, post: 1934164, member: 104363"] If you are loading under book minimum, it can be disastrous. "Bridging" or simultaneous combustion of most of the powder is a massive spike in pressure. Just stay above by a grain and work up to max. Head separation is usually head space errors. Belted mags when new, headspace off the belt. Once! After a few firings, each brass should stretch to the shoulder datum of your chamber. The shoulder datum should be checked on each brass before reloading. If they vary more than .003, you're not there yet. Anneal them at the neck/ shoulder, full length size without bumping the shoulder (measure!). Check for fit. Those should now give you a final headspace number after firing within .001 of each other. My 7RM cases stretch .019 on first firing at the shoulder datum. It's normal. This cartridge family, yours/mine were dangerous game designs where each cartridge is guaranteed to chamber and eject by basing the headspace of the belt first. Start measuring, look for bright rings above the belt, use the paper clip feeler internally to feel "under cuts" and/or start over with new brass. [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Reloading
Should I be worried?
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