01-16-2020, 03:22 AM
Here's a thought and probably not the problem but shows how headspace is not as simple as the length from datum to base.
I once had a 338LM, a Rem X 'Special' (everything's 'special' in the gun industry). Basically a Rem700LA with beefed-up rail screws. The hand-loaded full length rounds went into the chamber fine but after firing the bolt was always sticky to open...even on the mildest work-loads. Turns out the whole chamber was flexing/expanding and then contracting to grip the empty case on firing. Remington stopped selling that line shortly after. In a fixed model like the Rem700 as the calibre gets bigger, there is less meat around the case to support the pressure. They cashed in on the new popularity of the 338L the cheapest way they could, just use an existing design.
Took us a while to figure it out, it was lateral headspace (measured by the diameter or how fat the cartridge is), not longitudinal headspace (measured by how long the cartridge is base-to-datum). All rifle gauge brands concentrate on longitudinal headspace and machine their diameters generously; to make sure everyone's fire-formed handloads will fit down to the datum. As I understand it, Sheridan machine their gauges with proper reamers so all axes are considered.
It could just be a tight chamber requiring more sizing.
I once had a 338LM, a Rem X 'Special' (everything's 'special' in the gun industry). Basically a Rem700LA with beefed-up rail screws. The hand-loaded full length rounds went into the chamber fine but after firing the bolt was always sticky to open...even on the mildest work-loads. Turns out the whole chamber was flexing/expanding and then contracting to grip the empty case on firing. Remington stopped selling that line shortly after. In a fixed model like the Rem700 as the calibre gets bigger, there is less meat around the case to support the pressure. They cashed in on the new popularity of the 338L the cheapest way they could, just use an existing design.
Took us a while to figure it out, it was lateral headspace (measured by the diameter or how fat the cartridge is), not longitudinal headspace (measured by how long the cartridge is base-to-datum). All rifle gauge brands concentrate on longitudinal headspace and machine their diameters generously; to make sure everyone's fire-formed handloads will fit down to the datum. As I understand it, Sheridan machine their gauges with proper reamers so all axes are considered.
It could just be a tight chamber requiring more sizing.