entoptics
Well-Known Member
- Joined
- Jan 16, 2018
- Messages
- 881
Just installed a new barrel, and went to shoot it today. Brass sticks in chamber so bad, primary extraction is damaging the rims, and a rod is needed to drive them out.
I used once fired brass (Sig) from a previous barrel, and though it chambers OK, after firing it sticks.
Before I buy new brass, and/or call (call out?) the manufacturer, I'm hoping someone can measure the diameter of some virgin 300 Win Mag brass right above the belt (flush to perhaps 0.2" forward), so I can gauge whether that will mitigate the issue.
To head off discussion of "causes" I've already discounted...
1) Loads were not hot. I started at 5 grains below book max, primers looked peachy, and velocities were in the ballpark compared to previous data from the first firing of this brass in the last barrel (Shilen). 73 grains of H1000 behind a 208 ELDM produced 2850 fps (26" bbl) and case was still stuck as tight as a duck's butt. This Sig brass is stout, so definitely needs less powder like ADG. For comparison, 79 gr of the same lot of H1000 was my go to in the Shilen in MAI (Norma) brass, which drove a 208 at about 2860 in a 24".
2) I've loaded for six very different 300 Win Mag barrels; a 1960s era Winchester 670, 3 x Savage OEM, and a Shilen Match Select. All were fine digesting each other's fired brass, as long as base to shoulder was adjusted as needed by FL sizing to the appropriate BTS for that barrel.
3) Brass was full length sized, and sizing marks went all the way to within a tenth of an inch of the belt, so I don't think any amount of full length sizing is gonna get me where I need without ramming the shoulder back way too far. Base to shoulder on the 3 fired and stuck pieces is actually 0.001" longer than what came out of the Shilen, so more FL sizing is not an option unless I want head separations...
4) I've never needed the Larry Willis die in >5000 rounds of 300WM, 7 RM, and 264WM, and am not about to go that route to solve something that shouldn't need solving...
Anyway, I'm pretty sure the chamber is tighter than it should be back near the belt, based on the scuff marks, though if you have theories beyond what's mentioned above, let me hear em.
I'd really appreciate it if someone(s) with some virgin brass could measure the diameter in front of the belt, so I can predict if just getting some virgin brass will solve the issue. Of course, even if that works, I'm not tickled about losing access to several hundred pieces of brass with a few firings left in them, but $150 worth of brass is better than disassembling the rifle and sending the barrel back to the manufacturer.
I'll be buying Peterson Long or ADG, so data from that would be ideal, but I figure any brand will give me an idea.
Thanks in advance.
I used once fired brass (Sig) from a previous barrel, and though it chambers OK, after firing it sticks.
Before I buy new brass, and/or call (call out?) the manufacturer, I'm hoping someone can measure the diameter of some virgin 300 Win Mag brass right above the belt (flush to perhaps 0.2" forward), so I can gauge whether that will mitigate the issue.
To head off discussion of "causes" I've already discounted...
1) Loads were not hot. I started at 5 grains below book max, primers looked peachy, and velocities were in the ballpark compared to previous data from the first firing of this brass in the last barrel (Shilen). 73 grains of H1000 behind a 208 ELDM produced 2850 fps (26" bbl) and case was still stuck as tight as a duck's butt. This Sig brass is stout, so definitely needs less powder like ADG. For comparison, 79 gr of the same lot of H1000 was my go to in the Shilen in MAI (Norma) brass, which drove a 208 at about 2860 in a 24".
2) I've loaded for six very different 300 Win Mag barrels; a 1960s era Winchester 670, 3 x Savage OEM, and a Shilen Match Select. All were fine digesting each other's fired brass, as long as base to shoulder was adjusted as needed by FL sizing to the appropriate BTS for that barrel.
3) Brass was full length sized, and sizing marks went all the way to within a tenth of an inch of the belt, so I don't think any amount of full length sizing is gonna get me where I need without ramming the shoulder back way too far. Base to shoulder on the 3 fired and stuck pieces is actually 0.001" longer than what came out of the Shilen, so more FL sizing is not an option unless I want head separations...
4) I've never needed the Larry Willis die in >5000 rounds of 300WM, 7 RM, and 264WM, and am not about to go that route to solve something that shouldn't need solving...
Anyway, I'm pretty sure the chamber is tighter than it should be back near the belt, based on the scuff marks, though if you have theories beyond what's mentioned above, let me hear em.
I'd really appreciate it if someone(s) with some virgin brass could measure the diameter in front of the belt, so I can predict if just getting some virgin brass will solve the issue. Of course, even if that works, I'm not tickled about losing access to several hundred pieces of brass with a few firings left in them, but $150 worth of brass is better than disassembling the rifle and sending the barrel back to the manufacturer.
I'll be buying Peterson Long or ADG, so data from that would be ideal, but I figure any brand will give me an idea.
Thanks in advance.
