So I've got 100 once fired factory loaded hunting brass from my M305. The primers seem very tight, (broke my decapper). I also have a new to me digital caliper. Going off the max case length in Hornady's 8th reloading manual only 6 out of 20 are under 2.015". Many of the over length are 2.022"-2.027". I know I've read some of the answers before, but a search of M305 didn't turn up what I'm looking for. Perhaps an M305 reloading guru can answer everything at once. I'll check the stickies too. Thanks.
M305 once fired brass dimensions?
- Thread starter emerson
- Start date
After first firing I only neck size (Lee collet neck sizer) and rarely need to trim at all after that. After firing over 200 handloads that where only neck sized I have had zero jams as a result.
I did test a batch of 20 cases only neck sized and none of them jammed so I did 50 more that fed and ejected flawlessly. Since then I have only ever neck sized brass fired in my M305. Past 200 now with no feeding jams as a result (though I have had one or two stovepipes but those where probably caused by deflecting off my scope mount.)
When firing factory ammo I find I often need to trim quite a bit off. Sometimes with Winchester ammo I would have to remove upwards of 0.8mm (0.03") from the cases after first firing. After neck sizing and second firing only 1 in 25-30 needs any trimming at all and generally only about 0.05mm (0.002").
My load is:
Remington 150gr MC (FMJ) BT
45 grains of H4895
CCI large rifle primers
My M305 seems to prefer hotter loads. I know some who load with only 40-42 grains of H4895.
I've only run into tight primers in military brass. I have broken a decapping pin in .308 brass but it's because I was using the wrong shell holder so it didn't line up properly.
I did test a batch of 20 cases only neck sized and none of them jammed so I did 50 more that fed and ejected flawlessly. Since then I have only ever neck sized brass fired in my M305. Past 200 now with no feeding jams as a result (though I have had one or two stovepipes but those where probably caused by deflecting off my scope mount.)
When firing factory ammo I find I often need to trim quite a bit off. Sometimes with Winchester ammo I would have to remove upwards of 0.8mm (0.03") from the cases after first firing. After neck sizing and second firing only 1 in 25-30 needs any trimming at all and generally only about 0.05mm (0.002").
My load is:
Remington 150gr MC (FMJ) BT
45 grains of H4895
CCI large rifle primers
My M305 seems to prefer hotter loads. I know some who load with only 40-42 grains of H4895.
I've only run into tight primers in military brass. I have broken a decapping pin in .308 brass but it's because I was using the wrong shell holder so it didn't line up properly.
I always full length size my 308 for M14 loads. Sometimes factory brass is already at max length when new and for whatever reason flows/stretchs even more on the first firing and sizing. I'd FL size and trim them all then shoot again and check length on the next firing. Next time they won't likely need a trim for a firing or three.
As mentioned above some people have great results neck sizing for theirs. Just make sure as with any M14/M1 loads that your bolt is completely locked up before firing.
Not sure why they were hard to decap, but I would buy a Lee $8 Universal Decapper as well as fixing your die so you can knock the primers out of any shell if a pin breaks again. Ammo made on military loading lines can be crimped and harder to decap.
As mentioned above some people have great results neck sizing for theirs. Just make sure as with any M14/M1 loads that your bolt is completely locked up before firing.
Not sure why they were hard to decap, but I would buy a Lee $8 Universal Decapper as well as fixing your die so you can knock the primers out of any shell if a pin breaks again. Ammo made on military loading lines can be crimped and harder to decap.
Cameron SS
CGN Ultra frequent flyer
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I have had a few friends report that their NORC M305 had out of spec chambers that had excess headspace. If you are measuring case length and trimming before full length sizing, that could be a part of the problem.
I have frequently found winchester factory brass .02" too long after a first firing, but have never had anywhere near that much stretch afterwards.
Neck sizing is a good idea to cut down on overworking your brass.
I have frequently found winchester factory brass .02" too long after a first firing, but have never had anywhere near that much stretch afterwards.
Neck sizing is a good idea to cut down on overworking your brass.
