Here it goes so please be gentile.On my way to reloading.My wife is buying a press for my birthday in two weeks so I started buying odds and ends,I picked up a vibrating case cleaner/digital calipers/deburring-chamfer tool/books.Have a question ,I'm going to neck size.After the brass is fired and it starts to stretch,If it's first fired brass and its 2.010(which is because I've been saving all my brass) and max is 2.015 Do you keep using it till it gets to just about 2.015 and trim it back to 2.010 or keep firing it until it stretches out to 2.015 and after it stretches more trim it back to 2.015.Also lets say it started out at 2.010 and it gets to 2.014 and dosent need trimming until 2.015 and you seat the bullet,does it matter if more of the bullet shows because the neck would be longer?I have no time on a reloader ,just some things I cannot figure out in my brain.Thanks for answering my nubie questions if they make any kind of sense.
when to trim case /for my .308
- Thread starter 20Incher
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Re: when to trim case /for my .308
How do you know it doesn't need trimming till 2.015? I assume you are using the given number but as you (since you are neck sizing) it is important to make the brass as close to chamber specs as possible. I suggest reading Tres Mons sticky (which I am linking) because it will answer your questions and teach you how to measure the actual length you need. Hope it helps
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1696162#Post1696162
How do you know it doesn't need trimming till 2.015? I assume you are using the given number but as you (since you are neck sizing) it is important to make the brass as close to chamber specs as possible. I suggest reading Tres Mons sticky (which I am linking) because it will answer your questions and teach you how to measure the actual length you need. Hope it helps
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1696162#Post1696162
Re: when to trim case /for my .308
Sinclairs sells a "Chamber Length Gauge", this is the only way to determine what your rifle trim length is, it is a soft mild steel plug you insert into a modified case, trim length is .010 shorter.
Sinclairs sells a "Chamber Length Gauge", this is the only way to determine what your rifle trim length is, it is a soft mild steel plug you insert into a modified case, trim length is .010 shorter.
Re: when to trim case /for my .308
Trimming (camfering/beveling) brass isn't just about length and keeping things safe: it's also about accuracy. Any sharp edges that might grab or scratch the bullet could cost you in the accuracy department. I re-learned this lesson recently after I started tumbling with the new stainless media: it ever-so-slightly peens the brass mouth. My accuracy went to hell even though the cases looked "pretty good" and did not need trimming length-wise. Once I trimmed the brass: accuracy came right back. So, I trim every firing just to keep the mouths free of burrs or sharp edges. It helps that I have a Giraud trimmer.
Otherwise take good care of your case mouths between trimmings.
Regarding you "when to trim" question, do not wait for it to hit the max length: better to keep it closer to the trim length for safety and accuracy reasons. You don't want to risk having the barrel crimp your case mouth under any cirumstances.
Trimming (camfering/beveling) brass isn't just about length and keeping things safe: it's also about accuracy. Any sharp edges that might grab or scratch the bullet could cost you in the accuracy department. I re-learned this lesson recently after I started tumbling with the new stainless media: it ever-so-slightly peens the brass mouth. My accuracy went to hell even though the cases looked "pretty good" and did not need trimming length-wise. Once I trimmed the brass: accuracy came right back. So, I trim every firing just to keep the mouths free of burrs or sharp edges. It helps that I have a Giraud trimmer.
Regarding you "when to trim" question, do not wait for it to hit the max length: better to keep it closer to the trim length for safety and accuracy reasons. You don't want to risk having the barrel crimp your case mouth under any cirumstances.
Re: when to trim case /for my .308
I am using the given number ,Thanks guys ,I have alot more reading.
I am using the given number ,Thanks guys ,I have alot more reading.
Re: when to trim case /for my .308
Trim when the hit 2.015" or buy one of the sinclairs chamber length tools... sacrifice a case and insert the tool and chamber, remove and measure. Thats the length for that rifles max length.
Up to you, but trimming back to 2.005 wont hurt.
Trim when the hit 2.015" or buy one of the sinclairs chamber length tools... sacrifice a case and insert the tool and chamber, remove and measure. Thats the length for that rifles max length.
Up to you, but trimming back to 2.005 wont hurt.
Re: when to trim case /for my .308
The chamber has a length from the breech face to the end of the chamber neck.
That length MINUS the distance the firing pin pushes the case forward is how long brass may be used.
If long brass does a crimp job on the bullet when chambered, a deformed bullet and pressure spike may result. Lots of pressure.
The firing pin pushes the case forward the difference between the head space to should in chamber and the distance from case head to case shoulder [ determined by how far the shoulder was pushed back with the sizing die].
This means that if you are reloading the same ammo for a number of rifles of the cartridge, the max case length may not be driven by the rifle with the shortest cartridge space.
Or you can just over trim per load book instructions.
The chamber has a length from the breech face to the end of the chamber neck.
That length MINUS the distance the firing pin pushes the case forward is how long brass may be used.
If long brass does a crimp job on the bullet when chambered, a deformed bullet and pressure spike may result. Lots of pressure.
The firing pin pushes the case forward the difference between the head space to should in chamber and the distance from case head to case shoulder [ determined by how far the shoulder was pushed back with the sizing die].
This means that if you are reloading the same ammo for a number of rifles of the cartridge, the max case length may not be driven by the rifle with the shortest cartridge space.
Or you can just over trim per load book instructions.
