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Neck sizing 308
notnow
Member Posts: 1,852 ✭✭✭
I'm going to load up some 308. Neck sizing. While i've done this before and somewhat often, here's my question. Do I necessarily need to check the case length and trim it if it's needed. Common sense tells me no.
Comments
I believe you've answered your own question right there.
One of the advantages you get when neck sizing is that cases don't elongate as much as they do when you size the body of the case. But they still do get longer and will need trimming when past the max length.
Why not?
And a too long case jamming into the throat will raise pressure, perhaps to a dangerous level!
Brass from a bolt does not expand or lengthen as much and therefore my bolt brass does not get trimmed as much.
That said, I always check the length anyway after sizing.
"and trim it if it's needed"
I believe you've answered your own question right there.
One of the advantages you get when neck sizing is that cases don't elongate as much as they do when you size the body of the case. But they still do get longer and will need trimming when past the max length.
Right about answering his own question: NEEDED trimming
I believe you've answered your own question right there.
I sometimes trim rifle cases about 5 thousands less than min, especially if they are new or first or 2nd fired brass, because the brass is usually going to stretch close to max if you are shooting or testing a hotter reload and some new brass will stretch to max on first firing and I've seen new Winchester, Remington, Federal brass that needed immediate trimming before first loading. Don't assume that new brass don't need trimming, but I don't count this new brass trimming as a REQUIRED trimming due to it being fired in a gun. Main thing is I keep a log of the required NEEDED trimmings and when it gets to three NEEDED trimmings (note I said trimmings and it may have been reloaded several times before it gets to the third trimming by neck sizing) the brass is placed in a zip loc bag after the 3rd NEEDED trimming and labeled as for reduced loads only and labeled as to how many times it's been reloaded. II know it's been trimmed 3 times already because it's in the reduced load sack. I've reloaded some 30:06 cases as many as 20 times by neck sizing and shooting mild accurate loads and only trimmed 1 or 2 times.
I have several very accurate at 100 yards reduced loads, low velocity, low recoil loads (30:30 velocities) for several caliber guns, including belted magnums calibers that I reload using the LABELED reduce load brass with no brass issues. Women and grandkids that are sensitive to recoil can hunt or practice with these low recoil normally hard kicking scoped rifles.
I've found from experience that after rifle brass has NEEDED trimming 3 times it's usually close to starting neck cracking or web head separation if shooting regular reloads. I don't bother trying to use a sharp object and feel inside at the web for thinning, it's as waste of time if it's been reloaded 3 times. I do watch all brass for the telltale light colored ring that indicates the web is about to separate. I also do not buy used brass or brass that is labeled once fired from a store. You do not really know that it's once fired, may have already been reloaded several times and you are asking for troubles. Buy new brass and keep a good running log from the start and it will save you lots of time a pain.
Keeping a good log of your reloaded brass will give you a heads up as to it's needed attention, rejection, etc.
I have an Odd answer, I have a few .308's that have dedicated brass to each rifle & chamber 1 of them is finicky about length, Why? I have no clue. It's a standard chamber, But it seems it likes just short of Min. It will still fire after a third loading, but the groups go to crap.
Reloading using matched weight brass:
I've got some very accurate hunting rifles, glass bedded and whole works and couple are real fineky about the weight of the brass for good groups. About 6 grains difference in the weight of the brass will shift group to different point of impact 2 inchs or more at 100 yards.
In other words I can take the fineky gun and shoot 1/4 to 1/2 inch group at 100 yards if I keep the brass weight matched within 2 grains, but if I mix up the heavier and lighter weight brass with same powder load the guns will go to 2 inch or more groups. I therefore make sure that the reloads for these two guns are using matched weight brass for excellent groups.
You might try weighing your brass and testing with your fineky gun.
It might be a female gun, kinda touchy and set in it's ways!