Case length, major factor?

WhelanLad

WhelanLad

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Howdy lads,
Newbie to the reloading game with a question.

Does the lenght of the case have THAT MUCH to do with accuracy?

I load only for hunting, so im not all that worried about puttin every shot right next to the other on paper, just consistantly around the place im aiming.

An i have measured alot of my cases, some are R-P 270 necked up, some federal 30-06 Necked up and Once fired RP 35w fired in my rifle, There is some variable readings on my didigtal measure stick.

So i thought il ask the Question to people who may know more than I.

Is Case length a major factor?.
Is OAL length a major factor?

Variables are say 2.475-2.485 of all cases.
Same cases around .005

once I get to Max case length, how far back should i Trim?

Thanks for your time in answering.

W.L
 
Hi. You want your cases to be all the same length so the OAL will end up the same when you seat the bullet. OAL can affect accuracy, but it's more about being consistent, even you hunting ammo.
"...how far back should I Trim..." To the trim-to length given in your manual. Max case length is 2.540". Trim-to is 2.530". Max OAL is 3.340".
 
sunray said:
Hi. You want your cases to be all the same length so the OAL will end up the same when you seat the bullet. OAL can affect accuracy, but it's more about being consistent, even you hunting ammo.
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Case length has nothing to do with where the bullet is seated, the seating die seats the bullet relative to the bottom of the case, not the top of the neck. Case length will affect the crimp if you are crimping, but not the OAL.

Mark
 
mmattockx said:
Case length has nothing to do with where the bullet is seated, the seating die seats the bullet relative to the bottom of the case, not the top of the neck. Case length will affect the crimp if you are crimping, but not the OAL.

Mark
Click to expand...

Have to agree with Mark here. A couple of times I've noticed reloads that seemed to have the bullet deeper in the case than other rounds as the cannelure was less visible, closer inspection, and measuring, confirmed the COL was the same, just some brass had longer necks. Your press seats bullets to the same COL, which has nothing to do with a short or long neck.

Really, EVERTHING affects accuracy. But for hunting puposes, as long as your necks aren't so long they keep your bolt from closing properly, it won't mean much at all.
 
Really said:
Yep, for my f-class 308 I uniform case length.

For my hunting loads, as long as they function.

I guess it would depend somewhat on the hunting style. Say if you're trying to brain something at 1000 yards you'll probably want to take all factors out of consideration. But hitting a pie plate within a couple hundred yards, I wouldn't sweat it myself.
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For safety reasons, case length needs to be less than "max length".

Provided that it is less than that, there is little to no accuracy difference in having wildly varying case lengths.

Note that .270 Win is a fair bit longer than .30-06. Not sure what max length is for .35 Whelen (I assume you are loading for that?) but do make sure you are less than max length for your cartridge, after you've necked up.

Once you hit max case length, trim it back. You can go to "trim-to", which is pretty nominal and is usually .010" shorter. Provided you have enough bullet engagement in your neck there's nothing wrong at all with trimming them .015" or .020" shorter than max.
 
I reloaded for many years without any type of caliper to measure cases. My case length guide was a new, either case, or factory loaded round of the calibre I was loading for. I simply laid the case I was loading along side the new one. When the case appeared longer than the new one, I cut it back.
Also, it has been mentioned about the different length of the 270 as compared to the 30-06. I would size 30-06 down for 270 brass. They would be about 100/1000 of an inch short. We just shot them and eventually the 270 case grew to what the book said it was supposed to be. If there was any difference in accuracy, I couldn't detect it, with a very accurate 270 with good scope.
 
If brass is too long, it resists opening up to release the bullet from the neck and this causes very high pressure.

if you have mixed brass, trim it all to min length and you should be good to go for a long time.
 
Thanks heaps guys,
I only ever use one sort of shells at a time per loads, if that makes sense.

yeah well im convinced there will be no major accuracy issues with case length for my hunting -150m.

max case length for the 35W is 2.494 an OAL is 3.340, im well below them so should be right.

Thanks again, i feel kinda stupid asking some questions but i know some of you guys are very serious about reloading so i dont hesitate.
 
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