Silverbuck
Beginner
- Jan 13, 2023
- 1
- 0
I just took a once fired brass 308 and nosler 150 gr. Spritzer bullet and checked my overall lengt.It is 2.852.I was just wondering if 2.850 would be a good start.
OAL
- Thread starter Silverbuck
- Start date
300WSM
Handloader
- Dec 24, 2011
- 839
- 470
SAAMI MAX is 2.810
With the information you provided...(not enough)
Are you just starting to work on loads on this?
If you are I would never start by running it against the wall right off the bat.
Two thousandths of an inch is nothing in the grand scheme of things. It's two human hairs.
That's just asking for trouble.
When I'm starting a load I actually start ten thousandths below SAAMI's max OAL.
Too many intangibles to just start at only .002...two thousandths off the rifling.
hunter24605
Handloader
- Apr 30, 2016
- 2,377
- 3,654
Another consideration is when you are measuring off the tip of the bullet, there's too much variation in bullet OAL to be able to consistently measure .002" from base to tip, Some will be shorter, and some will be jammed into the lands. Now, unless you are shooting extreme distances, you'll never notice the difference .002" makes. In fact, the human factor will most likely negate any difference that .002" makes. I'd suggest using an OAL gauge, comparator and modified case to measure off the ogive, that will be much more consistent. I usually start, for cup and core bullets, about .015" off. For bonded and mono's, I usually find accuracy by jumping them .050' to .100" sometimes more. If they are to be hunting rounds, I never load them kissing the lands, it's just asking for a magazine full of powder if you have to eject a live round that's been jammed into the lands. Oh, and welcome aboard, we’re glad to have you.
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What Hunter said. For hunting rounds I like a minimum of .025 jump. That gives enough leeway you shouldn't get in trouble even with variation and grime on the head case, or anything else that can happen with cartridges going in and out of hunting coats and whatever else comes about during a hunting season. I don't like to run things tight on hunting round. Function, function, function when it comes to hunting rounds for me.
As far as using overall length for your measurements, I measure 10-15 bullets out of a box and get a length that is the most common average. I then take a bullet of that length to measure to the lands. I also use a bullet of that length to seat .0xx off the lands when setting my seating die. When I want to try a change of a different measurement off the lands, I use a bullet of that length out of the box. That way I know I changed exactly .0xx from my other load based on my O.A.L compared to before.
Your bullet seater should be seating off the ogive of the bullet, not the tip. So once you check your length to lands with a specific length bullet, and you get your favorite distance off the lands with that same length bullet, the differences in lengths after that doesn't matter ......or very little. A shorter bullet because of the tip that ends up making it a different O.A.L. is the same distance off the lands to the ogive as a longer one.
So when using the total overall length as your guide, the key is to use the same length bullet to check to the lands as you do to set your distance off the lands.
As far as using overall length for your measurements, I measure 10-15 bullets out of a box and get a length that is the most common average. I then take a bullet of that length to measure to the lands. I also use a bullet of that length to seat .0xx off the lands when setting my seating die. When I want to try a change of a different measurement off the lands, I use a bullet of that length out of the box. That way I know I changed exactly .0xx from my other load based on my O.A.L compared to before.
Your bullet seater should be seating off the ogive of the bullet, not the tip. So once you check your length to lands with a specific length bullet, and you get your favorite distance off the lands with that same length bullet, the differences in lengths after that doesn't matter ......or very little. A shorter bullet because of the tip that ends up making it a different O.A.L. is the same distance off the lands to the ogive as a longer one.
So when using the total overall length as your guide, the key is to use the same length bullet to check to the lands as you do to set your distance off the lands.
DrMike
Ballistician
- Nov 8, 2006
- 36,915
- 5,100
You've received some excellent advice. Welcome aboard.
Joec7651
Handloader
- Apr 7, 2019
- 936
- 1,258
Welcome to the forum. Everyone here will treat you right. Great people.
RL338
Handloader
- Mar 23, 2017
- 2,779
- 4,368
What measurement is this? Max mag length or touching lands?
hunter24605
Handloader
- Apr 30, 2016
- 2,377
- 3,654
Ah-ha! pertinent information I didn't think of, good catch !...I guess I just assumed it was to the lands, because 2.852 seemed awfully short for a mag length, our short action mags, Win and Savage, are both right at 3.00. Guess we'll find out when the OP chimes back in.
wvbuckbuster
Handloader
- Nov 5, 2015
- 2,360
- 1,870
Welcome to the forum. The guys have given you good info. Only thing I might add is make sure it fits in your magazine box as you don't want to load up several rounds and have a single shot if your rifle is a repeater. Dan.
