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View Full Version : Seating depth overall length of 243 70gr NBT HELP


chironomidkraut
06-03-2017, 12:24 PM
I'm reloading a 70gr NBT in 243 with 39-40gr of varget and I have 2 seating measurements depths, 1 according to hodgson is a overall length of 2.625 and my nosler reloading book says 2.680"
I split it and made them 2.662" am I still good or should I go with one or the other
Thanks guys

purgatory.sv
06-03-2017, 12:32 PM
I do not have the answer,but a link to nosler on line.
https://load-data.nosler.com/load-data/243-winchester/

chironomidkraut
06-03-2017, 01:08 PM
Thank u but the info on the page are exactly from the reloading manual which I already have

waterhaulerhunter
06-03-2017, 01:37 PM
Find the proper OAL for that bullet in your gun. Google just that and there and tons of methods. I've never once used a reloading manual OAL.

Dick284
06-03-2017, 01:53 PM
Do they fit in your mag?
Then how far off the rifling are you?

10 thousandths of an inch off the rifling is a good start point.

Don't get all hung up on the numbers from the books, as they are just what they used. Seating depth isn't like charge weights, btw.

Deer Hunter
06-03-2017, 01:56 PM
That's a pretty short bullet for a 243. I would seat it so the start of the boat tail is right at the base of the neck. Or thereabouts. And not worry so much as to where you are in relation to the lands.

chironomidkraut
06-03-2017, 02:02 PM
The reason why I chose the overall length is because factory federal premium 70gr nbt are right at 2.662" and they shot really nice groups outa my savage

Deer Hunter
06-03-2017, 02:34 PM
Good plan. Same bullet, try same oal.

BigJon
06-03-2017, 04:47 PM
Load them up and try it out. Unless shooting a veeeeery short throat that bullet is too stumpy to seat to the lands and still have a reasonable amount of bullet in the case. At any rate, that bullet tends to do well when driven hard and jumping long.

gitrdun
06-03-2017, 05:04 PM
I like to have my bullets seated at least fully engaged in 2/3 of the neck length (not counting the boat tail section of course). If doing so and I have a lot of free bore (as I do with my Howa 1500) I tend to disregard the larger bullet jump to lands and hope for the best. However, when this occurs, I ensure that my bullet concentricity is less than 0.002". I claim this because I think that consistent neck tension trumps bullet jump. Case in point, I've had bullets jump a whole 0.125" to lands and still achieved stellar accuracy. Achieving consistent neck tension isn't that hard to accomplish. Jump to lands is something that you don't always have control over.

Digger1
06-03-2017, 05:12 PM
Find the proper OAL for that bullet in your gun. Google just that and there and tons of methods. I've never once used a reloading manual OAL.
This! .020" off the lands usually works for me, after trying anything up to .045".

gitrdun
06-03-2017, 06:03 PM
I seat my 70gr Sierra Match Kings at 2.603" in order to provide me with ample neck tension. My firearm does have ample free bore. I use 39.5 gr of IMR4320. Now, be advised that I don't use COAL to measure consistent measurements. I use a comparator to measure from the ogive. Different bullet, different gun. You'll have to experiment with what works best in your combination.

Coyotebutcher
06-05-2017, 05:41 PM
I see it far too often to not say something at least once. It is HODGDON not hodgson. Carry on....