Question on seating depth and bullet weight/length

[Tonmarchelli]

Getting ready to load my first rounds for the first time. but i have a few questions on seating depth vs the length of the bullet and how far it will seat to give my .010-.020 jump to the lands.

I'm loading a 300WM Remington 700 Sendero II. Using a hornady OAL gauge and giving myself a .010 jump to the lands it doesn't seem like the bullet seats very far at all into the case. I don't have an exact measurement at the moment but see the picture below for a reference. I bought hornady BHTP 168gr match bullets. Should i have bought heavier/longer bullets for this particular rifle or am I OK with what I have?

Side note. using my reloading manual, and IMR4831 im measuring 68.6 gr which leaves airspace in the case when the bullet is seated. enough that I can shake the bullet lightly and hear the powder shake around in the case. Concern?

thanks so much for the help

 

[sako.308]

Re: Question on seating depth and bullet weight/length

"looks" about same seating depth i have on my rifle with .308 smk 155-168. my throat on my 700 is 2.989 iirc using the same OAL gague.

i did find that lapua bullets are "longer" but i have not fig how much is acually "in" the neck.

 

[targaflorio]

Re: Question on seating depth and bullet weight/length

168 is a smallish bullet for a 300 win mag. I'm loading up to 230 grs. Maybe you are varminting? You shouldn't have any trouble with the bullets staying seated, if that is what you are asking.
By seating your bullets long, you have room for more powder. Which can get you more velocity.
Your manual is giving you charge weights based on sammi spec oals, so you have to be careful. I have read that running this cartridge below mins can be dangerous.
What is your oal vs book oal?

 

[littlecalm]

Re: Question on seating depth and bullet weight/length

In my TRG22, I am way above published OALs with 175 SMK, 155 Scenars and berger 175 OTMs. And this is with a .02 ogive jump. Same is true for my 208 AMAX's in my Savage 110 BA 300 WM.

 

[Tonmarchelli]

Re: Question on seating depth and bullet weight/length

thanks for the comments. I decided to get a little bigger bullet so went and got a box of hornady interbond 180gr bullets. they are a little longer than the 168s. re measured the round and got the same Ogive as the 168gr. but the bullet is seated deeper in the case and i can use a little more powder to push the slightly heavier bullet and take up that free space in the loaded case. Right?

book OAL is 3.340, Im getting 3.505. round feeds fine and fits in the magazine fine too.

now i need to start with a powder measure ladder test. what is a good starting point for my lowest measure? book seems to show about 71gr for a medium velocity.

any good links to a good ladder test writeup?


thanks again