300 WinMag - Nosler Ballistics Load 180gr

[astroman86]

Going to start reloading for my .300 WinMag (Winchester Model 70, 26"bbl), and already purchased some supplies based on the Nosler Ballistics Room:

http://www.nosler.com/index.php?p=15&b=30cal&s=349

The IMR4350 at 70gr really looks nice, and nice enough at 66gr too, so went with 2lbs of that. (also have that nice Nosler brass!)

But, I bought both the ballistic hunting tip and the e-tip (someone recommended it), but when I got home I noticed the e-tip is significantly longer than the ballistic tip.

So, two questions:

1: How does this affect seating - does the longer bullet seat deeper? Won't this affect pressure and such?

2: Will the greater surface area contact from the e-tip bullet against the barrel also affect pressure?

I wouldn't expect much difference in accuracy between the e-tip and regular. Or should I?

Lastly, 180gr at 3130fps with 70gr IMR4350 seems really fast...is it safe, or should I just stay at 66 or 68?

Little new to this (well, getting back into it after a 15 year hiatus - school, university, etc), so appreciate the help and wisdom!

Cheers.

 

[chet]

#1 yes and yes
#2 yes
difference in accuracy? most likely
fast? yes
safe? possibly.... start with 66 and work up.

I use 71 grains of IMR4350 and 180 grain partitions and only achieve 2950fps...... it's my experience that the Nosler manual embellishes velocity....

both bullets should shoot well and both will likely have a different point of impact.

Good luck, be safe, and keep us posted.

 

[DrMike]

astroman86,

Welcome aboard. Hope to see you contributing in coming days. Seating may be determined by the location of the ogive (the point that the bullet reaches bore diameter). Some bullets are longer, but the ogive is farther back than on other bullets. Generally speaking, you will want a seating depth at least equal to the bullet diameter. Having said that, for many rifles, overall length is determined by the magazine depth, so the issue becomes somewhat moot as you load to the magazine. This is not a big deal, only introducing a different parameter for accuracy.

The more surface in contact with the bore, the greater the potential for pressure to build. Accordingly, the Etip potentially will generate greater pressure if everything else is held constant because there is more resistance as it passes down the barrel.

You should question velocities as they are reported, especially if you don't know the source of the reported velocity. However, Nosler is careful to test their posted data to meet SAAMI standards. The loads are pressure tested. This would hold true for most (if not all) major bullet manufacturers and major powder manufacturers. They have a vested interest in safe loading data.

 

[JD338]

astroman86

Welcome to the forum. Glad you have decided to get back into reloading.
I would recommend you start low and work up to the Max loads.

Every rifle is different so you really can't predict what the velocity will be. Load for accuracy and let the velocity be as is.

I have used the following load in 3 different rifles and there are several others here that have also used this load and accuracy for all is well under MOA.

300 Win Mag
180 gr PT/BT/AB
75.0 grs RL 22
W-W case
Federal GM215M primer

This is a MAX load so start low and work up.

JD338

 

[astroman86]

Thanks for the replies guys.

@chet - well, even at 2950fps, I should still see better ballistics than with the Remington cheapie loads.

@DrMike - thanks for the vote of confidence on the Nosler load. I'll give it a shot.

@JD338 - good point, I'll try a few different grain loads and see what gives the nicest group.


I know I should just a read a book, but, what signs do you watch for for over-pressure problems?

 

[JD338]

I know I should just a read a book, but, what signs do you watch for for over-pressure problems?

astroman86

It is highly recommended you pick up 2-3 different loading manuals and read up on loading procedures and over pressure signs. Having several reloading guides will allow you to cross reference load data.

Over pressure signs include
sticky bolt lift
sticky extraction
flattened primers
shiny spots on brass head
excessive velocity on your chronograph

Good idea to read up on this topic.

JD338

 

[chet]

it is my experience that with the 300WM the sticky bolt is the first sign to arrive....
but please watch for ALL signs of pressure

 

[SJB358]

I second JD338. RL22 is excellent in the 300 Win Mag. I shoot 200gr Sierra Gamekings, but the 180gr BT will be excellent also. Haven't heard too much about the 180gr Etip in the 300 Win Mag, but I could only imagine it is excellent and will be a great big game bullet. Scotty