Go Back   The Hunter's Life > GUNS & AMMO > RELOADING
 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next

Re: .338 MAI and .338x284 Win
  #12  
Old 04-07-2021, 01:27 PM
gitano's Avatar
gitano gitano is offline
Administrator
 
Join Date: Oct 2004
Location: Wasilla, Alaska
Age: 69
Posts: 19,543
gitano is on a distinguished road
Default Re: .338 MAI and .338x284 Win

As I am wont to do when I have to wait for something to show up at my door, I occupy the time fiddling with numbers. Some of you may recall that I have distilled the criteria for my "ideal" hunting rifle/cartridge combination down to two simple values:
1) In calibers greater than .264, deliver at least 2000 ft-lb of energy to 300 yd. In calibers smaller than .284 and greater than .22, deliver at least 1500 ft-lb to 300 yd. And,
2) Not exceed approximately 4000 ft-lb of energy at the muzzle, and preferably, not greater than 3500. (This is essentially a 'felt recoil' criterion.)

Unfortunately, those criteria in combination put me back in the "BC matters" arena. The reason that it is unfortunate is because as soon as you start buying bullets based on their BC, you put yourself at the mercy of the integrity of the manufacturer and their marketers. Ptooey. While it is true, in my experience, that today's manufacturers are LESS inclined to tell bald-faced lies about their bullets' BCs than they used to be, some of them still DO. It is therefore up to ME to determine if they are lying or not. I shouldn't HAVE to do that, but sadly, that is the nature of the world today. The GOOD news is that there are bullets 'out there' with TRULY excellent BCs, AND excellent terminal performance as hunting bullets.

As a rule, I am loathe to speak highly if ANY bullet, but personal experience simply leaves me no choice but to choose Nosler's Accubonds for their high BCs (that I have actually verified), as well as their very impressive terminal performance on big game, that again, I have first-hand experience with. Sadly, true to all of Nosler's products, they are priced at the maximum "the market will bear".

SO...

I have been fiddling with delivering the most energy to the greatest range with the 28-inch barreled .338x284 Win on the Ruger No.1. Since there is a 250-grain .338 Accubond, I decided to compare its external and terminal ballistics with the 225-grainer that I use in my .338 MAI.

In the Ruger No.1 rifle/cartridge combo, I can reasonably use a max pressure in the neighborhood of 56000 PSI, and drive that 250-grain bullet to a MV that will deliver 2000 ft-lb to 510 yd. The impact velocity is 'only' 1900 ft/sec at that range, (I'd prefer 2000 or more), but 1900 is well above Nosler's minimum velocity spec for 'as-designed' terminal performance in the Accubond. The muzzle energy is 3828 ft-lb.

By comparison, the 225-grain bullet delivers 2000 ft-lb to 515 yd, but the impact velocity is 2000 ft/sec. Interestingly - to me at least - the muzzle energy at 3891 ft-lb, is only very slightly more than the 250's.

HOWEVER...
I don't shoot big game at those "2000 ft-lb" ranges. So, droping back to a range I would shoot a big game animal at - say 325 yd - the comparison is:

2585 ft-lb impact energy and 2275 f/s impact velocity for the 225, and,
2562 ft-lb impact energy and 2148 f/s impact velocity for the 250.
23 ft-lb difference . . . . . . . . . . 27 f/s difference.


To my eye, they are essentially identical. No need to go looking for any 250-grain Accubonds. HOWEVER, as it turns out, it is much easier to find the 250s IN STOCK, than the 225s. Which are out of stock EVERYWHERE. I have time to mull this over. I wonder if the heavier bullets might shoot straighter? Oh, I have not calculated Optimal Barrel Timing nodes for the two bullet weights. That MIGHT make a difference, but I kinda doubt it.


Paul
__________________
Then you will know the truth, and the truth will set you free. John 8:32

"We make men without chests and expect of them virtue and enterprise. We laugh at honor and are shocked to find traitors in our midst. We castrate and bid the geldings be fruitful." ~ C.S. Lewis.

Do not confuse technical skill for wisdom and do not confuse strength for skill. Paul Skvorc

Last edited by gitano; 04-07-2021 at 02:20 PM..
Reply With Quote
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT -5. The time now is 03:18 PM.


vBulletin skin developed by: eXtremepixels
Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.