A few days ago I did post about this very same subject on this 300 norma thread...
http://www.snipershide.com/shooting...252699-300-norma-vs-300-hulk.html#post3136462
Interesting that some folks who want to upgrade the WM are realizing the potential of some casings in std. bolt faces.
I am a huge fun of the 308 bore. I have been shooting the 308W and winmag for many years and I cannot get enough of it.
I tried larger and small bores and like them too for several purposes but for a do it all, do it pretty well always come back to the
308 and that includes also shooting within a reasonable budget.
I know what you are thinking, if you are shooting the winmag what else could possibly be needed but let me tell you ocassionally
you will reach for the heaviest bullets your case can launch at decent speeds and wheter is for an moose hunt using a long shot
or just to see if you can hit some target very far away you want grain.
Of course is not just the grain alone but some decent ballistics that can take that grain to some distance and still retain the velocity
to do whatever needs to be done. In case of game you want to stay withing the minimum recommended by the manufacturer and
if you can maybe look for a softer bullet depending on the game and weight.
The win-mag might be overkill for many situations but at the other hand if one gets comfortable with it one might find surprising how
versatile it can be. With all that said the winmag suffers from a little problem that might not be well known but that it definitely can impact
its performance.
Before you jump into the RUM and 300-378 or any other crazy alternative please hear me out. Those are clearly overbored, also suffer
from case design problems and or they require very expensive equipment that is hard to justify.
The winmag might not be perfect but it is super popular and unlike conventional thinking it can be very accurate for a belted magnum just
like the 7rem mag and several others.
The issue is that if I take the best bullets that the 308 department has to offer then the winmag falls a tad short literally. Not by much but the long
case with short neck and the imposed max COAL by the longest magazines makes one wonders if there is an easy popular upgrade
without going with exotic options and w/o overboring.
These are the options I have been considering for re-barreling a heavy rifle.
Initially I though about the popular WSM reamed to work in a long action using one of the extra free bore match reamers. It makes sort of a 6mm
norma BR in 308 version and on steroids. I looked at the data and ran the nrs. in quick load and found no benefit in spreads and reach. I needed more powder.
The next I looked at what is a very popular wildcat that is the 300/375.
Here is the 1st from the left. This is nothing more than a ruger 375 case necked down to 30 caliber.
pic courtesy form nz.hunting friends and forum.
This follows the right directives and I would not be surprised for this to become a successfully commercial version but
I don't want to deal with wildcats for this and also I don't think the 375 ruger takes maximum advantage.
You see, here is the catch...
Ruger and Hornady made a very wise move offering a sensible yet powerful rimless straight case option that works
on popular actions like rem 700, savage 10/11 and mauser actions among others w/o requiring extended actions,
and custom and expensive cuts for the action. Also uses a rim size of .534 that is the popular bolt face for many magnums
belted and straight. But since the appearance of the WSM and RUM line among others one wonders why not to go
with a slightly rebated rim and wider base/case that will further add to the capacity like the case with all the derivates
from the 404 Jeffry and beyond.
So one starts thinking like what about a cartrige that is a tad shorter than the winchester magnum with a more reasonable
neck, with the full .550 diameter at the base vs. the .534 of the 375 ruger but yet it provides a rebated rim of .534?
Many have gone the route of pushing back a RUM for the purpose of using the best and longest bullets and w/o running
over the ogive. One might also think why not use a 300 norma magnum or 338 lapua magnum and neck this down but
then again those use special bolts, are very expensive and will end up super overbored. Plus those work great for what
they do that is in the 338 department.
So going back to the RUM one would think why not to push those back and get some more efficient case that will also allow
the use of the best bullets? Well, the answer is that this was already done in the year 2010 in response to the 375 saturday
night fever and success. They called the shorter RUM the RAM line for (Remington American magnum).
.300 Remington American Magnum - Wikipedia, the free encyclopedia
But then if you really look at the design closely one arrives to the conclusion that an improved case of these characteristics
is nothing more than the nice yet exclusive 300 Dakota. I actually took some of the cases I have from collection and from shooting
with other people and compared to the advertised RAM and gave me something very similar in practical terms.
300 RAM (Shortened and improved 300 RUM)
Parent case .404 Jeffery
Case type Rimless, bottleneck
Bullet diameter .308 in (7.8 mm)
Neck diameter .344 in (8.7 mm)
Shoulder diameter .525 in (13.3 mm)
Base diameter .550 in (14.0 mm)
Rim diameter .535 in (13.6 mm)
Rim thickness .050 in (1.3 mm)
Case length 2.580 in (65.5 mm)
Overall length 3.340 in (84.8 mm)
Case capacity 105 gr H2O (6.8 cm3)
Rifling twist 1-10"
Primer type Large rifle magnum
Maximum pressure 65,000 psi (450 MPa)
And this is the 300 Dakota...
300 Dakota next to a "skinny" 30.06.
But if you noticed the Dakota cases have actually a tad larger rim. Don't ask me why but they require a special bolt and custom actions
from Dakota rifles or you have to machine one. Or you can actually chamber the rifle to work with the standard magnum rim and then forget
about the Dakota ammunition that it is not that affordable nor exactly the objective.
So after much research on the subject I am left with the dilemma. I don't find a cartrige that is 100% what I want. This happens to many people
and probably the reason they end up reaming a variant or wildcat for their F-class competitions, long range hunting or whatever they do with them.
Also the 300 winmag performs so well in a wide range of applications that one feels it can do anything. But when exposed to the best bullets
then the obvious issues show up. At least berger bullets have created a tactical 308 bullet in 230gr that is not as nice as their top 230gr
hybrid but it works well in the longest magnums that otherwise will run out past max COAL before a bullet can be properly seated.
Also I got some of these hoochie mommas below to try and for this a specialized caliber with plenty free-bore is the ticket. However I need
to step down to 1:8 twist that was already in the plans anyway. That is the price you pay for shooting some of the solids / CNC cut that are much longer
than the lead filled counter parts.
Type: Solid copper hybrid profile.
Grains: 197
Ballistic Coefficient G1 of 0.827
So I have not decided yet. This is a long process for me that might take months and probably try some other rifles.
The RAM variant is looking good. I wish winchester had a long WSM that is better and harder brass though.