Can you load a .300 Win Mag light like a .308?

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Astute Observer

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Hey all

I own a .308 and a .300 Win Mag. I was reloading for both (178gr Hornady BTHP for the .308, and 208gr Hornady AMAX for the .300 WM) and I had a thought. Would it be possible to load the .300 Win Mag with a load that would replicate a .308 ballistics? Essentially use the .300 Win Mag to push a lighter bullet at moderate speed using less powder?

My rationale is that I currently only have convenient access to a 200m range, and while I'd like to push the .300WM to the limits, I don't need the velocity or super high BC for the time being. Would a light, easy load with .308 levels of power be feasable? Or would there not be enough pressure in the chamber?

Would such a load offer less barrel wear and increase brass lifespan?

I could just shoot the .308 yes, but I really prefer my .300 Win Mag as a rifle in terms of ergonomics, comfort, and (I'll be brutally honest here) it's aesthetics. But my .300 Win Mag is just not getting to stretch its legs right now.

Thanks for any advice you all can offer.
 
Yes but you should use a bulky powder to take up space in the case.

Most magnum rifles produce their best accuracy when they are pushing maximum pressures.
 
You can do it using 4895 powder, probably other powders as well. But you'll use about 35% more powder in the 300 than you will in the 308 to get the same velocity, and you might find it's not as accurate as the 308.
 
Thanks for the responses both, it's appreciated. Sounds like it's possible, so I'll give it a shot - But only a small batch, if the accuracy stinks I'll abandon the idea. I'll definitely take the advice to go with a bulkier powder. Would H1000 work? It's pretty chunky. The Win Mag has a 27" barrel, so it ain't a shorty by any means, and slow burning powders are no problem for it.

Again, thanks!
 
i've just started working up a load for the wife to hunt out of her 300 wsm, using 150 grain bullets and h4831sc. They're pushing about 2800fps. So far it seems good enough to hunt with, but I still have some testing to do before I'll be comfortable with it. It's probably not the best powder to use, but I was trying to find a temp stable powder that I could run in several different rifles.
 
Astute Observer said:
Thanks for the responses both, it's appreciated. Sounds like it's possible, so I'll give it a shot - But only a small batch, if the accuracy stinks I'll abandon the idea. I'll definitely take the advice to go with a bulkier powder. Would H1000 work? It's pretty chunky. The Win Mag has a 27" barrel, so it ain't a shorty by any means, and slow burning powders are no problem for it.

Again, thanks!
Click to expand...

H1000 probably won't work very well, you need a faster powder.
 
I've loaded my 300 Win. Mag. down to 308 speeds with lighter bullets. Re15 worked well for me and required less than 60grs. I used the data in Speer Reloading Manual No.12 as a guide.

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35380306672_cf7f4d3693.jpg
 
Yes, easy to down load the 300Win Mag down to a 308 velocity.

Just use the Start load in your manual for your usual powder. That will give you 308 max velocity.

H4350 55.6
IMR4350 56.5
IMR4831 58.0
A3100 59.7
RL-22 59.2
H4831SC 60.1

All these yield about 2400 fps with the AMAX 208
 
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For a number of years, I loaded both the 300 Win Mag and the 308 Norma Mag with the same reduced load, as follows.
CCI 200 Primer, 180 grain bullet [your choice of cup and core bullet] 50 grains of IMR 3031.
In several rifles, this produced around 2600 fps velocity, and most shot very well with it. One 308 Norma was consistently sub moa.
IMR or H 4895 will yield similar results. Dave.
 
According to hodgdon's website, you can load a 300WM with 18-25.5grn of trail boss, for a velocity of 1300-1687 ft/s. Using a 150grn bullet. This will probably feel less than an average 30-30.

My goal was to do the same thing you are doing, but with a 300wsm (eg load a 300wsm to 308 performance), and use cheap campros. This would make inexpensive reloads with very little recoil for new shooters. The shorter case should help me a bit compared to 300WM, but the principle is the same. My plan is to use the 60% formula for H4895 when I can grab some. I have IMR 4895 but I don't think it'll perform as well as H4895 in reduced loads.
 
I'm using high 50's of 8208 powder behind a 150 gr bullet that is very comfortable to shoot and took a bear. moose and deer all over 200+ yards . Accurate and deadly
 
You do realize you're in the Reloading section right? So advising the OP to go buy another gun when what he has can be downloaded seems a little foolish at best. Harold
 
I developed two light (.308 ) loads for my .300 wm. (1 ) 70 g IMR 4350 CCI mag Primer 150 gr sierria nice load for white tails out to 250 yds
2) 58.5 gr. IMR 4064 CCI mag primer 150 gr. Hornady SST vel . 2775 fps out of my short bbl 300.Unbelievable accuracy.
Regards :
TGReaper
 
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