Talk me out of a 20 inch 300 Winchester magnum… or not.

arios2

Well-Known Member
LRH Team Member
Joined
Jul 7, 2018
Messages
293
Location
houston
So, I want to build a 20 inch 300 win mag to use primarily for hunting and occasional long range shooting fun out to 1000yds. Currently I hunt everything with a custom 16 inch 308 suppressed and has worked perfect out to 400yds. I want a caliber I can comfortably hunt out to 800yds with and of course there are a numerous amount of options, but I have my own personal preference I'm trying to satisfy.
My requirements are:
* maximum of a 20 inch barrel as I only shoot suppressed and a silencerco Omega adds an additional 6 inches
**Ammo has to be very readily available as I do not reload or intend to reload in the future**
* ammo has to be reasonably priced, $35 or less per box of 20 for match or quality hunting ammo
* caliber has to support a 1000rd barrel life (No 28 NOSLER! lol)
* Recoil sensitivity is a non issue….

Now, I KNOW there are much better caliber options for hunting, but I can't stress how important it is to be able to go to ANY sporting goods store and buy a box of ammo if I need to. This will be a dedicated hunting rifle and I have had numerous hunting trips where I have to buy a few boxes of ammo on the day of my hunt. 300 winmag has a ton of factory ammo offerings from light to heavy and I can't think of another caliber that offers as much of a variety. Barrel length is my Achilles heel, I KNOW Im giving up precious precious muzzle velocity by limiting myself to a 20 inch barrel but Im in Texas and do all of my hunting either in a blind, or walking through thick brush, and maneuvering a jousting lance of a rifle with a 24 inch barrel and a 6 inch suppressor is not gunna do it for me. I love shooting suppressed as well and a silencerco omega is gunna live on the muzzle. So i'm looking for some opinions on if there is a better caliber option that meets my personal requirements for the listed reasons, or am I moving in the right direction for my needs? Now I've seen good comparisons as in a 20 inch 300winmag is a 28 inch 308, which i'm more than excited about, but I've also heard potential negatives like a 20 inch 300winmag leaves too much unburnt powder in a suppressor. Let me know what you think, and if anyone has a 20in 300winmag tell me about it! Thanks
 

Slick8

Well-Known Member
Joined
Aug 13, 2012
Messages
561
Location
The Republic of Texas
I'm on the same boat but I'm going to build a 300 WSM or Sherman.

I think it's the best option to sling heavy lead from a shorty but its not factory ammo friendly. I not only handload but enjoy it and the flexibility it gives me in bullet and powder selection which lends itself to the shortly as well.

I can't think of one better to do the job you're looking to do in a factory offering.
 

808caliber

Well-Known Member
Joined
Aug 30, 2020
Messages
62
Location
Oahu
I dont have it yet but i have my allterra stock on order and bartlein carbon barrel.
Plan to build a 20-22 inch 300prc on a kratos lite.
My constraints for barrel length are slightly diff. Mostly because i hunt in thicker brush on a mountain so its nice to not carry around a jousting stick.
I also hunt with a 20" 7ss and its been a hammer. Never felt the need to have more barrel.
Hope we both have success this upcoming year brotha!
 

arios2

Well-Known Member
LRH Team Member
Joined
Jul 7, 2018
Messages
293
Location
houston
and just for reference and fun, I primarily shoot 200-300lb hogs at 100-200yds, and deer 100-400yds, but want to take more 400-800yd shots at my new lease. I'm still chasing the spotted one…


IMG_0936.jpeg
IMG_1167.jpeg
IMG_3161.jpeg
WGI_0290.jpeg
 

nmbarta

Well-Known Member
Joined
Mar 8, 2014
Messages
753
Location
billings mt
Lots of unburnt powder going into that can.
If you were reloading you try to stick with the fastest burning powder possible and try to help with. Given that factory 300wm ammo is designed for 24-26" barrels your stuck with what you can buy.
I don't knkw the numbers, but I'd be curious to see what you really gain with factory ammo over a 21-22" 308 (same length rifle) I'm sure it's significant, but might be less than you'd think, which might make a guy wonder if it's worth it.
Not that i care at all about being powder efficient, don't get me wrong.
Biggest concern to me would be the flash in the can.
 

Argon Glen

Active Member
Joined
Feb 6, 2018
Messages
41
@nmbarta has some good points and, in particular, about 300 Win Mag ammo for longer barrels and unburned powder in your suppressor. I understand you're not going to reload but don't rule out having a load developed for your custom rifle. Send in your rifle and get it back with ammo tailored to your rifle and use. From there out any reloading service can duplicate the ammo for you. Somebody will come along and help you with choosing a business local to you in the Houston area. I'm sure there are several.
 

Maol

Active Member
Joined
Oct 14, 2016
Messages
31
I'm on the same boat but I'm going to build a 300 WSM or Sherman.

I think it's the best option to sling heavy lead from a shorty but its not factory ammo friendly. I not only handload but enjoy it and the flexibility it gives me in bullet and powder selection which lends itself to the shortly as well.

I can't think of one better to do the job you're looking to do in a factory offering.

Factory Tailor Mades? Since I don't like belts on cartridges and the art has advanced so much I would be on the WSM or PRC. But you still have to handload to optimize a shorty... So I would go Sherman.
 

1894C

Well-Known Member
Joined
Jul 15, 2020
Messages
218
Location
Georgia
I won’t try to talk you out of a 20” 300win. What I would do and I assume a lot more members here would do is try to talk you into handloading for it.

to avoid excess powder going into your can I would try to shoot the fastest burning powder you can. In factory ammo you’re going to get loads developed for 26” barrels. Your can is not going to appreciate this. I’ve never understood the idea of having to have $35 a box off the shelf ammo in a fully custom rifle. Nobody puts a cheap set of tires on a Lambo. Why would it be different in a high performance rifle?


a 20” 300win is going to give up a couple hundred FPS. With handloads you can possibly shrink that gap a little bit but factory ammo that 300win is going to be severely handicapped. Given your needs I would lean closer to a 30-06 with factory loaded 185 bergers.
 

25WSM

Well-Known Member
Joined
Oct 17, 2011
Messages
2,604
Location
New Castle PA
30-06 is probably what I would do with your list of requirements. It's found in most any store that has ammo. It's cheap. Gives you a boost over 308. Won't be nearly as handicapped with a short barrel compared to a win.mag. A friend of mine used a 20 inch 7 mag for yrs and loved it. No can.
Shep
 

Wolf76

Well-Known Member
Joined
Jan 5, 2014
Messages
750
Location
Grandville, Michigan
you're asking for a unicorn.
cheap ammo, widely available, extended range, a cartridge safe with your can - while using a very short barrel, won't reload.....
something has give. powder still burning after the bullet has exited the barrel is going to be hard on your can. You not reloading doesn't allow you to change to a faster powder. Having custom ammo made isn't cheap and not available everywhere.
At least one (probably 2) of your variables needs to change to get the desired result.
 
Last edited:

TAZMAN

Well-Known Member
Joined
Oct 23, 2003
Messages
375
I built a 18 inch 6.5 Creedmoor from a Remington LTR base gun. DMR did the work. I can tell you the short rifles are very handy but they are also very loud. The muzzle blast is noticeable but with a CAN it was not bad. There is a difference in the carbon contamination in the suppressor though. I actually sold the gun and just shoot my 20 inch without a CAN. I also have a 22 inch 30-06 that is about perfect as a all around rifle. These were all proof sendero barrels. My 6.5 PRC is also a 20 inch large diameter proof barrel. It was a special run and looks awesome. With RL26 and a magnum primer you can get velocity but my experience has been the 18 inch barrels seem to be the edge of the complete burn on a lot of powders I tried. I now use 20 inch as my lower limit.

Just my experience for what it's worth.
 

Primary

LRH Assistant
Here are some related products that LRH members are talking about. Clicking on a product will take you to LRH’s partner, Primary, where you can find links to LRH discussions about these products.

 
 
Top