WinMag question, opinions requested.

[gsd1983]

I might have lost my mind on this one, but I figured I’d run this past y’all and let you chime in:

I’ve got a silly urge for a short WinMag. How short you ask? I’m thinking 18”.

So far the plan is:
Factory ammo
Origin Long Action
Green Mountain 1:7.5 barrel
Magpul Hunter LA (already have this)

I know Browning and a couple others have a 1:8 on some XBolts, but those are longer sticks. I also know that Bill M. over at RifleShooter did a 16.5” that seemed to behave well enough for him a few years back, but that was also a 1:10 twist.

Think it would work? Or am I lost in my own musings and about to waste a barrel blank?

 

[DangerRanger]

Hell ya, Why not?

Im having a 21” 300 win/300prc/30nosler (indecisive) being built right now.

twist seems a bit fast... irk what bullet you’re wanting to shoot. My rock is a 10 so 10-? Since they are gain twisted

 

[gsd1983]

I want to run factory ammo, so I’m limited in my options as far as that goes. Loads range 150-230gr, so I’d probably start right in the middle at 180-190 and see how it shook out.

 

[wade2big]

You better like it because you won’t be able to sell it.

i am interested in how it turns out though.

 

[spife7980]

That seems like a fast twist to me?

 

[FatBoy]

Worst case, you spend $500 and put a new tube on. Not sure what kind of MV you'll get but it'll certainly work.

 

[nn8734]

300 Winchester Magnum: How Does Barrel Length Change Velocity- A 16″ 300 Win Mag?

Introduced by the Winchester Repeating Arms Company in 1963, the 300 Winchester Magnum (300 Win Mag) is based on the 375 H&H case shortened to fit a standard length action and necked down to 30…

rifleshooter.com

double up on ear pro.

 

[GBMaryland]

My TRG-42 300WM (not short) 11:1 twist shoots everything up to 220gr under 1MOA.

If you plan on loading your own, and are thing about solid bullets (Barnes or, esp., Warner Tool), you can get away with your crazy fast twist rate. However, I don’t think <8:1 is going to be useful for you... you certainly wont be able to shoot lead core jacketed rounds at near 3000fps with that twist rate,,,

 

[gsd1983]

So, on the RifleShooter MV year the 16-18” run about 2600-2700fps. No, as I stated he ran a 1:10, and used the 190 FGMM.

So I’d estimate 2600 or so.

 

[Terry Cross]

I would love to have an endless budget and build two identical rifles to your spec except make one a 30-06.

With that barrel length, I would wager the 06 would be really close to the WinMag with those bullet weights. The 30-06 would have terrible muzzle blast but the WinMag would be epic. Especially if you box yourself into factory ammo which has propellants optimized for longer barrels.

Capacity / Bore ratios are a thing and certain ratios hemorrhage a ton of MV per inch compared to less overbore cartridges.

Would love to have you dig this thread up and post an update with results if you execute as described above.


./

 

[nn8734]

@DaveThomas83 I’d recommend running a can to make it more palatable/fun to shoot.

Edit: I would also like to hear how things turn out once you have it together.

 

[Totoro]

My 2 pennies FWIW, 7.5 is pretty dang quick in that short tube slinging the bullet weights you mention.

My 300mags roll 1-9 up to 230gr and 1-8 for the 230+

Factory ammo wise 200gr ELDX, 215 and 230 Berger are the heaviest offerings available.

What elevation are you planning to use the rifle in?

Just a thought, maybe plug in data at Bergers (or others) stability calculator just to see if barrel twist is appropriate.

I will say that a shorty 300Winnie is gonna be STOUT at both ends,

 

[GBMaryland]

Warner tool company has actual lists of twist rates versus their bullets on their website… Which tells you what twist rate will it will work with

 

[z7.jled]

If you have ever shot an m44 mosin nagant.....(a friend has one with a 16” barrel, 7.62x54r)

The muzzle blast will be punishing, and die say with the right break you will get epic fireballs

If it is heavy enough it could be a handy hunting rifle though, if it is too light it will knock your teeth out, too heavy it won’t be handy

Sounds like a fun build

 

[waveslayer]

I know Desert Tech sells a factory conversion kit for the SRS. Its 18" , weighs 4.18 pounds, and has a twist rate of 1/8. It's on DT's website.

I shot with a guy that had one! It was brutal, very loud and with the SRS in your face loud, but a can solved the problem

 

[rustyinbend]

Um ... one question ... "Why?"

Like the other dude said ... love it or eat it, cuz nobody will want to buy it used.

I have a 24" MPA 300-WMBA that shoots a mile. It's amazing - got me addicted to ELR shooting ... so lucky to have an awesome 2,000-yard range here in Central Oregon. Couldn't imagine how (or why) I'd shoot it with an AR-length barrel. The purpose of a 300-WM is to take out the Zombies before they ever get to your neighborhood.

Hey ... you asked.

 

[Terry Cross]

@DaveThomas83 I’d recommend running a can to make it more palatable/fun to shoot.

Edit: I would also like to hear how things turn out once you have it together.

I would highly recommend that anybody planning to mount a 30cal. can on a short .300 Win Mag get with the can's manufacturer while still in the planning stage.

The port pressure on a 18" magnum will be significantly higher than longer barrels. Check with the can maker regarding this combo. Most will likely give it a thumbs up but some may not even if their can is normally rated up to .300 Win Mag.

This is like mounting a light weight 223/5.56 rated can on an SBR. You could swell the OD of the can and/or break internals loose if the can is not rated for a higher port pressure.


./

 

[rustyinbend]

I would highly recommend that anybody planning to mount a 30cal. can on a short .300 Win Mag get with the can's manufacturer while still in the planning stage.

That is REALLY good advice.

 

[nn8734]

I would also consider a .338 caliber suppressor given such a short barrel. Use a muzzle brake for the adaptor. AAC and Surefire come to mind.

I would highly recommend that anybody planning to mount a 30cal. can on a short .300 Win Mag get with the can's manufacturer while still in the planning stage.

The port pressure on a 18" magnum will be significantly higher than longer barrels. Check with the can maker regarding this combo. Most will likely give it a thumbs up but some may not even if their can is normally rated up to .300 Win Mag.

This is like mounting a light weight 223/5.56 rated can on an SBR. You could swell the OD of the can and/or break internals loose if the can is not rated for a higher port pressure.


./

 

[gsd1983]

I don’t have a can suited (or rated) for 300WM, nor is it in the budget for this one. I may just have to get used to being “that guy” at the range.

This build may get scrapped before it even gets off the ground.?

 

[cleric]

Is this a because I can build or a legitimate idea?

i can’t image any reason to nerf a 300 WM to 18in especially in production ammo. it Will be unpleasant to Shoot.

 

[DangerRanger]

I’m doing it to keep the overall length down on a suppressed hunting rifle, were it not for the can if just do a more normal length.

But, short guns look cool so I’m still hoping you do it.

 

[gsd1983]

Is this a because I can build or a legitimate idea?

i can’t image any reason to nerf a 300 WM to 18in especially in production ammo. it Will be unpleasant to Shoot.

Bit of both actually. I’m a huge fan of short maneuverable rifles.

 

[cleric]

Bit of both actually. I’m a huge fan of short maneuverable rifles.

that’s a lot of powder for a few hundred fps...

what are you hunting? How far?

 

[gsd1983]

Who says it’s for hunting?

 

[FatBoy]

Who says it’s for hunting?

In my case, I assumed it was for hunting. Otherwise, there isn't a real use for it.

Edit: not a criticism. I build silly shit all the time ?

 

[cleric]

Then why build a short maneuverable rifle?

 

[gsd1983]

Then why build a short maneuverable rifle?

Because I started shooting with a Gen1 RPR in 243 and a 26” barrel was annoying. I prefer shorter rifles.

 

[kingzero]

I get boner'd up over short rifles but this doesn't seem remotely interesting to me. I don't see the up side of neutering a WM if it's not going to be used for hunting. As others said, it will be obnoxiously loud and sticking to factory ammo will not yield the best possible results.

If you do this, buy a barrel with a long enough tennon to allow you to set it back and rechamber to something else when the novelty wears off.

 

[GBMaryland]

I’ve got a 375H&H you can have... chop the barrel to 16.25 inch, and give it a try. GA Precision did the original work,,, even put on a JP muzzle break.

Hell, I’ll even throw in a 100 rounds of 265gr BTBT ammo... so ling as I get film rights!

 

[GBMaryland]

I would also consider a .338 caliber suppressor given such a short barrel. Use a muzzle brake for the adaptor. AAC and Surefire come to mind.

Actually, I use a 338 can on my 300WM... sorta need it. ...and my barrel is 26in.

 

[fdkay]

I would be more inclined to build a short mag if you're insistent on 18" barrel

 

[nn8734]

@DaveThomas83 Have you considered a Desert Tech with perhaps a 22” .300 Win Mag barrel?

Seems like it would keep OAL down while allowing for a decent barrel length.

 

[gsd1983]

The cost of a DT in .300 is prohibitive for me, especially as I already have the blank and the chassis.

Y’all are doing a good job of convincing me to scrap this idea.

 

[Dirty D]

I don’t have a can suited (or rated) for 300WM, nor is it in the budget for this one. I may just have to get used to being “that guy” at the range.

This build may get scrapped before it even gets off the ground.?

I have a braked 18” 308 and no one wants to shoot next to me, watching you clear out a line would be hilarious!

 

[Terry Cross]

Because I started shooting with a Gen1 RPR in 243 and a 26” barrel was annoying.

If you want annoying, rock a short barreled magnum, because that is how you find annoying.

If you can't budget a bad ass suppressor, you will need foamies under muffs with gel cups and a full face motorcycle helmet over that.

If you can't swing that budget either, I would suggest getting with you nearest SWAT team and volunteer as an aggressor for their room clearing exercises. I would recommend getting flashbanged at least 20 times to partially desensitize yourself to your new magnum.

If you build this new dream gun, you should also consider changing your SH screen name to Helen Keller since you will be running around with the same hearing ability.


./

 

[isofahunter]

I would circular file this project.

 

[nn8734]

The cost of a DT in .300 is prohibitive for me, especially as I already have the blank and the chassis.

Y’all are doing a good job of convincing me to scrap this idea.

We’re saving you from further aggravation (not to mention $$$) after it’s built.

I would build a nice 22” win mag with the components you already have (swap the 7.5 twist blank for one with a 10 twist) and stick a good optic on top. then when you’re able to, put a can on it. You will be a lot happier in the end.

 

[FatBoy]

Terry must have hit the aiming juice hard last night. That was about as subtle as a brick to the face.

Reub, you sick fucker.... ?

 

[Long Range 338]

If you want annoying, rock a short barreled magnum, because that is how you find annoying.

If you can't budget a bad ass suppressor, you will need foamies under muffs with gel cups and a full face motorcycle helmet over that.

If you can't swing that budget either, I would suggest getting with you nearest SWAT team and volunteer as an aggressor for their room clearing exercises. I would recommend getting flashbanged at least 20 times to partially desensitize yourself to your new magnum.

If you build this new dream gun, you should also consider changing your SH screen name to Helen Keller since you will be running around with the same hearing ability.


./

Thats epic! I damn near spit drink all over my keyboard...

I'm just educating myself with this thread and Terry has been beating me to the punch with all of his answers to my questions, so cheers to Terry.

Personally I'm a long barrel guy, I love 26 inch barrels on 308s and 28 inch barrels for something like 300NM. 24 inch barrels are my short barrels.... However I am starting down the rabbit hole of suppressors and am willing to consider shorter barrels for suppressed use. If one were to build a 18 inch 300WM and ended up shooting a load with heavy bullet and SLOW powder what would the worst case scenario be? Is detonation in the can an actually concern or would it just be hard use required a full auto rated can?

Sorry for the dumb question derail, these things occur to me from time to time...

 

[Dirty D]

...If one were to build a 18 inch 300WM and ended up shooting a load with heavy bullet and SLOW powder what would the worst case scenario be?...

 

[Dirty D]

If you want annoying, rock a short barreled magnum, because that is how you find annoying.

If you can't budget a bad ass suppressor, you will need foamies under muffs with gel cups and a full face motorcycle helmet over that.

If you can't swing that budget either, I would suggest getting with you nearest SWAT team and volunteer as an aggressor for their room clearing exercises. I would recommend getting flashbanged at least 20 times to partially desensitize yourself to your new magnum.

If you build this new dream gun, you should also consider changing your SH screen name to Helen Keller since you will be running around with the same hearing ability.


./

Damnit Terry, type louder because I can’t hear you over the ringing in my ears.

 

[Long Range 338]

View attachment 7211876

I assumed this would be the normal 16" 300WM factory loadings....

 

[Terry Cross]

@DaveThomas83, I was not trying to be an ass or belittle your idea. I was just in a good mood, had coffee and was trying to interject a less serious reply.

We are all super lucky to live in a place where we can entertain all sorts of rifle ideas. Rock on with whatever blows your skirt up brother. That's called living your life and not enough people do that while they can.

./

 

[McGilbery]

My Thunderbeast 30P1 can is rated for 300 WM with a barrel length of minimum 24". I believe my SWR 30 cal SpecWar is the same. You would have to run a 338 can for a short barrel 300 WM

 

[lawofsavage]

I might have lost my mind on this one, but I figured I’d run this past y’all and let you chime in:

I’ve got a silly urge for a short WinMag. How short you ask? I’m thinking 18”.

So far the plan is:
Factory ammo
Origin Long Action
Green Mountain 1:7.5 barrel
Magpul Hunter LA (already have this)

I know Browning and a couple others have a 1:8 on some XBolts, but those are longer sticks. I also know that Bill M. over at RifleShooter did a 16.5” that seemed to behave well enough for him a few years back, but that was also a 1:10 twist.

Think it would work? Or am I lost in my own musings and about to waste a barrel blank?

nothing of value to add other than I got bit by a similar bug except the 7RM variety and now have an 18” 7RM prefit on the way for a Tikka and can’t wait. Should make for a handy mid weight hunter that still isn’t crazy long when I want to use a suppressor ...

 

[cleric]

My Thunderbeast 30P1 can is rated for 300 WM with a barrel length of minimum 24". I believe my SWR 30 cal SpecWar is the same. You would have to run a 338 can for a short barrel 300 WM

think saker is 20in...don’t know any shorter than that. Maybe a 338 can could

 

[fdkay]

nothing of value to add other than I got bit by a similar bug except the 7RM variety and now have an 18” 7RM prefit on the way for a Tikka and can’t wait. Should make for a handy mid weight hunter that still isn’t crazy long when I want to use a suppressor ...

Likely would be better off with a .280 or possibly 7 SAUM, which would likely do well out of a long action.

 

[2aBaC̶a̶]

Nothing ventured, nothing gained.

Do it.

 

[chevy_man]

Are you going to actually gain anything over a 30-06 at that length?


At a certain point you're just tossing powder out of the barrel. There's a reason you don't see short barreled magnums often, as you can burn half the powder for 95% of the speed.


I pack a 24" barrel with a 6.5" can hunting. It's not crazy long and still handles quite well.