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USMC .300 WinMag

bradthemarine

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Full Member
Minuteman
Nov 14, 2012
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Anybody know the components/specs of the new Marine Corps .300 WinMag? I read it's going to have a Mk 13 mod 7 chassis but that's about it.
 
I read Remington Long Action .300WM, Lilja barrel, on a Accuracy International chassis with Nightforce ATACR (zoom range wasn't specified).
 
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US Military can not unfuck themselves when considering shit like this.
Why do Americans have such hard-ons for cartridges with a completely useless belt that does nothing but interfere with proper feeding and headspacing?
Why are they so hell bent on a .30 cal?
At least they went with Stiller, but they insist on the damn remington footprint and 90 degree bolt throw.
 
Why are they so hell bent on a .30 cal?

You need some history books.

The US Military--'unfucked' or not--is under a fair amount of pressure from a lot of angles when they make decisions like these, and when they make a decision as much a watershed as this one, they have to be ready to stand by it. Budget being one of these considerations, in that the Marine Corps probably already owns millions and millions of .30 caliber match-grade projectiles of almost any variety you can buy (and some you can't), .30 caliber makes more sense in reality than it does on a forum with so many internet gurus like this one.

Paired that with so much development of .300 Mag loads and rifles by the Navy--under whose umbrella the Corps operates--and you can see where maybe .300 is a lot easier plug-and-play solution than something else.

The other side of the coin is horsepower. They are looking for a round that will go further, flatter, and faster BUT still deliver more pounds of energy on target than the .308 rifles they already have.

I know, I know, rhetorically, the 6.5mm and 6mm rounds are SOOPER cool, and SOOPER flat, and SOOPER long range, but if you compare energy on target--which is what can make all the difference when what you're shooting at can shoot back--the heavy .30s win big time.

Recoil is a non-issue for their rifles because of 3 factors: 1) they are suppressed; (2) they are heavy as fuck; (3) these are goddamned US Marines. (Which, yes, is a legitimate factor in their mindset regarding pain and ability on rifles, both.)

Something I have wondered before is whether, if suppressor technology had been available, WWII era-and-forward snipers would have been using .300 H&H instead of the Springfield round. It would have been worth 200+ fps more speed than the -06 with the same bullet, (100 fps being the general litmus for something that starts to "matter" for decision making) and was actually less than 100 fps behind the .300 Win Mag, but predated the Winchester by almost 40 years.

I think, if given the choice, the Marines would have chosen the heavier cartridge, same as their grandchildren have done now.

-Nate
 
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US Military can not unfuck themselves when considering shit like this.
Why do Americans have such hard-ons for cartridges with a completely useless belt that does nothing but interfere with proper feeding and headspacing?
Why are they so hell bent on a .30 cal?
At least they went with Stiller, but they insist on the damn remington footprint and 90 degree bolt throw.

The only time the belt is an issue is for brass life. The military isn't concerned about that. A 300WM feeds perfectly fine out of magazines and is a hell of an accurate round.

30 cals hit hard and 300WM has the horsepower to double as anti personnel and can also pull some light anti material roles like shutting down vehicles better than the smaller stuff (and 308). 300WM will do 90% of what a 338LM will do with less recoil and far less ammo costs.

That's why they went 300WM and I think they made a great decision.

There's nothing wrong with a Remington footprint or a 90 degree action. It's been working great for over half a century.
 
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I meant have a century. 700's came about in the 60's.

I know what you meant, but 90-degree bolt throw bolt actions are a helluva sight older than the Remington. Remington did almost nothing to innovate the bolt action except make it easily and quickly produced, and cheaply, and they happened to be in the right place at the right time when Winchester--and the rest of the economy--went to shit.

Short of that event, we could all still be using CRF M70 actions. That wouldn't be all bad, either.
 
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So what happens when you burn out a barrel? Is it deadlined back to PWS or to Crane?

No modern issue precision rifle should require rebarreling above the user level.
 
the 90° bolt through has 30% more cocking distance, making trigger selection and FP spring a no brainer for positive ignition. It also allows a much easier bolt lift when shit does go over pressure, because your shooting a 220gr bullet way the fuck over max in say, a desert environment., have wet ammo or a filthy rifle from moving place to place not in a $250 range queen drag bag.

It ain't sexy, but it it's a proven platform.

personally, I think they should just go back to the 700/300. Better cheek weld, no fucking doo-dads to fall off and get lost. A little lighter and IMO easier to carry. I guess they like the DBM, so this is the next best thing if you don't want to just use an M5 LA floorplate.

Guys who want to see our troops with AI guns won't be happy with anything else, but this is a solid platform with a proven round that is accurate, shootable and available now.
 
So what happens when you burn out a barrel? Is it deadlined back to PWS or to Crane?

No modern issue precision rifle should require rebarreling above the user level.

Who knows at this point, they've made the selection. Who knows if they've even finalized details for service.

The second part is funny because every brand of our military is using platforms that aren't end user serviceable. Not that a barrel change is hard, a lot of people aren't the mechanical type and this can include mil snipers. Probably a safe bet to just have them go back and be delivered a serviceable weapon.

personally, I think they should just go back to the 700/300. Better cheek weld, no fucking doo-dads to fall off and get lost. A little lighter and IMO easier to carry. I guess they like the DBM, so this is the next best thing if you don't want to just use an M5 LA floorplate.

They've gotta be able to run clip on NV's so by the time you embed a EFR in the chassis (which I'll never trust to be as aligned as a machined rail) and get the proper ring height for the day optic to line up right then you're at the same result. Nothing with a clip on is going to have an ultra tight cheek weld without the use of a adjustable cheek riser outside of an AR platform.
 
They've gotta be able to run clip on NV's so by the time you embed a EFR in the chassis (which I'll never trust to be as aligned as a machined rail) and get the proper ring height for the day optic to line up right then you're at the same result. Nothing with a clip on is going to have an ultra tight cheek weld without the use of a adjustable cheek riser outside of an AR platform.

The McCann rail was the initial answer, but I agree with what yours saying. As I have both, I have a clear favorite BUT I don't run a clip on.

image_56963.jpg
 
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You need that extra distance in a 700 action so the bolt knob doesn’t come off when you have a hotnround get stuck. Friend kicked the knob off his trying to get a round unstuck from an M40 in Central America.

If you can’t rebarrel an AI you have no business being a sniper.

The round should be a 300NM with a 215 Berger anyway.
 
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The McCann rail was the initial answer, but I agree with what yours saying. As I have both, I have a clear favorite BUT I don't run a clip on.

View attachment 6890920



The MIRS is a cunthair closer to the center of bore than a typical chassis with continuous rail but it isn't a whole lot and it's still enough where you're going to want an adjustable riser. At that point it doesn't make much difference in how much higher it is so long as you're not talking inches.

The chassis also gives the user far greater flexibility for mounting IR lasers and illuminators vs a traditional stock.
 
The chassis also folds and is much more durable.

On an AI you can take the whole thing down and put it in a small case. Talked to a military user that needed that sort of thing once. When you need it you need it.
 
The round should be a 300NM with a 215 Berger anyway.

Whos gonna supply the ammo? USMC isn't going to source it from a foreign manufacturer, and those are the only options.

Let's say LC, Black Hills, Remington, Barnes, or somebody tools up to make it. How long is that going to take? How much more is that ammo going to cost over 300WM? What is the 300NM going to do that the 300WM won't that's already in their arsenal and contracts already exist for multiple ammunition types?

Those questions are why a 300NM wasn't chosen.
 
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I know what you meant, but 90-degree bolt throw bolt actions are a helluva sight older than the Remington. Remington did almost nothing to innovate the bolt action except make it easily and quickly produced, and cheaply, and they happened to be in the right place at the right time when Winchester--and the rest of the economy--went to shit.

Short of that event, we could all still be using CRF M70 actions. That wouldn't be all bad, either.

Amen to that, from what I understand the military in Vietnam thought their pre-war M70 to be better than the 700 however it was no longer being produced and the 700 was better than the post-64 M70.

I sometimes wonder how much different the shooting market would look if Winchester simply never changed the M70 and the military adopted it as the standard over the 700.
 
Several of the manufacturers you listed already load for that caliber. And USMC already uses significant quantities of specialty ammunition from manufacturers in NATO nations.

Also, mags for 700 pattern guns are crap.
 
Amen to that, from what I understand the military in Vietnam thought their pre-war M70 to be better than the 700 however it was no longer being produced and the 700 was better than the post-64 M70.

I sometimes wonder how much different the shooting market would look if Winchester simply never changed the M70 and the military adopted it as the standard over the 700.

It would look like a k98 or 1903 with a modern stock and barrel profile.
 
Several of the manufacturers you listed already load for that caliber. And USMC already uses significant quantities of specialty ammunition from manufacturers in NATO nations.

Also, mags for 700 pattern guns are crap.

Not a single manufacturer that I mentioned lists any 300 Norma ammo.

Mags for 700 pattern guns are crap huh? Army, Navy, USMC, and SOCOM have been using AICS pattern mags for years in 700's with no issue. The long action mags which the MK13 Mod 7 uses are derived from the AWM and AWSM sniper rifles which have been in military service for over 20 years.

The commercial market is now standardizing on these magazines.... Yep, they're crap.


Are you trolling or are you really this misinformed?
 
Amen to that, from what I understand the military in Vietnam thought their pre-war M70 to be better than the 700 however it was no longer being produced and the 700 was better than the post-64 M70.

I sometimes wonder how much different the shooting market would look if Winchester simply never changed the M70 and the military adopted it as the standard over the 700.

Well, I mean I wasn't born yet, so I can't stand in perfect judgement of the economic reasons why Winchester was trying to reduce manufacturing costs of what was their flagship weapon.

I just know that it didn't work out, and we lost an architecturally stronger receiver for one that was cheaper. The post-64 CRF is just as good an action as any Remington 700, and has since been realized to be such. Unfortunately, the nails were LONG in the coffin of New Haven before that realization in the mind of the American shooting enthusiast, which was approximately as impressionable and fickle then as it is now.

-Nate
 
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I just read that the USMC was getting 346 of these bad boys at a cost of 4.3 million dollars. That works out to a smidge over 12k per. What in the name of all that's good could cause it to cost so much? I must be missing something in my math somewhere, but it surely escapes me right now.... Someone educate me, please. Honestly curious to know.
 
I just read that the USMC was getting 346 of these bad boys at a cost of 4.3 million dollars. That works out to a smidge over 12k per. What in the name of all that's good could cause it to cost so much? I must be missing something in my math somewhere, but it surely escapes me right now.... Someone educate me, please. Honestly curious to know.
Well remember they aren’t just getting guns they are also probably ordering extra parts per in order to service them. Also government procurement contracts always cost more because of how laws are written and rules etc etc etc. someone here who has been in that position before can explain better but it’s not that they are being ripped off it’s just that there is a lot of compliance bullshit that goes with it as well. Why do you think manufacturers of anything love govt contracts. They are very lucrative.
 
Not a single manufacturer that I mentioned lists any 300 Norma ammo.

Mags for 700 pattern guns are crap huh? Army, Navy, USMC, and SOCOM have been using AICS pattern mags for years in 700's with no issue. The long action mags which the MK13 Mod 7 uses are derived from the AWM and AWSM sniper rifles which have been in military service for over 20 years.

The commercial market is now standardizing on these magazines.... Yep, they're crap.


Are you trolling or are you really this misinformed?

Listed? Cute. Might not be listed but it’s shipping.

AICS mags are shit. AWM mags work fine for what they are but they are single stack and center feed. So 1999.
 
You need some history books.

The US Military--'unfucked' or not--is under a fair amount of pressure from a lot of angles when they make decisions like these, and when they make a decision as much a watershed as this one, they have to be ready to stand by it. Budget being one of these considerations, in that the Marine Corps probably already owns millions and millions of .30 caliber match-grade projectiles of almost any variety you can buy (and some you can't), .30 caliber makes more sense in reality than it does on a forum with so many internet gurus like this one.

Paired that with so much development of .300 Mag loads and rifles by the Navy--under whose umbrella the Corps operates--and you can see where maybe .300 is a lot easier plug-and-play solution than something else.

The other side of the coin is horsepower. They are looking for a round that will go further, flatter, and faster BUT still deliver more pounds of energy on target than the .308 rifles they already have.

I know, I know, rhetorically, the 6.5mm and 6mm rounds are SOOPER cool, and SOOPER flat, and SOOPER long range, but if you compare energy on target--which is what can make all the difference when what you're shooting at can shoot back--the heavy .30s win big time.

Recoil is a non-issue for their rifles because of 3 factors: 1) they are suppressed; (2) they are heavy as fuck; (3) these are goddamned US Marines. (Which, yes, is a legitimate factor in their mindset regarding pain and ability on rifles, both.)

Something I have wondered before is whether, if suppressor technology had been available, WWII era-and-forward snipers would have been using .300 H&H instead of the Springfield round. It would have been worth 200+ fps more speed than the -06 with the same bullet, (100 fps being the general litmus for something that starts to "matter" for decision making) and was actually less than 100 fps behind the .300 Win Mag, but predated the Winchester by almost 40 years.

I think, if given the choice, the Marines would have chosen the heavier cartridge, same as their grandchildren have done now.

-Nate
The US Military does not own a stockpile of match bullets. (with the exception of the shooting teams that handload).
They purchase ammunition from ammunition plants, they can specify ANY cartridge/bullet/accuracy/velocity threshold they want to.
It would have made much more sense to go with the .30-375 as it is the exact same footprint, but gains around 5 grains capacity, allowing them to shoot at the same velocity with lower pressures, or higher velocities.
Suppressors were available and used during the first world war.
 
US Military can not unfuck themselves when considering shit like this.
Why do Americans have such hard-ons for cartridges with a completely useless belt that does nothing but interfere with proper feeding and headspacing?
Why are they so hell bent on a .30 cal?
At least they went with Stiller, but they insist on the damn remington footprint and 90 degree bolt throw.



I'll tell you. By 2006-2012 fiscal standards the 338 Lapua in theatre cost the US taxpayer roughly $25 for every round expended. The logistical challenges of Finland to Middle East were not cheap. It became apparent that its not self sustaining. It's not the easiest round to shoot sustained for prolong periods either.

So, an alternative was pursued. The MK248 Mod 1 was the answer. Nothing more than a 300 Winchester Magnum gassed up with a 220 grain Sierra and throttled at 2850 +/-50fps.

The advantages of this:

  • 3.5 more rounds per pound loaded on a person when compared to the 338LM
  • Readily available in the current US supply chain because of Lake City Arsenal, they've been making 300WM since before most of us were born
  • Almost ballistically identical to the 338LM when its loaded with a 250G Scenar projectile
  • Standard magnum length magazines
  • Standard magnum length actions
  • Reduction in recoil to shooter, means more effective use when deployed
  • Reduction in costs

Challenges early on:

Guns built for Naval Special Warfare had chamber issues. They'd pressure up and bolt lift got real heavy/sticky. Secret squirrel guys didn't want to use them because of it. That problem has been solved. 90* turnbolt actions have been in circulation since before WWI. The fact that they are still here today is a testimony to the design's success. The wheel is round enough...

Middelton Tompkins, someone I have known since I was 20 years old and respect tremendously proved that the most accurate projectile for 300m 3 position international was a 168 grain Sierra MK in a 308Win. The 30 works and works extremely well. Its also well supported. The most efficient bullet in the world is not much use if you can't get them. . .

Things to consider for folks who might dabble with this cartridge. The MK248 Mod1 is the envelope of the 300WM. As you push anything towards the limit of capacity, service intervals increase and service life diminish. This is intended as a "fire and forget" cartridge so if your looking for 5-10 reloads from brass its going to be a challenge to get that far.

Setup properly it feeds great, chambers just fine, and shoots very, very well. Remember, Carlos Hathcock won the Wimbeldon Cup in 1966 with a 300WM.

Old, not flashy, not "operator", but the cartridge still gets it done.

A classic never dies...

C.


PS. I was involved with this heavily about 6 years ago.
 
I'll tell you. By 2006-2012 fiscal standards the 338 Lapua in theatre cost the US taxpayer roughly $25 for every round expended. The logistical challenges of Finland to Middle East were not cheap. It became apparent that its not self sustaining. It's not the easiest round to shoot sustained for prolong periods either.

So, an alternative was pursued. The MK248 Mod 1 was the answer. Nothing more than a 300 Winchester Magnum gassed up with a 220 grain Sierra and throttled at 2850 +/-50fps.

The advantages of this:

  • 3.5 more rounds per pound loaded on a person when compared to the 338LM
  • Readily available in the current US supply chain because of Lake City Arsenal, they've been making 300WM since before most of us were born
  • Almost ballistically identical to the 338LM when its loaded with a 250G Scenar projectile
  • Standard magnum length magazines
  • Standard magnum length actions
  • Reduction in recoil to shooter, means more effective use when deployed
  • Reduction in costs

Challenges early on:

Guns built for Naval Special Warfare had chamber issues. They'd pressure up and bolt lift got real heavy/sticky. Secret squirrel guys didn't want to use them because of it. That problem has been solved. 90* turnbolt actions have been in circulation since before WWI. The fact that they are still here today is a testimony to the design's success. The wheel is round enough...

Middelton Tompkins, someone I have known since I was 20 years old and respect tremendously proved that the most accurate projectile for 300m 3 position international was a 168 grain Sierra MK in a 308Win. The 30 works and works extremely well. Its also well supported. The most efficient bullet in the world is not much use if you can't get them. . .

Things to consider for folks who might dabble with this cartridge. The MK248 Mod1 is the envelope of the 300WM. As you push anything towards the limit of capacity, service intervals increase and service life diminish. This is intended as a "fire and forget" cartridge so if your looking for 5-10 reloads from brass its going to be a challenge to get that far.

Setup properly it feeds great, chambers just fine, and shoots very, very well. Remember, Carlos Hathcock won the Wimbeldon Cup in 1966 with a 300WM.

Old, not flashy, not "operator", but the cartridge still gets it done.

A classic never dies...

C.


PS. I was involved with this heavily about 6 years ago.
So, do you not think the AI or TRG actions are superior? (serious question)
What is the accuracy life on barrels firing this hopped up, high pressure loading?
Wouldn't it have been better to explore an option that obtained the same results with lower pressure?
I have nothing against the .30 cal in particular, but, contrary to US Military doctrine, there are capable projectiles available in other diameters, particularly 7mm.
I am well versed in ammunition stockpile management.
 
Who makes that tan stock?

That is a McMillan A2 Inlet for the mk13 L shaped recoil lug. I ordered it to be exactly like they provided Crane in the 90s. I guess the Anschutz rail was added at Crane.
 
A2 Probably a NSW turn-in BTDT version

Mine was built for me two years ago, before the BTDT stocks were out. If I was doing it over again, I'd have bought the stock kit here. You save a shit load of time, save some money (as it has everything but the barreled action) and these stocks have providence. A bargain for those building a mk13 mod0 or a 700/300 (if they just use a m24 scope rail instead of the McCann).

edit:

to expand on what Chad said, here is a pic of some of my handloads and some mk248 mod1, shot in my A191 chamber (m248 mod0). The 10 of the left were Mod1. The two rows with red are a 230gr Berger OTM load at 2780 and the ones on the right are a test with Sierra 210 SMKs at roughly 2810fps.

I shot these all at 1k on an IPSC. The 210 and 230s made a nice round ~10" group . I then loaded of the mod1s, made no corrections and shot 6 rounds. Every one of these was 9" higher than the group average and that ammo held 1" of elevation at 1k fir 6 shots. Group was ~ 7" wide, waterline. I was ticked shitless until I looked at the brass. Junk. Every one of them flowed into the ejector and had a slight crater. For a fire and forget case, no big deal but I would have to tweak my chamber and throat to get the pressure down.

something else to consider. Carl Kovalchik still holds the 1k Prone Any Rifle record with a 300wm shooting 220gr SMKs. Old 90s profile. This record has stood since 1996.


20180707_192103.jpg
 
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That is a McMillan A2 Inlet for the mk13 L shaped recoil lug. I ordered it to be exactly like they provided Crane in the 90s. I guess the Anschutz rail was added at Crane.
Looks slick, love the color. Great looking rifle. Those classic stock styles just scream "theres a badass behind this thing", instead of the newer and more common, "theres a video game, computer nerd, internet ballistician, wirelessly controlling this expensive, ridiculous, ( albeit accurate), comic book rendition of a rifle" and before I forget to mention....nice rifle.
 
Thanks, I find it easier to carry than the chassis. Besides the cheek piece, nothing to fall or of get snagged on shit either. K.I..S.S.
 
My win mag is in a B&C sendero stock, and fielded with empty mag, its 12.3lbs with 26" tube. Want to change stocks and this mk13 bit is right on my radar. Just dont want to add significant weight
 
So I take it the M40A6/7 is dead then? What do they do with all of those short actions? Reservist?
 
So I take it the M40A6/7 is dead then? What do they do with all of those short actions? Reservist?

Latest Leatherneck says they will stay in school house for training.

Perhaps CMP will get some.
 
One can only hope CMP gets some.


considering what the 10x Unertls went for, more mortals will not be able to own one if this does happen. I'm glad that there will be people out there that can add them to collections, but it's sad to me that a shooters tool ends up racked with a toe tag, only to be seen by a few and never shot again. Seems like a waste, but better than being de-milled and thrown out.

a buddy of mine got an original mk13 lug. Anchor stamp and serial number on it PLUS 1" of the barrel and 2" of the action. Fuckers cut it off on each end with a touch. Just sad...
 
considering what the 10x Unertls went for, more mortals will not be able to own one if this does happen. I'm glad that there will be people out there that can add them to collections, but it's sad to me that a shooters tool ends up racked with a toe tag, only to be seen by a few and never shot again. Seems like a waste, but better than being de-milled and thrown out.

a buddy of mine got an original mk13 lug. Anchor stamp and serial number on it PLUS 1" of the barrel and 2" of the action. Fuckers cut it off on each end with a touch. Just sad...
Savages
 
US Military can not unfuck themselves when considering shit like this.
Why do Americans have such hard-ons for cartridges with a completely useless belt that does nothing but interfere with proper feeding and headspacing?
Why are they so hell bent on a .30 cal?
At least they went with Stiller, but they insist on the damn remington footprint and 90 degree bolt throw.

Wow that's quite the word salad right there.

You do realize that the Marines are probably not getting brand new rifles?

The Mk.13s have been in service in some form or another for over a decade. They are probably getting rebuilt guns that the SOF guys no longer use because they have the MSRs. It's basically a lateral move on CRANEs part.

The ammo already exists in the supply system. The maintenance program already exists. The supply chain exists. The combat performance already exists. The Marines didn't start from scratch to come up with the Mk.13.

The belt is a total non-issue. The performance of the 300WM is also a huge leap above 7.62 NATO, and on par with 338 Lapua for most practical purposes. It's the largest cartridge I would want to carry.

The 300 Norma and 6.5 Creedmoor junk is on the way too; but it's not going to line companies in the Army or Marines.
 
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NSW has been running 300WM since the 80's. SOCOM elements have been running it since before there was a SOCOM.

The Marines are going to get new MK13Mod7's, built on stiller actions. They aint paying $5M for rebuit or used rifles.

The MSR is a piece of shit and will be replaced. The current iteration of the MK13 is a much better built and reliable weapon system.
 
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