A " new" 30 Cal

I thought the 300 Win Mag that should have been was called a 300WSM ;)

I thought the 300 Win Mag that should have been was called a 300WSM ;)

Yes - they took away the belt - a marketing anachronism
Then they made it fit in a - short action , another market driven design change

I do however believe that there is some difficulty in finding brass for the 300WSM ?
Whereas brass for the 300WM is very plentiful
Personally I do not like short dumpy fat arse cartridges
Why do I see so many people battling to feed and chamber the 6mm Dasher ?
I like my cartridges classical - svelte and in proportion - like my woman

I will be doing something similar for the 7mm Rem mag and the 8mm Rem Mag - ALL based off the same 300 / 375 H&H the father of all medium calibre belted magnums
Perhaps the 338 Win Mag as well ?

Do I get this right?

Take a 300WM case, cut away the belt, shorten the neck, blow out the case to almost AI dimensions?

Then take a 300WM barrel, shorten the chamber, and voila?

Do I get this right?

Take a 300WM case, cut away the belt, shorten the neck, blow out the case to almost AI dimensions?

Then take a 300WM barrel, shorten the chamber, and voila?

Lengthen the neck - shorten the case COAL
Otherwise correct
A standard 300WM barrel will need to be set back a bit and re-chambered ( slightly )
Optimum bullets will depend on the original barrel twist rate ( apparently somewhere around 1/10 is good ? )
As far as I can see no change to the bolt face
Still working out the dimensions for the - throat / leade / freebore / lands etc ( need expert input here )
Will be a slightly longer throat for long VLD / monolithic type bullets

At least that is the intention
The proof will be in the firing ( the simulations are good )
Not looking for anything more than a good accurate easy to reload lower recoil everyday use cartridge

What twist rate are you going for?

1:10 for hunting or 1:7 for shooting high BC target bullets?

Which speeds do you want to obtain, with which bullets?

What twist rate are you going for?

1:10 for hunting or 1:7 for shooting high BC target bullets?

Not sure yet
Perhaps similar to the 300 PRC ?
1:9 ?
Going to use existing barrel to test before deciding on final new barrel
Still LOTS of work

Which speeds do you want to obtain, with which bullets?

Simulations indicate somewhere near 3,000fps with a 175 / 180 gr 61,000 psi with @ 65,000psi max pressure
All depends on what powders and bullets are available here
Still LOTS of work and testing

This is a quickly put together QuickLOAD simulation
Image of a screenshot from QL

[attach id=478 width=1024 height=768]Hybrid-100v.jpg[/attach]

As a comparison and check

Load data from the online calculator at Hodgdon

300 WM load data

As can be seen the results are very close - with a little less powder
It appears that with nearly all the Magnums the best loads are at or near max

A favour ...

I am trying to find out what the maxCOAL of the HOWA standard length action is on their 300 WM is ?

Anyone with a HOWA in 300 WM that can check and measure what the longest cartridge is that they can fit in the INTERNAL box magazine ( and feed reliably )

HOWA produce a 300PRC in "standard length action" with a 26" varmint barrel
However the COAL of the 300PRC is in the region of 90mm - much beyond the 300WM

HOW is this done ?
Is the 300PRC a completely new action?
or
Is a little machining involved in order to provide the extra space ?

Anyone know ? ( any gunsmiths out there )
Anyone has one and can check

From what I could find and this is not my "know" only my Google.
Long/standard length actions accept cartridges that are over 2.8 inches in length but under 3.34 inches. The 30-06 and 270 Winchester are popular long action cartridges. Short actions accept cartridges that are under 2.8 inches in length and generally any cartridge over about 2.3 inches.16 Mar 2023

You need a CIP Mag and action.

Dunno if this helps.

Thanks Treeman

My digging around

300 Win OAL (case head to bullet tip) = 3.690? = 93.726
30 Nos OAL (case head to bullet tip) = 3.595? = 91.313

The Howa / Vanguard and traditional Sako (e.g Finnbear) magazine is 91mm or 3.543”

HOWA produce a 300 PRC on their standard action so in that case COAL must be whatever SAAMI is = 93.98

So it appears some modification on the 300PRC action ?

We really need someone to do an actual proper hands on measurement ( surely gunsmiths do this ? )

It will mean I can extend MY COAL from 87mm to something longer - helps with getting longer bullets up out of the powder
Easy enough to have a long throated reamer but not if you are restricted by magazine length ( COAL )

How does this differ from a 300 Norma Magnum, other than the fact that the 300WM brass used to modify, is easy to obtain?

How does this differ from a 300 Norma Magnum, other than the fact that the 300WM brass used to modify, is easy to obtain?

300 Norma Magnum very different cartridge based on the 338 Norma Magnum - based on the 416 Rigby ( also parent case for the 338 Lapua Magnum )

Perhaps you mean the 308 Norma Magnum ?

308 Norma Magnum

Which is based off the same parent case as the 300WM and came out earlier

This The 300 Norma magnum history and performance should answer some of the questions.

My cartridge is somewhere between the 300WM and the 308 Norma Magnum

Got it!! It's a smooth feeding ectomorph version of a 300WSM ;D

Should be a winner as a long distance hunting round.

Got it!! It's a smooth feeding ectomorph version of a 300WSM ;D

Should be a winner as a long distance hunting round.

Will only know when I actually get a reamer and do the conversion
The 7mm Rem Mag modified in similar way will I think perhaps be a better long range cartridge ?
Higher velocity on the same weight 150 /165 gr projectiles
Perhaps an 8mm ( 323) for heavier bullets ?

I like the way you think, but then you are going into 280AI, 7mm Tombi, 284Win and 7mm WSM territory. Either of which would be my preferred long distance hunting caliber, if only there were guns and brass easily available in one of these.

By guns I mean a choice of standard or heavy barrel Howa (or there about) and brass, off the shelf quality like Lapua or Norma. Its just getting so hard to find stuff these days that I can understand people going for the 4 gun combo of 12g, 223, 308 and 9mm.

I like the way you think, but then you are going into 280AI, 7mm Tombi, 284Win and 7mm WSM territory.
if only there were guns and brass easily available in one of these.

You missed out the Sherman offerings as well as the 7x64 Brenneke ( more or less the 280 )

I am not trying to compete with whatever else is out there
Just making something that appeals to me - and - is at least as good as the parent cartridge
Parent cartridge being popular with lots of brass
That works well as a hunting - or casual target rifle cartridge
Where the modified cartridge has the same head stamp as the original

An Update;

SO ..
Courtesy of a kind gun-shop I was able to do some testing
I could not get a definitive answer as to the maximum Cartridge OAL of the HOWA 300WM
I have read that the Remington 700 action has a COAL of 92mm ( 3.622 )
This dimension was something I needed to verify for purposes of my project

I am happy to disclose that my dummy round at COAL of 87mm ( 3.425 ) fit without any problems in the internal box magazine of a HOWA 300WM.
In fact could probably add an extra mm or two
The dummy round fitted snug in the magazine and was held by the feedrails no problem
Bolt picked it up OK and could feed fine
Indicates no modifications to bolt or receiver ( action ) necessary

Next step now is to order the reamer.

I like the way you think,
By guns I mean a choice of standard or heavy barrel Howa (or there about)
Lapua or Norma.

HOWA available in 300WM in a 26" Varmint ( heavy ) barrel at HABITAT AFRICA George branch
Norma as well as Lapua brass available for the 300WM

I like the way you think,
By guns I mean a choice of standard or heavy barrel Howa (or there about)
Lapua or Norma.

HOWA available in 300WM in a 26" Varmint ( heavy ) barrel at HABITAT AFRICA George branch
Norma as well as Lapua brass available for the 300WM

That's where I shop. I basically had a choice between the 26" Heavy barrel Howa in 308 and 300WM. I went for the 308. A real conversation stopper. Like telling your friends you bought a new car, a white Toyota Carolla 1.3. Nobody even goes outside to have a look. I hope I have no regrets not super sizing and going for a 300WM.

TStone over on GS has Howa working rifles which he speaks highly of. He's probably taken more game himself than all of my hunting friends put together and then some so his opinion carries weight for me. My favourite vehicle of all time after my Landcruiser was a 1.3 white Corolla btw 😉.

I have a Howa and have worked on a good few of them. I can only say in the world of cars, whatever your Toyota, ford is, the Howa's will fit in nicely as a Hyundai or Havel. They here, they not going away and more and more people are realizing just how the same or better they are.

That's where I shop. I basically had a choice between the 26" Heavy barrel Howa in 308 and 300WM. I went for the 308. A real conversation stopper. Like telling your friends you bought a new car, a white Toyota Carolla 1.3. Nobody even goes outside to have a look. I hope I have no regrets not super sizing and going for a 300WM.

I have seen the HOWA in .223 as well as .308 in "varmint" barrel configuration - I really like them
The 300WM comes into it's own with heavy bullets 200gr up at longer range - this is where it surpasses the .308
Also for large heavy game = Eland
You now have a good excuse to buy another rifle
However with a 26" barrel you will have to look at a - REFLEX suppressor ....
BTW;
Toyota TAZZ STILL selling at a premium people who have them do not want to sell
Your "friends" are rather stupid :)

I have a Howa and have worked on a good few of them. I can only say in the world of cars, whatever your Toyota, ford is, the Howa's will fit in nicely as a Hyundai or Havel. They here, they not going away and more and more people are realizing just how the same or better they are.

I would suggest a HOWA is a - HILUX
BOTH made in Japan NO Chinese / Korean "junk"
Should you wish a "Gelandewagen" you will have to buy an after-market action ... BAT / BORDEN / DEFIANCE and so on

Custom Actions

Be prepared to fork out anything from R50.000.00 upwards

The Good The Bad and The Ugly

Toyota TAZZ STILL selling at a premium people who have them do not want to sell
Your "friends" are rather stupid :)

After 150,000km of abuse, I sold my white Tazz to the company I worked for. They drove it for another 200,000km loaded with hefty nursing sisters and a 150kg driver over the worst township roads imaginable.

I should have bought two, put them on blocks and saved them for my kids ;)

My mothers Tazz is 22 years old. I offered her a Susuki as a last living years car !!!!!!!!!!!!!!!!!!!!!!!!!!
No way Hoze", she is not parting with the Tazz.

An update ..
A kind soul gave me a few PEREGRINE Glider 216gr long bullets
I was then able to load up a few dummy rounds at .. 88mm / 89mm / 90mm COAL
Would have been good to have had a few more similar bullets to check - but - alas none were forthcoming

Finally managed to visit the gunsmith in Bloemfontein
Tested with the actual rifle

All rounds fitted in the internal magazine perfectly internal feed rails were fine
All rounds were picked up by the bolt and fed and ejected fine.

Last thing to do thing is finalise the design of the - throat / leade / freebore
Then get a chamber reamer cut

[attach id=758]Peregrine-Glider.jpg[/attach]

becoming interesting 8)

becoming interesting 8)

Here are a few LONG .30 Cal bullets I would like to try and obtain - to test further

Barnes 180gr

Barnes 190gr

Berger 215 gr

Sierra 195gr tmk

Nosler 210gr accubond long range

Swift Scirocco 180gr