.375 Norma

[80Rooster]

Thanks Swamplord
I am on the same thought process as you on this one. My early estimates on case capacity are +/- 90 grains of H1000 or equivalent I am looking at a 26" # 5 fluted brux barrel and I think it should push the 260 gr Accubond in the 3000 - 3100 fps range my stiller action showed up on the 22nd hoping to have the rifle chambered in the next couple of weeks I am putting it in a Mcmillian Weatherby mark 5 stock and topping it with a Swarovski 3-18. I project the rifle to come in just under 9 pounds which will be almost 4 pounds lighter than my .330 Dakota I ain't got no brown bears to try it out on but I think it will be a hell of an elk round that won't be a bother to pack.

 

[Kennibear]

80Rooster

I currently own a 26" barreled Savage in 375 Ruger. I have worked with the 68mm Mannlicher case in 6.5 and it's base diameter is 0.010" smaller. The shoulder of the 8X68 MS is a gentle 14 1/2 degrees and shorter than the Ruger to the shoulder and about as long to the shoulder neck junction. The 6.5X68 MS has a lot more case capacity than the 264 WinMag but I doubt the 68mm MS case is a match for the Ruger.

That all being said the Ruger holds 95 grains of Superformance or 89 grains of RL 19 to the bottom of the neck. My Savage detachable box is 3.49" inside and I load Speer 270's and Sierra 300's to 3.45" without jamming the rifling. They feed up just fine even though they are 0.110" longer than SAAMI max-COAL. I don't know what powder capacity you are aiming for but 90 grains is a bunch and the Ruger case can accommodate all of that. I have an unfired test load for the Speer 270 that is 3.4" COAL w/ 86.5 grains of Superformance and there is still room in the case. That COAL puts the bearing surface of the bullet shank even with the neck/shoulder junction for maximum bullet support. Only the Boat Tail is in the powder space - and with room still left over.

As for velocity, I just started with the Nosler 260 AB and 79.5 grains of WW760 drives it 3022 fps Av w/ a SD of 9 fps. But it is a 26" tube and that load is absolute max. Hodgdon's lists the pressure @ 61 Kpsi and my Pressure Trace II confirms it. I could use a lot more WW760 but the load cannot be increased. My next powder will be RL 19 or maybe Superformance. I would like to try Ramshot Hunter but cannot find any.

Good luck on your wildcat but those who sell the 375 Ruger short don't own one. It was designed by Hornady to match the 375 H&H.... but with a 20" barrel. To do that it burns 9-10 grains more powder. The 375 RUM is really the next step up. Look at it this way 375 H&H = 80 grains, 375 Ruger = 90 grains and 375 RUM = 100 grains. Only the Ruger fits a standard length action.

Just my experience so far. Bought the Savage in 375 Ruger to deliver a ton (2000 ftlbs) @ 500 yards. The Nosler 260 AB @ 3022 fps delivers it out to 630 yards... mission accomplished!

KB

 

[Swamplord]

**update on the 375 PRO.. (375-338 Norma Mag**

my 375 PRO (375 Precision Rifled Ordnance) is a necked up, blown up to 35 degrees wildcat, based on the 338 Norma Mag case, also use 338 Lapua brass with neck cut off, sized down, fireformed via cow and 20 gr of Blue Dot, then neck turned

the 1st photo explains why I developed it......

just fire formed 30 pcs of 338 Norma cases using 75 gr of RL 19 and 300 gr Sierra Game King bullets jammed into lands
will proceed with load development as time allows next week.... 375 RUM starting loads will be used since this wildcat is almost identical in capacity.......

rifle specs are

chrome moly Rem 700 (300 RUM donor)
McMillan swirly Rem Sporter stock (70% black, 30% Olive)
29" 12 twist #5 contour fluted Brux barrel (4 port brake machined into extra inch)
Jewell trigger
Extreme Hardcore Gear 20 moa picatinny base
Vortex 1" rings
Sightron SII Blue Sky 3-12X 42 mm scope

9 lbs 4 oz total weight
barreled action will be Cerakoted black after load developement

will be packing it around in Alaska this spring on a brown and black bear hunt then a moose hunt in the fall ........

will be loading WS2 coated Cutting Edge 320 gr (.830 bc) bullets to 2800 fps.... to deliver a ton (2006 ft. lbs.) at 1140 yards and 1102 ft. lbs at 1760 yards (1 mile).....

3252 ft. lbs. of energy at 630 yards compared to the 375 Rugers 2000 ft. lbs. ........... mission accomplished !

 

[etisll40]

Both those 375 cases are sexy! haha...

I like that shorter oal a lot. How long will the brass last with all that work?

Looks like a super wildcat for future development to me. I can't believe the energy out to 1 mile!

 

[Swamplord]

Both those 375 cases are sexy! haha...

I like that shorter oal a lot. How long will the brass last with all that work?

Looks like a super wildcat for future development to me. I can't believe the energy out to 1 mile!

All I did was run the 338 Norma Mag cases through a 375 expander and fire formed with a mild 375 Ruger load...... cases should not have been affected as the shoulder still needs to sharpen up a bit,
alternatively you can run the case neck up to .400" then size down to .375" far enough to create a headspace shoulder and use the cream of wheat fire forming method, I did not have an expander that size and did not want to work the case neck too much by expanding to .416" and back down again......

Just for reference I necked up the 338 NM and 338 LM cases up to 375 and checked for case water capacity...... the 375-338 Norma still leaves the 375 Ruger in the dust dragging arse...... fire forming to the 375 PRO gained 6.4 gr more, further widening the gap......

the 375-338 Lapua is identical in capacity to the 375 RUM,
... note that these are new unfired cases just necked up to 375, fired cases would show slightly more.... improving the 375-338 Lapua case will yield about 8-12 gr more ...depending on body taper, neck length and shoulder angle.... but running the long high bc Cutting Edge bullets will have to be single shot as they are too long for the AICS cip length mags, seating the bullet deeper will reduce the capacity and bring it closer to the 375 PRO.... all this was taken into consideration and I went with the 338 Norma Mag over the 375 RUM and 338 Lapua for my wildcat...

Norma and Jamison make 338 Norma brass and if need be I can make brass from 338 Lapua cases by cutting the neck off and sizing down to .375" far enough to chamber and cow banging it then turning the neck down to proper dimensions...

theres numerous manufacturers making 338 Lapua Mag brass
the excellent Lapua stuff
Norma, Nosler, Jamison, Hornady all make the stuff and theres HSM and Horneber if ya can find it.... also available is Swedish RUAG once fired brass and Lapua made Military brass .... all you need to do is PAY for it, lol!
........

 

[etisll40]

This is probably the most interesting 375 on the table, that I've seen. Not that I'd know! But I really like that shorter oal. As far as dangerous game type rifles, extraction and such, will your Remington have anything special done to it? I wonder if a Ruger action or Sako might be better suite?. If it works out, I might build one on some action, maybe Remington even. Not knocking a Rem 700 as I like the trigger options and lots of gunsmith's work on them. Brass life will be interesting to see. Lots of test cases though. It will be interesting to see what the best brass solution is. Could be an official SAAMI cartridge eventually! It would be cool if Norma or Lapua takes a look at it. No forming and some factory ammunition would make it an instant success.

 

[IdahoCTD]

I bought 500 of these cases in anticipation of doing a 375 and maybe a 416 just like this. They are made by Lapua, I just don't know know how tough they are. I will probably build a die from my 30-338 Norma Imp. reamer to try and neck some down to 30 in the meantime.

Graf & Sons - DAKOTA BRASS 423 DAKOTA UNPRIMED BULK PER 20

 

[Swamplord]

I bought 500 of these cases in anticipation of doing a 375 and maybe a 416 just like this. They are made by Lapua, I just don't know know how tough they are. I will probably build a die from my 30-338 Norma Imp. reamer to try and neck some down to 30 in the meantime.

Graf & Sons - DAKOTA BRASS 423 DAKOTA UNPRIMED BULK PER 20

Hey.. thanks for the heads up on the brass at GRAFS
I just ordered 500 pcs........

gonna need it, I have 5 wildcats I developed off the 338 Norma Mag case....

the 423 Dakota will work great for my .416, .458 and .500 cal wildcats ...

 

[etisll40]

Great idea. If you neck some down to shoot in your 30-338 Norma, let us know how they hold up to multiple firings. This might be a great brass deal waiting for people to figure out! Thanks... I wonder how they'd hold up to just a 338 Norma, pretty cheap way to shoot a lot of that caliber if they are like typical Lapua quality.

 

[IdahoCTD]

It will take a bunch of dies to get it to .30 cal but I'll make a .375, .338, and .30 dies to try it. It's about 1/3 the cost of Norma.

 

[sp6x6]

Swamplord, Really like what you did, the improved was a substantial gain. Seems like a perfect rifle for AK to me.

 

[Swamplord]

I bought 500 of these cases in anticipation of doing a 375 and maybe a 416 just like this. They are made by Lapua, I just don't know know how tough they are. I will probably build a die from my 30-338 Norma Imp. reamer to try and neck some down to 30 in the meantime.

Graf & Sons - DAKOTA BRASS 423 DAKOTA UNPRIMED BULK PER 20

Necking down from .423" to .308" is do-able, as long as you do the sizing down in several stages
I managed to neck down the .500 Jeffery (.510") down to .308" .... it's a lot of work and requires patience and the desire to mess with the process, for me it is a full time hobby that I enjoy immensely, guys I know freak out from seeing the stuff I do to cartridge cases and want nothing to do with wildcats,
I will see if I can run that brass down to .308", I already have the dies I need to do that as I have several wildcats on the 338 Norma Mag I have been messing with , I gotta admit the Norma brass has been very easy to neck up and down, I hope this stuff will be every bit as good as Lapuas 338 Lapua Mag brass ...

Here's my Precision Rifled Ordnance (PRO) family of wildcats ...,
338 Norma Mag parent case


6.5mm, 7.62, .375, .416, .458 and .500 , the 500 is my newest project and is gonna be a stomper !!
also have a reamer in the 338 version and will be working on it after the 500...also have been thinking of doing a 7.92 cal !

 

[Swamplord]

the 500 PRO with bullets from 350 gr CE to 700 gr T. Rex Thumpers
the ring in the middle of case neck is the shoulder from the 338 Norma and will iron out by fire forming , using 338 Lapua brass is 100% a go as shown in the last dummy cartridge next to a 338 LM case, just cut the neck off a bit high and fire forming will pull back extra length to fill out the wider top of body dimensions !

I think I'm gonna like this one the most !!!



.......

 

[etisll40]

Vry sext, I may put this next to the model on the wall. Love the one on the end, kinda like a 458 socum?