.338 Lapua or .300 Norma Magnum

[Ronin]

There are no bugs with Norma Magnum

Just full length size the brass 

 

[Moorlander]

300NM is not a Wildcat or an unknown quantity  , its been CIP listed since 2012 and has been taken on by the US Military , brass is freely available  so I dont see any issues...other than the expense of buying and feeding one.

Vihtavuori even have load data

[John MH]

2 minutes ago, Ronin said:

Just full length size the brass 

I did with a Whidden Bushing FL Sizer die, might be my chamber of course, but the Tubb 33XC die reduces the base from 0.5850" (fired in my chamber) to 0.5820", virgin unfired Lapua Brass measures 0.5815" at the same place on the case head. The Whidden FL Bushing die reduced the base to 0.5845", CIP specs a chamber measurement of 0.5854" at the same place on the case, however without a fixture to hold the case to ensure measurement in exactly the same place on each case there will be some variation in dimensions although it (the 33XC die) definitely reduces the base dimension.

[meles meles]

We generally tend just to neck size our brass and keep a separate batch of cases for each rifle. Ought we to be doing differently if we go down the .300 route? 

[John MH]

1 minute ago, meles meles said:

We generally tend just to neck size our brass and keep a separate batch of cases for each rifle. Ought we to be doing differently if we go down the .300 route? 

No not necessarily, every rifle chamber is going to have slight variations. Neck sizing only might work for you but when shooting against the clock FL sizing reduces the chances of having to faff around to get a cartridge to chamber.

[John MH]

.300NM alongside 33XC and 37XC, base dimensions very similar.

[meles meles]

Any results in from the Flatliners yet, ooman ?

[meles meles]

Update:

 

We eventually chose to go down the .338 path, oomans. Your advice on loads (bullet, case, powder) for ranges from 1,000 mards out to 2 miles will be greatly appreciated. Our barrel is a 1 in 9 twist Bartlein, 32 inches long...

[Popsbengo]

2 hours ago, meles meles said:

Update:

 

We eventually chose to go down the .338 path, oomans. Your advice on loads (bullet, case, powder) for ranges from 1,000 mards out to 2 miles will be greatly appreciated. Our barrel is a 1 in 9 twist Bartlein, 32 inches long...

1:9 should stabilise big bombs.  I suggest you buy very, very expensive solids and "lend" some to your mates 🤗

Personally I like Lapua 300gn Scenar, Viht N570, 92gn in Lap brass with CCI magnum primates.  Mine's a 32" 1:10 Truflite,  as you know.  Typically 18 mil at 1mile (100yd zero).

I don't bother with 250gn Lap Scenars now.

Initial tests of the 285gn ELD-Ms seem to be groopin' good at 200yd with 93.5gn of N570 and a 10' jump.  Our little Eskdalemuir jaunt should prove interesting - calculations indicate 15.8 mil at 1mile (200yd zero) - darn slippy those red tipped 'Merican beauties.   Time will tell.

Milky Milky

[The Gun Pimp]

On 5/27/2019 at 3:10 PM, John MH said:

.300NM alongside 33XC and 37XC, base dimensions very similar.

 

[The Gun Pimp]

John,

Have you done any load dev with the 33XC yet?  Powder choice etc?

[John MH]

Not yet but have some RS76 to try.

[tackb]

I have a 300rum which I built to replace a 338 lapua when they were banned on gallery ranges , I am achieving 3260fps with the 208 amax , I shot alongside JMH at the roundhouse ELR and have to say his rifle was a hammer! and although he wasn't getting my velocity those 225 eld-m's he was using really seemed to carry their energy better !

I would likely go 30nm when I change my 300rum , and having had a 338lapua whilst it is a good round I wouldn't go back for ELR use , in fact I would likely go big 7mm for ELR and manage without the recoil etc 

[terryh]

Went with a 300NM build for ELR ‘lite’ ie not the CheyTac type. So hopefully 2000 yard potential.

As it shoots very similar to the 338 could see no advantage in going for a cartridge that was banned from some ranges?? 

300NM has been round for a while, the Smith who built my rifle did though wait for some clarity on chamber and reamer detail as he builds for LEO needed to ensure no issues, I managed to slip my rifle in with 3 test builds that had been required 👌. I’ve not experienced any chambering problems of resized brass.

The bulging of cases near the base is not new, all be it slightly different reason, 300WM has special dies available related to this ref accuracy innovations.

My NM pushes the 230g Berger Hybrids around 2950. With a suppressor it is not at all unpleasant to shoot.RS 80 has worked out well for me.

T