300 Norma Improved 35 degree

[kfreeze]

Kyle,
I haven't tried 24N41 yet in the 300 NMI but I will say this. - In Larger capacity cartridges (338 Lapua Imp. being one of them) 24N41 has a very similar burning rate to V/V N570 but doesn't yield the velocity that the high energy double based V/V N570 does. - IMO it (V/V 24N41) would be a very viable option in the 300 Norma Mag. Imp. - My observations of V/V 24N41 are that it is slightly faster in burn rate than Alliant Reloder 33 in the 338 Lapua Imp. - I can also state that 24N41 is faster burning than H50BMG in larger capacity cartridge cases without a doubt. (In a "50" I would use 24N41 for lighter bullets - i.e. 640 gr but not anything over 700 gr. and a 750 gr. A-max or a 800 gr. lathe turned solid are considered as "standard" competition weight bullets in a 50 bmg.)
I applaud you for keeping an open mind and thinking when it comes to using "available resources".

All The Best !

Thanks! I remember you mentioning that, but I saw h50bmg being used in the 300 nmi and was hoping someone had tried the 24n41 in it. I snagged an 8lb jug of h50bmg the other day, but have seen 24n41 available several times since this whole scarcity stuff came around. What I read with the h50bmg was similar to your results with the 24n41. It had a little less velocity, but the es was really good.

 

[kfreeze]

Kyle,
I haven't tried 24N41 yet in the 300 NMI but I will say this. - In Larger capacity cartridges (338 Lapua Imp. being one of them) 24N41 has a very similar burning rate to V/V N570 but doesn't yield the velocity that the high energy double based V/V N570 does. - IMO it (V/V 24N41) would be a very viable option in the 300 Norma Mag. Imp. - My observations of V/V 24N41 are that it is slightly faster in burn rate than Alliant Reloder 33 in the 338 Lapua Imp. - I can also state that 24N41 is faster burning than H50BMG in larger capacity cartridge cases without a doubt. (In a "50" I would use 24N41 for lighter bullets - i.e. 640 gr but not anything over 700 gr. and a 750 gr. A-max or a 800 gr. lathe turned solid are considered as "standard" competition weight bullets in a 50 bmg.)
I applaud you for keeping an open mind and thinking when it comes to using "available resources".

All The Best !

Here it is on the h50bmg. Thought you would like this. I was thinking that with a 245 berger or 250 atip the h50bmg may be decent. And more so if I run at least a 30" pipe. He only had a 26".

 

[LA50SHOOTER]

Here it is on the h50bmg. Thought you would like this. I was thinking that with a 245 berger or 250 atip the h50bmg may be decent. And more so if I run at least a 30" pipe. He only had a 26".

For the 230's on up Kyle, - I'd go with the H50BMG rather than 24N41 and never look back. - H50BMG is a good powder in over-bore and large capacity cases - period. - I love it in a 35" barrel in 30-378 with 230's.

Another group of powder(s) you may want to consider and this is based on both price and availability is surplus WC-860, WC-867 & WC-872. - These can be had for $60-$70 bucks for an 8 pound jug (plus shipping & Haz-Mat). And they are available.
The thing about the surplus ball powders is there can be considerable Lot-To-Lot variations, and they seem to want to operate good at +90% case fill & up. - Also in hot climates they can exhibit pressure spikes where loads were developed in cooler temperatures. - So, its a matter of managing the pressures in relationship to temperatures. - The old Hodgdon H-870 was "touted" as a "go-to-powder" back in the early days for big over-bore magnums, - it was a surplus military powder, but Hodgdon ran out of it so it's not on the market.
The ones I've mention are similar to the H-870, and for WC-872 I use H-870 in Quick-Load to find my starting point when I develop loads.

I'm not trying to steer you away from H50BMG at all, you've probably picked one of the Best powders for Heavy Bullets in the 300 Norma Mag Imp. - Just pointing out that there are options available for these larger capacity cartridges.

All The Best ! - Ron

 

[kfreeze]

For the 230's on up Kyle, - I'd go with the H50BMG rather than 24N41 and never look back. - H50BMG is a good powder in over-bore and large capacity cases - period. - I love it in a 35" barrel in 30-378 with 230's.

Another group of powder(s) you may want to consider and this is based on both price and availability is surplus WC-860, WC-867 & WC-872. - These can be had for $60-$70 bucks for an 8 pound jug (plus shipping & Haz-Mat). And they are available.
The thing about the surplus ball powders is there can be considerable Lot-To-Lot variations, and they seem to want to operate good at +90% case fill & up. - Also in hot climates they can exhibit pressure spikes where loads were developed in cooler temperatures. - So, its a matter of managing the pressures in relationship to temperatures. - The old Hodgdon H-870 was "touted" as a "go-to-powder" back in the early days for big over-bore magnums, - it was a surplus military powder, but Hodgdon ran out of it so it's not on the market.
The ones I've mention are similar to the H-870, and for WC-872 I use H-870 in Quick-Load to find my starting point when I develop loads.

I'm not trying to steer you away from H50BMG at all, you've probably picked one of the Best powders for Heavy Bullets in the 300 Norma Mag Imp. - Just pointing out that there are options available for these larger capacity cartridges.

All The Best ! - Ron

Thanks for that info Ron! I'm just happy I was able to see 8lbs of h50bmg and get it in time. Lol

 

[X-Caveman]

Anyone running 199 Hammer Hunters? I have H1000 or N165, for a in 26” 9 twist Proof.

 

[rhovee]

I haven’t run them in a 300 NMI, but have in 300 wsm along with the 260’s in 338 NMI. Both shot great at .010 off. H1000 would be great. I would follow the 215 Berger load data with H1000.

 

[Wildcats]

What freebore are y'all running for the 230s,245s and 250 A tips.?
And where does the boat tail junction end up in the neck area?

 

[Alex Wheeler]

What freebore are y'all running for the 230s,245s and 250 A tips.?
And where does the boat tail junction end up in the neck area?

Unfortunately all of those need a little different. What is you first and second pick, then I can give you an idea.

 

[kfreeze]

Who is the best company to get dies for the 300 nmi? I've heard a few people talking about how some companies have the 300 nmi figured out a little better than others, because the brass behaves differently?

 

[Wildcats]

Unfortunately all of those need a little different. What is you first and second pick, then I can give you an idea.

230 and 250 A- tips

 

[Alex Wheeler]

2 very different bullets. You have to pick one. The 230 will work with others in the 260-280 range the 250 is all by it self.

 

[Wildcats]

I figured that the 250A tip wouldn't work with the other 230s. so settling on the 230 berger and 230 Atip
Can always try the 245 berger. didn't think the 250s would work with a 9 twist and also being longer.

 

[X-Caveman]

Has anyone run 230s with US869 in Alex's chamber with success? LGS has loads of it...

 

[Ledd Slinger]

Getting ready to build my 3rd 300 NMI. Picked up a BAT HR Lapua action, BnA TacSport Pro trigger, and a Hart 1 in 10” barrel that slugs very nicely and the bore finish is a work of art.

Probably going to go with a B&C Long Range Hunter stock.

Haven’t fully decided on an optic yet. Might bring my Trijicon 4.5-30x56 over from the other NMI or might go with something lighter.

So I’m wondering if I should try a different reamer? Mine works good enough but I think I have kind of wrung what I can out of the design after two rifles on the same reamer now. My current NMI will shoot between 1.5”-2.5” groups regularly at 500 yards with Berger 220s so plenty accurate enough for hunting. But I think other designs can do a little better. What’s the best accuracy you guys are currently seeing with other designs?

 

[Alex Wheeler]

Your reamer design is not holding you back. I dont know what your first build was but I think your current one is a proof barrel? I think going to a steel barrel will help, and so will a little heavier rifle. In my experience you do give up a small amount of raw accuracy with carbons. They can shoot very well, and some are excellent but on average an all steel barrel is going to shoot a little better. Not an issue for a hunting rifle.

 

[Ledd Slinger]

Yeah the B&C Lr Hunter stock without the adjustable cheek piece is 2.5 lbs. The Hart barrel is Remington factory Sendero contour I believe or maybe a heavy 5 so it’s has some heft. Depending on scope, it should all add up to about a 10-11 lb rifle.

My first NMI had a huge 30” broughton on a single shot Defiance but it was an 8” twist. The 9” twist definitely shoots better with anything up to 230gr but I think the new 10” twist will do even better with the 220s I’m using.

I’ll never do an 8” twist for any big fast 30 cal again. I think 9” is even a little too fast for anything up to 230gr. For those bullets, I bet optimal twist rates would be 9.5” on the tight side and 10” for running top speeds in a big 30. So perhaps 9.75” would be perfect. Not sure yet. Will see how this 10” runs the 220s

 

[MagnumW]

40 oz stock and steel sendero barrel hard to see under 12#-13#

 

[Ledd Slinger]

40 oz stock and steel sendero barrel hard to see under 12#-13#

Yeah I’m wishful thinking. But I bet I can keep her around 12 or under with the right scope and rings so not too bad.

2.5 lb: stock (not fully decided yet)
2.5 lb: BAT HR receiver/BnA trigger
4 lb-ish: 26” barrel, probably flute the barrel too. (my unchambered 28” blank is 4lb, 15.8 oz)
2 lb: scope and rings
1 lb: Hawkins M5 CIP dbm and 3 round Accurate Lapua mag (probably weighs less than 1 lb)

 

[Alex Wheeler]

Got some feed back on one I just sent out,

Of course I built it on a Bat HR action, full nitride, integral 20 moa rail and lug, CFE 9 3.990" Wyatts bdl box, timed from the factory for a trigger tech, but also times to a Jewell or Bix. Superb ignition, as straight as it gets, massive lugs designed from day one to handle the .580 case head.
I bedded it into a Manners PRS1 stock and used a Hawkins M5 bdl. I also fitted a CIP length DBM floor plate so you can swap from a BDL to a DBM for competition as this is a dual purpose hunting/steel/elr rig.
The barrel is a 9 twist 5r Bartlien at 26" that he runs suppressed.
After the barrel broke in and finished speeding up the final load ended up at 90.7 of N570 with a fed 215 primer. 230 Berger .030 off the lands, annealed on an AMP with .003" neck tension. This runs about 3080 fps. He tested one piece of brass, 7 times at 3130 fps and 3 more at 3080 to verify this was not hurting brass and would last. No issues, primer pockets tight, no sizing or extraction issues as it should be. This load has been repeating in the 3-4" range at 1100 yds for him.

 

[nakneker]

This load has been repeating in the 3-4" range at 1100 yds for him.

Wow!