300 Norma Improved shoulder angle?

[NormaMag]

Hello

I`m planning building a 300 Norma imp for long range shooting and 1000 yard bench rest.
What is the best shoulder angle for best precision? Don't know if I should go for, 30,32.5, 35, 37.5 or 40 deg.
I know Tom Sarvers 300 Hulk is 33 deg shoulder and extreme accurate.

 

[bjay]

Hello

I`m planning building a 300 Norma imp for long range shooting and 1000 yard bench rest.
What is the best shoulder angle for best precision? Don't know if I should go for, 30,32.5, 35, 37.5 or 40 deg.
I know Tom Sarvers 300 Hulk is 33 deg shoulder and extreme accurate.

Nop tom sarver is 37*.. im building 300NM improve.i had the choice to go with 30* 35* 37*(hulk) or 40*..we have brothers here wiling to rent 30 35 or 40 or go with tom hulk 37..i choosed 35*..becoz im planing to magazine load and i beleive 40* might give feeding issue and ackley prefer to run hot high preaasure..(barrel too expensive)..i wouldnt go anything above 35*.. i already think 300nm is overbrassed even up to 240gr pellets..let alone improving

 

[NormaMag]

Thanks for the quick reply bjay.
I asked Tom yesterday and he told me 33 deg on the Hulk.Hmm..
Does your 35 degree use standard 300 Norma body taper, or did you go less?

 

[DAVETOOLEY]

For pure accuracy the 300 NM is a bit overbore even with 240's. If you want absurd horse power I've been chambering a 300 Yogi, 300-338 Lapua Imp 30' shoulder. One thing to consider when going to a sharper shoulder are the many factors that come into play when resizing brass. I've found anything sharper than 30' increases the difficulty of precise sizing. The stock body taper on the 300 NM is as straight as you want to go.

 

[NormaMag]

Thanks Dave
I just ordered my first "wildcat/improved" reamer (300 Blaser 37.5deg imp with 300 Dakota body taper.) . Think the case capacity will be around 95 grain of water.
What do you think the perfect case capacity for pure accuracy will be for 220 Scenar, 215/230 Berger?

 

[DAVETOOLEY]

300 WM capacity or so. The WSM has been kicking ass the last few years. I look for good brass and then design reamers. I've been shooting a round based on the RWS 8X68 case for a lot of years. Love it. 70+ grs. of powder most bullet right at 3000 FPS or just under. My favorite bullet 187 GR. FB Bib would get to 3150 FPS depending on what lot of powder I was using.

 

[NormaMag]

Perfect
Maby my 300 Blaser imp is all i need for the 220/230 grains bullets.
The case capacity is just above win mag, but 404 based with a longer neck,0.200 throat and good brass from Norma.
I`ve heard a lot of good things about the 30x68 cartridge. Is your improved with less body taper and 30 degree shoulder?How is barrel life?

 

[DAVETOOLEY]

I did a 2.5" long 30 based on the 404 case years ago. It shot very well. Royal pain in the ass making brass. I don't get crazy with body taper either. Again it gets back to sizing. I use .010" taper per inch. Back before this business became a real job I shot quit a bit of 1K comp's. I planned on replacing barrels every two years to keep them fresh for National Championships. I probably put 1000-1300 rounds on them. They were still shooting well but I wasn't shooting steel. A rifle had to be capable of sub .5 MOA at 1K to get noticed.

 

[Donald]

Moving the shoulder forward making the neck a little shorter and a 40 degree would be my choice.

 

[bjay]

No i did not pushed shoulder forward.. just improved it to 35* and lessen body taper. Basically its a hulk with 35 not 37*

 

[NormaMag]

Thanks Bjay.What is case capacity on your 35* version? Strange Tom told me the Hulk is 33* If its 37*. 336" neck?

 

[bjay]

Go'in hot said:
Tom Sarver of Thunder Valley Precision builds the 300 Hulk. He starts with 338 Lapua brass and has a 4 step process to make brass for his Hulk. His Hulk is a "basically" a 300 NM Imp with a 37° shoulder.*

Go'in hot also using same but 40* and he also said that 40* norma improved has same inside dimension as 338 lapua here:http://www.snipershide.com/shooting/sniper-hide-gunsmithing/252699-300-norma-vs-300-hulk.html:

 

[Brasscow]

Guys,

I have to say... I built a 30-338 lapua (29" barrel on AIAX) and was not impressed by the performance. I don't know if its worth increasing the capacity by much over a 300 norma. I could push 230s to 3150 but was way over pressure... It seemed like 3050 was about max. I tried most things from retumbo to h50bmg and even with h50bmg i couldnt go to 100% fill capacity before pressure problems.

This large case capacity with small fill (92gr retumbo was max) created other problems, like hangfires with CCI LRM primers. Meanwhile my 338 norma with 92gr of retumbo and the same problems fires 100% reliably. You may say that this is unique, but I've done a bit further research and a well respected smith and bench resterr agree... 3000-3100 is about the ceiling with the 230, almost regardless of case capacity.

Make sure you do your research before you make the leap. I couldn't find info like this before my venture and now that I finally figured it out I'm sitting on a $1000 barrel and brake, 1500 230s, 300 220 scenars, 400pcs of lapua brass, redding comp die set, my own reamer, a wilson in line seater i had done, etc. Could have bought a hell of a nice trip out west to shoot my 338 norma for that amount of money

 

[Chandalar]

If one is shooting 230s and 240 grain bullets in the 300 Norma, what is your recommendation for best twist rate?
Thanks

 

[NormaMag]

If one is shooting 230s and 240 grain bullets in the 300 Norma, what is your recommendation for best twist rate?
Thanks

You can use 1-10 with 230,but i think you need 1-9 with 240?

 

[DAVETOOLEY]

No need to go faster than 1-10 unless your planning on shooting subs. I've had customers shoot 240's in an 11.

 

[NormaMag]

Thanks for all the help guys
As Dave and Brasscow says it might be too much overbore, at least if I go with minimum body taper and 35-40 degree shoulder.
For pure accuracy with 215/230 Berger and 220 Scenar/240 SMK i might should have pushed the shoulder back and made a 30-35* with a case volume of 95-100 grains of water?
I have a 338 Norma already, and like the design(short and fat) but i don't like the shallow shoulder angle

 

[DAVETOOLEY]

Shoulder angle changes are greatly over rated and expensive. Good dies and ease of making concentric ammo is more important. I have a customer who shoots a 300 Norma in 1K comp. It works but he has moved to a WM capacity cases and gets better accuracy. YMMV

 

[NormaMag]

Shoulder angle changes are greatly over rated and expensive. Good dies and ease of making concentric ammo is more important. I have a customer who shoots a 300 Norma in 1K comp. It works but he has moved to a WM capacity cases and gets better accuracy. YMMV

Straight 300 win mag or wildcat Dave?

 

[DAVETOOLEY]

Wildcat based on the RWS 8X68 cases. Great brass that's tough as hell. WSM's are winning also.

 

[steve123]

Thanks Dave
I just ordered my first "wildcat/improved" reamer (300 Blaser 37.5deg imp with 300 Dakota body taper.) . Think the case capacity will be around 95 grain of water.
What do you think the perfect case capacity for pure accuracy will be for 220 Scenar, 215/230 Berger?

Just a FYI, i'm running 230 hybrids at 2940 fps out of a 30-375 Ruger/30" with a 35 degree shoulder.

Where are you buying the 300 Blaser brass from?

 

[NormaMag]

Just a FYI, i'm running 230 hybrids at 2940 fps out of a 30-375 Ruger/30" with a 35 degree shoulder.

Where are you buying the 300 Blaser brass from?

Hello Steve
What is the case capacity of your Ruger?
I buy 300 Blaser brass from Norma Sweden.

 

[steve123]

I haven't tested water capacity but my load is 78.1 grains of Retumbo at mag length for 300WM AI mags. I went as high as 81 grains/3004 fps but the rifle didn't shoot well there.

 

[MAF47]

Hi bjay,
as you did, I am also planning to get a solution for the combination 230-240grs / 3k fps.
I tried to contact Tom Sarver in order to get details about his 300 HULK, but I experienced the same problems you had with: no way to get a response, neither by mail, nor to the messages left on the phone.
So, looking back to your threads about the search of something similar I understood that you found a solution with the 300/338 NM with 35° shoulder angle, wich seems to be not so different from the HULK.
Did you have your build with that? Thanks for informing, because I am very interested to go with the same caliber.
I also will appreciate your help for the reamer and the case forming.

 

[jaybigboy34]

No need to go faster than 1-10 unless your planning on shooting subs. I've had customers shoot 240's in an 11.

So you think the 230's will not shoot well when going subsonic at distance in a 1-10? thanks

 

[DAVETOOLEY]

This thread is over 4 years old.
There's now data that shows an increase of twist rate faster than 1-10 helps when any aggressively designed bullets reaches the transonic area. Personally I wouldn't go faster than a 1-9. The faster the twist rate the more perfect the bullet has to be.

 

[wildcats]

This thread is over 4 years old.
There's now data that shows an increase of twist rate faster than 1-10 helps when any aggressively designed bullets reaches the transonic area. Personally I wouldn't go faster than a 1-9. The faster the twist rate the more perfect the bullet has to be.

I agree 1-9 is what i went with my first 300 norma ,and it shot the 240 smk quite well.also improved it to 30 degree.
Imo i don't see much gain going beyond 30 -35 degree shoulder.

 

[bjay]

I agree 1-9 is what i went with my first 300 norma ,and it shot the 240 smk quite well.also improved it to 30 degree.
Imo i don't see much gain going beyond 30 -35 degree shoulder.

Ive done so much reamer improved for this cal..i shouldve just borrow yours back then WILL.
Id started with 35 37 30 and build hand full of rigs...my last one is 33 and i took dave advice dont get too crazy improving shoulder angle.you can get better concistency shoulder bump and headspace...doing 35 or less and 11/thousand body taper..this tweak and also dave advised me to make throat diam bit bigger for carbon build up..

 

[wildcats]

Ive done so much reamer improved for this cal..i shouldve just borrow yours back then WILL.
Id started with 35 37 30 and build hand full of rigs...my last one is 33 and i took dave advice dont get too crazy improving shoulder angle.you can get better concistency shoulder bump and headspace...doing 35 or less and 11/thousand body taper..this tweak and also dave advised me to make throat diam bit bigger for carbon build up..

Hey bjay,
Hope things are well over on your side of the islands.
I'm getting ready to build another 300 NM since i sold my other one ,in the anticipation of the new Lapua brass .
Going to wait for the new brass to get here before i order a new reamer.
Probably going to go 30degree again,or just keep it Saami and with a (no turn neck) and throated for the 225 ELD-M. Will stay with 1-9 twist.
Tired of buying custom dies..lol

 

[bjay]

Hey bjay,
Hope things are well over on your side of the islands.
I'm getting ready to build another 300 NM since i sold my other one ,in the anticipation of the new Lapua brass .
Going to wait for the new brass to get here before i order a new reamer.
Probably going to go 30degree again,or just keep it Saami and with a (no turn neck) and throated for the 225 ELD-M. Will stay with 1-9 twist.
Tired of buying custom dies..lol

Kauai still surviving after all them hurricane threat..(ty god)
Ive been using 423 dakota necked down lapua brass and also samples lapua brass i received to do testing.i also got couple hundreds 300nm ABM ammos with lapua brass..my earlier reamers had 341nk 3425s
And i dont neck turn..with my 30° and 33 both has 343nk loaded lapua brass with 230/215 hybrids is around 3375-338
I got better accuracy and lower SD giving bullets enough release room in chamber..with less than 002 not too good.
(This is not our benchrest 6mm round)
This size of magnum need more room for bullet release..the way i check if my neck reamer is good....i drop a bullet inside fired case l.if bullet drop freely,..im good to go.if it dont reamer neck is too tight and might need to neck turn brass.(I don't like neck turning lol)

 

[wildcats]

Kauai still surviving after all them hurricane threat..(ty god)
Ive been using 423 dakota necked down lapua brass and also samples lapua brass i received to do testing.i also got couple hundreds 300nm ABM ammos with lapua brass..my earlier reamers had 341nk 3425s
And i dont neck turn..with my 30° and 33 both has 343nk loaded lapua brass with 230/215 hybrids is around 3375-338
I got better accuracy and lower SD giving bullets enough release room in chamber..with less than 002 not too good.
(This is not our benchrest 6mm round)
This size of magnum need more room for bullet release..the way i check if my neck reamer is good....i drop a bullet inside fired case l.if bullet drop freely,..im good to go.if it dont reamer neck is too tight and might need to neck turn brass.(I don't like neck turning lol)

On the big 30cal magnums around .340 or .342 depending on the brass.
I rarely turn necks nowdays or do any wildcatting of cartridges.takes to much time and effort.
At my age ,i just i just want to do some reloading and shoot when i have time.besides their aren't any places here to shoot distance anyways.

 

[MAF47]

On the big 30cal magnums around .340 or .342 depending on the brass.
I rarely turn necks nowdays or do any wildcatting of cartridges.takes to much time and effort.
At my age ,i just i just want to do some reloading and shoot when i have time.besides their aren't any places here to shoot distance anyways.

Hi Wildcats,
Did you already try to use the 300NM case for fiereforming inside a 35° chamber?
I am plannng to go with this solution aiming to get a sort of 300HULK ctg.
Do you know if anybody experienced this solution?

 

[wildcats]

Hi Wildcats,
Did you already try to use the 300NM case for fiereforming inside a 35° chamber?
I am plannng to go with this solution aiming to get a sort of 300HULK ctg.
Do you know if anybody experienced this solution?

Fire forming new brass to 35 deg. was not a problem.

 

[SAPenguin]

Question for you experienced wildcatters... I have a AI AXMC in regular 300NM, but i want to step up to an improved version. However I want to make sure that the reamer is an exact match to the dies.... do you know of a place that will supply dies with dimensions matched to a reamer? Where did you guys go to get your dies / reamers?

 

[kthomas]

Question for you experienced wildcatters... I have a AI AXMC in regular 300NM, but i want to step up to an improved version. However I want to make sure that the reamer is an exact match to the dies.... do you know of a place that will supply dies with dimensions matched to a reamer? Where did you guys go to get your dies / reamers?

Whidden will make custom dies bases off of reamer prints or fired brass. They made my 6BRA dies based off of the reamer print I provided them.

 

[wildcats]

Whidden will make custom dies bases off of reamer prints or fired brass. They made my 6BRA dies based off of the reamer print I provided them.

Also, Warner Tool and many others based on the reamer print and like mentioned above.

 

[BCX]

So let me ask, is there a real world advantage to improving a 300NM? Im getting ready to build a 300NM or 7-300NM.

 

[wildcats]

So let me ask, is there a real world advantage to improving a 300NM? Im getting ready to build a 300NM or 7-300NM.

IMO, not a whole lot,considering all the trouble you have to go through to maybe gain 100 fps.
However,you if you're going to go through the trouble of necking down and fire forming for the 7/300NM ,i wouldn't go more than 30 degree

 

[BCX]

If i go w the 7-300 Nm i would improve it but i think i would just leave the 300 NM CIP spec.

 

[wildcats]

If i go w the 7-300 Nm i would improve it but i think i would just leave the 300 NM CIP spec.

The cip should work fine with the Berger 195s and the new Sierra 197 smk and even the Hornady 180 eld-m
Maybe someone here is running a similar set up and can chime in.
BTW go with a 1/8 twist or maybe even a 7.5.

 

[BCX]

I have a 7MM 1-7.5 twist in my hands. Waiting on my new action should be here thursday.

 

[RampedRaptor]

The cip should work fine with the Berger 195s and the new Sierra 197 smk and even the Hornady 180 eld-m
Maybe someone here is running a similar set up and can chime in.
BTW go with a 1/8 twist or maybe even a 7.5.

Wouldn’t a 7.5 and even a 1/8 twist be too fast of a twist for the 7mm jacketed bullets at the NM velocities ? That would be 285k+ to over 300k RPMs.

 

[BCX]

It wasn't meant for this cartridge. Im running a 6.5 147 from a 1-7 twist at 3150 fps w no issues. Not sure on the RPMs

 

[wildcats]

I can't speak for the 7.5,the 1/8 will work.

 

[BCX]

I don't think a .5 will make that much of a difference. Fast twist rule at long range!!

 

[wildcats]

I don't think a .5 will make that much of a difference. Fast twist rule at long range!!

I agree,sierra calls for a 1- 7/5 for their 197 smk

 

[wildcats]

My custom built 7mm STW with a Broughton 5C 1/8 28" barrel is getting 2850 fps with 180Lapua Scenars and moderate loads averaging .5 moa or better @ 100yds in an AICs 2.0 with cip mag