300 Norma Mag

[MontanaRifleman]

welp..i was wondering about this caliber a while ago and finally emailed Jimmie Sloan. He assures me that if the barrel is well taken care of the barrel should hold good accuracy from 2500-3000 rounds!!!...


Now.. I am no expert and I didnt design the cartridge... But similar cartridges in the same class get no where near that amount of barrel life. I have heard of the .300wsm getting 3000 rounds but I am sorry to have to disagree with mr. sloan. I doubt you would get 3000 rounds with the .338 norma. I was going to be excited if he told me that they were getting 1000 rounds down the tube before accuracy starts to fall off.

There are a lot of things that affect barrel life. The 300 Norma mag is maybe 3 or 4 gr less capacity than the 300 RUM. I don't know many people who will guarantee you 2500 rounds of barrel life out of a 300 RUM or even a 300 WM which has 18 water gr less capacity than the Norma. The Norma has a longer neck than the RUM, but sharper shoulder. If you blew the shoulder up to 40*, that would help a little and you would essentially have a RUM equivalent.

Headstamps don't determine barrel life. Powder, pressure, shooting rate, bore care, etc., do.

 

[Bart B]

Headstamps don't determine barrel life. Powder, pressure, shooting rate, bore care, etc., do.

So does the marksmanship qualities of the shooter. Ne'r do well's can easily get 4000 round of "accurate" barrel life with way overbore capacity 30 caliber magnums shooting 2 inch groups at 100 yayds. They're well satisfied with "minute of bear" accuracy.

 

[ishootkittens]

Around here we sometimes hunt deer and bear with slugs. Sometimes 2" groups or minute of "bear" is enough! Of course id never speak that blastphemy on this forum

 

[MontanaRifleman]

Around here we sometimes hunt deer and bear with slugs. Sometimes 2" groups or minute of "bear" is enough! Of course id never speak that blastphemy on this forum

Well, this is Long Range Hunting and most guys here are looking for 1/2 MOA accuracy or better with their rifles. 2 MOA accuracy is fine inside 300 yds but it really doesn't apply here. If I can't consistently hit 1/2 MOA plus or minus (Sub MOA total), @ 1000 yds then it's time for a new barrel for me.

 

[ishootkittens]

Of course id never speak that blastphemy on this forum

Good to know i can still use that shot out barrel under 300yds tho! Considering the longest game ive ever takin here in va was around 280. I forget u comp shooters arent happy with moa accuracy

 

[MontanaRifleman]

Good to know i can still use that shot out barrel under 300yds tho! Considering the longest game ive ever takin here in va was around 280. I forget u comp shooters arent happy with moa accuracy

I'm not a competition shooter but comp shooters are definitely not satisfied with MOA accuracy. Why would they be? Not going to win many competitions with MOA rifles or even 1/2 MOA rifles.

Accuracy and barrel life mean different things to different folks. I'm not trying to bash anyone. This is the Long Range Hunting site and and accuracy here usually means 1/2 MOA or better. Like the saying goes... Only accurate rifles are interesting to me. In other forums, accuracy means .1's and .2's and in yet others it means minute of moose.

You said that someone would GUARANTEE that the 300 Norma would have 2500-3000 rounds of "good accuracy". I find that incredible. What does he mean by "good accuracy". First, I wouldn't guarantee anyone anything, especially since there are so many variables involved. next, if anyone asked my opinion I would say you might expect XXXX rounds of life depending on what load your shooting and how you shoot it. Even then no 2 barrels are identical.

IMO, the 300 RUM is good for about 1000 rounds (of original or close to original accuracy) if you take care of it and don't shoot it hot. The 300 Norma mag is going to be very close to that as well if you shoot the same powders and pressures and rate. A 300 WM maybe 1500-2000 and a 300 WSM over 2000.

All that said, some barrels will continue to shoot well even when their fired cracked. My 25-06 Senderos was one of those. But I would never GUARANTEE anyone that just because mine shot well with a fire cracked barrel, that theirs would also.

To me when you guarantee something, you back that guarantee with $$$$. Anything else is just empty talk.


EDIT: It was "assured", not "guaranteed".... same thing to me.

 

[ishootkittens]

Not accusing you of bashing anyone and I know the definition of accuracy is differrent from shooter to shooter but the "someone" who told me the "barrel would last 2500-3000 shots depending on how you take care of the barrel" is jimmie sloan (the designer of the 300 and 338 norma.) That is the whole reason I posted to begin with. I never used the word guaranteed to begin with. I simply emailed him because no one I spoke with about the caliber has shot out a barrel yet, So I went straight to the source. I was going to be thrilled if he replied that he had 1000-1200 rounds down the tube before his groups start to spread (and who knows they may have) but in his reply he told me the barrel should last 2500-3000 rounds depending on barrel care and temperature. As I stated, I am no expert (hell I don't even have a .300 norma) but it isn't everyday that u get to speak to a designer of a cartridge so I decided to give you all some feedback that was given to me.

 

[MontanaRifleman]

Without trying to badger you, the bottom line IMO is that a 300 Norma Mag is not going to get anywhere close to 2500 rounds of accuracy... accuracy meaning if you start shooting 1/2 MOA with it, it's probably going to open up to greater than .7 MOA long before 2000 rounds if you're shooting 65,000 psi

The only way a case design will increase barrel life is to lengthen the neck and sharpen the shoulders. But even that benefit is limited. When you torch your throat and bore with heat and pressure, it is going to have an affect on the steel. The 300 Norma Mag has a moderately long neck but only a 20* shoulder. There is really little to nothing about the case design that is conducive to long accuracy life.

I'm sure it's a fine cartridge, although I think it would be better with a 30* or sharper shoulder.

 

[IdahoCTD]

I'm sure it's a fine cartridge, although I think it would be better with a 30* or sharper shoulder.

Or 35* . I'll have one before too long.

 

[ishootkittens]

Without trying to badger you, the bottom line IMO is that a 300 Norma Mag is not going to get anywhere close to 2500 rounds of accuracy... accuracy.

Badgering..no sir..im agreeing with u. I can only tell u what the designer told me. I have enough (maybe not as much as some) to know what affects barrel life and i see very little difference in the norma and the rum in terms of barrel eating ability! Just decided to post what i received from jimmy. Ive never even shot a norma so i couldnt speculate

 

[MontanaRifleman]

Badgering..no sir..im agreeing with u. I can only tell u what the designer told me. I have enough (maybe not as much as some) to know what affects barrel life and i see very little difference in the norma and the rum in terms of barrel eating ability! Just decided to post what i received from jimmy. Ive never even shot a norma so i couldnt speculate

I just read the writeup for the 338 Noram Mag in Ammoguide. It says it's supposed to have better barrel life than the 338 Lapua. Maybe just a tad since it's a tad smaller in capacity. Other than the Norma being shorter and fatter at the shoulder, it is very much like the Lapua. I would like to know his reasoning. Sometimes creators go a little overboard in their promoting.

 

[ishootkittens]

I agree. We all saw how long the .300 lapua lasted. There aare a few here and there but they eat through barrels like it's jello! Id say the .300nm will get u a LITTLE more barrel life.

 

[RockyMtnMT]

Old thread, but a good one. I wanted to add to this one as it pertains to what we are working on.

We just got a customer rifle done and started doing load development. It is a 300 Norma mag improved. Rifle is Defiance Deviant action, Proof carbon fiber Sendero contour at 26", medium Pain Killer brake, Jewel trigger, AG Composite sporter stock, topped with Nightforce SHV 5-20X56. The improvement picked up about 6.5g in powder capacity. We got about 1/2 of the brass fire formed and just couldn't wait to work loads, so we stopped forming and went to loading. The Proof barrel is a 9.4" twist so we designed a 200g Hammer Hunter for it. We also HBN coated them.

Started load work up with RL-26 but stopped after a few rounds as it was looking like we would not be able to get enough load density with it. We then tried RL-33 and ran out of case capacity and barrel length to get to pressure. Next on the list was H1000. This turned out to be the ticket. We reached about 98% load density, just under compressing, at 90g and 3250fps. At this point the load was just starting to show some pressure with slightly flattened primer. If it were our rifle and it was staying here we probably would have taken it higher to see top end, but there was no point as this rifle will be living in Missouri. We backed down a grain to 89g for a vel of 3215fps and single digit sd's. Very happy with this cartridge and load. Shooting RUM velocities with 10g less powder and a significantly shorter cartridge. Fits nicely in standard magazine with bullets seated out long enough to stay out of the powder column.

Rifle looks like a very good shooter. So far only shot at the short 200 yard range. All of the load development fell inside 3" and the final load was shooting inside 1". This rifle is at 10.5lb and very comfortable recoil wise. About like .243.


This is a pic of fire forming before and after.

Steve

 

[shootlapua338]

Thanks, I've got a surgeon rifle in this caliber and just st getting started. I'll let you know how it works

Merry Christmas!

Mark