300 vs 30-338

[krazy]

I currently have a Rem 700 chambered in a 300WM. I am considering a custom barrel for it and it has been suggested to me that I should consider the 30-338. The barrel on it now is 24 inches and throws a 165 Barnes TSX about 3150 fps. I'm a bit of a speed freak (hence the 165) so I would definatley not want to go to something slower. One problem I have with my current set up is that I can not get many different light for caliber bullets out to the lands and still have 'enough' bullet in the neck for my comfort level. For example I would like to shoot the 165 accubonds but @ .01 off the lands (where they seem to shoot best) it leaves me about .25 in the neck. That's why I went with the barnes - they are a bit longer for the same weight. From what I have been able to determine from the load data, the 30-338 should shoot about the same velocities as the 300WM. So my questions are:

Book data is one thing but can anyone speak from experience on the velocity levels that I should expect from the 30-338?

Also wondering if anyone has any information on the chamber specs of the 30-338 with repect to OAL. In other words, I'm wondering if the 30-338 will allow me to seat the lighter (165ish) bullets out to the lands while still leaving a comfortable amount of bullet in the neck?

Any other info on this caliber would also be appreciated.

Thanks for your help!

[horshur]

30-338 is just a 308 norma mag isn't it?

[krazy]

Originally Posted by horshur

30-338 is just a 308 norma mag isn't it?

from the info i dug up on it, it is not a 308 norma but has similar ballistics.

[horshur]

Buddy who had one used 308 Norma data. Ask "Weatherby" on this site he has that gun now but I have not seen him post much lately.

[ruttinbuck]

Krazy.
The 30 cal barrel turner in town happens to have a 30-338 he competes{or did} with at long range.I've had some discussions with him about this caliber as he is a big fan.More efficient case the 338 is,he gets the 300WM performance with less powder.He swears it is also more inherently accurate.Did I mention he has the reamer ready to go.
Looking at the case diagrams in the nosler book the OAL of the 300WM case is .12 longer, the base of the shoulder is .156 longer on the 300WM case and the top of the neck is .174 longer on the 300WM case.Setting your barrel back .20 {thats 2/10 of an inch} will get you the new chamber if there is enough room safely on your barrel.Go see him and see what he says you can do.RB

[Pat Brennan]

What you need is a barrel throated appropriately for the lighter bullets you want to shoot regardless of what caliber you choose.
Should be nothing wrong with a 30-338, though dies will cost more and resale will probably be less since it isn't a factory round. Many would make the point that it is what the 300 Win Mag should have been.
Before rebarreling I'd decide what accuracy level I wanted and for what purpose ( being realistic with my own abilities), and see whether the current barrel was capable of that.
Nothing at all wrong with a 300 Win Mag. I had a factory barreled 700 that shot amazingly well and I believe they have competed very successfully in many long range events.

[krazy]

RB
I spoke with Mick - he is the one that is suggesting the 30-338. He could not, however, answer my question on weather or not the OAL for the same bullet that I use in my 300 @ .01 off the lands would be shorter or longer in the 30-338. I found his lack of knowledge on that a bit concerning. I guess I could bring him a 165 AB to seat to the lands in his 30-338 and see how it sits. After all his chamber would have been made with the same reemer that he would use for mine so it should be the same - I think?

PB
My factory barrel shoots fine when I can get the bullet out far enough. With certain bullets that I would like to use, however, I am not comfortable hunting with so little bullet in the neck. The barnes seem to work for accuracy and velocity but to be honest I am not that happy with their performance on game. Without getting into a bullet debate I can tell you that I have shot nosler's (bt pt and ab) almost exclusivley over the last 20 or so years with very good success - most game dropping in its tracks. The barnes seem to whip right through game leaving a small exit hole and the animal running off (sometimes quite a distance) before expiring. I also don't like the BC of their bullets but that's another story. I was also thinking that if I re barreled I could opt for a 26" giving me 2 more inches and therefore even more velocity?

Thanks for the help and Merry Christmas to everyone!

[260_Rem]

get a custom barrel installed and have the throat cut so you can touch the lands from the magazine with whatever bullet you plan on using

[Pat Brennan]

Not that I'd try talking anyone out of a custom barrel, but one option would be to try some 180 Partitions in your rifle with a few different powders and chronograph the speeds. 3150 with 165s isn't giving you much if any more speed than a good load for 180s, and naturally trajectory is going to be very, very close. The 180s should give you a bit more of the bullet in the case.
I've used 180 Partitions out of a 300 Win Mag and can tell you that it is a very effective game load, up to big bull moose (penetrating through both shoulders and exiting).

[Downwindtracker]

The shorter 30-338 and the 308Norma are a better fit in the standard 30.06 box,the longer neck and the five grains of powder less will give a more accurate round.Your velocity loss(less powder) will be in the neighbourhood of 2%,a so what.If you have any of the post 64 M-70s or M-700,you may want to climb the ladder to a 300Weatherby or better yet a 30-8mmRM.

[krazy]

Originally Posted by Pat Brennan

3150 with 165s isn't giving you much if any more speed than a good load for 180s, and naturally trajectory is going to be very, very close.

When I first started loading for the 300 i thought i would be able to get close to 3300 fps with a 165. Turns out that I maxed out at 3200 but I backed off another half grain for hunting and ended up at about 3160. I thought about the 180 but was told that (and most books show) a max velocity of 2960 so I stayed with the 165. I have very little experience with the 300WM - are you saying that I should be able to get the 180 going faster than 3000ish?

260Rem, this is what I don't understand. Would the throat be cut during the barrel making process or chambering or is this something that could be done after the fact? Could I just get the throat cut back on my existing barrel? I was thinking that the throat is cut during the reaming of the chamber and therefore is set to a certain spec. When I spoke to a gunsmith about this he told me that the reamers are SAMI spec and there is nothing I can do about the distance to the lands. Then again he could have misunderstood what I was asking. If I could get mine cut back I would seriously consider it.

[Pat Brennan]

I had my 300 before I had a chronograph, but I'd try a box of 180s with an appropriate powder before tossing a barrel that shoots well. I'd expect to get over 3000 with them and have seen published speeds in the 3100 range.
I think that the heavier bullets are where those big belted cases really shine.
What powder are you using with the 165s?

[krazy]

Pat

I am using RL22. How i got there is a bit of a story:

I started with the 165 TSX @ .03 off the lands. The accuracy was excellent but about half way up the powder scale I maxed out. I did not pressure out - the velocity just maxed out. I think I loaded from 75 - 80 grains in 1 grain incriments. At 77 grains I was going 3125 with no pressure. At 78 - 80 grains the rifle kicked more and there was still no signs of pressure but velocity remained the same and the ES (extreem spread) got much bigger.

Thinking that I was using too slow of a powder I tried IMR 4831, then H4831, then IMR 4350. The results - velocity plateaued at around 3000 fps with so so accuracy. I even tried a slower powder (H1000) with similar results - I could shoot right through the powder charge range but the velocity peaked at about 3000.

On a suggestion from a friend I backed the the 165 TSX off to .05 from the lands. This time I was able to go to 79 grains with RL22 before velocity peaked at 3200 fps. Unfortunatley the accuracy opened up a bit, I believe due to the greater distance from the lands, but it was still 'hunt worthy'. 80 grains did not increase velocity and signs of pressure were evident. So I backed of to 78.5 for about 3160 fps and left it there.

That is what got me thinking that I needed to be farther into the case as it was obviously effecting the loads. i can accually shoot faster with the same powder charges when I seat the bullet deeper into the case. I verified this with some Nosler BT's (165). Same thing, @.01 I got excellent accuracy but could not get to 3100 fps. At .03 I can get to 3150ish but the accuracy sucks.

Sorry for the long post. I just wanted to explain how I came to the conclusion that if I want to stick with the lighter bullets that I may need to go to a caliber that inherintly has a shorter throat - hence my questions on the 30-338. As I stated in a post above, I do not know if I can simply get the throat adjusted on my current barrel but if I can I would consider trying that first.

After all that, I do load a 180 Accubond for my bro's 300. He is not that particular about speed so I stopped the load development when 74 grains of IMR 7828 put 3 shots under 1 MOA at just over 2900 fps. Oh ya, he has a clip so his OAL is WAY off the lands. Some guys have all the luck!

I will definatley try your suggestion this spring. If I can get a 180 going 3100 then the higher BC should do the rest and it will probaly be as flat as the 165 at 3160 anyway.

Thanks for the help

[Cariboo]

In your rifle a 100 fps difference in velocity makes less than 1/2" difference in drop at 400 yards. That amount of difference is "lost in the shuffle" as it will not be noticed at all within a sub-moa group.

Typically seating bullets further off the lands changes the pressure curve the cartridge produces and allows for higher velocities in most cartridges.

Finally, seating bullets close to the lands is done to minimize the effects of non-concentric rifle chambers and/or cartridges. It is one of those platitudes that has been repeated so long that a lot of people seem to think it is gospel. In truth however if your chamber is properly cut and your cases have less than .004" runout at the bullet shank any jump to the lands that is less than the bullet diameter - your 30 calibre bullet for example cold make a jump close to .30" - accuracy can be just as good - or better - than if it is nearly in contact with the lands.

[Downwindtracker]

I have a 308Norma.The Norma chambering is a freebore,so I have a jump,as well as having a standard 30.06 box. Using either Sierras or Interbond 180s,I get 3150 with a 26" barrel and 74.0gr of N560.(< 1/2 MOA or <1MOA) But I'm not shooting a copper or copper clad bullet. Copper is higher friction,it slows velocity and increases pressure. That's the trade off for the better terminal performance. You should see 3100-3200 with a 180 Accubond and a 300Win.