300 Win Mag Build and Loading Questions.

[Bart B]

There is no reason to reinvent things.

Nothing's being reinvented.

'Twas proved back in the 1960's that 30 caliber magnums with 1:12 twist barrels shoot heavy bullets very, very accurate. It happened. It's a fact. Sierra Bullets lists a 1:12 twist barrel testing their 220-gr. hunting bullets for 30-338 Win Mag load and accuracy data.

Why, BEEMAN, don't you believe that?

 

[BEEMAN]

By "reinvent" I mean why waste components and time when so many other guys have great success with the load I listed. Also Berger call for a 1 in 11 twist to run the 215's. When I built my 300 WM I asked Broz for advice and my outcome could not have been easier. I never stated a Sierra 220 gr bullet. I was advising on the Berger 215 which a lot of people use in a 300 WM with great success, with a 10 twist.

 

[Bart B]

By "reinvent" I mean why waste components and time when so many other guys have great success with the load I listed. Also Berger call for a 1 in 11 twist to run the 215's. When I built my 300 WM I asked Broz for advice and my outcome could not have been easier. I never stated a Sierra 220 gr bullet. I was advising on the Berger 215 which a lot of people use in a 300 WM with great success, with a 10 twist.

Do you think my comments on the success of 30 caliber magnums with 1:12 twist barrels shooting heavy bullets have no credibility and the OP's current 1:12 twist barrel is not going to work well?

 

[TOM H]

On the 1:12 twist.... I talked to Boots Obermeyer to order a barrel. Told him I wanted a 1:10 twist to shoot 180-200 grain bullets for a long range rifle.He wanted to know exactly what I was hunting. . After I gave home the info he said he was going to make me a number 4 fluted barrel 26" with 1:12 twist. He said any twist faster in a 5r cut rifle barrel at 300 WM velocity has caused jacket seperation.

His exact words are below:

(The 10 twist in 30's came from the 30-40 Kraig prior to 1900 shooting bullets around 220. The
10 twist kept going through the 1903 Springfield's and the M1 as all the equipment was set up for 10.
When the M14 came on the twist was slowed to 1-12 and bullet over 170 were often used.
Now it the spin rate in Rev's per second that generate the centrifugal force to keep the bullet
stable so with higher speed you want less twist for the same Rev's per second. Also very important the
thrust on the jacket is reduced causing less jacket breakage which means a shot way off target. For
target rifles for 1000 yards twist are slowed down, sometimes to 1-14)

So with that being said I felt it safe to trust his recommendation.

I got question to ask. Your already shooting but with factory ammo a 300mag and you taken some animals with it. When you talked to Obermeyer did you mention using VLD bullets?

In his exact words there no mention on bullets to use. I have two 30-338mag and one has 1/12 twist barrel and latest build has 1/11 twist barrel and I use both for hunting. I'm not going to say I made bad choice on the 1/12 as I knew what bullets I was going to hunt with.

 

[Wisner74]

I got question to ask. Your already shooting but with factory ammo a 300mag and you taken some animals with it. When you talked to Obermeyer did you mention using VLD bullets?

In his exact words there no mention on bullets to use. I have two 30-338mag and one has 1/12 twist barrel and latest build has 1/11 twist barrel and I use both for hunting. I'm not going to say I made bad choice on the 1/12 as I knew what bullets I was going to hunt with.

It seems to me that this question now has me with a not in my stomach. I did not tell him I would be using VLD bullets. I have sent him an email regarding which bullet he suggest loading in this set-up and will let you know.

 

[bigngreen]

If you look at the bullets guys talk about with a 1-12 twist as being awesome there bullets from 20 years ago that are today's equivalent of a brick in today's bullet world. I have a 30-338 win target rifle set up like Bart is talking, shoots awesome till you go to get some free windage with BC then it all goes tits up and you drop bullet out of the group like crazy. If you look at Litz's work with the Nosler ALR he had to twist them up much faster than recommended to get the BC and accuracy benefit from such an aggressive design. Old school is great to learn from but you have to beware they may be stuck in their glory years, bullet design has come a long ways and especially when talking hunting as many don't have any idea that were shooting well beyond the norm!

 

[barefooter56]

I have a hard time going against what a guy says who has been making barrels for 40 years. I will defiantly look into the 200 grain Game King. I never plan to shoot less than 180's out of it. I'm just happy he got it done in a week. Everyone else was 6 months out and I have a goat hunt to get ready for.

Wisner74,
I agree with you on Boots. Most of the barrel makes today learned from him. The issue with bullet failure he has MAY be due to the 5R rifling and possibly the length of the barrel. More friction on the bullet makes heat and that can lead to bullet failure. In a 4 groove barrel that MAY not be an issue but you need to be aware of it especially if you get up to around 3400 FPS. Run some scenarios on our twist rate calculator or on Bryan Litz's Twist rate calculator on the APPLIED BALLISTICS WEBSITE. Just glancing through our .30 caliber hunting bullet list the 168 CLASSIC HUNTER and VLD , and the .30 caliber 185 grain CLASSIC HUNTER and VLD bullets have the 1-12 twist rate listed as the OPTIMUM twist rate to be used with them. Hope this information helps you with your decision.

 

[Bart B]

With Wisner74's list of game animals to hunt, I think 180's to 200's would be the best bullet weight range choice to use and from a 1:12 twist barrel.

In shooting events where best accuracy is the objective, the ones doing best use the slowest twist possible to stabilize their bullets. Anything faster causes the unbalanced ones to jump further off the bore axis upon exit. All bullets are not perfectly balanced.

 

[Wisner74]

Wisner74,
I agree with you on Boots. Most of the barrel makes today learned from him. The issue with bullet failure he has MAY be due to the 5R rifling and possibly the length of the barrel. More friction on the bullet makes heat and that can lead to bullet failure. In a 4 groove barrel that MAY not be an issue but you need to be aware of it especially if you get up to around 3400 FPS. Run some scenarios on our twist rate calculator or on Bryan Litz's Twist rate calculator on the APPLIED BALLISTICS WEBSITE. Just glancing through our .30 caliber hunting bullet list the 168 CLASSIC HUNTER and VLD , and the .30 caliber 185 grain CLASSIC HUNTER and VLD bullets have the 1-12 twist rate listed as the OPTIMUM twist rate to be used with them. Hope this information helps you with your decision.

I ran some scenario's and it seems that most bullets I ran, come up on the bottom end of the comfortable stability. I noticed if I Increased the twist rate the stability increased.

I find it interesting that this post was generated to look for answers regarding loading for this round and the barrel I have bought. It seems the twist has become the topic

 

[barefooter56]

Bart B makes a good point on bullet balance and twist rate. Wisner74 , if your SG (stability factor) is 1.5 with the 1-12 twist rate that is optimum for that bullet. Mores law can apply to a point. Bart B makes that point in his post. MORE and MURPHY are brothers in LAW.

 

[Wisner74]

I just want to make sure I am building the right rifle to shoot 180 grain bullets. I mean I have the option to have another barrel made(the gunsmith can sell this one). For some reason I feel like that is what most people here Are telling me.

 

[Jaxdialation]

Having the flexibility to go with heavier bullets down the road is worth thinking about. Therefore a faster twist merits at least a conversation with your 'smith.

There are several bartlein and kreiger barrels with 10 twist for sale with no wait.
third generation shooting supply, bullets.com and several others have them.

I just want to make sure I am building the right rifle to shoot 180 grain bullets. I mean I have the option to have another barrel made(the gunsmith can sell this one). For some reason I feel like that is what most people here Are telling me.

 

[Wisner74]

Bart B makes a good point on bullet balance and twist rate. Wisner74 , if your SG (stability factor) is 1.5 with the 1-12 twist rate that is optimum for that bullet. Mores law can apply to a point. Bart B makes that point in his post. MORE and MURPHY are brothers in LAW.

So what your saying is that as long as the SG is 1.5 minimum it will shoot just fine.

 

[Bart B]

I just ran Bergers stability calculator for Nosler's Accubond Long Range 180-gr. 30 caliber bullet leaving at 3100 fps from a 1:12 twist in 30 and 90 degree temps at 5000 feet elevation. Results were SG's at 1.51 and 1.70 stating good stability.

If best accuracy is important, do not use the powder that loading data says gives the highest muzzle velocity. 180's on 300 Win Mags do best accuracy wise with stick powders in the IMR4350 to IMR4831 range. Slower powders will shoot the bullets out faster with the same peak pressure but they'll have a greater muzzle velocity spread because their pressure curves aren't as repeatable in shape. Stay far, far away from ball powders.