300 Win Mag Build and Loading Questions.

[Wisner74]

Hello Everyone,

I sure hope these are not stupid questions.

I am building a rifle(gunsmith is). Defiant Hunter action-Obermeyer 26" Barrel 1:12 twist.

The barrel is on its way to the gunsmith and not chambered yet. This is a hunting rifle for Elk, Sheep, Goat and what ever else i can draw. I am hoping this will be an accurate Long Range Rifle. What i think I need, is help on a Load/bullet selection for this gun so I can give the gunsmith an Idea of what bullet I will be shooting. From what I have read on here is I don't want to tell him to chamber it to shoot all ammo off the shelf.

I am new to reloading but a quick learner.

1.) What bullet and weight for this set-up would you recommend??

2.) What powder, primer, complete load détails do you recommend??

3.) Do I tell the gunsmith the exact bullet I want to load?? for example a 190 Berger VLD or 190 Nosler Accubond LR???

4.) Any recommendations on bullets would be great. It seems the Nosler has a higher BC than the Berger.


I sure appreciate all the help I can get.

 

[Catahoula]

Hey Wisner, I question the 1:12 twist? Might want a tighter twist for heavy bullets which is what works great in the 300. The 2 powders that have worked the best in my 300 are H1000 & IMR4831. I would lean more to Accubonds than Bergers as I have had train wrecks shooting Bergers at anything bigger than a coyote.
PM me & we can trade phone numbers if you would like. The 300 is my go to gun.
Thanks, Kirk

 

[Sully2]

Its a 1 in 10 on factory rifles....?

 

[Wisner74]

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.

 

[Michael Eichele]

Personally I think that 12 is a bit slow. Even in 308s these days, 11 and 11.25 are very common. I am a fan of the 12 twist but you will be limited to 200 grain bullets and it will be very marginal at best for some of the very long 200 grain bullets like the Hybrid and ELDX. Bullets like the 200 grain Game King will stabilize just fine. The 190 VLD will do ok in 12 but the 190 ABLR is marginal in the 12x.

The 11 will handle the 208, 210s with ease. It will even handle the 215 hybrid if you decide to go that heavy as well as all the 200s and 190s assuming they're jacketed lead. If you want to run all copper bullets, you WILL need to go tighter.

I ran a 12x in a 300RUM years back and it shot very well with 180-200 grain ACCUBONDS. I also had an 11.25 300RUM and it did very well too with 180-208 grain bullets.

My vote is 11 or 11.25x. 10x if you want to go above 210.

Regarding the statement of bullet destruction with a tighter than 12 twist in 5R at 300 win velocities...I must call BS in a resounding fashion on that.

 

[Wisner74]

Personally I think that 12 is a bit slow. Even in 308s these days, 11 and 11.25 are very common. I am a fan of the 12 twist but you will be limited to 200 grain bullets and it will be very marginal at best for some of the very long 200 grain bullets like the Hybrid and ELDX. Bullets like the 200 grain Game King will stabilize just fine. The 190 VLD will do ok in 12 but the 190 ABLR is marginal in the 12x.

The 11 will handle the 208, 210s with ease. It will even handle the 215 hybrid if you decide to go that heavy as well as all the 200s and 190s assuming they're jacketed lead. If you want to run all copper bullets, you WILL need to go tighter.

I ran a 12x in a 300RUM years back and it shot very well with 180-200 grain ACCUBONDS. I also had an 11.25 300RUM and it did very well too with 180-208 grain bullets.

My vote is 11 or 11.25x. 10x if you want to go above 210.

Regarding the statement of bullet destruction with a tighter than 12 twist in 5R at 300 win velocities...I must call BS in a resounding fashion on that.

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.

 

[bigngreen]

I would go no less than 10 twist and even seeing some faster for improved accuracy at long range, keeping the twist rate to a min used to be how it was done but with the bullets these days twisting them is improving accuracy and keeping BC where it should be. The 300 Win is definitely one of my favorite builds to do, I would not shoot a 190 Berger or Nosler at win velocities though some do so and do well, thee bullet in a 300 Win is the Berger 215 under H1000. A quick search on LRH will yield tons of solid info on this combo!!
We have one 30 cal barrel left that is less than a 10 twist and it sits in the corner because it suxs with thee best bullets available to day!

 

[Michael Eichele]

If you don't want to go against what you were told initially, why did you ask us for input??

Making barrels for 40 years makes for a good barrel maker. It doesn't mean he's an expert in ballistics.

 

[MagnumManiac]

I am of the opinion you have been dudded by being talked into taking a 1:12" twist barrel.
I have a 1:13" twist barrel chambered for a custom 300WM which negates the belt and headspaces off the shoulder from the get-go. It will NOT stabilise ANYTHING heavier than 175gr, it shoots 155gr Palma and 168gr Match bullets superbly, but since moving to longer ranges, it no longer gets a look in, my 1:10" twist barrels get used for everything now.
I honestly do not believe what you were told is the truth.

lightbulb

 

[AZShooter]

I had a 1 in 12 twist lilja that I got on sale. It was chambered as a 300 RUM. It shot the 200 gr accubonds just fine. It would shoot nothing longer or heavier.

As for what bullet to shoot in your 300 win mag I agree with what Bigngreen said the 215 Berger match target hybrid is THE BULLET. Read this thread and tell us otherwise. (thanks again to Broz for his hard work documenting this remarkable bullet)

I linked this long thread on page 14. There were a few antelope taken in previous pages but this is where it gets interesting. I will quote Jeff's aka Broz recent comments on which bullet for the 300 win mag first:

Note he mentions 31 first shot kills



Broz Platinum Member

Location: Townsend, Montana.

Posts: 8,332




Re: Best high bc bullet for 300wm for elk?


Well here is what I use. The 215 Berger Hybrid. Right now my 300 win is at 31 and 0 for first round kills on big game out to 1300 yards. Mostly elk. I trust this bullet to help me place it well with its high BC and have had good expansion down to impact velocity of 1700 fps on soft antelope. I logged the first 20 or so kills with documentation in this thread.
Comparing the Berger 210 VLD to the 215 Hybrid

With 300 win muzzle velocities at around 3000 fps, don't expect exits to be common on elk until you get past 5 to 600 yards. However you may have some at the very close distances too. In that thread you can see for yourself the terminal damage that is most common to vitals. I place the bullet behind the front shoulder in the crease just below center mass and they don't go far at all.

I do inspect all the tips on my hunting rounds to be open all the way back to the lead which is about .400" with the 215. But I find very few that are clogged on the 215's. Still worth checking though. I use a small pin vice and wire drill. But a pin would also work for a quick check.

The short bearing surface of the Berger Hybrid should allow very good velocity from the 300 win. With H-1000 I have seen several with 26" barrels go 2950. 28" barrels at or just over 3000.

I want the bullet that will increase my odds all it can at the longer pokes , yet still get the job done at the closer shots. This is a hard combo to come up with and there are no perfect bullets to do all jobs. But the 215 works well for me and I have not had one failure. This year we hosted a management hunt for elk on the ranch I manage. We too 60+ elk during this season. Mostly with Berger Hybrids either 300 grain or 215. The results and terminal performance were great.

Look that thread over and see if the terminal performance of the 215 is suitable for your personal needs.

Jeff


link to 215 Berger performance with excellent documentation:

http://www.longrangehunting.com/forums/f19/comparing-berger-210-vld-215-hybrid-88657/index14.html

 

[Capt RB]

Order this barrel today and send the 12 twist back
Shop the Bartlein T10565 - .308 5R 1:10 Twist, 26" Finished, #3 Barrel at Bullets.com
Fixed. They have it in stock and you could overnight it if needed

 

[Bart B]

I've worn out four 30-338 Win Mag 1:12 twist barrels shooting 190 and 200 grain match bullets leaving about 100 fps slower than a 300 Win Mag would shoot them. All tested 15 to 20 shots under 5 to 6 inches at 1000 yards. Two were Obermeyer and two from Kreiger. That twist was also popular for 308 Norma Mags in long range matches.

Had one Obermeyer 26" 300 Win Mag hunting rifle barrel with a 1:13 twist and .307" groove that shot Sierra 180's into 10" at 1000 yards. Not bad at all for a 9 pound scoped rifle.

Boots Obermeyer along with Jack Kreiger are correct in using 1:12 twists for these cartridges. People laughed at the USN Rifle Team members shooting Sierra 190 HPMK bullets from 1:12 twist 7.62 NATO Garands in long range matches but shut up when that combo won. Famous barrel maker Harry Pope put 1:12 twist .30-06 barrels in the US Palma Team's M1903 rifles because he knew a 1:10 was too fast for best accuracy. Win 70 target models in 308 with 1:12 twist barrels shot WW and WCC 190, 197 and 200 grain match bullets very accurate.

Frankfort Arsenal spec'd M14 barrels at a 1:12 twist because it was better for accuracy for the 30 caliber bullets up to 174 grains used leaving 100 fps slower than the 30-06 shot them. Therefore, it should be obvious that popular 30 caliber magnums shooting those same bullet weights faster could do well with that same twist.

Don't forget; 308's shooting 155 grain bullets out at 3000 fps get record setting results in Palma matches with 1:13 twist barrels.

If a 300 Win 1:12 twist barrel won't shoot bullets up to 220 grains sub MOA through 1000 yards, the twist rate ain't the problem. Some people can't handle the truth because they don't understand, nor are aware of, the details making it so. Whatever twist and velocity combination spins bullets at the right rpm range for best accuracy is correct. If 30 caliber 190's leaving 2600 fps from 308 Win 1:12 twist barrels are very accurate at long range, they'll do just fine leaving 3000 fps or more from a 30 caliber magnum 1:12 twist barrel.

Spin rate in rpm equals velocity in fps times 720 divided by twist in inches.

 

[Canadian Bushman]

Slow twist barrels will almost always will shoot smaller groups than tighter twist when rung out to maximum accuracy potential.

The problem with this is that drag can and probably will vary a larger amount in different weather conditions. This is very difficult to accurately predict.

Tight twist will reduce accuracy because lateral throw off from inherent bullet imbalance. This is fact, and noticed by competition shooters at the highest level. In a cold bore, hunting situation this marginal decrease in attainable accuracy potential is more than lost in the noise.

 

[BEEMAN]

BignGreen said it perfecly. There is no reason to reinvent things. I also would not get the 12 twist. Get a 1 in 10 some H1000, Fed GM215M and 215 Bergers and be done with it. This combo just WORKS.