Tuff time making a final decision

I am currently planning to build a 6.5-06 AI. I chose it for deer hunting and actually found the 130 grain Berger to outperform the 140 in both trajectory and wind drift out past 800 yards "my max". 3150 should be quite do able in the 28" shilen I plan on building. The Scirrocco 2 is also a great long range hunting bullet but unlike the Bergers it penetrates and retains 80+ percent weight. I narrowed my choice to the 6.5-06AI, 280 AI, and 6.5-284 and decided that the 6.5-06 would feed flawlessly in my savage 30-06 action. Being a ballistic twin to the 6.5-284 I chose the 06 over the 284 to avoid feeding issues. I determined the 6.5-06 would deliver adaquate energy to 800 yards and 280 AI simply could not deliver the same accurcy due to lower initial velocity and the external ballistics were just better on the 6.5.

PS: You can fireform Norma 25-06 brass to get 6.5-06AI brass with little problems.

I'm not going to second guess your choice... most of your reasons sound good. But, I'm thinking a 280 AI, which is almost the ballistic twin to the 7mm RM can easily push a 150 bullet (with probably a slightly higher BC than a 130) at 3150 and probably better out of a 28" barrel?

Im about to put together a 6.5-06 myself. leaning towards an improved, 26" barrel and a 1-9 twist. now thinking a 1-8.5. I will shoot antelope with the 130ab. thanks for the ideas.

Montana the BC on the 6.5mm 130 Bergers is .595 and the Scirrocco 2 is .575. I have not seen anything above .515 in a 150 grain 7mm despite the SD of the 150 being slightly higher. If Berger made a 150 grain 7MM game bullet I think that would be the ticket.

I am not certain how the velocities for the 7mm 150 and 6.5 130 would work out but the 150 is larger in diameter and higher in sectional density so I would expect the 150 to be slower at equal operating pressures. As you stated though the numbers are pretty close.

Well, Here is one more to think about, a 7mm-300wsm.
1) Brass is handy to get ahold of, Winchester supposley got with the Lapua Brass Co. and figured were they were going wrong with there brass, so "It's" supposed to be better. BUT get 270wsm NORMA brass and run through a 7wsm FL die, load with 65.0gr of H4831 with 140AB and shoot.
Then take fired round and run through a 270wsm FL bushing die with a .312 bushing and load and watch the fur fly.

2) The WSM's are short action'd calibers where'as others stated are Long, But that might not be a issue, how ever weight would be cut just a little and chambering/cycling time cut in half.

3) 8 or 8.5 twist and u can shoot 140 AB's to the Berger 180's Good choice or bullet selections

4) No need for a 20 MOA scope base

3006savage said:

Montana the BC on the 6.5mm 130 Bergers is .595 and the Scirrocco 2 is .575. I have not seen anything above .515 in a 150 grain 7mm despite the SD of the 150 being slightly higher. If Berger made a 150 grain 7MM game bullet I think that would be the ticket.

I am not certain how the velocities for the 7mm 150 and 6.5 130 would work out but the 150 is larger in diameter and higher in sectional density so I would expect the 150 to be slower at equal operating pressures. As you stated though the numbers are pretty close.

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3006savage, .595 BC for a 130 gr bullet is very good. I didn't check the Berger site. I went to the Nosler site, because they have data for th 280 AI and I had checked it before, so I also checked their bullets. The BC of the 6.5/130 is essentially the same as the .284/140 in the AB's and the 150 BT is a little higher. According to their data (which I find consistant with my data in other cartridges) The 280 AI can push a 150 gr bullet at about 3100 fps out of a 24" barrel, which means it can probably push it at 3200 fps out of a 28" barrel. When comparing apples to apples, you get more BC, SD and vel out fo the 280 AI than the 6.5-06 AI. But... Berger doesn't offer a 150 gr VLD. So for grins I ran their 168 (BC .643) at an MV 0f 3050, which should easily be doable in the 280 (28" barrel) against the 6.5/130 at an MV of 3150. At 800 yds the external balistics are very close with the 280AI/168 surpassing the 6.5 down range. Terminal ballistics wouldn't be much of a comarison, with the 168 bullet having significantly greater mass, frontal, SD, momentum, and KE.

Having said that, I think the 6.5 AI is capable of taking a large buck at 800 yds, but the AI can probably do it a little better and farther.

Your other reasons for you pick are good ones, and it should get the job done with a little less kick.

Good shooting.

If you want to push it alittle bit further than the 6.5-06AI how about the 6.5 Gibbs.

Montana I do not want to come across as agrumentative but I would ask you to consider the following:

The 168 grain 280AI round at 3050 FPS is generating 3474 FTLBS/KE at muzzle.

The 130 grain 6.5AI at 3150 FPS is generating 2864 FTLBS/KE at the muzzle.

The two case capacities are identical. The comparison you ran assumed the 284 bullet from the same case generated 610 FTLBS/KE more than the 264 bullet. The small bore diameter difference of .02 should only contribute approx 150 FTLBS/KE more for the 280 AI.

I used a relatively conservative velocity estimate for the 130 grain bullet and the 3050 for the AI is MAX. That contributed to the different results but if you run numbers between the two and just allow an additional 150-200 LBS/KE for the 280 AI at the muzzle regardless of bullet weight you will be very close to the real world performance for the two. This yields a velocity difference of around 300fps between the two.

3006savage said:

Montana I do not want to come across as agrumentative but I would ask you to consider the following:

The 168 grain 280AI round at 3050 FPS is generating 3474 FTLBS/KE at muzzle.

The 130 grain 6.5AI at 3150 FPS is generating 2864 FTLBS/KE at the muzzle.

The two case capacities are identical. The comparison you ran assumed the 284 bullet from the same case generated 610 FTLBS/KE more than the 264 bullet. The small bore diameter difference of .02 should only contribute approx 150 FTLBS/KE more for the 280 AI.

I used a relatively conservative velocity estimate for the 130 grain bullet and the 3050 for the AI is MAX. That contributed to the different results but if you run numbers between the two and just allow an additional 150-200 LBS/KE for the 280 AI at the muzzle regardless of bullet weight you will be very close to the real world performance for the two. This yields a velocity difference of around 300fps between the two.

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Click to expand...

No worries here, not being argumentative either. The discussion intrigued me so I started doing a little research when I read the 6.5 was out performing the 280.

Yup, the 3050 fps estimate for the 280 would be max or close to it, and I have no data for the 6.5, so I have to go by what you say there. Can't comment much on their case capacities other than the parent case for both is the .06 and they are both AI's.

As for KE calculations that's basically a velocity squred times mass thing. So mass is a bonus and velocity is a BIG bonus... but... I personally dont put a whole lot of stock in KE. I used to, but not much any more. I look more at bullet structure and performance along with SD, frontal, mass, and momentum.

Also, when comparing the 300 Dakota to the 338 Dakota which also have the same case capacity and a .03 neck dif, The 300 drives a 180 bullet @ about 3100 and the 330 drives a 225 @ about 3100 for KE levels of 3840 and 4800, a dif of almost 1000 ftlbs from the same case. I dont know why, but there it is.

Bottom line is one guy chooses a 6.5-06 AI and another a 338 RUM for his own personal reasons. Me... I'm a 7mm to 300 kinda guy. The bigger the gun the more terminal thump it's going to give. A 7mm is going to give more thump than a 270 and a 300 is going to thump more than a 7mm and 388 is going to thump more than a 300, and all will have similar external ballistics give or take.

So enjoy your 6.5... it should be a sweet shooting gun to give you lots of memories.

Cheers,

Mark

I have seen one good solution. I personally use a 25-06 for Antelope in Wyoming and am successful out past 500 yards. If you are looking for something that is just different so you can spend money then it doesn't matter what you shoot. Off the shelf you can have a great rifle in 270 and spend the extra money on Glass and a decent range finder that is necessary to hunt Antelope. There are a lot of good bullets out there even Nosler builds a Long range AccuBond with good ballistics.

6.5 Saum

Y'all do realize this thread has been dead for almost 9 years, right?