6.5 vs .257 cartridge question

[Alex Wheeler]

Ebb, the Kulzer is a 25x47. I wanted to try one in BR. Glenn said he would do it, so he was the first one on the reamer. He did a lot of work testing powders, primers, NT, seating, ext. So now I can just tell a guy what to do when he gets one. He won the HG portion of the 24 IBS 1k nats with it. Thats a lot of effort so I called it a Kulzer. This year there was a handful at DC, as well as other ranges. Theres nothing really special about the reamer. But the 25x47 has proven to be competitive.

 

[Bill Norris]

Ebb, the Kulzer is a 25x47. I wanted to try one in BR. Glenn said he would do it, so he was the first one on the reamer. He did a lot of work testing powders, primers, NT, seating, ext. So now I can just tell a guy what to do when he gets one. He won the HG portion of the 24 IBS 1k nats with it. Thats a lot of effort so I called it a Kulzer. This year there was a handful at DC, as well as other ranges. Theres nothing really special about the reamer. But the 25x47 has proven to be competitive.

It certainly looks as if it might be a better wind fighter for sure. Cant wait to see how it acts at distance.

 

[Alex Wheeler]

It certainly looks as if it might be a better wind fighter for sure. Cant wait to see how it acts at distance.

100%. Dont expect it beat a good 6mm in perfect conditions (but it might). In the wind it beats a lot of them though. Your gonna be happy.

 

[Wild Bill IV]

How do you get 2 bullets of different diameter, but the same weight, to have the same BC? The smaller diameter bullet will be inclined to have a sleeker profile and likely a higher BC, correct? If you then give them the same muzzle velocity, the sleeker, higher BC bullet will retain more velocity down range.

The only way I can see to make this work having the same muzzle velocity, BC, and weight is for the larger diameter bullet to be of a different design/shape to get the BC numbers to match......which then is comparing apples to oranges.

I STATED, THEREFORE, THE LARGER BORE BULLET WILL BE HEAVIER!!!
I did not say pick the same weight for both calibers!!!
Did all the math mess you up???

 

[David Milisock]

What is the difference? I mean really. Can some one tell me.
Lets take the 30-06
Now lets stick a .257 bullet in it.
The 25-06 is way more snappy then the 30-06
I do prefer the 25-06 over the 30-06 in terms of precision. Ive just had an easier time tuning 25-06 loads over 30-06. That could be because of Bullet B.C...i dont know because ive never once paid attention to those numbers.
Now what happens with a 6.5 bullet? I dont know because ive never shot one, and i dont follow numbers.
I dont know of any bullet that has a larger selection of on the market like the diverse. 308
So now were back to the 30-06..
If i was shooting antelope in Texas id want a 25-06, if im after that trophy buck, its the 30-30, or 30-06..only because i have experience with those cartridge and know what they can do.
So where does the 6.5-06 fit into all this? What would you use it for..sound like its on the edge of a a barrel burner with not much to gain.
Im just curious
Thank you

Ok the 26-06 is not more snappy than the 30-06, it simply shoots a smaller diameter projectile, therefore it requires (at the same projectile weight) a slower powder and is best with 26"+ barrel lengths, especially with heavy weight, 128 and 134 grain ELDx and ELDM projectiles. It lacks the expansion ratio of the 30-06 and the 26 caliber (6.5mm) with equal barrel lengths. The 26-06 has been used for varmints as well as elk.

The 30-06 was designed as a military 30 caliber and as such it lacks sufficient case capacity to launch ELD 30 caliber projectiles to a velocity that competes with modern 30 caliber cartridges. With that said the 30-06 loaded to 60,000 PSI and a 26"+ barrel can launch 190 grain projectiles at velocities just under the 300 Winchester Magnum for hunting. I would not exceed the 212 grain Hornady ELDX. A custom throat helps! A tad light for brown bear but most everything else it works.

The 6.5-06 has a slightly greater expansion ratio than the 25-06 and my be useful with slightly faster powders (at the same bullet weight) than the 25-06, slower powders (at the same bullet weight) than the 30-06). Again the case capacity/bullet weight/expansion ratio works best with 26"+ barrel lengths. Bullet weights of 129 work well with deer, 143 have been used for elk and heavier used for moose.

 

[Wild Bill IV]

I'm gonna make sure I'm grasping this correctly. Using Nosler load data for 100gr Ballistic Tip bullets in both the 25-06 and the 6.5-06 A-Square, max loads and associated BC:



25-06: 3361 fps, .393 G1
6.5-06: 3547 fps, .350 G1

25-06 ballistic table:
View attachment 1684014

6.5-06 ballistic table:
View attachment 1684015

2206 -vs- 2219 fps
1080 -vs- 1094 ft lbs

Someone is going to have to help me understand how the 6.5-06 has 30% more energy at 500 yards compared to the 25-06??

.

The the bullets were not the same weight!!!
POST #48
117grain vs 140grain

25-06 117grain SBT SGK, MV:2900f/s, BC:403 between 2500-1800f/s,
Remaining v @500yd: 1864f/s, Remaining E@500yd: 980ft-lbs

6.5-06 140grain SBT SGK, MV:2800f/s, BC:480 2000f/s and below,
Remaining v @500yd:1972f/s, Remaining E@500yds:1172ft-lbs

And the muzzle velocity for the 6.5-06 was 100f/s slower!!!

6.5-06 with muzzle velocity at 2900f/s with the 140grain bullet now has a remaining velocity at 500yds at 2025f/s, with BC:490 between 2800-2000f/s, and remaining energy of 1275ft-lbs

1275ft-lbs vs 980ft-lbs. 30%increase in energy!!!

 

[Bill Norris]

100%. Dont expect it beat a good 6mm in perfect conditions (but it might). In the wind it beats a lot of them though. Your gonna be happy.

I was hoping to see it beat the 6BRX in the wind with the 105 gr. class bullets at 600 yds.

 

[Tangent]

I was hoping to see it beat the 6BRX in the wind with the 105 gr. class bullets at 600 yds.

How do you find the 25x47 compares with the 260 AI?

 

[Bill Norris]

How do you find the 25x47 compares with the 260 AI?

Have not had a chance to get it out to longer range but I think it will be a good race.

 

[Tangent]

Have not had a chance to get it out to longer range but I think it will be a good race.

I'll be interested to hear how you get on. Already planning out the replacement for my factory 260 Rem barrel. Either 260AI or 25x47 might be a candidate...

 

[Bill Norris]

I'll be interested to hear how you get on. Already planning out the replacement for my factory 260 Rem barrel. Either 260AI or 25x47 might be a candidate...

Yes Sir plan to keep updating my thread with all info as I go forward.