Longest Accubond Jump?

[D21ALASKA]

So we know that the bonded bullets(AccuBond) like a bit more jump normally than the cup and cores. Question is, how far have you actually jumped one?

I ask because I'm in the prelims of working a 180gr AccuBond load for a new Vanguard in .300Bee. Box length is going to be right at SAAMI max of 3.560"+-. They're engaging the lands at 3.982" COAL +- a few thousand because of tip differential. That's a 0.422" jump.

I thought the 375 H&H at a 0.260" jump with 260's was long...

It should wash out in the end as a different bullet design isn't going to make much difference. Was just surprised by the length of freebore on the rifle.

Thoughts?

 

[DrMike]

I believe the longest jump I ever worked up was with a Swift Scirocco in a 270 WSM. It was a jump of 0.250 inches. It was an accurate load, however. That was a cruel rifle that required some real finessing to get the load the client wanted.

 

[RL338]

With any Weatherby I wouldn’t worry how far you’re jumping them. Nosler shows 3.550” that’s where I would start.

 

[flyingagg]

I can tell you when I get home

 

[RL338]

Forgot to add this , 180gr AccuBond on the left.

 

[D21ALASKA]

With any Weatherby I wouldn’t worry how far you’re jumping them. Nosler shows 3.550” that’s where I would start.

That's the plan and what I figured. Was just surprised at the freebore.

View attachment 18863
Forgot to add this , 180gr AccuBond on the left.

Nice!
I just happen to have a bit of 100V laying around.

 

[lefty315]

My Remington 700 has 1/4 inch jump, .250!!! But it shoots

 

[flyingagg]

so, unless I am doing something wrong, 3 different Mark V, with 180 AB, I have over 0.300" jump, and all shoot 1/2" or better at 100

 

[NYDAN]

0.275" jump. See https://forum.nosler.com/threads/easiest-sight-in-and-load-development-ever.44288/

 

[NYDAN]

0.275" See: https://forum.nosler.com/threads/easiest-sight-in-and-load-development-ever.44288/

 

[Tjay]

What is the throat length (free bore) on your Weatherby rifles chambered for Weatherby magnum calibers?​

Cartridge	Throat length (free bore)
224 Weatherby Magnum	.162
240 Weatherby Magnum	.169
257 Weatherby Magnum	.378
6.5 WBY RPM	.105
6.5-300 Weatherby Magnum	.2037
270 Weatherby Magnum	.378
7MM Weatherby Magnum	.378
300 Weatherby Magnum	.361
340 Weatherby Magnum	.373
375 Weatherby Magnum	.373
378 Weatherby Magnum	.756
416 Weatherby Magnum	.239
460 Weatherby Magnum	.756
30-378 Weatherby Magnum	.361
338-378 Weatherby Magnum	.361

​

 

[flyingagg]

What is the throat length (free bore) on your Weatherby rifles chambered for Weatherby magnum calibers?​

Cartridge	Throat length (free bore)
224 Weatherby Magnum	.162
240 Weatherby Magnum	.169
257 Weatherby Magnum	.378
6.5 WBY RPM	.105
6.5-300 Weatherby Magnum	.2037
270 Weatherby Magnum	.378
7MM Weatherby Magnum	.378
300 Weatherby Magnum	.361
340 Weatherby Magnum	.373
375 Weatherby Magnum	.373
378 Weatherby Magnum	.756
416 Weatherby Magnum	.239
460 Weatherby Magnum	.756
30-378 Weatherby Magnum	.361
338-378 Weatherby Magnum	.361

Sorry, mistake.​

So, I have 5 rifles in 300WBY. I know I must be nuts. 4 MKV and one M70. With a 180 grn bullet, evern at magazine length, I still get about 0.4" freebore. Rifles all shoot well, except I have not tested the M70 yet. Am I doing something wrong?

 

[DrMike]

So, I have 5 rifles in 300WBY. I know I must be nuts. 4 MKV and one M70. With a 180 grn bullet, evern at magazine length, I still get about 0.4" freebore. Rifles all shoot well, except I have not tested the M70 yet. Am I doing something wrong?

You're doing nothing wrong if they are delivering the goods for you.

 

[Ridge_Runner]

I jam them into the rifling .008" in my 7mm Allen Mag, and they shoot awesome!

 

[Charlie-NY]

In order for the AccuBond ammo to fit in the magazine of my .308, the bullets need to be seated .165" off the rifling. Oddly enough, they grouped better there than closer or farther.

 

[Darkhorse]

It doesn't matter how long the jump or how short. As long as the bullet is seated in a node accuracy will be good.

 

[flyingagg]

It doesn't matter how long the jump or how short. As long as the bullet is seated in a node accuracy will be good.

Just think of all the Weatherby calibers. They are jumped a heck of a lot more, and thye groupd well. All about the tuning.

 

[salmonchaser]

I installed a Wyatts magazine in my 338 Jarrett a number of years ago so I could get the accubonds out to 3.670. I’m getting quarter inch groups with 250 grain Accubonds, slightly larger with 250 grain partitions. Both running at 2950 and change. Both seated about 15thousands off the lands.