Bullet Jump

[C.W. Richter]

Thus my mention of the VLDs vs most standard bullets (Swift Scirocco IIs come to mind, also, but nearly everyone has some skin in that game now.) When i say COAL, i typically do not mean SAAMI std, rather, the varying cartridge overall length (due to what you mention) with different bullets, set up perfectly for each particular gun. Even the old-school method of making a dummy round, knowing the seating depth of when it touches the lands, adjusting from there (and of course making measurement of where the cyl/ogive juncture is on a particular bullet) works wonders in proper reloading.

 

[375 Ruger Fan]

I ordered a Sinclair bullet seating depth tool. Anyone using this tool?

 

[375 Ruger Fan]

Another good video on the subject

 

[Pheroze]

I ordered a Sinclair bullet seating depth tool. Anyone using this tool?

I use it with every new reload. I think itnis great.

 

[crs]

CW mentioned hunting Pronghorn with a .264 WSM- took my first Pronghorn with a .264 Win mag. The buck was trotting left to right at less than 50 yards and went down at the shot. That was a very accurate long range rifle, but it was ugly and I sold it soon after wards.

 

[IvW]

The calibers I use I prefer enough jump. I dont want to be close to the lands.

 

[375 Ruger Fan]

The calibers I use I prefer enough jump. I dont want to be close to the lands.

So you prefer to be a bit standoffish???

 

[Hogpatrol]

Have tried different methods of finding the lands and for my rifles, Remingtons or clones, the Wheeler method works the best. I follow up with the Hornady tool for reference.

 

[C.W. Richter]

CW mentioned hunting Pronghorn with a .264 WSM- took my first Pronghorn with a .264 Win mag. The buck was trotting left to right at less than 50 yards and went down at the shot. That was a very accurate long range rifle, but it was ugly and I sold it soon after wards.

That's the cartridge that got me interested in the first place! Virtually same performance, better feeding, can argue about a bit better accuracy in short, fat cartridges (and my favorite-short, light super-accurate gun.) I'll never know why they didn't SAAMI-ize the 264 WSM (but the 6.5 craze has just made components disappear. 'Good thing I stocked up during the preceeding craze.) Was it a Win 70 that was ugly (beat up?) or something else??

 

[shootist~]

I ordered a Sinclair bullet seating depth tool. Anyone using this tool?

I use the Hornady tool which also requires ordering a threaded case for each cartridge you want to measure.

Hornady Lock-N-Load Overall Length Ga Bolt Action

The Hornady Lock-N-Load Overall Length Gauge is one of the best kept secrets to **NOT**PERMITTED**. This tool allows reloaders to quickly and easily...

www.midwayusa.com

The optional bushings allow you to also measure the max length at the Ogive in addition to the basic COL:

Hornady Lock-N-Load Bullet Comparator Basic Set 7 Inserts

The Hornady Lock-N-Load Bullet Comparator is perfect for the reloader looking to quickly and precisely measure seating depth of loaded ammunition from...

www.midwayusa.com

Sinclair makes the bushings (in stainless instead of aluminum) as well, (I have theirs for 6.5mm). So they probably have that style of system as another option.

 

[rookhawk]

I just ordered a 5/16”-32 tap today so I can make my own cases for the Hornady OAL gauge. Simple process if you have the tap and it saves you $10 or more per cartridge to buy the pre-made ones.

 

[Hogpatrol]

I just ordered a 5/16”-32 tap today so I can make my own cases for the Hornady OAL gauge. Simple process if you have the tap and it saves you $10 or more per cartridge to buy the pre-made ones.

Wrong tap. It's 5/16-36 Best to use a collet in a precision lathe. A cockeyed tapped hole will give incorrect data. Drill should be ground for brass too. A "K" or a 9/32 drill will work.

Best method is insert fired round that is (correction) NOT sized in a Wilson or other case gauge and then put it in a collet in the lathe. Center drill with an 0 then drill/tap. Make sure it's tight in the gauge.

https://www.amazon.com/16-Right-Thread-7-3mm-Drill/dp/B0195UFBUY

 

[rookhawk]

Wrong tap. It's 5/16-36 Best to use a collet in a precision lathe. A cockeyed tapped hole will give incorrect data. Drill should be ground for brass too. A "K" or a 9/32 drill will work.

Best method is insert fired round that is (correction) NOT sized in a Wilson or other case gauge and then put it in a collet in the lathe. Center drill with an 0 then drill/tap. Make sure it's tight in the gauge.

https://www.amazon.com/16-Right-Thread-7-3mm-Drill/dp/B0195UFBUY

You’re absolutely right. Thanks for correcting, 5/16-36 is the thread type.

 

[Bob Nelson 35Whelen]

@375 Ruger Fan just wanted to take this opportunity to thank you for feeding my OCD. The most eye opening part is about the bearing surface case mouth relationship. I never gave too much thought to this when I was running them out longer than normal, but I sure will now.

@Forrest Halley
Here we go again. As if a flys foreskin more ore less off the lands makes that much difference for the average person.
If I can I load for the magazine lenght but at times rifles suffer from one of two things. Long mag short leade or long leade short mag.
Where possible I load all my rifles between 30 and 50 thou off the lands.
My custom rifles I have the barrel throated to suit the max lenght of the case in the mag. This can result in lighter projectiles being a fair way off the lands but doesn't seen to affect accuracy as all my rifles group 3/4" or far less every day all day.
Accurate rifles instill confidence in the hunter but to many people get hung up on the mystical one hole group. If you have a rifle that groups an honest 1.5 inches game out to 300 yards will not be safe.
Bob

 

[CoElkHunter]

@Forrest Halley
Here we go again. As if a flys foreskin more ore less off the lands makes that much difference for the average person.
If I can I load for the magazine lenght but at times rifles suffer from one of two things. Long mag short leade or long leade short mag.
Where possible I load all my rifles between 30 and 50 thou off the lands.
My custom rifles I have the barrel throated to suit the max lenght of the case in the mag. This can result in lighter projectiles being a fair way off the lands but doesn't seen to affect accuracy as all my rifles group 3/4" or far less every day all day.
Accurate rifles instill confidence in the hunter but to many people get hung up on the mystical one hole group. If you have a rifle that groups an honest 1.5 inches game out to 300 yards will not be safe.
Bob

I believe Weatherby chambers all have a lot of "freebore" with no ill effects?

 

[shootist~]

Or do Weatherby chambers have (and require) more freebore so they can jack up the powder charges and velocities? Reminds me of the difference in 5.56 Nato and 223 Rem.

 

[CoElkHunter]

Or do Weatherby chambers have (and require) more freebore so they can jack up the powder charges and velocities? Reminds me of the difference in 5.56 Nato and 223 Rem.

Could be? Their more than normal (maybe extreme) free boring doesn't seem to effect accuracy though.

 

[375 Ruger Fan]

Reading one of the other papers that was linked to the initial article
https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

What Is Old Is New Again?​

While Mark and I were talking with Scott Satterlee at SHOT Show, Scott suggested that all of this stuff we were “discovering” might actually not be new at all, but us simply returning to what guys like Roy Weatherby and P.O. Ackley found to work best in the 1950’s. Chambers for Weatherby cartridges were designed with significant freebore, which means the bullet jump was also significant. Many today might even call it excessive – but in light of all this, it seems like it might just be a really good idea after all. We are just now catching up with them!

 

[CoElkHunter]

Reading one of the other papers that was linked to the initial article
https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

What Is Old Is New Again?​

While Mark and I were talking with Scott Satterlee at SHOT Show, Scott suggested that all of this stuff we were “discovering” might actually not be new at all, but us simply returning to what guys like Roy Weatherby and P.O. Ackley found to work best in the 1950’s. Chambers for Weatherby cartridges were designed with significant freebore, which means the bullet jump was also significant. Many today might even call it excessive – but in light of all this, it seems like it might just be a really good idea after all. We are just now catching up with them!

My large bore hero Elmer Keith. You can bet that's no "man bun" chambered rifle he's holding! Ha! Ha! Ha!

 

[shootist~]

IIRC (and it's been months since I read them), the point of this PRB series was that:
Precision accuracy can often be found with the bullet backed well off the lands. And when this is the case, that same high level of precision can be maintained much longer - possibly over the life of the barrel - without ever adjusting the load.

A pretty big deal to serious PRS competitors that burn through barrels and ammo much faster than the average bear.