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How much is too much? Thoughts on bullet jump also welcome.

340wby - was previously a 300wby
new barrel
mkV action

I know weatherby uses a long throat but is this ok?
I always set my dies by starting at the lans and backing off.


Reference left to right:
Hornady 250SP
Speer 225BT
Factory Weatherby brand 225 Barnes-X

The 250SP didn't even have lans marks on it yet either.



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I haven't seen a rifle with this much excess before. This seem within tolerance? I already have Saami case specs, is there any way to check the chamber + throat? I'm reluctant to take it back to the gunsmith unless there is a fault.
Thanks for all thoughts.
-TODD


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Thats the way WBys were designed they are designed to jump and that is refered to free bore! They get there velocity from this and allow higher charge or a bigger case load of powder running at max pressure as the bullet leaves the case it is almost or depends can be completely out of the case before it makes contact with the lands!

You will be very high in pressure using Wby loads of you stick it out to the lands if you can get there... any of mine I cant!

Some guns are cut with no free bore chambered in wby cartidges.. But most if not all guns factory wby, sako for sure have free bore...

So likely your looking for something that you cant find sticking your noise out to contact the lands! Load em to sammi OAL and let her catch hell you might be supprized on the accuracy, my 300 wby is a tack driver

And yes all my wbys . 378, 30 378 and 300 have that much free bore!
 
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My factory 300Wby didn't have nearly that much free bore with 180's(thanks for the correct term). I've got a full 1/4" over Max OAL sitting on 250's.

can be completely out of the case before it makes contact with the lands!
Click to expand...

Maybe thats why some ppl think Wby are more prone to throat erosion?
 
well it will be very intresting to see what velocity you can get out of it!

she might be a quick thumper!

I myself would shoot it and feel 100% safe, as long as they did not but your 300 bl on it lol!!!

I am sure your fine and good to go, but a second and third oppinion here and there never hurts, my sako's have lots of free bore in them more so than my remington.
I stuck a bullet out just hang on by the neck end and it did not contact the lands i wanted to see if it had a lot and i bet that on has a good 1/2 of bullet movement from sammi before she hits.
 
If the bullet will fully engrave into the lands BEFORE leaving the case neck, you will be able to get decent accuracy. Amount of needed engraving is dependent on the bullet.

I consider free bore to occur when the bullet leaves the case neck without contact with rifling. The definition varies.

If this happens, accuracy is mediocre to poor because under that much pressure it is very easy for the bullet base to be knocked sideways with the bullet hitting the lands cockeyed.

That usually happens just before a barrel set back or change.

Jerry
 
That's pretty much what I had to do to touch the lands in my Weatherby chambering. Accuracy was OK (not great) and cartridges were over magazine length.
 
Weatherbys have used varying freebore over the years. I have two early ones with about 3/4", one from the 60s with about 1/2", and some newer ones with 3/8". On the older ones, I can't actually get some bullets to reach the rifling. They are all 1.5 shooters though (the older ones, I mean), and in a big game rifle, that's pretty much all you need. - dan
 
mysticplayer said:
If this happens, accuracy is mediocre to poor because under that much pressure it is very easy for the bullet base to be knocked sideways with the bullet hitting the lands cockeyed.

That usually happens just before a barrel set back or change.

Jerry
Click to expand...

That's not always true. I have several rifles which are capable of MOA accuracies, yet do not engrave until the bullet is fully out of the case. They're certainly not the most accurate rifles I own, but they are capable of clay pigeon accuracies at 300 and sometimes 400 yards; plenty good enough for a hunting gun
 
No argument from me on hunting accuracy. 2MOA is more then enough for most hunting situations.

However, if that barrel was set back or a new chamber/barrel installed with a shorter throat/leade, accuracy would be much better.

Many like bughole accuracy even though it will rarely matter in the field.

Jerry
 
So I smoked a 250 bullet and found total length. 4.143 to lands = 0.58"+ travel (more on a lighter grain).

Thanks Jerry, good read.
Following your guidelines:
250's work with no jump
225BT and less do not, flatbacks maybe

With all this extra room I may as well start looking to load 300gr woodleigh or go stupid with 350gr from wildcat. Thanks a lot, now I'm into $1.50 a pill +.
 
I have a Ron Smith barrel chambered in .240 without the standard Weatherby free-bore. Ron removed the free-bore step on the reamer. I have no problem to touch lands and still be under magazine length. This rifle has only had handloads, but I would suspect that factory ammo would be hot.

Good Shooting
 
With most factory Wbys you wont get the bullet to come remotely close to the lands if you want it to fit in the magazine box

I load for 4 Wbys and I always use a COL thats just shy of the magazine box length

Don't get too excited about the long jump to the lands . Even though this is not the most ideal in the benchrest / precision rifle world my 257Wby and 30-378 will both shoot 1MOA

My buddy built a 257 Wby using a custom reamer with the freebore taken out. My loads that are perfectly safe in my MKV will loosen primers on first firing on his ( pretty scary actually )
 
I imagine Weatherby wouldn't want their name stamped on a barrel with the free bore shortened beyond their spec. I would think it could be a little hazardous shooting factory ammo in a reduced freebore custom chambering.
 
240 Wtby never had freebore...nor did the 375 Wtby.

My 257 has about .20" less than a factory Weatherby chamber. I can seat a 110 Accubond to .03 off the lands it'll be 3.370" OAL...and the bullet base is near the base of the neck...I've been up to max loads with Rel22 and it's fine.
 
Load your rounds to factory COL, and never worry about seating out. The free bore does not affect accuracy or velocity. I have owned quite a few, and always achieved published velocities and then some. Accuracy was very good too.
 
444shooter
The free bore does not affect accuracy or velocity.
Click to expand...

I think that it does. Look at TRG-42's findings:
. . . custom reamer with the freebore taken out. My loads that are perfectly safe in my MKV will loosen primers on first firing on his ( pretty scary actually )
Click to expand...

Isn't pressure is related to velocity?

I dropped 1K on a barrel so that I would have something a bit better than off the shelf, hopefully. Isn't that why we do this?
 
No, what I meant was not to worry about the free bore on Weatherby's. I never had any accuracy issues seating to factory OAL. My velocities where on par with factory loads. If you remove the free bore, you will need to drop the charge as pressure will increase. This is the reason Roy went with the free bore.
Regarding custom barrels..if you wanted more power than factory, you should have went to a larger cartridge! Weatherby (Norma) factory loads are already hot enough.
 
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