Has anyone ever re-barreled to a Weatherby chambering but with a normal length throat? I am considering re-barreling a rifle to 300 Weatherby and am wondering if I will be able to load to the full potential of the cartidge if I elimate the freebore. I am considering this option so I can control my seating depth and seat my bullets close to the lands.

The freebore is what allows Weatherby chamberings to be loaded to their potential. If it lacks the freebore you will reach pressure signs at about the same level as a 300 Win. You can also pretty much forget about shooting factory ammo through it.

Ken....

or selling it!

I tried it in a 257weatherby and its pretty much as heat described. I tried a lot of diffrent powders and bullet combos, but never really found a load that would shoot under 3"moa. 100 yrds.
it was really bad at longer distances.
Velocities were never consistent.
Ended up having the rifle rechambered.
Now take the 340 and +40* shoulder and a 30cal bullet and you might just have something.

quote:

Originally posted by Heat:
The freebore is what allows Weatherby chamberings to be loaded to their potential. If it lacks the freebore you will reach pressure signs at about the same level as a 300 Win. You can also pretty much forget about shooting factory ammo through it.

Ken....

Amen... I have a 300 Wby reamer that I had most of the freebore removed, and this is exactly what I found to be true.

What the WBY freebore does, essentially, is increase the size of the combustion chamber. And not the best way of doing so, BTW. A larger capacity case will do the same thing and allow you to control bullet seating depth for better accuracy. I don't know of any Benchrest shooters who use a chamber with WBY-style freebore.

JMHO

Ray

quote:

Originally posted by agr516:
Has anyone ever re-barreled to a Weatherby chambering but with a normal length throat? I am considering re-barreling a rifle to 300 Weatherby and am wondering if I will be able to load to the full potential of the cartidge if I elimate the freebore. I am considering this option so I can control my seating depth and seat my bullets close to the lands.

I sympathize with your goal of getting rid of the freebore to potentially improve accuracy. I also agree with others that it creates a problem for you or anyone else who might in the future unknowingly or inadvertantly use factory or other ammunition that is intended for a freebored chamber.

My suggestion would be to use a slightly different cartridge. The .300 Jarrett, which is essentially a necked-down 8mm Rem Magnum, about duplicates (or very slightly exceeds) the case capacity of the .300 WBY. You can also use the .300 RUM in any action you would build a .300 WBY on, and it will exceed WBY velocities at the same levels of pressure.

Thanks for the replies and good information. I am curious to know what kind of loads and velocities the benchrest shooters are getting out of their non-free bored Weatherbies. Also, if there are no gains to be made over a 300 Winchester, why would a benchrest shooter choose the Weatherby cartridge?

I would talk to the wby custom shop about their Krieger barrels, I have one on my Accumark, shoots very well freebore and all.

John

quote:

Originally posted by agr516:
Thanks for the replies and good information. I am curious to know what kind of loads and velocities the benchrest shooters are getting out of their non-free bored Weatherbies. Also, if there are no gains to be made over a 300 Winchester, why would a benchrest shooter choose the Weatherby cartridge?

agr

Only a very few Benchrest shooters use a 300 WBY chambering, and I know of none of them who have their chambers cut with the WBY freebore. Most use cartridges such as 300 Ackley, 300 WBY Improved, 308 Baer, etc. Since they load for accuracy first and foremost, velocities will be in the 2900 to 3200 fps range with the long, heavy custom bullets.

I don't know where you got the idea that there are no gains over a 300 Win Mag. That simply isn't true. A larger case = more capacity = more velocity. Otherwise the entire science of ballistics would be turned on it's head.

Ray

I was responding to a statement made by Heat in his reply to my original post. It was later seconded by Terry Blauwkamp.

Heat wrote: "The freebore is what allows Weatherby chamberings to be loaded to their potential. If it lacks the freebore you will reach pressure signs at about the same level as a 300 Win."

I agree that physics do not back these statements. I was questioning the logistics of this reasoning in my second post. I can see how some velocity may be lost by eliminating freebore but if so, how much?

quote:

Originally posted by agr516:
I was responding to a statement made by Heat in his reply to my original post. It was later seconded by Terry Blauwkamp.

Heat wrote: "The freebore is what allows Weatherby chamberings to be loaded to their potential. If it lacks the freebore you will reach pressure signs at about the same level as a 300 Win."

I agree that physics do not back these statements. I was questioning the logistics of this reasoning in my second post. I can see how some velocity may be lost by eliminating freebore but if so, how much?

With all due respect, I believe Heat and Terry are right. Perhaps they should have inserted the word "full" in there to make clear to you what they are trying to tell you. It is the freebore which allows the Wby rounds to reach their full potentials.

You say you already know that, and what you want to know is how much potential is lost by eliminating the freebore.

There is a simple generalization to answer that question. "No one can tell you with any certainty exactly how much you may lose."

Why not? There are a bunch of reasons. Here's just a few:

1. No two barrels, even of the same make, perform exactly the same, even when chambered by the same 'smith with the same reamer on the same day... Occasionally exceptions may occur and both perform exactly alike, but that is more chance happenstance than anything that can be both reliably & accurately predicted.

2. There is so little difference in potential between the .300 Winchester and the .300 Wby, that it is not too unusual to have a "fast" .300 Winchester perform pretty much the same as a "slow" .300 Wby...especially with different lots of bullets and different lots of powders....even though the bullet and powder designations may be the same too.

3. The only way to tell how much actual "potential" would be lost is to chamber the SAME barrel in .300 Wby without freebore, work up to maximum loads for it and chrono the results. Then freebore that same barrel without otherwise modifying the chamber, and work up the max loads again, and chrono them. The difference is the increase (or possibly, even decrease) in potential.

Not even that will give a perfect answer, as a barrel without a freebore MAY exhibit a preference for a slightly different powder than will the same barrel WITH a freebore.

When it comes to splitting 100 fps hairs, the only 100% rule is that there aren't any 100% rules.

That's why riflery is partly an art and not a pure science.

so, like the others have said, you'll have pressure problems.

I'll be MORE plain, if you want a 300 winmag, sell your webby and get one.. its cheaper

if you want a hunting rifle ( this AINT a benchrest gun, so all of that rabbit trail doesn't matter) and you want a 300 webby, then you better well chamber if for a 300 webby, otherwise you ARE shooting factory ammo in a wildcat chamber.. good luck with that..

all in all, a bad idea, and anyone that tells you the rifle aint accurate because of freebore if FULL of S.. SH.... STUFF

quote:

Originally posted by jeffeosso: . . and anyone that tells you the rifle aint accurate because of rebore if FULL of S.. SH.... STUFF

I guess that means me. Note that I said "Benchrest shooters". I don't know one who chambers their rifles, whether long range or point blank, with more freebore than necessary to properly seat the particular bullet they are shooting. Excessive freebore makes extreme accuracy very hard to acheive. Guys with hunting type rifles can still learn a few things from Benchrest shooters. There's no reason a WBY cannot be both efficient AND accurate.

And who on this Forum shoots factory ammo???

Ray

Ray
wasn't calling you out.. was saying i have heard alot of GUFF that says "well, a weatherby cartridge / rifle is only good for 2 moa" .. and its that.. guff.. if the thing shoot 3-4 moa, with factory ammo, SEND IT BACK .. they will fix it

my 416ar, 458 ar, 470 ar, 500 AR and my own 500 jeffe all have a TON of freebore .. .375 to .500 .. and all are moa or better guns.. seriously ... freebore has nothing to do with HUNTING accuracy call it 1/2 moa and up ...

under 1/2 moa, well, i think there's alot of chicken blood used to flush chambers when reaming some benchrest guns .. I can stay 1/4 to 1/3 with a really well setup gun .. can't break 1/4 to save my life, but my wife, with the same gun, same ammo, same case, same day, can shoot in the 1s .. thats AT LEAST 50% smaller groups, and its all the shooter..

but a 300 weatherby aint a benchrest caliber, and a markV or vangaurd aint a benchrest platform, so everything about "benchrest" doesn't REALLY matter... yes, if you use every benchrest trick in the book, you can make THAT platform shoot better.. but it will NEVER be a 1/2 or better gun... ever, so why waste time talking about it?

all of these guns are .5 freebore .. all seated NOWHERE close to the rifling .. at least .500 off, ... heck, the most accurate rifle i currently own, a 257 roberts, likes to be nearly .125 off

470 AR


458 ar--


FREAKISH 416 ar target. it is really 3 shots.. the gun is usually 1 moa

quote:

Originally posted by agr516:
Has anyone ever re-barreled to a Weatherby chambering but with a normal length throat? I am considering re-barreling a rifle to 300 Weatherby and am wondering if I will be able to load to the full potential of the cartidge if I elimate the freebore. I am considering this option so I can control my seating depth and seat my bullets close to the lands.

Pretty good artical in P O Ackley book vol II about freebore/pressure. Older reloading manual use to warn about rifles with no Wby freebore reduce loads 5/10%.

I just had a 257Wby build with no Wby freebore plus a 300Wby and barrels are so marked.

What your looking at in Wby loading data the start loads more than likely will be your max loads but your velocity will be at max loads.

In the two rifles I'v shot I never loss velocity and depending on barrel/twist etc you may gain alittle velocity over published data.

One thing I've done is had them headspace the wby case on the shoulders and I plan on having another Wby build that way just cann't decide between the 270Wby or 7Wby.

Here is something from Shilen
http://www.shilen.com/faq.html#question3

quote:

I am curious to know what kind of loads and velocities the benchrest shooters are getting out of their non-free bored Weatherbies.

Assuming by "potential" you mean accuracy rather than speed, not a great impromement and at a large cost in speed.

It isn't the freebore, as such, that's a potential accuracy issue. It's more about how snugly the freebore fits the bullet diameter.

quote:

Originally posted by agr516:
I was responding to a statement made by Heat in his reply to my original post. It was later seconded by Terry Blauwkamp.

Heat wrote: "The freebore is what allows Weatherby chamberings to be loaded to their potential. If it lacks the freebore you will reach pressure signs at about the same level as a 300 Win."

I agree that physics do not back these statements. I was questioning the logistics of this reasoning in my second post. I can see how some velocity may be lost by eliminating freebore but if so, how much?

Yes, you are correct in your assumption. You will lose some velocity but still be above 300 Win levels. I should have been a bit more clear but the charge will need to be somewhat reduced with less freebore. I can't tell you what the velocity loss would be however.

Ken....

FWIW Stonecreek is right about the 300 Jarrett. I've had both and I think it is the better cartridge. Mine was called the 300-8 Mag but I think the Jarret name ahs much better resale potential.

For what it’s worth I’ll contribute my experiences:

I had a Winchester Model 70 chambered in 300 Weatherby. It shot reasonably well as a hunting rifle with factory ammo groups around 1.5 inches and served me well on my first plains game hunt shooting a handload of 200 grain Nosler Partitions.

I got a “bug” for wanting more accuracy and had Mark Penrod rebarrel it with a 26” Krieger with a 1 in 10 twist in his “Penrod” contour which is about like a #4 Heavy Sporter. Mark cut the chamber with a smaller or perhaps an “in between” amount of freebore such that I can safely shoot Weatherby factory ammunition in it and still handload bullets out “closer” to the rifling with the magazine box being the limiting factor overall. It plain works. Weatherby factory ammunition with 200 grain Partitions shoots just under an inch and some discontinued Federal Premium with 200 grain TBBC shoots into ¾ inch. I have a 200 grain Partition handload that will safely get 3100 fps (generally not possible in the 300 Win or WSM) and it shoots into ½ inch.

With regard to the difference between the 300 Weatherby and the Win or WSM I think it is differentiated by the ability of the Weatherby to handle heavier bullets. I loaded some 220 grain Partitions and they were pretty accurate but could not get the velocity I expected without excess pressure signs. I plan on testing some 180 and lighter bullets to see what they can achieve for velocity and accuracy. The Jarrett and some of the other 300 mags will probably exceed the Weatherby with heavier bullets but at the cost of more powder, flash and recoil. I’d keep it as a 300 Weatherby….it has worked for 65 years.
Good luck,

quote:

Posted 24 June 2009 08:12 Hide Post
all of these guns are .5 freebore .. all seated NOWHERE close to the rifling .. at least .500 off, ... heck, the most accurate rifle i currently own, a 257 roberts, likes to be nearly .125 off

470 AR

I am just going to have to agree with you 100%. Long a go I bought a .300 WBY with a 26" "B" barrel. I floated it and bedded it. I worked loads from minimum to max and not a single group was over 1/2" with any load. Back then it was surplus 4831, I started at 83 gr and went to 88 gr, NOT SAFE TODAY! I stayed with 88 gr and the gun was deadly to over 500 yd's. I head shot a chuck from a sitting position at 550 yards with it.
There is just nothing wrong with a normal Weatherby and the Vanguard is also one of the most accurate rifles I ever shot. A friend brought one over and it was amazing.
Forget the freebore and make the gun shoot and shoot it will!

Common thinking says boolit jump is very bad in a revolver or rifle. Now here is boolit jump for you. 1/2" down to 7/16" at 50 yards is common as is way under 1" at 100 yards and it clangs steel to 500 meters. This 45-70 will out shoot every single 45-70 rifle there is and you need a light to see the boolit nose in the chamber.