I just rechamber one Rugerr 77 rifle in 25 -06 caliber , to 257 Wby mag.
I have the following problem .
my cases get very sticky te extract despite my my loads are a loy under saami max

I'm using hornady 100 gs bullets under 68 gs of IMR 7828
Max IMR manual is 73 gs
I also fire 66 gs and the problem continue .
I'm using Wby cases and WW 264 WM forming cases .
all the same.

Reamer is a Clymer , and chamber has standard measurment and has no problems
Chamber is also very fine polish , free bore is ok .

Have any one can guide me on that problem?

Thank you in advance

Raul,

Are your primers flattened or cratered?

The chamber may be fine, but your rifle's throat might be short, or your brass may be long.

Take one of your loaded rounds and blacken the bullet with a Magic Marker or Sharpie. Chamber the round and close the bolt. Do not fire.

Remove the round and check the bullet for rifling marks. Also, check the neck of the case for signs it is being pinched.

¡buena suerte!

George

George
Primers are ok .
My load of 68 gs 7828 gave me only 3350 fps and 66 3170 fps
magne that pressure is underground
Cases are ok also and doesn't touch rifling as well . 264 WM brass is almost 1,5 mm shorter than wby's

Raul,

If you try to rechamber a spent round that had sticky extraction, do you have difficulty closing the bolt?

George

George

yes definitely , fired cases almost no rechamber . and if do , bolt is very sticky

I have seen this type of reaction when a rifle is chambered (or rechambered) and the headspace gets excessive. The case jumps forward, jamming the neck into the throat, raising pressure, then the case sets back as the pressure builds, and the case is stretched.

Running a 257 WM reamer into a 25-06 chamber doesn't take a lot of metal removal, and in my experience belted magnums are the easiest type to overcut. (I think the 458 WinMag is one of the hardest cartridges to cut without a boo boo, for instance) Try taking a new case, measure it carefully, load it and fire. Then measure the fired case.

Another question is, how do you know the throat and freebore are OK? They are not easy to measure. There are a lot of Weatherby reamers popping up with no freebore. I suppose there is an experimental phase going around. if you bought the reamer used, it may be a special or have been reground. Don't assume that because you used a factory reamer, it has a standard throat and freebore unless you bought it new.

Art S
Headspace is Ok with No go gauge the bolt dont close.
Reamer free bore is 9.6 mm like weatherby standard
I think that in a time the standard was 13 ,3 mm
raul

Raul,

It sounds like your brass may be 'soft' and stretched beyond its ability to spring back.

Do you have any factory .257 Wby. brass, or 7mm Remington Magnum brass avaiable to you?

George

yes as I said before
my brass is WW 264 win mag and Wby factory
I had shot both new and reloaded and the problem is exactly the same in both cases

Fire factory loads to see if the problem occurs.

Make certain to wipe the sizing lube wax off the cases before firing.

Check your powder for deterioration.

Check your scale for accuracy.

Keep your ammunition out of the sun at the range.

George

George
don´t have any factory ammo here in my country
I wipe ell cases and tumble them after sizing
I use the same powder can to load 6.5x65 RWS and 7mm STW
I thought that the scale was wrong , check it ( is a RCBC electronic scale )( the velocity of 3170 fps with 66 gs tell me that is correct )
In my range there is no sun , I shot under a roof

George really is very strange
raul

Raul,

It's possible that the .264WM brass is small internally; weigh a fired, empty case (primer still in it).

Then, fill it with water to the top of the neck and weigh the case again.

A .257 Wby. factory case holds ~84grs. of water; if your reformed .264WM does not hold that much, load pressures will be higher than in a factory .257 Wby.


George

I had a similar problem with a new S&W .44 mag., even the lightest loads were hard to extract, primers showed no signs of pressure. After much fussing I found that the factory had left the slightest ridge right at the mouth of each chamber, probably left over from when they milled recess for the extractor. I could barely feel it with a sharp pointed probe. I ended up spinning a case coated with a bit of lapping compound in each chamber and it cleared the problem. You might try sliding a probe along the chamber walls right at the entrance and see if it is as smooth as you think?
C.G.B.

George
as I told you I had used both factory Wby cases and WW 264
Also I had used 66 grs that is SEVEN grains minus maximum
with both brands
so the problem is not here
CGBach
once I thought that there was the problem , so with my gunsmith take away the barrel and polish it like a mirror all way long

as I said before it is very strange

It's either the ammunition or the gun.

I take it that you can chamber and eject loaded rounds with no problem.

Have you measured the cases just above the belt before and after firing them in your chamber?

Can you post a photo of a loaded round next to a fired round?

George

Case length is a critical sign of pressure. Might figure out how long your cases should be via chamber measurements using a casting medium.

MOA Tactical
as I told before I had used WBy cases 2.541 long and WW 264 2.457 long with the same load both .Problem is equal
I agree with you y¡that lenght is critical , but if cases go into throat will press bullet and preassure raise , AND if you want to put a bullet in the fired case you can´t . This situation doesn´t happen and my bullets fell down into cases all

Measure a fired case at the shoulder and along the body to see if the chamber is properly tapered. The Weatherby case has a minimum taper to begin with. If, for some reason related to the reamer or the use of the reamer, the chamber becamer larger at the shoulder than intended this might result in a chamber which is virtually as large in diameter at the shoulder as at mid-body, thus creating a situation in which you are getting considerably "drag" when attempting to extract a cylindrical (or worse, pear-shaped) case.

Alternatively, a wobbly reamer can make an egg-shaped chamber, resulting in similar difficulties.

Make those measurements and report back on what you find.

Also, if you'll coat most of the case with candle black, then insert and fire it, the marks on the extracted case on the candle black will indicate where the bind is occuring.

Stonecreek
We had measured chamber with cerrofase and it is correct in all dimensions.
brass dimensions also are ok and are perfectly round not egg shaped
In minutes I ´ll go to range and will fire without extractor to see how sticky are empty cases .
I´ll fire 1 new Wby brass with 100 gs and 69,5 gs of IMR 7828
1 used WW 264 brass with 100 gs bullet and same load
1 used Wby brass with 100 gs Barnes TSX and 67 gs of IMR 4831
I´ll told you what happen

Take a fired case and a 257 bullet, try to put it into the case mouth before you sized it. If it will not slide easily into the case you have a tight neck problem.

The neck may be getting thicker as you resize...Have you reamed the necks?

No matter what the symptoms, I always try it out with factory ammo

I´d just came from range

I had fired the 3 rounds as I explain before
ALL fired cases practically don´t get stick in the chamber . As I explained I take away the extractor from bolt and fired the 3 rounds.
I put a rod from muzzle and with a very light push , the fired brass went away from chamber.
So brass doesn´t stick in chamber.
Jim Kobe yes bullet go through case mouth without problem and very easy.
SO WHAT DAMN PROBLEM IS HAPPENING.
After doing all experiments I think that there is a problemm with the extractor. Don´t know what is , but I think that brass get some kind of preassure against extractor and this one trough receiver or elsewere , and then the extractor get harder to push away with fired brass.Without brass it work fluently
I let you know any knew

A long shot...but are you sure the bolt has been opened up sufficiently and is the bolt body concentric with bore?

do you gt a "shine" or burnish on one part of the rim.

You mentioned extractor...has that been opened up to co incide with the larger diameter case?

Duane
rifle is a factory ruger 77 that I think it is ok in concentricity terms between bolt and barrel
obviusly extractor has been opened to magnum brass

as I told you I think that it could be something is happening with extractor tension , movement or whatelse that make bolt to be hard to push back
Not when lever it till possition , despite when yuo push back to extract brass fromm chamber

What would the extractor issue have to do with not acheiving the level of velocity from your loads you want before you have a pressure issue? I think you need to take your rifle to a more competent gunsmith than the one your dealing with now if you want the problem resolved.

Also, have you checked the bore/rifling dimensions of the barrel? Perhaps it is slightly undersized and not an issue with 25-06 velocities but becomes an issue with a higher velocity load. Barrel restriction so-to-speak.

Rul,

Please post photos as requested.

George

George
tomorrow will go to range with another extractor installed .
will post the photos you required

I may have missed it, but how long is the barrel?
The Go/No Go gauges likely only go as far in as the cartridge belt; not very far. As mentioned above, a chamber cast using Cerrosafe (available from Brownells) should show if the Whole Chamber conforms to CIP Specifications.

The length of the chamber could be fine, but the diameter of the chamber may be too wide/fat. Again, a chamber cast would show if that is what is wrong.

If the extractor checks out to be okay/fine, it might be worth your while to buy a blank .257" barrel and have it chambered. Then you would have a long enough barel for top velocity within safe pressures, and there will be no question about the prior chamber leading your reamer astray.

When I have had factory barrels re-chambered in a similar way to what you had done, I learned (the hard way) to ask the gunsmith/machinist to turn the barrel two or three turns and the breech end of the barrel cut off enough to be sure that the new reamer is cutting metal and not cutting air.

Good luck.

At 3300 fps with a 100 grain, overpressure for darn sure isn't the problem. You should be able to go 3600 fps with a .257 Wby. You have some kind of mechanical issue. Can't tell what over the internet, but it most certainly isn't pressure, or brass flowing into the extractor cut that is the problem.