Once fired brass sticking (that was fired from the same rifle?)

Wookie316

Wookie316

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Well, I am not sure what to do next? I'll start off with all the details of the load & rifle.

24 1/2" (cut down from 26" originally) #2 contour Ted Gaillard barrel chambered in 264 Win Mag. Chamber is throated long for a COL of 3.495 with a 140gr Accubond. I seat the bullet so my COL is 3.480.

http://www.shootingpaul.netfirms.com/GAILLARD.html

Barrel is fitted to a Sako AV action that has been trued & trigger set to 2 1/2 lbs. Barreled action is bedded to a Brown Precision stock. A 4.5x14x40mm LR Leupold B&C reticule. Scope is mounted with Talley high rings & mounts (high mounts fit me much better than low mounts).

DSC_2777.jpg


The load is as follows.
Win brass
215F match primer
140gr Nosler Accubond
72gr H870 (down from 74gr as I was getting pressure signs & extraction issues with new brass)

Now I was having problems at 74gr as described above, so I dropped down to 72gr. Now new brass seems to work fine at 72gr, no extraction issues, also the fired new case will go back into the chamber no problem.

My once fired brass (out of this rifle) is a different story. I first thought it was a trim issue because my first 20 rounds I didn't trim & was over the 2.500. It was not by much though, 2.509.

The next 20 once fired rounds were trimmed back to 2.486. Today's field test came up with the same thing, a little tug after the bolt is lifted to extract the shell. I am getting light scratching above the belt on the once fired rounds?

Funny thing is the measurements on the new brass & once fired seem to be the same above the belt. .513 above belt & .493 at the shoulder.

Normally I neck size cases, but I decided to F/L size these. Reason being when I was working up a load for the rifle, I wasn't as good at keeping brass separate as I should have been. I knew some of the loads were a bit warm. Now most of the warm loads brass was pitched, but rather than pitch the rest I figured a F/L sizing would get me back in check for the most part.

Now if it was the odd once fired round that was sticking, I'd write that off to a hot load case that got mixed in the batch of brass, but it seems I am getting sticky extraction each load with the once fired brass.

Would my load still be too hot? I am 2gr less than max in the Nosler manual, 6.3gr from max in the old Hornady manual, 4gr from max in the old Speer manual & 1gr from max in the Hodgdon manual.

With my load I am right around the 3100 FPS range according to my chrony. I checked my balance beam scale to verify it was correct with another one I have & found it to be good.

I am hoping I have over looked something & don't have to drop my charge anymore. Does anyone have an idea out there?

Thanks
 
You seem to have covered the bases.I am not familiar with the cartridge.
I would suggest you examine oal and trim length very carefully,as this custom rifle may have very small specs.I would also step down the charge to where there is no sticking,then slowly go back up again.
 
Mmmm, puzzling. A full length resize and trim should have solved the problem. What type of crimp are you using? Too much crimp might cause excess pressure, but if your not close to max powder charge this should not be an issue.
 
No crimping on the brass.

I am going to inspect the chamber better because the scratching on the brass is just ahead of the belt on the once fired. A simple polish may fix it up?
 
Had this prob with my 300 win had to drop the load a bit more. are you touching the lands if so try giving it some jump some times if just touching lands you can get weird pressure prob.Just my thought.
 
I had a 264 mag a few years ago that was really particular about what you fed it. It was only really accurate when loads were stupid hot. The other thing was they got stupid hot very fast.

I would drop the loads way down and work up again. Try reloser 22
 
A custom chamber may or may not represent book specs. Throat length comes into play, but perhaps your throat is is tight, and this will have an effect on pressure. Work up your load in one gr increments using a chronograph and watch for the velocity to plateau. This will indicate the maximum pressure and the next increment will result in a sticky bolt. You might not be able to match the maximum book load, but you should be able to match the maximum book velocity, although the difference of 100 fps won't mean much. A 6.5 140 at 3000 ain't bad and I think the expectation of 3200 or better is unrealistic.
 
Barrel was shortened from muzzle end. I use Redding dies with the comp shell holders. The shell holders go from +.002 to +.010. I am using the +.002 right now.

New loaded shells (my loads) go in & out of the gun no problem, as well as the once fired brass that has been sized. It is after the once fired brass is fired that I require a tug to get it out.

Last night I neck sized a once fired round with the 72gr H870 load. I trimmed brass to 2.486, cleaned burrs off the neck & loaded again to 72gr H870. I also cleaned the chamber in my rifle. It was dirty, but nothing out of the ordinary. After the neck sized round was fired, my case stretch was only .001 as I measured it at 2.487. It still needed a light tug to extract the fired shell.

On closer inspection it appears to be scratching ahead of the belt about a 1/8" wide mark on the case. I cycled the spent case back into the chamber about a 1/2 dozen times in the field & it appears there is about 1/2 dozen 1/8" marks ahead of the belt on the case now.

I am thinking that there is a rough spot where the belt ring was cut into the chamber now. What do you guys think?
 
Sounds like a rough spot in the chamber.

But, the 6.5 bullet is very long. This bullet is famous for developing pressure very fast.

Did you start low and work your way up? The velocity quoted seems high for that barrel length.


I have seen a 6.5 rifle that blew the primer and locked the bolt on the "START" load. Don't forget the "MAX" in the book is for their rifle, not yours. There is easily a 10,000 PSI difference between one rifle and the next and 100 fps, too.
 
Sounds like some of the issues I had with the 264 I once had. The only thing I could figure is that pressure was still too high and had to drop down. Mind you I had one of those short throated Model 70's that were even more of an issue with conventional bullets......The symptoms remain the same.
 
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