Hello folks;
Lookin for ideas on a temperamental Ruger 77/22h. I have a batch of once fired brass that I was getting ready & noticed the normal swell about an 1/8" above the extractor groove only goes about 2/3 of the way around the circumference of the case. The remaining 1/3 is smooth with no swell. I have heard & read more than once that the two piece bolt may need to be tightened up since the locking lugs are in the rear of the bolt. I have done some tinkerin' but no serious gun work & not sure where to look. This gun is like my golfing, it will shoot a decent group every now & then, but I'd hate to have to depend on it. If anyone has any experience like this, I'm all ears. Thanks.

I think the first thing I would do is make a casting of your chamber. Looking for a wallow-out or out of round chamber. I have found that out of round chambers is more common then I would hope. There is more knowledgeable people on the list then I. You will be getting some other good ideas. Best of luck finding out your chamber problem, Twyman

Sounds like a chamber problem.....as the other post suggest the chamber cast is a good way to find out..mark the case and reload it and make sure the expanded part is at the top of the chamber/then see if the expanded spot shows up at the bottom this time after you shoot it the second time,...the #1 and 3 did better for consistancy in the Hornet.....but I didn't keep the 77 long as another Hornet came along in a different gun and I swapped....the Hornet can be choosey about small changes in anything reguardless of the type bolt lock up.....some respond to a primer change.....Rem 6 1/2 were made for small rifle cases such as the Hornet and help sometimes??? good luck and good shooting-loading!!

Don't discount the possibility of brass that is thicker on one side causing the problem. This will allow the brass to expand at diffetent rates along it's circumference. Will this be enough to produce what you are experencing? Probably only in the more extreame cases. But this is worth a look see.
This would show up in the brass as unequal neck thickeness. Probably most easily measured as neck runout after resizing. Most accurate way to measure would be with a ball micrometer. Cut a few cases in half just above where you are concerened. Measure the brass thickness at the site of concern.
As was mentioned a chamber cast will tell if it is the rifle causing the problem. It is a little tricky to do a good chamber cast unless you have had some experence(I found out the hard way).
muck

>>I have a batch of once fired brass that I was getting ready & noticed the normal swell about an 1/8" above the extractor groove only goes about 2/3 of the way around the circumference of the case. The remaining 1/3 is smooth with no swell.<<
Your brass is not centered in the chamber when fired. This is often due to the extractor pushing the case to one side of a generous but not necessarily oversize chamber. It happens because functional clearance has to be designed between a max cartridge and a minimum chamber. My TC Hornet also does this. This condition is found to an extreme in .303 Lee-Enfields. Brass with a larger head diameter or a smaller diameter chamber will prevent this. I have also heard that wrapping a narrow strip of tape around the solid case head section can cause the initial shot to center the brass better. I don't shoot my Hornet enough to worry with trying to wrap the case head with tape for the first shot.

I'd recommend you don't worry about the brass too much for now.
The best thing I ever found for my Ruger was Lil'Gun powder. You can't fit too much in a Hornet case. I used 13.2 grains of Lil'Gun, a Federal #100 small pistol primer, and a 40-grain V-Max, Berger, or Starke bullet, seated .020" off the rifling. The Ruger is easy to load single shot.
I'd also recommend you free-float your barrel, glass bed the action and first 2" of barrel, and replace that awful factory trigger with a SpecTech or other adjustable trigger, and a Volquartsen target sear.
You can check your headspace with a feeler gauge between the bolt halves with a sized case chambered. I installed a .0015" shim between my bolt halves, which did nothing for accuracy. If you've got a lot of clearance, Conneticut Precision Chambering does quite a lot of 77/22 work. You can "Google" them.
Regards, George.

First off, thanks for the quick replies to a newcomer!
I'm not familiar with a chamber cast or the procedure to do it, but I have a pound of "Li'l Gun" & a couple different brands of small pistol primers in the cabinet just waiting to be opened. Here's the loads I had for it:
#1 load
Fed 205 small rifle primer
11.8 gr Win 296
45 gr Sierra hornet #1210
1.785 OAL
This load had the best group, but it was about 20 degrees Farenheit when I tested it & it shot around 1" to 1 1/4". The warmer it got, the worse it grouped up to about 2.5 or 3".
#2 load
Fed 205
11.8 gr Win 296
Hornady 45 gr Bee bullet
1.703 OAL
I don't have a chrony "yet", so I can't tell you the velocity.
Would the cold weather groups be an indicator of the small rifle primers being too much or is that just a characteristic of the powder?

It could be you have a large chamber. If the cartridge is laying againsy the bottom of the chamber it can only
expand upward. The pressure of the load has nothing to do with it. Some people ignore it, some people
neck size only, and some people use "scotch" tape on the base of new brass to expand it evenly.
All schemes seem to work. The Hornet may be the touchiest cartridge to load for.
Good LucK!