Ruger 7x57 chamber lenght

[2shot]

Should read 7x57neck lenght


I was wondering if anybody else has had this problem that I have found with my Ruger Model 77. Most problems I hear about the Ruger 7x57 is that the throat is to long to accommodate shorter bullets. My own Model 77 tang saftey 7x57 that was bought back in the 70's has always been a dog as far as accuracy, factor loads, handloads, they all shot patterns instead of groups. On occasion I would get 2 shots touching and then the 3rd shot was 4-6 inches away. The only reason I have kept this rifle was because I had planed on having it re-barreled some day. Well the winter dull-drums hit me this last weekend and I got the rifle out from the safe after it had sat there for years and forgotten about. I also figured it would be a good time to tumble the 200 or so pieces of brass that I had for this rifle so that when things warmed up I could start once again to try and get this Ruger to shoot decent. I had some factory brass that was from the Remington 140 grain load that for whatever reason I picked up that factory brass and tried to take a bullet and put it back in the fired case. On about 3 of them the bullet would enter as it should with a fired case but on the other 17 out of that box the bullet would not enter, not even if I tried forcing the bullet back in the case. I though this strange so I measured the cases that the bullet would not enter and they all read 2.230- - 2.232 which is within specks for the 7x57 which has a max lenght of 2.235. The other 3 where the bullet did go in without any resistance measured 2.225. I then got out the other fired cases I had and tried the same thing. In ever instance where the bullet would not go back into the case the measurments were 2.230 or slightly over. The cases where the bullet entered freely measured 2.225 - 2.226. In the past while looking for accuracy out of this rifle I had always kept a close eye on the case lenght and had kept it under the maximum of 2.235. Now about this time I'm thinking that something is very strange so after all these years I decided to measure the chamber lenght of my Ruger. I waas shocked when the maximum lenght of my chamber was only 2.228. Some 6 thousanths of an inch to short. It's no wonder that I have never gotten any accuracy out of this rifle. Even with factory loads some of the cases were too long for my chamber. I have never experianced any signs of high pressure but then I never hotrodded this 7x57 either. With the longer case lenght the bullets were getting pinched down in diameter

So now I'm going back to the start and making sure that all my cases are max 2.225 and we will see what happens.

I have never heard of a Ruger 77 with a short chamber. Has anybody else come across this problem with the older Model 77's? It's no wonder that this rifle shot pattens. I used a plug gauge to measure the ID of one of the longer cartridges and it came out to .280. If effect the bullets were rattling down the bore and leaving the barrel unguided.

If I get it shooting good then I will get a finish reamer and get the case lenght to what it should be so that I can fire factory ammo in this gun without worrying about the cases being to long. After all these years of thinking the scope, the rings the bedding etc was wrong it's turning out to be something completely different and unexpected.


I have edited this to say that it's a neck lenght problem or should I say a lack of neck lenght. The rifle headspaces fine as it should it's just the neck portion of the chamber is short by at least 6 thousanths of an inch which pinches the bullet in the end of the case at the throat area.

2shot

[Larry Gibson]

2shot

Stranger things have happen but being able to trim the cases to fit the chamber precisely can be a blessing, especially if shooting cast bullets. You could always get an in spec finish reamer and clean up the chamber but I would do just as you're doing 1st.

Larry Gibson

[45 2.1]

I used a plug gauge to measure the ID of one of the longer cartridges and it came out to .280. If effect the bullets were rattling down the bore and leaving the barrel unguided. 2shot

You need to remove any pinch/crimp left from the original loading. Use a tapered punch for that and try again as it looks like you measured the wrong part. Nominal jacketed bullet diameter is 0.284" for the 7x57. A 70's era chamber is also throated for the factory 175 gr. loading just like the older 7x57 military rifles.

[2shot]

You need to remove any pinch/crimp left from the original loading. Use a tapered punch for that and try again as it looks like you measured the wrong part. Nominal jacketed bullet diameter is 0.284" for the 7x57. A 70's era chamber is also throated for the factory 175 gr. loading just like the older 7x57 military rifles.


Yep .284 it should be but it aint. The throat has pinched down the neck of the cartridge because the chamber neck was cut to short.


Larry;

This is the first time I have encountered a neck that was cut to short in the chamber. As a rule the companies tend to err on the long side of the chamber neck for people that don't check the lenght of their brass. I have resorted to trimming on the long side for several rifles I have because the chamber neck is cut long and it really helps with accuracy. With this Ruger I'll try cutting the necks back to fit the chamber. It's the easiest solution and I'll see what happens. I wish I had a good camera so that I could show pic's of the brass that's to long and has been fired. The Remington ammo has a three prong factory crimp and after firing in this tight chamber the factory cripm it still there. Not as pronounced as an unfired case but you can still see it. That's what made me try a bullet in the fired case, because I saw the crimp was still there.


Hopefully I'l be back to lobbing those 175 grain RN into tiny little groups. I like this rifle because the safety is where it should be on a hunting rifle.

2shot

[Larry Gibson]

Trimming the cases back to fit the actual neck is the easiest solution and should work fine. Let us know please.

Larry Gibson

[flounderman]

You should check the case neck after fireing by trying a bullet in them and if it's tight, trim the cases back. Measureing just tells you what it is supposed to be. You can also have thicker necks on some makes of brass.

[fouronesix]

Should read 7x57neck lenght
I was wondering if anybody else has had this problem that I have found with my Ruger Model 77.
I have never heard of a Ruger 77 with a short chamber. Has anybody else come across this problem with the older Model 77's?

I have edited this to say that it's a neck lenght problem or should I say a lack of neck lenght. The rifle headspaces fine as it should it's just the neck portion of the chamber is short by at least 6 thousanths of an inch which pinches the bullet in the end of the case at the throat area.

2shot
As a matter of fact---
Back in the mid to late 70s had two of them NIB. You know the old saying, "fool me once.... fool me twice...".

Had one in 270 Win with exactly that problem. Short chamber. Just about blew it up with a normal, proven charge of 4064 and 130 gr Jbullet where the mouth was crimped into the bullet when fully chambered. So, fooled me once.

Then a few years later, I guess the sting of the first experience had kind of worn off, so I bought one in 7X57. The chamber was plenty long but the shoulder and neck dimension was at least .030-.040 larger in diameter than spec. and not concentric to the bore! A bugger to resize cases that much-- so no case life in that future. No signs of pressure of course but a veritable scattergun. Dumped that one quicker than the first. So, fooled me twice.

Since then have completely sworn off Rugers- and there won't be a fool me thrice!

[2shot]

I'm with ya on that fouronesix! I have a #3 in 45-70 that's a real shooter, that's why I bought the M-77 figuring it would be too. This is the only Ruger bolt gun I have and I doubt that I would ever buy another. The #3 is a keeper but I've seen to many bolt guns that just weren't worth the asking price because of accuracy/bad barrels. I work to hard for my money to take chances that what I buy might not be good.
2shot