Ruger No. 1 headspace

[myfriendis410]

I have a 1976 vintage No. 1 in 7mm rem mag that has, I think, a headspace issue. I was wondering if anybody else here has had similar issues and what I can do about it. The darn thing eats brass--I get maybe two loads out of it before incipient case head separation. My A-Bolt in the same caliber exhibits NO signs of case separation after five or six loadings. Any thoughts?

[Moondawg]

What Excess 650 said. Adjust your sizing die so you headspace off the shoulder. What you are describing is a not uncommon problem with belted magnums.

[Tatume]

Go/No-go headspace gauge sets are not terribly expensive:

http://www.brownells.com/.aspx/cid=0/k=headspace/t=P/ksubmit=y/Products/All/search=headspace

If the rifle has excessive headspace Ruger will fix it.

[leadman]

Ignore the belt on the 7 mag and headspace it off the shoulder. I had the same problem with my Encore in 7 mag and did alot of investigating and measuring.

After talking with many techs at the powder companies and some gunsmiths I determined the problem is not so much with the headspace as the fact that almost all of the brass made for the 7 mag is short in the body.
This creates the same effect as an excessive headspace issue in a bottlenecked case like the 30-06.
What I do to correct the problem is prime the new cases, add 20grs of Unique, fill the remainder of the case with Cream of Wheat cereal and make a wax plug to keep everything in the case.
After firing the case fits the chamber so do not push the shoulder back. I went from 2 or 3 loadings to over 5 now. and these are close to max load with jacketed bullets.

[montana_charlie]

I have a 1976 vintage No. 1 in 7mm rem mag that has, I think, a headspace issue.
If you put a small piece of Scotch tape on the head of a new case, will the breechblock close on it?

How many layers of tape will it accept?

CM

[Lloyd Smale]

My #1 in 2506 is the same way. If you full lenght size brass will last 2 or if your lucky 3 firingings using dies set up for any other 2506. What ive come to do is just neck size for that gun.

[myfriendis410]

I really did not want to have to load specifically for that rifle. My other rifle takes an F/L sized case beautifully and won't accept one lengthened for the Ruger. I suppose that's my only realistic approach though......

[leadman]

Since the headspace is the distance from the rim to the rim recess in the barrel having the headspace corrected probably won't fix your problem.
I read where some are chambering for a 7mm mag without the belt.
This is more of the cases not being made long enough from belt to shoulder.

If you could find a gunsmith with a reamer ground shorter from belt to shoulder it would probably work good.

Another option is to use a different belted case like a 300 Win Mag and sized it to fit the chamber. It would be easy to tell these from cases for your other guns and if one did find its way into a 300 WM probably no damage would occur.

[myfriendis410]

I fired three rounds this a.m. and all three developed near case head separation. To the point that it dented the case below the shoulder from blow-by. Cases fell out of the gun and when a caliper was put on 'em they were at 2.507" which started at a trim-to length of 2.493". That's a LOT of stretch.

[Tatume]

Service inquires for Shotguns, Revolvers, 22 Charger Pistols
and all Rifles except PC4/PC9 Carbines.

Sturm, Ruger & Co., Inc.
Customer Service Department
411 Sunapee Street
Newport, NH 03773

Telephone: 603-865-2442 / Fax: 603-863-6165
(Monday through Friday 8:00am - 5:00pm EST)

[Lloyd Smale]

id usually agree with you but this particular #1 is a real shooter. So much so that id be afraid to send it to ruger and take a chance on getting it back with a different barrel (crappy one) i guess in this case its worth the extra to me.
I really did not want to have to load specifically for that rifle. My other rifle takes an F/L sized case beautifully and won't accept one lengthened for the Ruger. I suppose that's my only realistic approach though......

[Rico1950]

"What you are describing is a not uncommon problem with belted magnums".

+1 on that. I've had a Rem 700 BDL 350 mag since about 1975. Always set the dies to headspace off the shoulder. Brass will last alot longer.

[Clark]

http://i757.photobucket.com/albums/xx220/ClarkM/7mmRemMagchamberandcartridgedrawingswithdimentions andtolerances.jpg
The SAAMI drawing for 7mmRemMag is much like the drawings for other belted magnums.


.220 - .008" for cartridge belt
.220 + .007" for chamber belt clearance
---------------------
Belt specified to have between .000" and .015" clearance

2.2700 - .0070" for cartridge shoulder clearance
2.2791 + .0100" for chamber shoulder clearance
---------------------
Shoulder specified to have between .0091" and .0261" clearance


The brass I measure of many samples of many brands looks like .210" to .215".
So when I cut threads and the cut chamber on a 7mmRemMag rifle, I headspace the rifle at .215".

But the factory rifles are all more than .220"
I have a Ruger #1 7mmRemMag.

So what to do with a factory rifle?
The first time brass is fired, the belt will stop the forward movement of the cartridge when the firing pin pushes.

Partial neck size, neck size, or FL size and push the shoulder back .001".
Then on the next firing, the shoulder will be what stops the cartridge forward movement in reaction to the firing pin.

[Gtek]

+1 on what the others have said on creating false shoulder. 50/100 new and start is the way I go and serialized batch to individual weapon. I have even done quick anneal after first size and before first firing. You may also notice your groups will shrink a little, also paying attention to jump at about .010"-.020". Problem has been around since they made them, but being in the crowd that takes your brass home, welcome to the madness! Gtek

[leadman]

I chased this problem with my Encore for awhile and at some expense. I bought bag of different brands of popular brass and measured them. They were all short from the front of the belt to the shoulder.
Fireforming them as posted above has solved the problem for me. As mentioned the accuracy does get better with the fireformed brass. I investgate if my groups go over 2" at 200 yards as it will usually keep a group size about 1.5" at that range.
You may want to do a chamber cast so you can see the various dimensions of your chamber and then fireform your brass to fit. Pushing the shoulder back with the die screwed down to touch the shellholder will recreate your original problem.

[myfriendis410]

I have loaded three rounds, mid-range, with the false shoulder. I will try to get them through the gun Monday. I will post results. The one good thing is I have a boatload of 7mm r.m. brass so sorting and identifying for one gun should not be a big deal. I just hate to do it.

[Crusty Deary Ol'Coot]

Because of manufacturing tolerences that we all live with, using one set of full length dies for a number of firearms is very likely false economy. It may work or it simply may not.

Back toward the start of this topic it was said that a belted case should be head spaced on the belt. Simply WRONG!!!!!!!!!!!!! most of the time.

That may work and work well in some cases, but far better results will, and this goes for all bottle neck cartridges including the belted kind, be had if you always size the case just enough to allow for a cartridge fired in your chamber to again chamber in your chamber.

Size all bottle neck cartridges the minimum amount possible for best brass life and consistancy.

In most cases, head spacing a belted cartridge on the shoulder will give far better results and MUCH longer case life.

Been there and done that years back with my first belted cartridge rifle, also a 7mm mag.

AND ----------- for most of us and in most of our reloading, a set of properly adjusted full lengthy dies is all you need and the purchase of a neck sizing die is only taking money from your pocket and moving it into someone else's.

Keep em coming!

Crusty Deary Ol'Coot

[myfriendis410]

So I finally got to the range and ran 6 rounds through. Two loads: a mid-range load with a 140 gr. Sierra and a hotter 150 gr. Barnes TSX. Both were tight in the gun with the false shoulder and when fired dropped out of the gun with no sign of case failure. I put a tool into the cases and no sign of a ring forming either. Interestingly; the cases only stretched .003" in overall length. The loaded rounds that were giving me trouble measured .018" larger after firing.

Thanks for the help, guys!

[Ed in North Texas]

[QUOTE=leadman;1745377
snip
I read where some are chambering for a 7mm mag without the belt.
This is more of the cases not being made long enough from belt to shoulder.
snip
[/QUOTE]

Help me out here. Some folks are cutting a 7mm Remington Magnum chamber without a recess for the belt. How does a case with a belt chamber in that rifle? I just can't wrap my mind around a 7mm Rem Mag chamber without a cut for the belt. I must be missing something.

Ed

[myfriendis410]

A case with a belt wouldn't be able to chamber if the belt cut is not present. They would have to rely on custom ammunition.

[Crusty Deary Ol'Coot]

I have a friend who has, "a thing" about belted cartridges.

Guess that is OK, everybody needs a thing about something I guess.

But since I learned to properly set up full length sizing dies for bottle neck cartridges - that was way back with my first #1 which happened to be a 7mm mag. - belted cartridges have been NO ISSUE any more then any bottle neck cartridge.

That was back in the 70s, and the same thing applies to all bottle neck cartridges, always and forever only size those cases enough to allow cases fired in your chamber to again be chambered in your chamber after sizing.

If your following some of the manufactures directions for setting up sizing dies, your simple over sizing most if not all of your bottle neck brass.

Will gladly share a document I've written on the subject with anyone interested. Just ask.

CDOC

[leadman]

They just turn the belt off the mag case. I see it as the way it should have been made in the first place.
I can understand the belt on the 300 H&H, but not on almost all of the belted cases that followed.
Look at all the current crop of ultra-mags and short mag, no belt.

[Tatume]

The basic belted case was designed by Holland and Holland to provide a means to headspace the cartridge that was as reliable as a flange, while allowing the cartridge to feed reliably from the magazine of a bolt action rifle. No consideration was given to reloading the cases. If only the first firing is considered, the belted case should be considered a success.

When the more recent belted magnums were designed reloading was a common practice, and in that light the belt can be seen as a design flaw. The matter is one of perspective.

[nanuk]

I remember reading an article where it was stated the Brass case elongates as the body is sized, THEN the shoulder is pushed back

I was reloading for a 300WinMag, and had trouble. I think that elongating was causing me the trouble

[Crusty Deary Ol'Coot]

Have reloaded for belted cartridges for YEARS, and quite simply if the full length die is properly set up, the belt is just not an issue.

True and very likely, it was seldom if ever needed, but in anything close to a properly functioning rifle, the belted cartridge feeds and chambers as smoothly as any non-belted cartridge.

Now if your like my friend that has a, "thing" about belted cartridges, so be it, enjoy your "thing". I have a few of them myself.

Just don't try to make the belt, needed or not, something it isn't, a problem.

How many of you have bought a car at least partly because you liked it's looks?

I'd guess many of you, Ford even sold some edsels.

And you can bet that even though it didn't make .02 cents worth of difference to the balistics, the belt did sell some rifles.

So ------------- Just set your sizing dies up properly and enjoy the belted cartridges for what they are.

Belt or no belt, most of them are balisticly fine cartridges!

CDOC

[birddog]

Cut to the chase and take the gun to the local smith to be checked with no-go headspace. If a problem is relevant then send it to Ruger for your free repair short of shipping.
Charlie:wink:

[Crusty Deary Ol'Coot]

No need Birddog,

Once fired brass will fireform to the chamber, and then providing your sizing dies are properly adjusted, your good to go!

All brass fireforms to the chamber to some degree, the trick is to once it is fireformed to not over size.

Simply with all bottle neck cases, size the minimum amount that will allow brass fired in your chamber to rechamber after sizing.

Almost always, a new case fired in your chamber will return to that chamber without sizing after the first firing, so anything beyond sizing just enough for the bullet to be properly held in the reloaded case, is in most cases, over sizing and cutting your brass life short.

CDOC

[myfriendis410]

Well; that's what I'm gonna do with mine. I'm not about to send my gun back to Ruger 'cause they'll return the trigger to factory specs, which I'm not about to see happen. This gun used to shoot "Mickey Mouse" groups with the Barnes so it's going to be another project to it back to where it used to be.

[Ed in North Texas]

They just turn the belt off the mag case. I see it as the way it should have been made in the first place.
I can understand the belt on the 300 H&H, but not on almost all of the belted cases that followed.
Look at all the current crop of ultra-mags and short mag, no belt.

Turning the belt off the cases, and the answer from myfriendis410, are the only things I could think of. I knew the belted cases could not chamber, but it just didn't make sense to me to go to the trouble of turning the belt off the cases when you can just not full length resize and keep the case set for the chamber. Guess simple, easy and effective doesn't work for some people.

Ed

[Crusty Deary Ol'Coot]

Well, as I have already said, properly sized, brass fireformed to your chamber will HAVE NO HEAD SPACE ISSUES! Plain and simple.

However, for those with "issues" about a belt just, buy one of the short and non-belted magnums and be done with it.

However, in spite of the media hype about how much better the short mags. are, it has yet to prove out in reality. BUT they have no belt.

The advantage if there is one, is a shorter and lighter action.

A friend who owned a 300 Weatherby, was being pressured to get rid of the Weatherby because of how much better the new short mags were.

Well just a bit of info from any number of reloading books quickly put that to rest.

Good as the new calibers are, they have yet to out pace the older rounds. Equal possibly, but no better.

CDOC

[myfriendis410]

I agree. I've loaded for several short mags (don't own one) and run the loads over the chronograph. None of 'em equal any of the belted mags. They shoot well usually, but if I can get velocity AND accuracy I'll take that any day of the week.

[Multigunner]

I vaguely remember an article on non belted 7mm and .30 wildcat magnum capacity cases, made from some obsolete British big game cartridge cases.
Seems to me these were for a Jefferies cartridge, but can't say I'm sure of that.
Possibly this cartridge
http://en.wikipedia.org/wiki/.404_Jeffery
The cases used were larger in diameter that the basic Mauser/Springfield sized cases, with the same sort of extraction groove. They may have also had a rebated rim.

[myfriendis410]

A great example of a non-belted magnum would be all of the ultra-mags. They are WAY out there in performance with good case life, but the downside is short barrel life. Any time you load over 100 gr. of powder into a bottlenecked case you are building a BIG flame.

[leadman]

The Ultramags are based on the 404 Jeffries IIRC.

[myfriendis410]

Duh! Stupid of me. You're right.

[leadman]

My Encore 7mm Rem mag has excessive headspace because the recess for the belt is .006" to long, which is max., but it also has .004" clearance between the barrel and the breach. The brass tends to flow into the open area at the front of the rim recess after a few reloads.
There is even a company(can't remember the name) that makes a die to size this part of the case only. Most commercial dies won't, especially if you are not full length sizing.
So far it has not been a problem for my brass as it flows a little then stops.

Wonder how a sleeve would work to eleminate the recess??

[nanuk]

read THIS (http://blog.sinclairintl.com/2011/01/31/setting-up-your-full-length-sizing-die/), it might work for you

CDOC has explained it, and appears to do the same thing....

[jblee10]

I fired three rounds this a.m. and all three developed near case head separation. To the point that it dented the case below the shoulder from blow-by. Cases fell out of the gun and when a caliper was put on 'em they were at 2.507" which started at a trim-to length of 2.493". That's a LOT of stretch.

If you are getting dented shoulders you must have more problems them just "some headspace". I would send it back to Ruger. Better to have to get another trigger job than to get a new glass eye!

[Crusty Deary Ol'Coot]

A case would normaly only stretch in total length to that degree with extreme pressures.

2.493 to 2.507, if this is in fact total - from head to mouth - case length stretch would not seem to indicate a head space problem, but rather over pressure.

A head space situation would cause stretch from the head of the case to the shoulder of the case, not in total case length.

I have seen a case stretch in total length, from "trim length" to beyond "needs to be trimmed length" in one firing one time.

That being when a case from an odd lot number, but same brand of cases was included in some load development tests.

This extreme amount of case stretching in one firing was only one of the signs that this case had been subjected to VERY HIGH presures.

CDOC

[jblee10]

You may have a headspace or high pressure problem but I still don't see how headspace or high pressure alone could cause a dent in the shoulder. Have you done a cast of the chamber? I wonder if there is groove or some other defect in the chamber. Pay particular attention to the neck area.
As far as loading single shots for long case life. Just bump the shoulder back far enough for easy chambering of a reloaded round.

[leadman]

With the new brass being too short from the front of the belt to the shoulder the shoulder of the case blows forward when the gun is fired. When the shoulder finally reaches the front of the chamber it seals the chamber and the gas. But before this happens some gas will bypass the neck and run into the shoulder on the way to the rear of the chamber.This is what puts the dents in the case.
This is similar to a headspace problem with a case like the 30-06 that headspaces on the shoulder, but the belted cases aresupposed to be headspaced on the belt. If you cut off the case in front of the belt and put a primer in the base and load it in the chamber it will fire. Unless a gun for a bottlenecked case has a claw type extractor and you do the same thing it is unlikely that it will fire.
A chamber cast of the OP rifle would probably be enlightening as to the dimensions.