excess headspace in Rossi '92

[Black Jaque Janaviac]

Is there anything that can be done to correct an excessive headspace problem in a Rossi '92?  It's chambered in .357 and has a 24" octagon-to-round barrel. 

[Black Jaque Janaviac]

Well, I own three .357s, two lever actions, one wheel gun.  This one lever action in question has given me the most problems with what I thought was high pressure signs.  Tophatted primers, pierced primers, case-head separations and sometimes with loads that you wouldn't expect this to happen with (9% below max).

Then I learned of a fairly cheap way to check the head gap.  Start putting masking tap layers on the head of an empty case, going one layer at a time until the bolt won't close.  I got an astonishing number of layers on, I don't have my notes with me, but something like 1/2 dozen.  Use a caliper to measure case length with and without masking tape.  Subtract the "without tape" measurement from the "with tape" measurement - that gives you the amount of gap. 

Another way to check that I tried was to use heavy card stock (like a primer box sleeve) and make a washer with a 3/8" hole punched in the middle.  Slide the washer over the .357 case down to the rim.  Then check to see if the bolt will close.  This method doesn't lend itself to measurements very well except to measure the thickness of the card.  The gun in question was able to close with one of these cardboard washer slipped over the case.

I have another Rossi '92 that has a much tighter head gap - and guess what?  Nary a problem with "high pressure" signs.

[Black Jaque Janaviac]

Oh.  And yeah I was afraid of that "correct gunsmithing" fix.  Normally it's not a big deal unless you've got a barrel that needs a specific orientation like dovetails and octagon profile.  That would just stink if to get the correct headspace you end up with the sight dovetails canted 30 degrees or one of the "points" of the octagon on the top!

[buck460XVR]

Most pistol caliber carbines have a problem with headspace. It has to do with the way a lever locks up at the rear. When fired, the bolt can ''spring'' back slightly allowing the case to stretch. This is why many reloading manuals advise you to use virgin or once fired brass only for magnum loads in these firearms.

[jimster]

I also agree if it's headspace the barrel might have to be turned in, rechambered, and then you have another problem with the where the mag tube attaches to the barrel, that won't line up anymore. Might be another way to fix it, I really don't know. Sounds like you are doing some good head space checks with what you have on hand, enough to tell there is a problem.  What are the chances of shipping to Rossi customer service and having them work on it?

[WyrTwister]

     I discourage people from using t5ape and cardboard .  It is much more likely to crush than metal .

     The correct way is to buy a no-go gauge .  They are not that expensive .

     If you are not going to do that , go to your favorite auto parts store and buy a cheap feeler gauge , calibrated in thousandths of an inch .

     Cut a circle  , the diameter of the base of the brass ( with tin snips ) from the .002" , .004" , .006" , etc.  .  Now do the same as you were with the tape .  You can stack them up .   Find the measurment / amount it takes to just prevent the bolt from closing 100% .

     Now , with the same brass case , check the other guns .  ( You are writing this down , aren't you ? )

     Compare the results .  Now write a nice polite letter to Rossi , asking for help .

     In the mean time , for the one , problem , gun only , try seating the bullet long , until the bullet is jammed into the riflings ( not at 100% powder charge ) forcing the base of the brass back , hard against the bolt face .  See if that helps ?

     Even better , put that gun in the safe untill the issue is resolved .

     If Rossie does not help you , one possible repair for a darn good gunsmith , is to either weld up the face of the bolt , adding metal & then machining it back down to give the proper head space ?  Or , maybe , I do not know about this , silver solder a shim to the face of the bolt ?

     In either case , care must be given as to the heat treating of the steel of the bolt .

God bless
Wyr
Happy New Year

 

[Black Jaque Janaviac]

I discourage people from using t5ape and cardboard .  It is much more likely to crush than metal .

     The correct way is to buy a no-go gauge .  They are not that expensive .

You're point is taken.  However, I look at it in terms of risk-benefit.  The $20 for a no-go gauge is a petence when considering a major "fix" such as re-barreling.  However, when one doesn't have the correct no-go gauge, the cost of a few layers of masking tape certainly is worth the try - so long as one doesn't base expensive desisions on the results.

So. . . before I spend the money on the "fix" I will certainly spend the money on a no-go gauge or at the very least I'll see if I can find a local 'smith that has one.  But I'd imagine that's unlike for a .357. 

I will contact Rossi and see if I can get any luck.  I'm skeptical however, as this is looking like the gun has been modified what with the octagon-to-round barrel

I may just sell it as it probably is more valuable to an avid CAS shooter (it eats .38s just fine). 

[Black Jaque Janaviac]

Sent it to M&M Gunsmithing and they found it to indeed have excess headspace.  They turned the barrel in a full 360* which seems to have solved the problem.  It certainly doesn't flatten primers like it used to.  Still feeds .357s and .38s.  I do see that the lever doesn't come into full contact with the stock when the action is closed though. 

[Les Staley]

That is great news..  good on you..    I had some trouble with a new Puma in 44 mag..  slugged the bore at .433-434.. was very inacurate with jacketed bullets.. factory loads.. Winchester white box.  Sent it in to LSI and they installed a new barrel..  same deal.. overbore.    talked to customer service again, and they said send it in... came back with a GOOD barrel this time.. will hold 2 inch group at 100 yds with Winchester white box..  It was worth the trouble.    Killed three boars and two Morino rams on Niihau Island April 07..  no problem..    Les

[Kmrere42]

Here are 2 other options for checking the head-space on a rifle with a rimmed cartridge.


1)  Find someone who has a lathe and make a set of gauges out of aluminum or mild steel.  (doesn't need to be hard for just a few uses)



2)  screw the primer knockout pin on the sizing die so that it just pushes out the spent primer a little and then take the case and chamber the bolt down on the case and the primer will be pushed in to the depth of the head-space.  Measure the rim and add to it the height of the primer and there is the measurement.




Paul