73 Bolt Alligment

[Hawkeye Kid]

Broke out a 73 Uberti in 45 caliber that I heven't shot in a long time.  The tab on the bottom of the bolt was hitting the bottom edge of the carrier.  The carrier was rising slightly too high.  Loosening the tension on the carrier spring solved the problem.  Checking my other 73s, no matter how much tension applied on the spring, the bottom bolt tab would not hit the carrier.  Has anyone else experience this problem?  What was your fix?

[CodyMaverick]

Yes, the tab had a crack at the seam and was bent down a little.  Had to remove the bolt to see it.  

 

Fixed by replacing the bolt. 

[twelve mile REB]

That is actually common using after market carriers in most Uberti 73's.   The fix Cowboys and Indians uses is to cut a relief in the rear of the carrier so the tab ramps up slowly rather than banging into the rear of the carrier.  I don't know if this is common with brass carriers. 

[Garrison Joe, SASS #60708]

Shows that timing is slightly off.  Fix the timing and you get rid of the tab and carrier colliding.     

Bolt needs to fully retract before the carrier AT SPEED rises to the level where it can hit the tab (as the lever opens the action).    And carrier needs to come up to the correct height so that the bolt cleanly enters the cartridge channel in the carrier block without impacting any of the carrier, as the lever is closed.

 

Some adjustment of the apparent timing can be done with the lifter tension screw, but I find that will drift off of the correct timing setting.  I like to do it the conventional way, with adjusting the timing pads on the lifter arm.

 

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Checking my other 73s, no matter how much tension applied on the spring, the bottom bolt tab would not hit the carrier. 

That test shows those other guns are timed with the pads, not the tension screw.    Which means you can disassemble, clean and reassemble them and they run well without having to adjust lifter arm tension just right.

 

Good luck, GJ

[Hawkeye Kid]

The tab is not bent.  The carrier is an aftermarket aluminum carrier with a short stroke kit installed.  I have shot this rifle before without an issues.  It's probably sat in the safe for a few years.  Just weard not using the rifle would cause a problem that didn't exist before.  Will you twelve mile REB suggestion to cut a relief in the carrier slot.

Just I will have to start shooting all my guns so they don't feel neglected.

[Hawkeye Kid]

Follow-up on GJ comments.  The collision occurs when closing the action.  I know adjusting the pad on the bottom of the lifter arm will adjust the timing on opening the action to extract the bolt fully.  What is the adjustment on the lifter arm for correcting the carrier height?

[Garrison Joe, SASS #60708]

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The collision occurs when closing the action.

Meaning that the bolt is starting it's forward travel and the support tab catches on the back face of the carrier block because the carrier is still too high up?

 

I've either slightly bent the lifter arm or filed a little off the top of the lifter arm contact point out at the tip where the arm touches the carrier.   Either can lower the height that the carrier rises to at full open action position.  Sometimes the carriers are not well machined to hold the same tolerance on the height of travel.     

 

But I'd check with the manufacturer of your short stoke kit to see if that is what they recommend.  Assuming you have this gun SS'd.

 

Good luck, GJ

 

 

[twelve mile REB]

KH24, GJ is a very respected and knowledgeable member of our circle and right a lot more often than not but please don't cut anything unless you can verify that there is a timing issue.   The '73 feeds slightly better in 357 caliber (using 38s) if the carrier finishes just slightly high( my opinion).  As I've said at least one respected smith is cutting a relief in their carriers to protect the tab.     

[Hawkeye Kid]

I checked 10 Uberti, 2 Winchester Miroku and 2 original Winchesters.  All the brass Uberti carriers have slight ramp milled in the back. The aftermarket aluminum carriers are flat,as are the original Winchesters.  Operating the action slowly, you can see the bolt tab every so slightly push down on the brass carrier to correct for the overtravel on the Uberti.

 

The timing on the Winchesters and a few of the Uberti with aluminum carrier is spot on, except for the one rifle in question.  Filing a little ramp fixed the problem.  As GJ stated correcting the timing is probably the best solution, the ramp was easier fix.

 

Thanks for the help.