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.38 Overall Length in a Uberti '73?


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Posted (edited)

There are a number of good posts here about reloading .38 and overall I get on well with my ammo. However, when it comes to speed with the rifle I find my lever 'cams' a bit; it feels stiff under speed even after a couple of polish and slicking operations on the action. I have the standard brass carrier block and use 130 grain lead projectiles. I'm starting to think it's the overall length of my ammo being a bit short and the possibility of the next round in the magazine tube poking out into the block meaning I'm forcing it back up the magazine as I crank the lever. It might be minor but it slows things down and one miss is 5 seconds, so easy on the cranking.. I don't use .357 even though my guns are chambered for both.

 

My ammo is admittedly short at 1.444" and thinking to load between 1.5 and 1.55" (the recommended OAL), but I am keen to hear from other .38 shooters with a '73 to see what OAL you find cycles really well?

Edited by TheProspector
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Posted (edited)

In my opinion 1.5 is about perfect.

I agree at 1.44; you are likely having rounds feed into the lifter block and then "have" to be pushed back into the magazine tube.

 

This adds effort to the lever stroke and can make it feel "hitchy".

Edited by Creeker, SASS #43022
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Been shooting OAL of 1.44" to 1.45" for years and years.  Even went out to 1.47"  a few times.  Backed off to the 1.44" to 1.45" area,  All my rifle shoot just fine with them. 

 

Having said that, the timing of the rifle is important.  More so than the OAL of your ammo.  

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Posted (edited)

With ANY ammo under 1.600" in length you're having a round partially feed into the carrier block.  When the lever is pushed forward, the block raises forcing that next round back into the magazine.  1.600" being the spec'd length of the carrier mortise.

Edited by Griff
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1 hour ago, Griff said:

With ANY ammo under 1.600" in length you're having a round partially feed into the carrier block.  When the lever is pushed forward, the block raises forcing that next round back into the magazine.  1.600" being the spec'd length of the carrier mortise.

I didn't know this, thanks for confirming. I was trying to find tech details on the carrier block. Think I might load a few sample rounds ~1.5" to 1.55" and see if better than current.

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I have 3 different toggle links in 45 Colt... they all take slightly different max overall length and function, so I just make my ammo to meet the requirements of the shortest of them.  

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Two thoughts.

Length of cartridge.

Longer is better so as to hold the next cartridge in the magazine tube and rely on the carrier to push the next cartridge off the carrier back in to the magazine tube.

 

Second, you can check this by examining the elevator lifter.

You are looking for a slight notch on the front end of the lifter where the second cartridge rim hits as the cartridge is pushed forward on the ramp.

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What is your bullet profile, I run 1.450 with turnacated cone bullets and no problems, of course as they say, they all run different!

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Posted (edited)

i found that you need to "tune" to each rifle by trial and error , my 45s were pretty easy as they seemed to all like pretty close to the same length , i fit it carefully till it worked in all interchangeably , there is only one that is a tad finicky , i just run it a tad slower , the 38/357 was easier as i only have one so far , i copied the OAL of a length that worked and set my system up for that , if i acquire another rifle i may have to tweak it a bit , ill cross that bridge when i come to it , , good thing is they all work in my revolvers 

 

oh , and came back to add ive found round nose flat point bullets to work best for me , the bullet profile can have a lot to do with function , it will most likely affect your length of cartridge and has nothing to do with cost or availability really , 

Edited by watab kid
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I use 357 brass and a RNFP bullet in my 73 and just load it with a 38 spl. powder charge.  Keeps them feeding good and not too much recoil. 

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If your bullets ever appear angled on the carrier, do not load to a max length, they will interfere with the carrier block operation. Honestly the '73 will be very forgiving with everything between a minimum and maximum length.

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Posted (edited)

The 73 lifter block has an angle machined into the front face that returns the "second" cartridge back into the magazine tube AS LONG AS THE RIM IS NOT SO FAR REARWARD AS TO CATCH THE FLAT INSIDE SURFACE OF THE CARTRIDGE CHANNEL INSTEAD OF THE RAMP.   This ramp is called the "cartridge return ramp."  So, you can measure that "flat" length inside the cartridge channel of your lifter block to get the minimum length of cartridge you can feed without jamming up the gun. 

 

Now, there is extra brass in the factory carrier block!  If you are careful to measure how much brass is there, you can file the "cartridge return ramp" back to just about 1.420" on most blocks, and get shorter cartridges to run more successfully (down to about 1.430" OAL or so).   Trying to get the ramp to allow shorter cartridge length than that, and you take a risk of filing back into the cavity for the lifter arm, ruining the block.

 

I have re-sloped the factory Uberti blocks in .38/357 rifles to allow the use of cartridges as short as about 1.45" 100% successfully.   Be aware that making the ramp angle more shallow like this means you do have to apply just a little more force to the lever because you are always shoving the cartridge stack back into the mag tube against the pressure of the mag spring, as the lever is closed and the lifter rises.  So, obviously, you want to trim the mag tube spring to as short a length as will always feed the last round out of the tube.   I find leaving 3" of free length on the uncompressed mag spring is enough if your spring is fresh.

 

As with many things, this is a balancing act between how short a cartridge you want to run, and how light a lever stroke you want to have.

 

But, balky feeding of the next round is never acceptable.

 

An overall cartridge length of about 1.45" is quite achievable with the factory carrier block modified to make the return ramp more shallow.   I set up a .38/357 Uberti lever gun to do that for a very fast lady shooter, and by loading .38 specials with standard bullet designs, the length of cartridge was good enough to run flawlessly. 

 

BTW - A truncated cone bullet design will automatically add 10 or more thousandths to the OAL in a .38 special load using same weight bullets as a RNFP.

 

good luck, GJ

 

 

Edited by Garrison Joe, SASS #60708
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1.47 works good in my 73.

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this was why i brought up the bulley design , i found the same thing when experimenting with nwhat worked in my marlin -

"BTW - A truncated cone bullet design will automatically add 10 or more thousandths to the OAL in a .38 special load using same weight bullets as a RNFP."

 

 

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I believe that the replies have pretty much nailed it down. I have a "66 in 38 Spl and several 73s in other calibers. In my 38 Spl I like to run 1.50", any longer and 10 will not fit in the magazine as the barrel is only 16". I've tested at 1.55" and didn't notice much difference. In the small caliber when the length approaches 1.45 there is a bit more effort when the lifter pushes the cartridge back in the magazine. The cartridges get a bit crooked. I believe a liner would be an advantage as it would keep the column of cartridges straighter inline. IMO to keep the rifle running smooth you want the cartridge a bit shorter than max. 

 

In 44-40 and 45 Colt, 1.55 is pretty much where most of the common bullet cannelures want the OAL for a decent crimp. 38 Spl is unique to the available calibers in that the design OAL of the cartridge is 1.550 and not 1.6"(ish) like 44-40 and 45 Colt. The second issue is that most bullet molds today are designed to seat properly in a 357 Mag and therefore 1.45" is a very common length if you seat to the cannelure. If the rifle runs at that OAL, good. 

 

Bullet shape is important, more so on the 38 Spl than on the bigger ones. In addition you want a meplat on the large and flat side. Too large is an issue as the meplat will catch on the mouth of the chamber if too large. Too small and the cartridges in the magazine will be crooked and movement will not be smooth. 

 

I prefer a 9mm 147 grain truncated cone 9mm bullet and i crimp into the bullet shank. I crimp deep enough so that the moth of the case even with the shank, it will not catch. It is a balancing act. The carrier has a ramp to push the cartridges back into the magazine, and that ramp becomes a gap that the cartridge has to slide over. You do not want to move that ramp back and increase that gap, IMHO. 

 

The 45 Colt works as the rim is such that the cartridge lies flatter in the carrier, and tends to feed straight. The 44-40 works because of the bottlenecked and tapered case and the bullet is much smaller than the entrance to the chamber. When the 32-20 was chambered in the 73, the tapered cartridge helped it work smoothly. The 38 Spl/357 Mag is less than ideal with its straight walled case and generous rim. This makes bullet shape a bit more critical. Still not bad, just a bit more finicky. 

 

[img]https://i.imgur.com/tnNLR0S.jpg[/img]

 

These work well, unfortunately that bullet is NLA.

 

BB

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I have used 1.435 overall length in my '66's since 2004 and when I got my '73's  about 5 years ago.. used the same OAL..  I use 110 grain  TCFP.. I did change the ramp angle a smite.. they have both been short stroked.. never a problem.. just sayin.. 

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I use a 125 gr rnfp and have always just crimped into the groove. Didn't worry about o.a.l it always worked in my '73 no problem. Just checked the other day with calipers and it measures at 1.43. Rifle is an Uberti purchased through Taylor and Co with a factory action and short stroke. I can add pictures of the bullet if it would help.

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Uberti's 73s stamped ".357" are intended for .357 cartridges with an OAL of 1.60˝. Even though you can chamber a .38Spec in a .357, getting the OAL close to the designed OAL of 1.60˝ will result in improved feeding. At 1.60˝ OAL the cartridge is virtually the same length as the elevator and doesn't have to push the next cartridge up the return ramp and into the magazine. If you use .38S shells, you may end up not being able to crimp in the cannalure - so be sure to get a good crimp against the bullet.

RR

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Because of the dimensional and even parts variability found in most 73s, if you are going to have a 73 built by a smith, you should provide at least a cartridge OAL that you plan to use.  Even better, provide 100 rounds of loaded ammo for a very good functionality test.

 

good luck, GJ

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LEP...

Nice article in the '08 Cowboy Chronicle (that was a period of really nice monthly hard-copy publications!). Nicely explains what happens with the interaction of the lifter and various cartridge lengths! Thx.

See ya in August!

RR 

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There is another little Tid Bit of information often overlooked when loading at less than optimum length.  The Magazine Spring.  With the OEM magazine spring, there is quite a lot of pressure exerted on the rounds in the tube.  Therefore, when running the rifle and having to push the following round back into the tube, that spring can give you fits.  The OEM Spring is too long and too heavy and can/should be reduced a bit.  Or, change the spring for an after-market Stainless spring and Stainless Follower.  You will notice a much smoother action.  The After-Market Stainless may also be a bit too long.

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Posted (edited)

CC ... All the more reason to have the OAL of the cartridges to be the same, or close to the same as the length of the lifter. A lot of effort is saved if the lifter doesn't have to push cartridges back into the magazine...

RR

 

PS: And, care must be taken to not make the spring so light that it can't push a row of 9 or 10 rounds into the lifter as fast as the action can be cycled, or gamers and/or poor feeding will occur (this is more prominent on 180g-200g bullets in .45LC, but too light a spring on a .38 or .357 can still be a problem).

Edited by Roger Rapid
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