Use guys have Caused me a Problem Already

Bass Ackward

Active Member
A little misalignment can smear the bullet on one side. Having .432 throats and a .429 barrel doesn’t help either.

That can happen if your lead is too soft, with soft being defined by the gun. To get hardness “right” for that gun / design, cheat and ask Professor Gun what’s hard enough.

Assuming that all the chambers are aligned the same, pick one chamber, load & fire that same chamber with the other chambers empty, 6 times. Change targets. Now repeat this test on the SAME chamber with loaded rounds in the other chambers. If bullet hardness is sufficient for THAT weight (length) bullet design, then groups should be the same. If they’re different, your bullet’s not hard enough “for THAT” weight / design in THAT gun. :)

Your other problems can be “fixed” by sizing .001 over bore. Then using a gas check, a base protector, & a bore condition stabilizer. Oh wait, those are all the same thing! Silly me. Correct your sizing before running that test cause a smaller diameter will have some flexibility of movement too allowing you to use a softer mix.

You know, a GC could also be named a revolver correction device. Revolver Improvement Device? I'll think about it.
 
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Bass Ackward

Active Member
If you don't want or can't go harder, then misalignment needs corrected or the revolver sent packing. If you want to use PB, you will have to run pressures to obdurate the test minimum hardness at THAT bullet diameter. So PB use has been .... restricted by the gun to that pressure operating range. Most folks think of PB as a low pressure slug. Wanna know, just ask Professor Gun.
 
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Pistolero

Well-Known Member
I am amazed that not only have some not seen thread choke, but actual hypothesize that it
isn't possible. I can assure you, from many personal measurements and repairs, it is very real
and is pretty common in S&W. Probably because most folks don't have gage pins, they don't know that
they have it. Typically it is from 0.001 to .002, but I have one Thunder Ranch .44 Spl Model 21,
which had a 0.004 thread choke. Which explained it's mediocre shooting. The bbl was removed,
about .002 taken off of the rear shoulder and it was reset with locktite. Much better now, although
I need to make a taller front sight blade, it is factory sighted for 200 gr bullets, and I want to use
the 250 Keiths.

So far, fire lapping hasn't done a thing for my friend's Model 29, but I will be making up another
batch of abrasive loaded bullets and loading them and we will have another go at it. I don't use
GCs in handgun loads, I have found no benefits that couldn't be equaled or exceeded by PB with
proper design, lube and loading (pressures and diameters), if the revolver is made correctly or
remade to proper dimensions. Throats about .001 to .002 larger than groove, ideally, and no
thread choke. I have a SBH with .433 throats and .429 groove, that works fine with 12 BHN
Keith 250s from a special GB mold that drops .434 and will size nicely to .433. Slightly outside
the ideal, but workable, for sure.

Bill
 
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Brad

Benevolent Overlord and site owner
Staff member
Taller front sight is on my need list too. The 624 hits a bit high for me with my load and I am out of adjustment in the rear sight.
 

Pistolero

Well-Known Member
Fortunately, Brad, my TR M21 has a pinned in front sight blade, easily replaced. Does your 624 have
and integral front sight? That requires a mill and a 1/8" keyway cutter....OH, what a good thing, now
you have a mill. :) Have to set the gun up exactly sideplate level, and mill off the front sight blade, then
use the key cutter to make a plunge cut into the ramp about 0.175 or so. Then cross drill for 1/16" roll
pin. Get some 4130 plate (available in 9x9 sheets here in KC for aircraft parts) and saw and file, and mill
out what you want.

And, none of my Rugers have ever had any thread choke. They seem to understand how to screw in
a bbl without choking it. I have seen many S&Ws that, after you unscrew the bbl, you check, just for
grins on where it first came tight....some are greater than 30 degrees from vertical, and they just tightened
them in. And created thread choke. No more than 5 degrees is my rule, and just hand tight is fine with
locktite.

Bill
 
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Brad

Benevolent Overlord and site owner
Staff member
The 624 front sight is pinned. I need to pull it and make a tracing.
 

358156 hp

At large, whereabouts unknown.
Bill, I promise everyone here that it is real. I have firelapped a number of revolvers, S&W and Rugers to clean up thread choke. Ruger stainless is so abrasion resistant that it's almost unreal! It takes almost twice the lapping of a S&W to clean it up.
 

Brad

Benevolent Overlord and site owner
Staff member
The Ruger stainless is that tough. I go to a coarser grit for 25-50 shots then the normal grit.
My Gp100 had a tough and the SRH too. Not any more.
 

Brad

Benevolent Overlord and site owner
Staff member
The mill will be used to drill the hole in the blade?

This damn job of mine keeps getting in the way.
 

Pistolero

Well-Known Member
Swatting a fly with a sledge hammer, but the fly will definitely be dead!:rofl:

No doubt that a mill is the world's finest drill press.
 

Ian

Notorious member
+1 to thread choke being very real and Ruger barrel steel being harder than coffin nails.

Ruger does not have a good system for timing barrels anymore, in fact I've seen a video on it and its more like put a big wrench on there and pull it until the front sight lines up. If that requires 270 degrees after contact with the shoulder, so be it.
 

358156 hp

At large, whereabouts unknown.
I've heard a number of complaints from single-action owners about crooked front sights in the past as well. At one point S&W was reputed to be using slightly dissimilar thread pitch between the barrel and the frame. Again, the barrel would be tightened down until it was straight, and the thread interference would give us.... thread choke.