Concerns about Cylinder Throat Reaming

[Mixed Nuts]

As mentioned in another thread I have a Ruger Security Six revolver that leads with some lower power cast bullet loads launching 18BNH bullets.

Leaving off many of the details... I have one cylinder throat under .357 but over .356. The others have some slight variance but are all very close to .357 (three maybe exact) and smaller than .358.

I took a .357 FTX 158gr bullet and tried to push it through the cylinders. It got stuck in one cylinder, but went through the rest with a push or gentle tapping.

I now have a dilemma.

Another High Road poster mentioned he had some "heartache" shooting cast bullets through the "mild rifling" of the Ruger Six series revolvers...

My Security Six shoots jacketed bullets well. And when the 18BNH cast bullets don't lead they don't match what my gun can do with jacketed ammo.

The dilemma is that there is no guarantee that enlarging the cylinder throats will make the revolver any better with lead, but it will make the jacketed bullets a loose fit through the throats.

Unless there are a few High Road veterans who have had good luck shooting lead through their Security Six revolvers, I'm going to leave my new Manson Reamer in the tool box and leave my Security Six as is. I really like the gun and I'd hate to modify it and end up with a gun that shoots neither jacketed or cast bullets well.

I may look at making a different revolver my dedicated cast bullet .357 magnum.

 

[RON in PA]

Have you tried softer swaged lead bullets. My experience is that swaged lead bullets shot at moderate velocities lead less than hard cast bullets.

 

[Walkalong]

I have not shot any lead in my SS, and haven't measured the throats, but I would agree it may serve you well to try a softer bullet.

 

[reddog81]

Enlarging the throats typically doesn't harm accuracy when shooting jacketed bullets.

I've never heard of accuracy problems due to "mild rifling" or the six series rifling in general. I have no idea why mild rifling would be a problem with lead.

If it was me I'd try and get the cylinders to a uniform diameter.

 

[243winxb]

"mild rifling"

Never heard this before. I shot a Ruger ss with .3575" home case lswc , using range lead. No problems.

 

[243winxb]

I just tested my "tight throat" chamber. It did ok. As long as cast bullet diameter is the same or larger then groove diameter, i dont see a problem. Add/edit - Bullet diameter was .3579" for test. There was an issue with the new die. Lyman sent me a new replacement 358 H&I die. I then modified the problem die to size at current .3581" diameter. Great customer surface from Lyman.

 

[PapaG]

Three of the best shooting .357s I've ever had have been Security Sixes. My favorite load is the 357158 gas check cast of whatever lead I have laying around but most often wheelweights. Never leads. Tight groups. They also shoot the 148 hbwc well with no leading. You don't have enough difference is throats to worry about reaming or polishing.

 

[Mixed Nuts]

Enlarging the throats typically doesn't harm accuracy when shooting jacketed bullets.

I've never heard of accuracy problems due to "mild rifling" or the six series rifling in general. I have no idea why mild rifling would be a problem with lead.

If it was me I'd try and get the cylinders to a uniform diameter.

I may try this, Reddog81,for the one chamber that is smaller than .357. But it wont be me who does it as my reamer does .358 and I don't want 5 .357 throats and one .358. I'll call around and see if any pros have a .357 reamer.

243winxb, thanks for the posts. Feeling better about the Security Six and I enjoyed your very informative target photo . Was that with a scope?

Ron in PA and Walkalong, will definitely be trying a softer bullet. Now I just need to figure out how many 18BHNs should be mixed with half a pound of pure lead to get bullets in the 12-16 BHN range. I've ordered a Saeco hardness tester so the lead job awaits.

PapaG, may not do the 6 cylinders to .358 after all.

 

[Mixed Nuts]

I just tested my "tight throat" chamber. It did ok. As long as cast bullet diameter is the same or larger then groove diameter, i dont see a problem. View attachment 793970

Do you recall the bullet hardness for this range test?

 

[243winxb]

Was that with a scope?

Factory iron sights.

 

[Mixed Nuts]

Factory iron sights.

That then, is a pretty good test of "tight" chamber performance with cast 164gr LSWC in .357 magnum.

Do you recall the bullet (mould) and the hardness of the lead? Do you know - approximately or exactly - the diameter of the "tight chamber" and the bore?

 

[RealGun]

Tight throats raise pressure and sometimes QUITE noticeably. That was really brought home to me when discovering that my 5.5" barrel Redhawk 45 Colt was way too tight for what I was trying to do. Once throats were reamed along with recutting the forcing cone, it was far more manageable and friendly enough with "Ruger Only" loads. Your gun should have uniform throat diameters. What I have followed is the advice to have the bullet larger than the throats and the throats larger than the bore, so the progression is .358-.3575-.357. I have always specified .3575 for reaming throats of .357 caliber guns. I also resized bought bullets, if they came in a little large.

 

[243winxb]

Smith & Wesson M28 Groove dia .3575" Bullets sized same or larger to .3581"

hardness of the lead?

I test hardness by using my thumb nail or a screw driver blade.
My Lyman 357 H&I die always produced a .3575" bullet for many years using indoor range scrap. Then one day, i was given 2-40 pound blocks of scrap lead. Very soft if not pure lead. After adding some linotype, bullets dropped from the mould a little under .360" fine for sizing down in the 357 die.
But soft/pure lead does not spring back after sizing as much as harder alloys. The sized bullet was now .3571" to .3572" undersize. Scores were lower then normal, thinking it was me, till one day i got out the micrometer and found the problem. I now have 3 Lyman H&I sizing dies that may produce diameters of .3575" , .3581", .3583"

approximately or exactly - the diameter of the "tight chamber" and the bore?

Groove is .3575" Tight chamber takes a .3575" bullet. Will not take a .3581" bullet, other chamber will. The .3583" has to be jammed into the normal throats. All from the barrel side. I didn't try pushing them thru the chamber.

Using bullets as a measuring device is a poor choice. I am not making any adjustment to my very old revolver.

I would not buy this mold now, even with handles they seem over priced?

 

[Mixed Nuts]

Smith & Wesson M28 Groove dia .3575" Bullets sized same or larger to .3581"


I test hardness by using my thumb nail or a screw driver blade.
My Lyman 357 H&I die always produced a .3575" bullet for many years using indoor range scrap. Then one day, i was given 2-40 pound blocks of scrap lead. Very soft if not pure lead. After adding some linotype, bullets dropped from the mould a little under .360" fine for sizing down in the 357 die.
But soft/pure lead does not spring back after sizing as much as harder alloys. The sized bullet was now .3571" to .3572" undersize. Scores were lower then normal, thinking it was me, till one day i got out the micrometer and found the problem. I now have 3 Lyman H&I sizing dies that may produce diameters of .3575" , .3581", .3583"

Groove is .3575" Tight chamber takes a .3575" bullet. Will not take a .3581" bullet, other chamber will. The .3583" has to be jammed into the normal throats. All from the barrel side. I didn't try pushing them thru the chamber.

Using bullets as a measuring device is a poor choice. I am not making any adjustment to my very old revolver.

I would not buy this mold now, even with handles they seem over priced?
View attachment 794041

Interesting post, 243winxb. When you test with your fingernail or a screwdriver, what are you looking for - what does this test tell you?

 

[243winxb]

When you test with your fingernail or a screwdriver, what are you looking for

A thumb nail will not leave a mark on linotype or oven heat treated water cooled bullets. Bullets are very hard.

A faint mark can be made with alloys around 15 bhn. if you try extra hard. A good all around blend.

Plumbers lead/pure will mark easily and have some depth to it.

I have linotype, range scrap, wheel weights, magnum shot, plumbers lead/pure. This helps to learn the difference by casting some bullets of each. The screw driver is for ingots and how much pressure is needed to mark them.

Its a learning process that comes with experience.

 

[Mixed Nuts]

A thumb nail will not leave a mark on linotype or oven heat treated water cooled bullets. Bullets are very hard.

A faint mark can be made with alloys around 15 bhn. if you try extra hard. A good all around blend.

Plumbers lead/pure will mark easily and have some depth to it.

I have linotype, range scrap, wheel weights, magnum shot, plumbers lead/pure. This helps to learn the difference by casting some bullets of each. The screw driver is for ingots and how much pressure is needed to mark them.

Its a learning process that comes with experience.
View attachment 794113 View attachment 794114

Thanks, 243winxb. I wrote that down.

 

[FROGO207]

Being a plumber (some days) I get a fair amount of lead scrap. That mixed with plumbers silver solder (Silverbrite brand-mostly tin) in a 10 to 1 mix. This has yielded some really accurate 45 ACP, 38 SPL, and 9MM lead bullets for me while paying for just the cost of the silver solder and a bit of propane to mix them.
Also all the revolver cylinders that I have reamed have not ruined the accuracy of that particular revolver with jacketed or gas checked bullets.

 

[Jeb Stuart]

There have been many post on another forum about tight throats coming out of Ruger revolvers. A very well know long time gun smith on that forum very familiar with Ruger revolvers point out that many times Ruger does not change out the equipment used to ream the cylinders when they wear down, Just something to think about. Maybe need to check out the cylinders to be sure they were reamed correctly