sizing cylinder throats

[Bass Ackward]

Well, …. if you can’t win fair in life, CHEAT. Use the sizer that came with the gun.

Slug the bore and use that. It’s not flawless, but it will tell you if you have a problem(s). If want to shoot a lot, then you can use that same slug after your throats and bore wash up. If your using light / short for caliber bullets as defined by how far out any misalignment is, then you will have force executed on a side of the slug that will lead heavier at that point because of friction. This will tell you if you need a heavier slug (more time) (or sometimes a harder bullet) for the clocking to occur. It also keeps your throats from wearing oblong over time. If do you this every so many rounds, you’ll know the round count before you have to clean THAT gun. I always keep the initial slugs for judging wear.

[castmiester]

Well, …. if you can’t win fair in life, CHEAT. Use the sizer that came with the gun.

Slug the bore and use that. It’s not flawless, but it will tell you if you have a problem(s). If want to shoot a lot, then you can use that same slug after your throats and bore wash up. If your using light / short for caliber bullets as defined by how far out any misalignment is, then you will have force executed on a side of the slug that will lead heavier at that point because of friction. This will tell you if you need a heavier slug (more time) (or sometimes a harder bullet) for the clocking to occur. It also keeps your throats from wearing oblong over time. If do you this every so many rounds, you’ll know the round count before you have to clean THAT gun. I always keep the initial slugs for judging wear.

By eye I can't see any abnormal leading before. I'm loading 158 SWC and used them to measure the throats. Even with 9 BHN shooting ?


Never realized that much went into accurate shooting with pistols or even rifles too. I managed to narrow down my deer rifle accurizing and loading better.

[murf205]

castmeister, if you want to, you can go to Meyer Gage Co and buy individual pin gages for about $4 apiece. Then you can know where you stand with regards to cylinders and know whether or not to ream. I bought my 35 cal gages starting at .355 and went up to .360 in .001 increments. Make sure you clean the throats and LIGHTLY oil them. Meyers website is getting revamped right now but their phone calls are answered by very helpful people. There is no need for a boolit caster to buy the entire set, thank goodness. I bought pins for 44 cal as well as 45. The "Z" guages are accurate to .0001" which is plenty for a wheel gun. The pins are also a great way to verify your micrometer setting.

[castmiester]

castmeister, if you want to, you can go to Meyer Gage Co and buy individual pin gages for about $4 apiece. Then you can know where you stand with regards to cylinders and know whether or not to ream. I bought my 35 cal gages starting at .355 and went up to .360 in .001 increments. Make sure you clean the throats and LIGHTLY oil them. Meyers website is getting revamped right now but their phone calls are answered by very helpful people. There is no need for a boolit caster to buy the entire set, thank goodness. I bought pins for 44 cal as well as 45. The "Z" guages are accurate to .0001" which is plenty for a wheel gun. The pins are also a great way to verify your micrometer setting.

Ya that's what prevented me form buying them.... a whole set, ugh ! Thanks... I figured I could get individuals.

[castmiester]

On most Revolvers and especially the Ruger single action pistol's there is a constriction where the barrel is screwed onto the frame.
That play's havoc with accuracy as the constricted area will size down the bullet then you have a bullet that is undersized for the bore of the barrel.

I keep reading this from time to time.

I used to be a plumber, and understand pipe threads, the male threads are tapered and the fittings are not, maybe I'm on the wrong track here but how can a threaded barrel have a restriction in the threaded frame? They're straight threads. The pitch and diameter are the same, or are they ? I never hear about slugging a rifle barrel having this restriction.

[Three44s]

The threads are cut in separate operations and with the intent of the barrel ending up tight. The incidence of barrel constriction is very common.

But it is also not exclusively there as it can also be where a dovetail is cut for some reason like for a sight.

I do not have the correct attachment for my Sunnen Hone but being loosely familiar with them I can tell you that from many reports from members about Dougguys work and my basic knowledge about the hone he uses, I would send my cylinder to him for a job without hesitation.

In fact I likely will send him a cylinder to hone in the future, my main hold up is I need to get a dimension from my bore size on one revolver of mine that shows a couple of oversized throats. I would like to get a final bore dimension and get my throats sized accordingly.

Three44s

[castmiester]

The threads are cut in separate operations and with the intent of the barrel ending up tight. The incidence of barrel constriction is very common.

But it is also not exclusively there as it can also be where a dovetail is cut for some reason like for a sight.

I do not have the correct attachment for my Sunnen Hone but being loosely familiar with them I can tell you that from many reports from members about Dougguys work and my basic knowledge about the hone he uses, I would send my cylinder to him for a job without hesitation.

In fact I likely will send him a cylinder to hone in the future, my main hold up is I need to get a dimension from my bore size on one revolver of mine that shows a couple of oversized throats. I would like to get a final bore dimension and get my throats sized accordingly.

Three44s

Could you explain in threads are cut in separate operations?

[Tatume]

Listen to DougGuy, then send your cylinder to him. He will do a super job on the throats. Each one he has done for me has improved accuracy as a result.

[castmiester]

Listen to DougGuy, then send your cylinder to him. He will do a super job on the throats. Each one he has done for me has improved accuracy as a result.

Will do

[JonB_in_Glencoe]

Ok so my casts vary.. Someone mentioned elsewhere in another one of my threads about grip on the mold handles, and believe that's why the sizes are vary.... .358 to .361. Couple of days ago I laid sized bullets in the mold after taking it apart to inspect and clean it. The mold wouldn't close all the way and had a considerable gap. I was also told about over sized bullets .001 to .002. I just ran a sized .360 bullet that a friend honed my Lee sizer to .359 with, and it would not pass through with a light push, yep spring back. I asked for .359 and probably is but have spring back, forgot about the extra thou, shoulda asked for .360. Concerned about even with Cowboy dies with an oversized bullet would bulge the case and not chamber.

Calipers measured .361 on the throats, which trying to pass through a .360 bullet shows that calipers don't measure correctly. A .357 jacketed bullet falls through all buy one, that very light pressure is needed. A sized cowboy case is .373 OD and a seated bullet is .375. Typical .002 neck tension. Chambers freely. Does the Expander work in conjunction with the FL CB die ?

The cowboy dies....how far can a bullet be over sized before the sizer die doesn't under size the case and cause a bulged case that won't chamber ?

Funny no one has mentioned this yet, but unless you have a calibrated thumb, you can't measure lead bullets accurately with a Caliper. You should use a 0-1" Micrometer with a slip clutch.

Also, Calipers are designed to measure flat surfaces, you can't get a reliable measurement of a round hole.

To best measure a cylinder throat, you should push a pure lead slug through it, then measure the slug with a 0-1 Mic. repeat with a new lead slug for each throat in the cylinder. BTW, pure lead doesn't have spring back.

Good Luck.

[JonB_in_Glencoe]

I keep reading this from time to time.

I used to be a plumber, and understand pipe threads, the male threads are tapered and the fittings are not, maybe I'm on the wrong track here but how can a threaded barrel have a restriction in the threaded frame? They're straight threads. The pitch and diameter are the same, or are they ? I never hear about slugging a rifle barrel having this restriction.

I can't explain the "Why", but Thread Choke is a real thing in revolvers and Long Rifles.

Here is a thread that talks about it, and solutions.
https://castboolits.gunloads.com/sho...-in-a-revolver

[JonB_in_Glencoe]

Don't know where I should have posted this but, I figured this is a good a place if any.

Thoughts on the best or correct way of slugging or measuring all cylinder throats. I found this thread post here through google, and wish I had had better results searching here but I rarely do. So I think this guy has some good advice but maybe you all could chime in, thanks.

https://castboolits.gunloads.com/sho...=1#post5146641

Some specific things are best found with this websites "advanced search" but it helps to know some details about the thread you are looking for.

For general topics, I also use Google's website search. To search castboolits, you type your keywords and then "site:castboolits.gunloads.com"

So for this topic I typed in, measuring revolver cylinder throats site:castboolits.gunloads.com
and found pages of threads.
Good Luck.

[castmiester]

Some specific things are best found with this websites "advanced search" but it helps to know some details about the thread you are looking for.

For general topics, I also use Google's website search. To search castboolits, you type your keywords and then "site:castboolits.gunloads.com"

So for this topic I typed in, measuring revolver cylinder throats site:castboolits.gunloads.com
and found pages of threads.
Good Luck.

Hey thanks for the tip ! Appreciate it.

[DougGuy]

For anyone considering buying single pin gages from Meyer, you would want the ZZ minus pins ( -.0002") and be SURE to get them in .0005" increments instead of .001" yeah that adds a few more bucks to your order but .001" increments are too coarse for any serious cylinder measuring.

[bcraig]

DO NOT do this. This is the FASTEST way I know to ruin cylinder throats. I don't give a dang WHAT Veral says it it a NEANDERTHAL way of enlarging throats. There is NO WAY of achieving concentricity as you work, there is no pilot or guide to ensure the tool is parallel with the chamber, you have nothing accurate to go on, and your results MAY shoot a good group if you are lucky.



Nothing to it haha. What are you going to do when half the throats ream successfully, and the throats on the other side of the same cyilnder bog the reamer down until it is SQUAWKING when turned and you think you are going to break the shank off the reamer. Anyone who has reamed enough Ruger cylinders will undoubtedly have ran into this issue and know exactly what I am talking about.

Ruger cylinders are notorious for uneven heat treating of the billet steel rods from the steel mill, temper varies WIDELY from cylinder to cylinder and even from one side to the other side of the same cylinder.

In this scenario, the harder temper throats will finish considerably smaller in diameter than the throats on the softer side of the cylinder. The reamer itself is HSS and WILL CRUSH when forced through the harder throats and cut a smaller hole.

For THIS REASON I got away from reaming cylinders and adopted the Sunnen hone exclusively for ALL cylinder throat resizing. Not only is the finish superbly done, the stepless adjustment afforded by the hone allows for honing all the throats to consistency regardless of the temper of the metal or any changes in temper from throat to throat, allowing the user to achieve a consistent light drag fit on the pin gage, something that CANNOT be done with a reamer alone due to the variations in temper of the metal itself.

I am sure that your way of doing this is a Great way of doing this.
And I am sure that you do great work.

I am also sure that doing it the Way Veral Smith describes has worked for ME on 3 different Rugers.

Just trying to help the OP with his issues as it worked for me.

I only work on MY OWN guns as I enjoy it, BUT would think that Having a PROFESSIONAL such as yourself Do the work ,would be the Best way to get the best results .

[georgerkahn]

I just sent two Ruger cylinders -- the .45 Colt and the .45ACP cylinders from same revolver, to DougGuy and, imho, his work was/is "magical"! The best testimony I might add is ONLY financial constraints for me presently -- land taxes on six parcels, auto insurance premiums, and seasonally added heat/electric use expenses -- with Homeowner's premium due in February -- are keeping me "broke", and not yet having posted these to him! BUT, the moment I will (God willing) see the $$$-light at the end of then tunnel -- two Vaquero cylinders will be posted to him.
For "me" I have spent sooooo many dollars on any/every die, press, brass, primer-type -- you may know it as, too, you also may have been there -- to get those fired bullets into smaller groups. Who'd thunk a MAJOR contributor is not necessarily casting, sizing, and loading skill -- but that from which the projectile is being sent?
I can't wait (figuratively) until my forthcoming expenses are met and I may send those Vaquero cylinders to him!
geo

[Char-Gar]

Pin gauges are the way to go if you are starting in this. I bought a set of Starrett expandable hole gauges in 1969 and with a good Starett micrometer have been measuring the inside diameter of any hole since that time with these. Take a little time to get the feel for these, but then giver very accurate results.

[castmiester]

considering that a cast .359 fell through 5 out of 7 chambers, and two had to pushed relatively hard, I'd say the thing needs work. Cheap and effective way to check to do business with Doug. It's not a competition pistol, or a hunting pistol. Hunting pistols don't need to be that accurate, nor home defense pistols. I'll never get into competition so saying that, thanks for the help.

[Bass Ackward]

[QUOTE=castmiester;5663375]Even with 9 BHN shooting ?

If the 9 BHN is just lead tin? No. If you PC? No. If you use a base or gun protector? (Sometimes called a GC) No. If it is PB and has antimony in it? Yep.


Ever use sandpaper? The harder you press, the more it cuts. Now, using the same logic, and just picking numbers, what will 15 k psi push out harder on, 9 or say 18? I just rebarreled a 44 spc Blackhawk the grandkids abused and my 357 Freedom to include a new cylinder for just those reasons. Coarse were taking 10s of thousands of rounds. It also occurs if you clean more often.

[castmiester]

[QUOTE=Bass Ackward;5663791]

Even with 9 BHN shooting ?

If the 9 BHN is just lead tin? No. If you PC? No. If you use a base or gun protector? (Sometimes called a GC) No. If it is PB and has antimony in it? Yep.


Ever use sandpaper? The harder you press, the more it cuts. Now, using the same logic, and just picking numbers, what will 15 k psi push out harder on, 9 or say 18? I just rebarreled a 44 spc Blackhawk the grandkids abused and my 357 Freedom to include a new cylinder for just those reasons. Coarse were taking 10s of thousands of rounds. It also occurs if you clean more often.

aware it's not just lead, but just curious if it would take alot longer to wear out throats.