throats in my .45

[45sixgun]

I've been working with my .45 Ruger NMBH Convertible. Accuracy was not what I get with my .44 so I started looking into it. I read that I needed to ream the throats, so I got a Manson reamer and reamed both cylinders. According to the paperwork this should have put the throats right at .452. I tried pushing some commercial cast bullets through but they wouldn't come close to going through even though the box said they were .452. Next I pushed some of the bullets through my Lee .452 sizing die. The bullets were on the larger side, but after sizing them they still wouldn't go through the throats. After reaming my accuracy seems a little improved, but I'm still getting tons of leading in the barrel. I just ordered a .451 sizing die, and I'm going to try that next. Has anyone had a similar experience? Any answers or suggestions? With my .44 Special the bullets go through the throats with a tiny bit of pressure. That gun is as accurate as I can shoot it. BTW, in case you can't tell, I'm new to handguns and reloading. Thanks.

[jandbn]

I would hold off on the .451 sizing die until you measure grove diameter of a slug with a micrometer. Then using the same micrometer, measure the as bought-size. Then measure one pushed through the die.

If the lead is hard, there may be spring back preventing a sized bullet to be pushed through the throat. It could aslo be that your sizer isn't actually the size marked. Start with the barrel measurement first and go from there.

[runfiverun]

depending on where the bbl leading is would clue you in as to where/what the problem truly is.
a tight spot where the bbl screws into the frame is common.
lead angle into the bbl could be too shallow also and is shaving some lead.
or it's a bit off center with the cylinder cocking the boolit in the bbl.
or it has a lip.
or...
then again it might not be the gun, you might just be blowing the lube out of the cylinder gap.

[subsonic]

It seems like I have heard this story before.

I ended up using a split rod to open my throats to .453", as the reamer only took them to .4515" and I could not chamber WFN style boolits, or 300gr xtps seated out to the bottom crimp groove.

The best thing for your leading, IME, is to keep shooting it to smooth out the barrel. Shoot gas checked or jacketed for a couple hundred rounds, clean out any copper and try again. Repeat as necessary or if you have a bad problem, fire lap.

My .45 Ruger has given me fits. The same combination that shot well before any modifications is also the same that shoots the best now. Cast Performance 335gr WLNGC over a heavy charge of H4227 or H110 with a CCI300 primer.

YMMV, but this combo is definitely worth a try.

[45sixgun]

depending on where the bbl leading is would clue you in as to where/what the problem truly is.

The leading is long streaks down the barrel, doesn't seem to be much at the forcing cone.


I ended up using a split rod to open my throats

What is a split rod? Never heard of one.

Jandbn, I already ordered the die, so I'll go ahead and try it. I don't have a way to slug the barrel at the moment, but I'll keep that in mind as something to try.

[Larry Gibson]

Accuracy was not what I get with my .44



There are lots of things that affect accuracy other than undersize throats. A couple years back it seems all revovler throats were over size. Now it seems they are all undersize. I have yet to ream a rvovlers throats and I've got numerous revovlers and have shot a whole buch of others over the years....all with very good accuracy and all without reaming any throats. Reaming throats may be a rare thing to do but it should be a last ditch measure with positively known undersize throats.

As to the leading in the barrel what is the alloy, the bullet, the lube and the load?

Larry Gibson

[45sixgun]

Larry, I'm not saying you're wrong. I've no experience at all next to yours. The way it was explained is that the small throats constrict the size of the bullet excessively which then prevents the full obturation needed for it to seal inside the barrel. It made sense to me. I also read that a properly matched bullet and throat would allow the bullet to go through with a slight push. That is exactly what happens in my .44 and in my .357.

[subsonic]

A plit rod is just what it sounds like. A piece of steel rod that has been split on one end. You catch the end of a piece of abrasive cloth in it and wind it around until it is the correct diameter to slip fit in the throat and then run it in a drill to open up the throats. Google it, as there is more to it than that, and if you don't know what you're doing and aren't careful, you could easily ruin your cylinder. I'm feeling too sleepy to type it all right now, and there is a bunch of stuff that google will find.

Before you open your throats anymore, unless you are having difficulty chambering, shoot it a bunch more. Also tell us what load in detail you are shooting.

[45sixgun]

Thanks, subsonic. I'll google it.

I'm shooting 9 grains of Unique and 250 grain RNFP, HSM brand. Using Federal primers and Starline brass. I've been shoving the same bullet into ACP cases I scrounged and 6 grains of Unique. I can't remember if I got the leading before I shot the ACP rounds. I guess I should test that issue.

[454PB]

I'd say you need to do some measurements before you alter the gun anymore.

You can measure the slug you pushed through the cylinder throats, and also the boolits pushed through the Lee sizer. I have a Lee sizer that's labeled .451", but actually sizes to .4515".

That said, I'm betting your having a lube failure. What lube are you using?

[MtGun44]

I am getting really concerned that there are a lot of folks that are just willy nilly
reaming their cylinders and don't even have much in the way of precision measuring
equipment or even much of a really clear idea why and what particular problem they
thing they will be solving.

I have reamed a BH but I had accurately measured the throats with pin gages and
had a specific problem to solve.

Bill

[45sixgun]

I am getting really concerned that there are a lot of folks that are just willy nilly
reaming their cylinders and don't even have much in the way of precision measuring
equipment or even much of a really clear idea why and what particular problem they
thing they will be solving. I have reamed a BH but I had accurately measured the throats with pin gages and had a specific problem to solve.

I have a clear problem: the bullets won't fit through the throats properly. So far I've used precise tools (Manson reamer) and highly recommended methods (using a properly sized bullet to test the throats). Can't afford a set of pin gauges, but they don't seem absolutely necessary.

[tek4260]

That commercial cast boolit and the hard lube used to survive shipping is probably the problem. Try tumbling some in Alox and see if the leading goes away. Are they bevel base by the way?

BTW, I have never seen a Manson reamer that wasn't the proper size.

[subsonic]

That commercial cast boolit and the hard lube used to survive shipping is probably the problem. Try tumbling some in Alox and see if the leading goes away. Are they bevel base by the way?

BTW, I have never seen a Manson reamer that wasn't the proper size.

Big +1 on most commercial "cheapy" boolits leading up my guns.

It is a fact that a .452" object will not pass through a .452" hole without substantial force. The reamer I used on my gun was like a door knob. Everybody had their turn. So maybe it was worn.

[btroj]

I did use the split rod with wet/dry paper and oil to enlarge the throats on my BH in 45 Colt. I did it after owning the gun for a year or two and finding it tended to lead in the forcing come with almost every load.
I was sizing to .452 and the bullets were not even close to fitting thru the throats. I drove a bullet thru and it measured .449.
I opened the throats until a .452 bullets would barely fit thru with a bit of force.
I don't get the leading any more, accuracy is better too.

Like some have said, don't modify the fun unless the fun requires it. This idea that you must ream the throats right off is silly. I did mine because the gun needed it. I didn't see a way to get it to shoot well otherwise. I fel that shooting about 1 K thru it over a few years was a good test.

[Char-Gar]

Several thoughts come to mind on the subject at hand.

1. Don't start cutting on a pistol, until you have measured the throats and know what you have.
2. Don't try and determine the size of the throats, either before or after cutting with commercial cast bullets, or even soft lead slugs for that matter. Cast bullets, even after sizing are very seldom 100% round.
3. Do your measuring with either a machinest hole guage and micrometer or pin guages.
4. There are very few commercial cast bullets worth the purchase price. Most are too hard,with worthless wax lube.
5. You leading issues has good probablity of coming from your bullets and not your pistol.

[Char-Gar]

I am getting really concerned that there are a lot of folks that are just willy nilly
reaming their cylinders and don't even have much in the way of precision measuring
equipment or even much of a really clear idea why and what particular problem they
thing they will be solving.

I have reamed a BH but I had accurately measured the throats with pin gages and
had a specific problem to solve.

Bill

Bill, we have a gin-u-wine fad going on. Fads of any kind never had much reason to them, just follow the pack in the way it seems to be going. There are lots of screwed up sixguns out there and most of them will make their way into the used market, so caveat emptor.

[subsonic]

Yes, the fad that Ruger uses reamers for as long as possible to save cost because most folks:
A. Shoot a box or two and put the gun away.
B. Shoot a bunch of jacketed for every cast boolit.
C. Can't tell if a handgun is accurate, but all of them can tell if the price goes up $20.

There must be a full moon or nothing on the internet tonight.

I have pin gauges. I have a micrometer. I know how to use both of them. I have owned Rugers and Smith an Wessons that are good out of the box and jacked up out of the box. I'm not sure why, but Ruger seems to do a slipshod job on .45 revolvers and a pretty fair job on .44 maggies.

My best advice is to buy .44 Rugers or plan on overhauling the .45s.

[Char-Gar]

Subsonic...How long has it been since you bought a new Ruger 45 SA?

[subsonic]

It was about 10 years ago, when the Accu-Sports were first coming out.

After the issues I had with that one, I am not in a hurry to buy another.
I did just buy a SBH last fall and it measures .431" all around with two chambers tight on that pin gauge. But it has thread choke, a slightly rough bore, and a trigger that rivals a good Taurus. I have not shot it much yet, as it was a Christmas gift for my step son.

[45sixgun]

Some of you guys sound like grouchy old-timers....But I'm all ears and enjoying every bit of your feedback.

You make it seem like I just went out and got this gun, then couldn't wait to screw it up.

Here are the first eleven shots taken with the gun after reaming. First the Colt cylinder, then the ACP cylinder. This was at 25 yards (26 1/2 paces and I'm six foot with a healthy stride). No warm up shots taken. Keep in mind I've only been shooting for four months, one time a week.

Colt cylinder, two bullets went through top hole.

https://lh5.googleusercontent.com/-pJpFp5ro_q8/T0ZiEtCUQbI/AAAAAAAAaLU/MWZSl93ijck/s800/P1050192-1.JPG

ACP cylinder, first time shooting it ever and first time reloading for it. I only loaded five test rounds.

https://lh4.googleusercontent.com/-LPLNdrsxR4g/T0ZiPBmJJQI/AAAAAAAAaL0/nWPtHUJhG5M/s800/P1050204-2.JPG

I don't think I screwed it up. If anything it's shooting better.

I have a .44 Special I also bought new, which shoots like a dream. I haven't messed with it other than putting in a trigger spring (another one of them goldang fads) and I won't mess with it. It's my reference point. I'm going to speak with more authority than I've a right to: I've read enough authorities on this to assume that a properly sized bullet is supposed to go through throats with a slight amount of finger pressure. They shouldn't drop through, and they shouldn't get stuck. Yes, I'm using cheap commercial cast bullets. My budget has its limits, and I hope to start casting soon. The commercial bullets go through the .44 throats exactly as they're supposed to--with a little pressure. They didn't come close to going through the .45 throats. The box says the bullets are .452. Next I pushed them through my .452 sizer. The bullets were sized down in the die, every one I pushed through. So I think it's pretty safe to assume that they're at least .452, or very close. Yet after sizing they still don't come close to fitting through. When I reamed, every chamber lost metal, which leads me to assume they were indeed small and needed to be reamed.

Now I don't have pin gauges or any other fancy measuring equipment. The reamer was sent to me after being used on a handful (at most) of cylinders. It had the pilot pack with it. Maybe the leading is coming from the bullets. I'll try adding some other lube as was suggested. They are not bevel based. (Although the Laser Cast bullets I'm shooting out of the .44 are bevel based, don't lead, and are as accurate as I could ever hope for.)

Based on my experience, I feel like I addressed a real problem, was not following a fad, and am actually improving my gun. My reason for posting here was to figure out why the bullets are still so tight. My .451 die will be coming in a few days. I'll try that and see what happens. I've shot the .45 about 300 times. I know that's not a whole lot, but bullets are kinda precious to me and I'd rather not keep shooting them with poor accuracy if it's something I can fix. Manson reamers address a real problem with Ruger .45 throats. Are there some people out there reaming to add a little badge to their vest? Maybe, but I kinda doubt it. Too much at stake. In my short experience big bore SA shooters seem like the type that have level heads and a fair share of common sense.

I appreciate those who have posted here to answer my question.

[white eagle]

45 ,
I had 2 45 colts and one was the convertible like yours
I gave up on trying to get it to shoot the 44 just seems to get you to the dance so much easier and without all the mods and tweeks that a 45 needs
can't explain it but that is my take
probably burned up 12# of powder trying to get the damn thing to shoot good but I gave up life is too short

[45sixgun]

That may end up being my experience as well, white eagle. Thanks for sharing your story.

If I end up getting where I want to, then the effort will have been worth it. But of course there's no guarantee that's going to happen. I will say that at this point I'm still enjoying the challenge. Haven't come to the "life's too short" feeling yet.

[454PB]

I don't think any of us mean to chastise you, we just want you to succeed without doing unnecessary (and non reversible) modifications to the gun if the problems lie elsewhere.

If you're going to pursue this obsession, you need to invest in a micrometer and dial caliper. Both can be had new for $100 or so, and are extremely important for all handloading, not just casting. As to the pin gauges, you can measure a boolit that was used to slug both the bore and the chamber throats once you have a micrometer. I have pin gauges, and have compared their use for throat measurements to those done by "slugging" and found them to be the same. I've read some folks saying that boolits will "spring back" after slugging, but I've never seen it when using dead soft slugs.

A slug can be used over and over, all you have to do is put it in a vice and squeeze it back to a larger diameter. And.....make sure the slug is oversized a few thousandths before slugging.

[Char-Gar]

I prefer the 44 to the 45 for the simple reason that it is far easier to get a 44 to shoot well. The 45 Colt round wil shoot well, bit it will require more work. That has been my experience over 50 years with dozens of six guns in both calibers.

I have killed quite a good number of animals with both and have not seen any difference given bullets of similar design, weight and velocity. I killed my first deer with a handgun in 1966. The handgun was a Colt Gold Cup 45 Auto. The bullet was 452423 over 4.8/Bullseye. This is a wimp by current thinking bit it killed whitetail and mule deer grave yard dead.

I have also killed deer with the 44 Mag and 45 Colt rounds and they both did the job. This was long before the 45 was loaded with heavy bullets and higher velocity.

To tell the truth I have also killed deer with both the 357 Magnum and 32-20 rounds fired from six guns. Killing deer really isn't a big chore with any decent handgun. The real chore is finding the deer and putting the bullet in the right place.

[45sixgun]

you need to invest in a micrometer and dial caliper.

I'll look into getting these.


slug both the bore and the chamber throats once you have a micrometer

Sounds like this is what I need to do. I'm not sure how to do it on the cheap, but I'm going to try.


I prefer the 44 to the 45 for the simple reason that it is far easier to get a 44 to shoot well. The 45 Colt round wil shoot well, bit it will require more work.

This seems to be the more common experience. I'm happy right now to have a sweet shooting .44 and a .45 as a project gun. Hopefully "the project" will end well.

Thanks for the feedback.

[454PB]

I prefer the 44 to the 45 for the simple reason that it is far easier to get a 44 to shoot well. The 45 Colt round wil shoot well, bit it will require more work. That has been my experience over 50 years with dozens of six guns in both calibers.


My experience was different. I bought my Ruger BH convertible in 1980. Got it home, cleaned it, and fired the first 6 shot group off an improvised rest at 25 yards in my backyard. The load was 452424 sized .452", 10 grs. Unique, and a CCI 300 primer. All 6 shots were in a 1" group.

[PacMan]

My first step any more is to slug the barrel and then using that slug see if it will pass thru the cylinder throats. If so there is no need most of the time to open the cylinder throats.If they will not slip thru the throats then the throats most likely need opening up. Horse in front of the cart time thing.

[45sixgun]

That makes perfect sense, dwight. I'm so new at this, I acted with partial knowledge. The throats were definitely small in relation to .452, but I have no idea how they related to the barrel. I'll have to research slugging. I have no idea how to do it, or even if I can with the materials I have. I definitely don't have any $ to spend right now. Thanks!

[tek4260]

Now you need to re cut the forcing cone to 11 degrees.... The natural evolution of improving a Ruger 45 :)

Then comes the heavy hammer spring and light trigger spring
Then comes a bit of firelapping
Then a taller sight is usually required for me
Then a Millet rear pops up for sale and gets added.

[MtGun44]

Nothing specific to you, really. I was more generally commenting that many folks seem
to jump on the "ream it" bandwagon prior to accurate measurement, or significant effort
with reloading. Everyone is free to do what they want with their own gun, but I would not
want to personally contribute to a misperception on the part of beginners that may lead
them to do something irreversible that might be harmful to a gun when the problem may
lie elsewhere.

Bill

[subsonic]

I want to know how a newbie can cut a throat that's already .452" bigger by using a .452" reamer. Neat trick!

[tek4260]

I want to know how a newbie can cut a throat that's already .452" bigger by using a .452" reamer. Neat trick!


Isn't that Manson reamer a .4525" :)

[45sixgun]

Now you need to re cut the forcing cone to 11 degrees.... The natural evolution of improving a Ruger 45
Then comes the heavy hammer spring and light trigger spring
Then comes a bit of firelapping
Then a taller sight is usually required for me
Then a Millet rear pops up for sale and gets added.

Well, I'm not sure the forcing cone needs to be done, but I might be convinced....

I didn't know I could get a stronger hammer spring, but I did put in the light trigger spring.

I've read about firelapping, but the reports are too mixed.

I didn't need the taller sight.

I replaced the rear with a Bowen sight....better, but I still like the micro sight on my .44 Special more.


I was more generally commenting that many folks seem
to jump on the "ream it" bandwagon prior to accurate measurement, or significant effort
with reloading.

I plead guilty of not using appropriate measuring tools and of not putting forth significant effort with reloading. Although I do think I diagnosed a valid problem with my limited means and knowledge. Properly sized bullets are supposed to fit through throats, right? I'm not going to say I didn't jump the gun with the reaming. We'll see after some more testing.

[MT Gianni]

Isn't that Manson reamer a .4525" :)

The one I have is.

[45sixgun]

Isn't that Manson reamer a .4525"

Yes, that's what the paperwork that comes with it says.

I got my .451 sizer today and pushed some bullets through it. Now they finally fit through the throats. They don't drop through, but it doesn't take much to push them through. I stuck one in the bore through the forcing cone and it only started to go in. Hopefully .451 won't be too small to obturate sufficiently. Next step will be to slug the cylinders and bore to get some conclusive measurements.

I put some of the Alox over the commercial lube. Got 50 rounds loaded up. Finally no bulging cases and slivers of lead.

Hopefully tomorrow I'll be able to get out and shoot.

[45sixgun]

Got out early today to test the latest. I set up the target at 23 yards. I took no warmup shots, and used a tree branch to rest against. First shot (the low one) went off before I was ready, but it was still close to the bullseye. All five of the rest were in the bullseye, with three forming one hole. Upon quick inspection there wasn't leading. I'm happy. I don't think I ruined my gun.

https://lh6.googleusercontent.com/-hA4hQXPbcl4/T1vE24dbGJI/AAAAAAAAaMg/8t1SRgD5waA/s800/P1050671-001.JPG

[Char-Gar]

You done good!

[1bluehorse]

I've have 4 Ruger 45 colts. Had six, sold two. ALL SIX had tight throats. Measured .448 to .449. Yes I have pin gauges. Reamed them with a Manson reamer to .4525. A .452 bullet (through my sizer) will pass through with a little pressure. The bores measured .442-.443, groove dia. was .451. These guns are built to shoot jacketed bullets obviously. 45 Sixgun, to slug your bore go buy a package of #8 oval (hollow) fishing weights. Clean the barrel really, really, well, run a patch with a little oil down the bore then push the lead sinker down the bore. It'll take a pretty good whack to get it started. Use a wooden dowel (not much longer than the barrel) thats as close to bore size as you can. You'll have to use a pretty large hammer as you don't want to tap,tap,tap, it. Measure the slug with a micrometer. I can tell you what you'll find....barrel will measure .451 +/- a frog hair and you'll have a constriction at the barrel/frame joint...guaranteed. I've also done this to 3 Ruger45s that belonged to friends of mine. All were the same..they have all now been reamed, firelapped, and the bore polished as well, using Marshalls (Beartooth Bullets) lapping kit. Major improvement in all of them. None ruined. Out of the nine Rugers I've done this with, one is a Redhawk, two are BHs, 6 were large frame Vaqueros, 4 stainless 5 blue steel..Thats my experience with Ruger 45 colts.

[45sixgun]

Thanks, Char-Gar and 1bluehorse. I appreciate the instructions for slugging. I believe I'd find what you did. I'm thinking seriously now about firelapping.

[rststeve]

+1 for the fire lapping I have had to do this with all my 45 some resist this process but it works great good luck

[Doug Bowser]

I have seen Ruger .45 Blackhawk revolvers with chamber throats as small as .445". I belive they use the chambering reamers too long and they become smaller. I have the chamber throat reamer from Brownells. In the kit there are several sleeves from .445" - .450" that guide the reamer. The reamer measues .4525".

The small chambering throats seem to be a thing of the past but there are a lot of Ruger Blackhawks out here with small chamber throats.

I have reamed sevral of the .45 Ruger revolvers and the accuracy level has dramatically increased after the throats are opened up. If you need this operation done, PM me.

Doug Bowser

[45sixgun]

+1 for the fire lapping I have had to do this with all my 45 some resist this process but it works great good luck

I've been reading from Veral Smith of LBT on this topic. I'm a believer!


The small chambering throats seem to be a thing of the past

I wish that was the case, but my recently purchased .45 still had the small throats.


I have reamed several of the .45 Ruger revolvers and the accuracy level has dramatically increased after the throats are opened up. If you need this operation done, PM me.

Thanks, Doug! If someone hadn't already sent me a reamer, I'd take you up on that.

This morning I was able to get out for a little shooting. I shot this group at 23 yards after a few warmup shots. The noon sun was shining directly on the front sight which wasn't ideal, but I was happy with the results. I was resting my hand against a tree branch. I really don't think I could shoot better than this even if the gun was in its optimal condition. I might get closer to one ragged hole at that distance if my eyes were better, or with some sort of optics. Maybe I could with a standard sandbag equipped benchrest. I've never shot from one. I'm not getting leading, which is a good sign. I might try firelapping, but I might not because things seem to be really good as they are.

https://lh4.googleusercontent.com/-0VACpK0c-3A/T2zcZbP-t6I/AAAAAAAAaOA/zv2ac_I_V1g/s800/P1060165-001.JPG

After shooting at the target I wandered to another area where I had seen some coyotes. I just carved out a little caller and wanted to try it. I sent out some rabbit distress wails and didn't have long to wait. The problem was that the coyote came from my back. When I turned around it saw me and took off. No coaxing it back. Glad that it works and can't wait to drill one with the .45.

https://lh4.googleusercontent.com/-edby-zix8TM/T2TBp5vM0LI/AAAAAAAAaNA/RzBN6HBnNTI/s800/P1050809-001.JPG

https://lh4.googleusercontent.com/-MokY_iuSbrI/T2TBsFUjPJI/AAAAAAAAaNI/_LoujUEBqsI/s800/P1050816-001.JPG

[9.3X62AL]

Your load is a classic (9.0 x Unique under a 250 grain casting), your accuracy seems to be decent. Now all we have to do is get you pouring some boolits of your own, instead of those store-boughts. :)

[45sixgun]

your accuracy seems to be decent Thanks. I have been seeing some pretty phenomenal pictures of one ragged holes on the forums....


Now all we have to do is get you pouring some boolits of your own, instead of those store-boughts. I'm getting there. I have some molds and ww's waiting.

[gandydancer]

Yes, the fad that Ruger uses reamers for as long as possible to save cost because most folks:
A. Shoot a box or two and put the gun away.
B. Shoot a bunch of jacketed for every cast boolit.
C. Can't tell if a handgun is accurate, but all of them can tell if the price goes up $20.

There must be a full moon or nothing on the internet tonight.

I have pin gauges. I have a micrometer. I know how to use both of them. I have owned Rugers and Smith an Wessons that are good out of the box and jacked up out of the box. I'm not sure why, but Ruger seems to do a slipshod job on .45 revolvers and a pretty fair job on .44 maggies.

My best advice is to buy .44 Rugers or plan on overhauling the .45s.
Subsonic! where did you purchase your pin gauges from? Thanks. Gandy

[Mal Paso]

Subsonic! where did you purchase your pin gauges from? Thanks. Gandy

Might I chime in. I got a set (250 piece .251-.5) from Grizzly on sale for under $80 delivered just after Christmas. Good quality for the price.

[skandic]

witch pin gauge set is more suited for measuring firearms the plus or minus ones

[Thor's Daddy]

witch pin gauge set is more suited for measuring firearms the plus or minus ones


Minus.

As an example, if the largest size (minus) pin that will slide through your chamber throat is .4525, then that throat is indeed .4525. Minus pins are slightly smaller than the actual size of the hole, which allows them to slide through.

You can also find decently priced pins at gageshop.com.

I hope this helps.

[1bluehorse]

Most will use the minus set. A pin gauge will give you chamber and throat size and bore size. It will not give you groove size. If you want groove size you'll still have to "slug" the bore. BUT when using a pin gauge down your barrel it will find any "tight" spots. If a pin gauge will start down the muzzle it should go all the way. GENTLY is the word here, if there's a constriction the gauge will obviously get stuck, usually if you drop a smaller caliber bullet down the bore from the other end it will "jar" it out. (a smaller pin gauge may work here, IF it will fit inside the cyl. frame) Hence the "gentle" part of inserting it. I just did this to my wifes two 357 mags. there was a slight constriction about half way down the barrel on one and both had barrel/frame constrictions. Twelve firelapp rounds in each and a bore polish cleaned them up nicely.

[skandic]

Thanks guys

[1bluehorse]

I'll add this, while pin gauges make some of these measurments a little easier, and ..maybe.. a little more precise, doing the same thing with a soft lead "bullet" (hollow, oval fishing sinker) will pretty much give the same information.