ruger- cylinder gap

[nekshot]

I have this 70's era BH that is really ticking me off. This is the first ruger I have had that I cannot get to shoot at least good. This morning I wondered what the cylinder gap was and found this. A .oo4 and .003 feeler gauge go 3\4 of the way thru the gap, holding the gun grip to me and push gauge from left to right(loading gate) side. A .002 will slide thru. This gun will not chamber reloaded 38's unless I run them thru a 357 fl die. I really want to get this thing to shoot at least decent, any ideas?

[Outpost75]

Are the chambers REALLY clean, or are they constricted with years accumulation of old fouling?

Have you checked your reloads in a max. cartridge drop gage? If they don't enter the gage, the gun isn't the problem.

MEASURE your loaded rounds with a micrometer. If their diameter is larger than .379" anywhere forward of the rim, your dies are not set up correctly and your rounds are too large. Oversized bullets and inadequate case sizing are possible causes. Improper crimp is another.

Running the loaded rounds through a Lee Factory Crimp Die should fix the problem and it sounds like you may need one.

[ejcrist]

Based on what you did with the feeler gauge(s) it sounds like the face of the cylinder is not cut square, or somehow the cylinder is canted in the frame. I've never seen anything like that in a revolver before. Do you get these same readings (.007 and .002) at every position when you rotate the cylinder?

[Outpost75]

The cylinder gap has nothing to do with whether the rounds will chamber. But if there is lead buildingup on the face of the cylinder and/or barrel extension which protrudes through the frame this will affect gap. Normal assembly tolerance is 0.006" and the gun should pass 0.002" with no resistance to cylinder rotation and hold 0.008", showing resistance to cylinder rotation with no more than 0.0015" end shake, being the difference between measurements with and without the rear 0.059" Go gage in place.

[DougGuy]

Worst comes to worst, I do have a .357 finishing reamer that I had to buy to save a badly reamed cylinder. Two adjacent holes would not chamber a dummy that measured .379" behind the crimp. Ruger already had this revolver in their possession for repair, this was mentioned and they declined to fix it. These two holes were reamed with a worn reamer and it simply had worn to the point that it couldn't cut the holes big enough to chamber a .3585" boolit crimped into a nickel case. If yours is clean of carbon deposits, and won't chamber a round like Outpost75 and myself mentioned, send it this way and I will fix it. Might as well address the throats too if it needs it.

B/C gap should not be out of square. It should be even regardless of what thickness gauge you can or cannot get in there. It's possible the end of the barrel is not squared but very unlikely the face of the cylinder is out. I have the tooling to fix all that too. Let me know if you need any of my services.

[MtGun44]

One more comment that cyl gap has nothing to do with rounds chambering or not.
Most folks WANT a tight cyl gap for less side blast, noise and lost velocity. I would
scrub the front face of the cylinder and rear of the barrel well and recheck, these areas
are normally places where lead and powder fouling builds up and unless REALLY
scrubbed, can be coated with very hard residue which may make your gap
smaller and uneven.

As to chambering, make certain that you haven't been shooting a lot of .38 Spl
rounds in a .357 chamber and not scrubbing really seriously with a brass brush
and good carbon remover in the chambers. It is extremely common, essentially
guaranteed, to get a ring of hard deposits just fwd of the .38 Spl case and make
chambering .357 cases difficult or impossible, even if dimensions are normal.

[Harry O]

I had a S&W K-38 many years ago that was made when they were owned by a bowling company. Accuracy was poor. Like you, I found that the gap between the barrel and the cylinder was different from side to side. The back of the barrel was not square. I took a fine file to it and measured it frequently. When it was the same gap all the way around, I took it back to the range and the accuracy increased dramatically.

The chambering problem has noting to do with this. Whenever I have problems with ammunition, I buy a box of factory loads and try them. If the factory loads don't have the same problem, the problem is with the handloads. More often than not, playing around with the die adjustments, sizing die, crimping die, or the bullet sizing size, will eventually take care of the problem.

[nekshot]

When I mentioned the chambering situation I only wanted to bring out the various issues this specific gun has. There is no carbon deposits, it is cleaned to metal. I bought the gun because it was a local ranchers personal work/carry gun, as his widow said. I don't think he shot it much because the throats were extremely tight. I did not know that at first so I grabbed some factory 158's and told my son lets see what the old gun can do. I was always bragging to him how rugers are great handguns. I laid up on a sand bag and touched off a round and the gun disappeared, my hand was empty! My son was laughing because the gun flew back over my head and landed in the hay bales behind us. I never had a 357 recoil like this- it was close to a TC 45-70 I shot with the owner declaring it was a full load and he gave me a leather glove to wear for recoil. This gun kicked like a mule! I realised the tight chambers and throat was no doubt the result of worn tooling so the adventure began. I opened it up some and the recoil is normal as you would expect but it will not groub worth a darn. Yesterday I dug it out to have another go at it and that was when I discovered the angle on face of barrel, which I am not convinced matters. I find it hard to believe the barrel is installed wrong (how could that happen even if threads were crossed it will true itself enough to line up, or so I would think). I bought this gun as a project(the rear sights were busted off, and I had a rear sight from a security six I scoped years ago) so I want to see it be a "good" ruger again. I am not blasting ruger, less than best things happen with production lines. I only wish I could have seen the owners eyes after he touched off his first magnum round!

[nekshot]

As I was out feeding the animals after last post it occured to me that the difficulty in 357's going in the whole way is possibly from carbon deposit in front of chamber because of him shooting 38's only. I opened the throats but I did not mess with chambers yet. That still doesn't answer the reason handloads only go in a third of the way and get tight. Factory 357's do snug up the last 1/8 inch or so. The mystery continues, as I am trying to get this gun at least to shoot as good as the other 357 we have, a humble Taurus about 24 years old but one stingy tight shooter!

[44man]

Based on what you did with the feeler gauge(s) it sounds like the face of the cylinder is not cut square, or somehow the cylinder is canted in the frame. I've never seen anything like that in a revolver before. Do you get these same readings (.007 and .002) at every position when you rotate the cylinder?
Not .007" to .002". Just a good .002" gap. That is good and not the problem. I suspect, like others, crud in the chambers. He was not combining a .003" with a .004" gauge.
I suspect his dies.

[EDK]

As I was out feeding the animals after last post it occured to me that the difficulty in 357's going in the whole way is possibly from carbon deposit in front of chamber because of him shooting 38's only. I opened the throats but I did not mess with chambers yet. That still doesn't answer the reason handloads only go in a third of the way and get tight. Factory 357's do snug up the last 1/8 inch or so. The mystery continues, as I am trying to get this gun at least to shoot as good as the other 357 we have, a humble Taurus about 24 years old but one stingy tight shooter!

Carbon deposits in the chamber may have caused small pits which cause the problem in seating 357 factory loads. The undersized or worn factory reamer is a real likely candidate too. There are various "down home solutions" to the problem. Chuck a brass bore brush in an electric drill and polish away. Slot a dowel, use a bit of emery cloth in it and fire up the drill. Either take it to a gunsmith or get cylinder ball hones from BROWNELLS and polish. My choice is ship to DougGuy and let him work his magic. (I'm going to get my pin gauges out and send the worst offending cylinders to him. I sure miss having all the toys in the machine shop at work to play with. A hand drill or DREMEL ain't even close to a lathe or milling machine for projects!)

[ejcrist]

Not .007" to .002". Just a good .002" gap. That is good and not the problem. I suspect, like others, crud in the chambers. He was not combining a .003" with a .004" gauge.
I suspect his dies.

Oh ok. I totally misunderstood. I was thinking that's some kinda huge difference - bigger than anything I've ever seen.

[nekshot]

I spent the better part of the day messing with this gun. Slowly kept opening the throat till a 158 boolit could be pushed thru all of them equally. I would hone then shoot 6 and hone some more. The last groub was 2 inches at 25 yards compared to 9 inches when I first tried a groub with this gun. I will run a 357 chamber reamer in it when I get acces to one. I know that will get the chambers to correct spec. This gun has alot of honest holster wear and kinda looks neat in its rough and tumble way. Must admit its the worst looking handgun I ever had.I hacked off some of the handle to fit my hand. I am starting to really like this gun. 135296

[bedbugbilly]

"This gun will not chamber reloaded 38's unless I run them thru a 357 fl die."

I'm a little confused by the above statement? Are you reloading casings that have been fired in another handgun and not resizing them? I resize all of my casings because I have a number of different handguns I shoot them in. You must be at least neck sizing the mouth and then expanding to get good neck tension? Or are you using different FL sizing dies for your 28s and 357s? if so, you need to check you 38 sizing die.

Not all revolver chambers are created equal - some are on the oversize side and some are on the tight side but within specs. A casing fired and fire formed to an oversize chamber is not going to go in well if a chamber is on the tight side. As already mentioned - check in a cartridge gauge to see if they are within specs.

The cylinder gap doesn't sound like it is an issue at all. Once you figure out whats going on with the tight chambers - check your throats and compare with your bore and the bolts you are shooting. Tight throats that are undersize and which squeeze a boolit down to where it is under bore size is not going to be conducive to accuracy. Rugers are well known for having undersize throats - so check everything else out as well. If necessary, you can have the throats reamed.


Figure the "tight cartridges" in your chambers first - then once you get that figured out - if you still are having accuracy problems - check the other things mentioned.

[45r]

I spent the better part of the day messing with this gun. Slowly kept opening the throat till a 158 boolit could be pushed thru all of them equally. I would hone then shoot 6 and hone some more. The last groub was 2 inches at 25 yards compared to 9 inches when I first tried a groub with this gun. I will run a 357 chamber reamer in it when I get acces to one. I know that will get the chambers to correct spec. This gun has alot of honest holster wear and kinda looks neat in its rough and tumble way. Must admit its the worst looking handgun I ever had.I hacked off some of the handle to fit my hand. I am starting to really like this gun. 135296

My short barrel NM Blackhawk from the same time period needed the throats honed also.
I put in a new wolf trigger spring,Ruger transfer bar,hammer spring and SB hammer in mine and it has a very good 2 pound pull.
I polished and tuned all the internals.
I like mine a lot.
It still looks and shoots good.
It has good blue and no billboard.
I doubt I'll ever sell it.

[nekshot]

Sorry about my lack of clarity, but I'll try again. This gun chambers factory 357 ammo fine except they get snug the last 1/4 to 1/8 inch. I have 38 specials that are reloads from 2 differant sets of dies. Those only go in 1/2 way and really get tight quick. If I take the 38's and run them into my rcbs 357 sizer die the whole way then they load fine into the cylinder. My taurus 357 takes all of them with no problem. So it appears this ruger has minimal specs for the chamber. I would believe it is for a 9mm if it did not measure the correct length of chamber for a 357 cartridge. Hope that doesn't confuse matters more! The reloads I was shooting today are 357's.

[nekshot]

"This gun will not chamber reloaded 38's unless I run them thru a 357 fl die."

I'm a little confused by the above statement? Are you reloading casings that have been fired in another handgun and not resizing them? I resize all of my casings because I have a number of different handguns I shoot them in. You must be at least neck sizing the mouth and then expanding to get good neck tension? Or are you using different FL sizing dies for your 28s and 357s? if so, you need to check you 38 sizing die.

Not all revolver chambers are created equal - some are on the oversize side and some are on the tight side but within specs. A casing fired and fire formed to an oversize chamber is not going to go in well if a chamber is on the tight side. As already mentioned - check in a cartridge gauge to see if they are within specs.

The cylinder gap doesn't sound like it is an issue at all. Once you figure out whats going on with the tight chambers - check your throats and compare with your bore and the bolts you are shooting. Tight throats that are undersize and which squeeze a boolit down to where it is under bore size is not going to be conducive to accuracy. Rugers are well known for having undersize throats - so check everything else out as well. If necessary, you can have the throats reamed.


Figure the "tight cartridges" in your chambers first - then once you get that figured out - if you still are having accuracy problems - check the other things mentioned.

Sorry about not making the distinction between the 2 problems. I still find it hard to believe the barrel is not square but the feeler gauges don't lie and I stoned the surfaces lightly so I could see metal on barrel and face of cylinder. Bet I get flamed for doing that! I did not use a grinder but lovingly lightly stoned the metal to remove carbon.

[Bullwolf]

Sadly, revolver cylinders are not always made to the highest level of precision or exacting tolerances.

I have an unfired 6 shot Colt 357 Magnum cylinder (and 38 caliber barrel) purchased from Numrich ages ago, intended for a project that never came to fruition.

135317

Ordinarily the cylinder by itself wouldn't be special, but this particular cylinder has the absolute tightest chamber holes of any 38/357 revolver that I've owned or encountered.

This extremely tight unused cylinder makes an excellent minimum spec case gauge for me.

If a loaded cartridge fits in this cylinder, It will fit in just about any SAAMI spec, or even minimum spec cylinder I'm likely to encounter. I use it when making ammunition intended to fit in all revolvers, as opposed to a cartridge tailored for one of my specific revolvers.

I'd have opened it up long ago if it was in a pistol that I shot regularly, just for the sake of conformity.


- Bullwolf

[44man]

The tightest chambers I found on Ruger .44's were the SRH's. I had to have loads in different boxes for each because brass from my SBH would not go in the SRH.
I also neck size revolver brass a lot and that makes things worse so I need to sort according to the guns.
I totally got away from all dies except Hornady for accuracy, made a lot of good things from old RCBS dies.
My friend bought RCBS dies for his .357 and I load for him. They are for both .38 and .357 and work well. You sure do not need other dies for the .38. You can set for the .38 and use spacers the correct thickness under them for the .357 so you never have to adjust the dies.
I still prefer Hornady. The expander is right and I love the inline seat die.

[nekshot]

I will bring closure to this thread with this picture. This morning I loaded up a nice heavy load with the rd190 and really felt if this is not a tight groub(25 yards on a rest) my work on this ruger was in vain. I shot 3 shots and had a 1 1/2 inch groub and then I lost concentration and could only see double but I tried the other 3 and it did it open up. But even with my transmitters going nuts and basically guessing when I thought it was right for the last 3 shots I did good. I am satisfied a young buck could win some money with this gun. I hope the original owner135480 is watching his old gun shoot! one other thing, my 357 shotshell loads fit in the chambers now. Those slithering devils are in trouble because this is as good as a sawed off shot gun from the tractor seat!