Ruger 45 colt cylinder throat reaming

[2shot]

Measured the throats on my Bisley 45 colt and found three different throat sizes. .448, .449 and .450, these were measured with a set of MINUS plug gauges so they're a tad smaller that this. I'm going to ream them with a Manson .4525 reamer and was wondering what kind of accuracy improvment if any to expect from doing this? I also have the constrction in the barrel where it is screwed into the frame and I'm planing to fire lap that also. Now before fire lapping the barrel constriction measuers .451 with it being looser in the middle of the barrel and it seems that there is a constriction at the muzzle also but not as bad as where the barrel goes into the frame. It's a shame that Ruger can't get this right, it's a nice looking and handling gun but just doesn't shoot as well as I had expected it to.

2shot

[softpoint]

I had my 4⅝ black hawk reamed and the forcing cone re-cut at the same time. That gun regularly shot around 2" or so at 25 yards. After having the work done, the gun will occasionally go into an inch ,so you could say the improvement was near 100%

[Charlie Sometimes]

It will shoot better than you can hold it, and maybe see! Mine does now that I had the same work done as you are considering. I want to get a SS Bisley in 45 Colt and do the same to it for hunting. Love the Rugers! I won't own anything else- unless they don't make it.

[Changeling]

Measured the throats on my Bisley 45 colt and found three different throat sizes. .448, .449 and .450, these were measured with a set of MINUS plug gauges so they're a tad smaller that this. I'm going to ream them with a Manson .4525 reamer and was wondering what kind of accuracy improvment if any to expect from doing this? I also have the constrction in the barrel where it is screwed into the frame and I'm planing to fire lap that also. Now before fire lapping the barrel constriction measuers .451 with it being looser in the middle of the barrel and it seems that there is a constriction at the muzzle also but not as bad as where the barrel goes into the frame. It's a shame that Ruger can't get this right, it's a nice looking and handling gun but just doesn't shoot as well as I had expected it to.

2shot

First of 2shot I am not an expert on revolvers (rifles I know about). I'm answering because I believe something is wrong with your measuring. Either the tool or your procedure, not sure because you didn't specify.
You need to clean the barrel and cylinders spotless before you take measurements that will equate to changing the metal sizes of your revolver. Your measurements just don't make sense, it would be possible, but not normal or probable.

Get the barrel spotless inside (soak and clean till no residue) and then do a "slugging " of the barrel and cylinder throats for exact measurements. What tool are you using for measuring ?

Almost forgot, What bullets (brand and weight) have you been shooting?

[Dale53]

Before I reamed my SS Bisley Convertible .45 Colt/.45 ACP, i had leading with the Colt cylinder. The accuracy deteriorated as I shot. I couldn't even load the .45 ACP with cast bullet SWC's.

After reaming, I get NO leading and the accuracy is maintained as long as I shoot (five shots to several hundred). The .45 ACP cylinder now allows me to load my "loaded for the 1911" target loads and shoots as well as anything I have. That is to say, VERY well indeed.

I see no downside to reaming (if it is done in a professional manner) and certainly in my case (and that of two of my friends) the accuracy was much improved and leading ELIMINATED.

FWIW
Dale53

[2shot]

Scrubbed and cleaned the throats and measured with plug gauges (minus). There is no fouling or lead in the cylinder throads and those are the correct measuements. One at .450 three at .449 and one at .498.

Been shooting RCBA 270 SAA mostly and some Remington 255 grain lead. Tried Cor-Bon WFN freight trains and some jacketed 300 grain Hornady. Nothing shot much better that 3" at 25 yards.

This gun was bought when the Bisleys first came out so it's over 10 years old. I don't know if Ruger ahs improved their machining or not since mine was manufactured.

2shot

[NHlever]

The measurements you got are possible because Ruger used to machine the chambers with a three spindle multiple drill head. Three chambers were cut ( in stages, of course), and then the cylinder was indexed , and the other three cut. The final throat sizing was done from the muzzle end. Now all that machining is done on CNC machines, and I believe that everything is done from one end. I think that change took place a couple of years ago. Between all the indexing going on, and using three different tools at a time, the tolerances you saw are not out of the question.

[Dale53]

2shot;
I wouldn't presume to tell you what to do. However, this was my second Ruger .45 Colt that I reamed and I'll tell you, without reservation, that both of my revolvers (as well as my two friends revolvers) now shoot at NRA Match levels with my cast bullets.

If you don't have the machine shop experience to ream them, you can send cylinders only to Cylinder Smith for proper reaming and quick turn around for a small charge. That will be the best value you'll have in revolver smithing...

FWIW
Dale53

[stubshaft]

2shot:
Rest assured thast Ruger is NOT the only manufacturer that has this problem. S&W was even worse when they used to pin the barrels to the frame and I have a couple of SAA Colts that also show a slight restriction in the forcing cone.

[MtGun44]

My 45 convertible had .449 on one cyl and .450 on the other. Reamed both to .452 then
polished to .453. Reduced fliers, I presume the remaining fliers are my fault.
No leading, very good accy.

Bill

[azrednek]

I just had my Blackhawk Convertibles cylinders reamed to .452 by member JIMinPHX. Mine is a little more than a year old. It was a 2008 Christmas gift. My measurements were all over the place with the smallest being .448 and the largest .451. I'm no professional machinist like Jim but I believe he got similar measurements with his high quality tools. Jim also noticed the throats were slightly tapered.

I was going to have the throats reamed a short time after I got it but a member here or the Handloads group suggested I contact Ruger first. I sent Ruger targets comparing the group size using the same ACP loads in my S&W 25-2 and detailed the measurements of each of the cylinder's throats. Ruger just sent me a form letter saying I could return it to the factory for testing.

I decided to wait until the NRA Convention here in Phoenix this past summer and talk directly to a Ruger rep and see if I couldn't get them to ream it for me. The Ruger rep told me they would test fire it with factory jacketed ammo and if it was determined to be safe they would just return it to me. The rep was aware of the problem and mentioned he was a lead slinger but unfortunately they wouldn't ream it. The rep I'm sure following the advice from Ruger's legal dept, warned me, very politely but somewhat sternly that I could void the warranty if I altered it.

Hopefully I'll get a chance tomorrow to shoot it and see how much improvement there is. When I slugged the bore in Jim's work shop I could feel a slight restriction in the barrel right under the strap. If I don't get a major accuracy improvement, guess I'll have to have the forcing cone lapped. It is really a shame Ruger can't (or wont) ream the cylinders to a consistent .452.

It is bad enough that Ruger sends them out under sized but one would think they could at least get all the throats the same size.

[mtgrs737]

I had my New Vaquero throats reamed to .452" then hand polished to .453" so I could shoot cast without leading. I sent it off to the cylindersmith along with two others that were undersized, it was money well spent as I shoot lead only in most of them.

[2shot]

OK, I reamed my cylinder throats last night and now I at least have the same diameters on all the throats. I had two that were tapered and three different size throats on the same cylinder but that's all in the past now.

Now I have to check to see about the constriction in the barrel where it screws into the frame. I may do as Softpoint did and re-cut the forcing cone with an 11 degree cutter and see if that eliminates the constriction. The constriction isn't very long so the re-cutting just may do it. If re-cutting the forcing cone doesn't do the trick I'm back to fire lapping.

Stubshaft pointed out that there are other guns that are just as bad about cylinder throats. The good news about the Ruger is that there is enough metal left in the throats so that this can be corrected fairly easily. I like others find it strange that Ruger somehow can't get this right and maybe with their newer CNC machines they will.

2shot

[Dale53]

2shot;
Ruger tests their guns with jacketed bullets. Most manufacturers do NOT cater to reloaders (some of them think reloaders are sub-standard - and in some cases, no doubt, they are right). A jacketed bullet will shoot well with undersized chamber throats and a cast bullet will not.

Personally, I am almost thankful that my cylinder throats were undersized - it allowed me to custom ream them for best results. I had access to a reamer kit. If a person does not, then a quick trip of the cylinder or cylinders (discount for more than one at a time) to:

http://www.cylindersmith.com/

will solve that problem for you at minimal cost. I have been able to do my own, but I hear rave reviews about cylindersmith constantly. He has a reputation for excellent work and fast turn-around.

FWIW
Dale53

[Shiloh]

What dale said.

This guy has the tools, experience, and a stellar reputation.
It'll be done right.

http://www.cylindersmith.com/

Shiloh

[2shot]

Thanks for the link guys but I already reamer the throats in my Ruger. Did it last night with a Manson reamer that I borrowed from a guy that I shoot NRA Bulleye with. Now I have .4525 throats in 6 chambers.

Now I jst have to do something with the constriction in the barrel and I'll see how it shoots.

2shot

[Wireman134]

2shot;
I wouldn't presume to tell you what to do. However, this was my second Ruger .45 Colt that I reamed and I'll tell you, without reservation, that both of my revolvers (as well as my two friends revolvers) now shoot at NRA Match levels with my cast bullets.

If you don't have the machine shop experience to ream them, you can send cylinders only to Cylinder Smith for proper reaming and quick turn around for a small charge. That will be the best value you'll have in revolver smithing...

FWIW
Dale53

+1 What Dale53 says. 10% of the 45 job goes to a good cause.

[9.3X62AL]

Changeling et al--

WAY too many Ruger 45 Colt Blackhawks have the undersized throat problem to call the original poster's issue anything but a "product characteristic". Mine was similarly dimensioned, and after reaming and polishing out the throats to .453" (groove is .452"), .454" boolits of all descriptions shoot VERY well in the revolver. Prior to the 'operation', the revolver was a "One Boolit Wonder", only shooting decently with Lyman #454490, a SWC/GC design.

A 45 Colt owner should NOT require either a gas-check boolit design OR a jacketed bullet to obtain decent accuracy at 1873 load levels--but those were the requirements in the OEM Ruger I have. As for factory warrantee.......I don't give a rat's aspirations about a warrantee that only covers revolvers in poorly-dimensioned OEM condition, and goes void when someone does things right in the aftermarket.

[Railbuggy]

I bought a bearly used RugerBH in 45lc thurday.I googled the gun for info,then calapered my throats.All looked to be .449.# showed it was made in 93.Guess Ill be sending cylindersmith a email.

[Dale53]

John Taffin said something (I believe on Lee Martin's Single Action Forum) that kind of caught my interest. He stated (or words to that effect) that he doesn't even slug the barrel. He has little interest in what the barrel measures. HIS emphasis is the cylinder throats. THAT he slugs and measures carefully and takes appropriate action (that's EXACTLY what we have discussed here).

I have been doing the same for many, many years. Then, I do serious accuracy tests. You can test with a Ransom Rest (I have access to a Ransom Rest) or over sandbags. I do initial testing at 25 yards then move to 50 yards. If it is a hunting handgun, I move to 100 yards for final acceptance.

If you are shooting with sandbags, it is very helpful to use a scope or Red Dot sight. If you have good eyes, however, you can do VERY good work with issue iron sights. Personally, because of vision problems, I have to struggle with iron sights. I can still shoot them, but it IS a struggle. Mostly, I now use Red Dots (primarily) or a scope.

The purpose of this post is to suggest that before you get EXTREME with lapping or firelapping the barrel, you might want to seriously try accuracy tests. I'm betting that lapping or fire lapping will not be required. I am still a bit leary of lapping or firelapping. I fully understand the theory but it is MUCH harder to lap what needs to be lapped and not damage what does NOT than to ream the cylinders with a good kit like the Manson reamer kit.

Just a thought or two...

Dale53