proper bullet diameter?

[Matt N.]

Over the years I have made multiple efforts to get a super Blackhawk to shoot cast bullets accurately and without leading issues. I now have another Super Blackhawk and I am working toward that goal again. The pistol I have now has a bore that slugged .427 and the cylinder slugged .430. I recently ordered some gas checked bullets with a BHN of 22. The gentleman I talked to when I ordered the bullets advised that I get bullets sized to .430, so that is what I ordered. Is this likely to achieve my goal? Or, am I in for more lead buildup issues in the bore along with poor accuracy?

Thanks.
Matt

[Old Caster]

There is more to having lead problems than just too small of a bullet. That is just one of them. Rough bore, sometimes too hard of lead for the velocity, and soft bullets being swaged down by the cartridge case causing them to be too small without the shooter knowing it. Some pistols can be out of time, which will cause leading between the cylinder and frame, on the frame just outside of the beginning of the barrel. -- Bill --

[geargnasher]

Old Caster speaks wisely. Thread choke is sometimes another big issue, a restriction where the barrel is torqued to the frame causing leading right after the forcing cone due to gas leaks from the boolit being swaged too small as it enters the barrel.

.430" sounds about right, but if you're going to use boolits as hard as 22 BHN, I'd plan on working up your loads to full power levels. Harder is not always better.

Gear

[dualsport]

Fit is king. How many times have we heard that one? It is the fundamental rule #1 of cast boolit shooting. The .430s will stand a very good chance of not leading, based on your measurements. The simple test for a revolver is pushing one thru a chamber with a pencil. Shouldn't drop thru but should be able to push thru by hand pressure, just snug. Works for my old SBH, I use .431. Those gas checked 22 bhns you ordered will be good material for full house loads. Something softer in a pb might seal better in lower pressure loads.

[MikeS]

Personally I think a BHN of 22 is way too hard. You should try some plain based boolits with a BHN of 14-16 or so.

[Shiloh]

Seems to hard to me as well.
but if it works....

Shiloh

[Matt N.]

Actually I do plan on using these for hunting deer and hogs, so accurate full power loads that don't leave behind too much lead are really what I am after.

[44man]

That sounds pretty small for a Ruger barrel! I never seen one .427". Might have a restriction at the threads.
I lay a good hardwood stick across the recoil plate, drop in a brass rod then an over groove size pure round ball. I upset it a little against the rod and push it back out.
Then I put one all the way through and compare them.
Hard boolits are fine in the .44, I use 22 bhn myself for deer.
Mostly what fellas do is to use softer to get through the restriction, then expand again to seal but I never found accuracy doing that.
There is not a smooth transition and the boolit can get gas cut before sealing, if it ever does. Only takes one gas cut groove to lead the bore. Anything soft enough to seal fast has already slumped. Then you have to contend with skid, more gas cuts!

[Larry Gibson]

Matt

I also think .427 is a little small. If you only used one slug it is easy to get an off measurement. I like to use a minimum of 3 slugs so if one of them is off by more than .0005 then I know I just messed it up with one.

It appear you use commercial cast(?) and you've had leading issues with those in the 1st revolver and now the second. I would say it's not the Rugers but the lube on the commercial bullets. I have shot lot’s of commercial cast and many of them give leading problems with the hard wax lubes used. LaserCast uses a very good lube these days that doesn’t give leading even down at 600+ fps in CBA loads. I just finished an extensive test of CBA loads in .32, .38, .44 and .45 cals with their bullets and got no leading at all. An excellent softer cast bullets (20-1 alloy) with an excellent lube are the Desperado bullets out of Dayton, WA.

It is not the “hardness” either, but the lube that causes the leading. I have soaked (30 minutes) thousands of the commercial cast in Coleman fuel to wash of the lube and then relubed with LLA or preferably with Javelina, BAC or other 50/50 lube and never got any leading with low end to magnum level loads. This was with commercial cast of .429 of numerous makes.

Fit may be king but sometimes it will make you the court jester by chasing it. I have shot a bajillion .429 and .430 sized cast bullets in numerous .44 magnums over 40+ years with excellent accuracy and no leading. In many with even up to .433-.334 throats they shoot just as well as cast bullets that “fit”. I just size all my .44 cast at .430, load’em and shoot’em with the same accuracy and performance as cast bullets sized to “fit”. I do have to size bullets for my Colt Anaconda at .429 or they will not chamber in the .429 throats. That Colt also has a .429 barrel and is the most accurate .44 I have ever had. Not to say my Ruger with the .429 barrel and .431 throats won’t give it a run for it’s money. My old Hawes with a .4295 barrel and .433 - .434 throats does as well with .429 and .430 bullets as with .434 sized bullets. Sometimes having bullets sized to larger throats actually are less accurate because they get beat up and sized to much in the forcing cone and smaller .429 barrels. I think the bases get distorted too much.

Anyways, if those GC’d commercial cast are leading then look at the lube as the culprit.

Larry Gibson

[Matt N.]

I agree it would be a good idea to slug the bore again. BTW, I have not shot the gas checked bullets yet. I thought I would check to determine the probability of success before shooting.

[geargnasher]

Matt, does that thing have a five-groove barrel? Also, check the slug by measuring across the edges of the groove impressions on the slug, the bottom of the grooves on some Rugers are cut on a larger radius than groove radius, so the slug measures smaller on the center of the groove than on the edges. Or like we've said, it could have a massive thread choke. You need to measure the thread choke for sure to see what you have.

Gear

[runfiverun]

ruger must go through cycles with this throat [bbl constriction] thing.
or changes something in the machinery.
or uses different machines for the different steels.
i have several rugers most don't have a bbl throat issue,one has a couple of undersized cylinder mouths that affect accuracy and i have no leading with it.

[Matt N.]

I have measured that slug many times now and the largest measurement I can get is .427. I count 6 grooves.

[Larry Gibson]

I have measured that slug many times now and the largest measurement I can get is .427. I count 6 grooves.

If that one slug came out wrong you can measure it six ways to Sunday and it will still be wrong. Suggest you reslug with 3 new slugs making sure all are at or over .435" before slugging. Then measure all three.

Larry Gibson

[ShooterAZ]

Did you measure slugs with calipers or a micrometer? Calipers are not as accurate.

[geargnasher]

ruger must go through cycles with this throat [bbl constriction] thing.
or changes something in the machinery.
or uses different machines for the different steels.
i have several rugers most don't have a bbl throat issue,one has a couple of undersized cylinder mouths that affect accuracy and i have no leading with it.

I know for a fact that Ruger updated their barrel fitting methods a few years back, probably wasn't the first time they tried to streamline this time-consuming and tedious task. I don't know what method they use currently, but measuring and sorting the barrels and frames each into three piles and mating those up by torquing to degrees rather than to yeild point or friction force will give a wild variance in amount of thread crush from one gun to the next.

The problem with the cylinders is the gang-boring. At any given time there might be three new bits two worn out bits, and a resharpened, undersized bit in the mix, or any combination therof. If you're lucky enough to get a revolver with a cylinder bored right after a reamer change, you'll have a good one. OR, you could have one like I typically encounter, three or more grossly undersized holes, and at least one badly out-of-round hole because of a worn bearing in the gang-boring head. This cylinder boring process saves lots of time and allows Ruger to sell us their guns on a lower "price point", but quality suffers as a result. The cylinder throats can be uniformed easily, but if they're not all accurately bored in line with the barrel, that's a job for an expert revolver tuner to fix.

Gear

[Matt N.]

Did you measure slugs with calipers or a micrometer? Calipers are not as accurate.

Yeah. I measured the slug with calipers. I will try to come up with a micrometer and re-slug the barrel.

What if the barrel does measure .427?

Thanks.
matt

[Larry Gibson]

What if the barrel does measure .427?

Best to cross that bridge if we come to it, we can "what if" ourselves silly.

However, a .427 barrel with .430 throats should shoot .429 or even .430 cast bullets just fine.

Larry Gibson

[Matt N.]

I recently shot this pistol with 296 and 240 grain XTPs. Interestingly the point of impact was so high at 25 yards I could not sight it in. this leads me to think the bore is .427.
The accuracy was poor too. So I am thinking there is a constriction.
Send it back? Or is there a solution?
Thanks.
Matt

[geargnasher]

What if the barrel does measure .427?

Best to cross that bridge if we come to it, we can "what if" ourselves silly.

However, a .427 barrel with .430 throats should shoot .429 or even .430 cast bullets just fine.

Larry Gibson

+1.

My money's on a .427" groove in the frame area and .429" the rest of the way, with maybe a constriction at the top of the barrel under the front sight and another one where all the roll-lettering is on the left side of the barrel. I have a New Vaquero that had .448" at the frame, an elliptical .450"x.451" at the roll lettering, and about half a thousandth crush at the front sight. After reaming and hand-lapping the thread choke out, it woulds still streak lead after the lettering and again after the front sight right at the top for the last 1/4" of the muzzle. I finally gave up and firelapped it into submission, it's now about .4515" the whole way and I reamed/polished the cylinder throats to a uniform .4527" and re-polished the forcing cone with a lap. It shoots great now on five holes, the sixth always flings one, I think it doesn't line up right with the bore. It's marked and loaded so it shoots last.

Gear

[Larry Gibson]

I recently shot this pistol with 296 and 240 grain XTPs. Interestingly the point of impact was so high at 25 yards I could not sight it in. this leads me to think the bore is .427.
The accuracy was poor too. So I am thinking there is a constriction.
Send it back? Or is there a solution?
Thanks.
Matt

Matt

Don't get offended here because I am trying to help.

There is always a large vertical change in POI between a light cast load and a heavy load, especially with a load of 22-23.5 gr of 296 under a 240 XTP(?), with a revolver such as your BH. If the sights are cranked up for the lighter cast bullet zero the zero can be as much as 12"+ different at 25 yards. Also the 240 XTP over a top end load of 296/H110 has always been the most accurate load in every .44 I've ever shot it in and that's been quite a few.

I would suspect in your shooting you did not rezero and you were looking for bullet holes instead of focusing on the front sight. Our mind makes us do things like that when we suspect the problem is the gun. In reality we are more the problem than the gun.

I suggest you reslug the bore with at least 3 slugs as I suggested earlier. That will tell us if the barrel is really a .427 grooved one. If there is a constriction consider shooting 200 - 300 rounds of magnum loads (the 296/XTP load would do fine) to "break in" the revolver. Run the rear sight to 5 clicks from the bottom and zero from there. I have yet to find the dreaded constirction after such a break in with any 44 magnum revolver, or any other revolver for that matter. I have yet to fire lap a new revolver or return one as having a "defective" barrel either.

Lastly we have no idea of what you shooting ability is or what "poor accuracy" means. Are you shooting off hand or with a rest....we do not know? Let me suggest you take 50 of those hard commercial cast GC'd bullets (assuming 240 - 250 gr) and load them over 9.5 gr of Unique. Shoot them for group at 25 yards using a solid bench rest with a sand bag front rest. Take your time and focus on the front sight and shoot several 10 or 12 shot groups. That will give us a much better idea of the accuracy capability of the BH and you together.

Will you get any leading was your original question? Well that is going to depend on the lube the commercial maker used on those bullets. Some makers are using much better lubes than the hard wax ones they used to and leading is minimal if at all. Considering you are using commercial cast bullets i would suspect the lube way before I suspected anything wrong with the revolver.

Larry Gibson

[luvtn]

Matt

I also think .427 is a little small. If you only used one slug it is easy to get an off measurement. I like to use a minimum of 3 slugs so if one of them is off by more than .0005 then I know I just messed it up with one.

It appear you use commercial cast(?) and you've had leading issues with those in the 1st revolver and now the second. I would say it's not the Rugers but the lube on the commercial bullets. I have shot lot’s of commercial cast and many of them give leading problems with the hard wax lubes used. LaserCast uses a very good lube these days that doesn’t give leading even down at 600+ fps in CBA loads. I just finished an extensive test of CBA loads in .32, .38, .44 and .45 cals with their bullets and got no leading at all. An excellent softer cast bullets (20-1 alloy) with an excellent lube are the Desperado bullets out of Dayton, WA.

It is not the “hardness” either, but the lube that causes the leading. I have soaked (30 minutes) thousands of the commercial cast in Coleman fuel to wash of the lube and then relubed with LLA or preferably with Javelina, BAC or other 50/50 lube and never got any leading with low end to magnum level loads. This was with commercial cast of .429 of numerous makes.

Fit may be king but sometimes it will make you the court jester by chasing it. I have shot a bajillion .429 and .430 sized cast bullets in numerous .44 magnums over 40+ years with excellent accuracy and no leading. In many with even up to .433-.334 throats they shoot just as well as cast bullets that “fit”. I just size all my .44 cast at .430, load’em and shoot’em with the same accuracy and performance as cast bullets sized to “fit”. I do have to size bullets for my Colt Anaconda at .429 or they will not chamber in the .429 throats. That Colt also has a .429 barrel and is the most accurate .44 I have ever had. Not to say my Ruger with the .429 barrel and .431 throats won’t give it a run for it’s money. My old Hawes with a .4295 barrel and .433 - .434 throats does as well with .429 and .430 bullets as with .434 sized bullets. Sometimes having bullets sized to larger throats actually are less accurate because they get beat up and sized to much in the forcing cone and smaller .429 barrels. I think the bases get distorted too much.

Anyways, if those GC’d commercial cast are leading then look at the lube as the culprit.

Larry Gibson

Thanks for the info on the Hawes. I just bought one 1 month ago. It shoots great! While I was checking out a new Blackhawk, I did the same for the Hawes. A .430 cast bullet just drops right through the cylinder. It had me all concerned, til I realized it is a shooter. Your info coroborated what I'd found.

Regarding the OP. A boolit witha BHN of 22 doesn't need a gas check in my opinion.
lt

[454PB]

I must be really lucky. I've owned (or own) over a dozen Rugers in the last 40 years and have never had one with mismatching throats/bore. My BH 45 Colt convertible was built in 1980 and has .453" throats and a .452" barrel.....and these were supposedly one of the worst offenders. A couple of them "seemed" to have a slight restriction at the breech end, but after 500 rounds, it disappeared. I never attempted to measure how much restriction, I could just feel it with a tight cleaning patch.

I'm a gas check junky. I got hooked on them many years ago when I started shooting .357 magnums and had leading problems at anything over 1300 fps. I still use them for top end .454 Casull and some light boolit .44 magnum loads, and ALL of my rifle boolits with the exception of 45/70.

I have never seen leading while using gas checked boolits in anything. What I have seen is groups start opening up at velocities of 2400 fps and up. My .222 will still shoot 2" groups at 100 yards pushing a 55 grain RCBS gas checked boolit at 2700 fps., but that is an exception.

Now that gas checks have become so expensive, I've started reducing my use of them as much as possible by reducing velocities, but generally speaking my guns shoot tighter groups when their boolits wear boots.

[Matt N.]

Hey Larry G.
I am defiantly not offended. I appreciate the assistance. I have yet to try cast lead in this pistol. I recently purchased the gun new from Buds. All I have shot through it so far is the 240 gr XTPs. So far it shoots best with 23.5 grains of 296, but the poi is so high it will not sight in at 25 yards. So I am working on an original sight in, not a re zero load difference issue. I guess I could shoot long range with it (lol).
As far as my accuracy requirements go and my shooting. When developing loads I shoot 5 shot groups off a bench and rest. My Super 7.5" Redhawk shoots 1 inch groups at 50 yards (it's scoped), my .44 mag Contender shoots 1.5" at 100 (it's scoped too). I don't remember what kind of groups my 4" 629 shoots but I remember they were good, and I remember nailing a 8 point buck at 47 yards off hand with it.
I like the idea of shooting about 300 rounds of stout xtp loads.
I will re-slug. I need to obtain some more lead goof for the task first.
Thanks.
Matt