Ruger Super Blackhawk Hunter way out of spec.

[g20gunny]

I have a newish Super Blackhawk Hunter in 44 mag, I have been working and working on this dumb thing trying to get a load to shoot well. The problem lies in the .4365 cylinder mouths and the .4355 bore, logically this should be a fine relationship between cylinder and bore but my .437 bullets (thanks Accurate Molds for a beautiful mold) bulge the brass too much to chamber.
The only load I have had mediocre success with is an undersized bullet and powdercoat which I hate to do when I could skip that whole process with a correct cylinder/bore.
I guess my question is has anyone had to deal with this? it seems like a $750 revolver should be a little closer to spec. I have contacted Ruger awhile back and they want me to pay to ship it to them with no guarantee of repair. All they have to do is say it is within their tolerances and charge me to ship it back.
I have never shot jacketed bullets out of it and don't plan on it but can't imagine it will give good results.145758145759

[DougGuy]

How are you gathering these measurements? Your figures are what seems way out of spec. I seriously doubt your bore diameter is any bit larger than .431" and since they don't even MAKE a .44 caliber throating reamer that will cut a throat that big, something is definitely amiss.

Ruger barrel diameters have been very consistent over the last 30+ yrs, the .44 caliber barrels are usually .429" or .430" and I personally have never measured so much as a .432" on a Ruger .44 caliber revolver even from the very early ones. It is RARE that you get a .431" barrel. It is more common that someone with a .430" comes up with a .431" measurement but a .435? No way.

I do a lot of cylinder throat work for members here, if you want to send the cylinder I would be more than glad to take a look at it and measure it with pin gages, this is the *proper* way to gauge a cylinder. Going by my experience, I would be willing to speculate that your cylinder might have uneven throats, which is VERY common, but that none of them would be over .4325" which is about perfect to use .432" boolits with. Likely you may have two throats that are larger than the others because Ruger gang reams these with a machine that uses 3 reamers, each cuts two throats, and they are rarely ever the same size since they replace these reamers one at a time as they wear down. 3 different sized reamers from normal wear at the factory = 3 pairs of cylinder throats, all different diameters.

Btw, welcome to the forum..

In a perfect world, the Ruger revolver would have dimensions that read somewhat like a funnel. The largest dimensions at the back, and getting progressively smaller as the boolit finds it's way to the muzzle. This way the boolit is always being subjected to a smaller sized opening it must pass through, insuring a good seal against powder gases escaping along the sides causing leading and deteriorated accuracy.

Boolit diameter should be at the very minimum equal to groove diameter of the bore, but for best results, .001" ~ .002" over groove diameter works like a champ. To keep these boolits from being sized down or swaged down by tight cylinder throats (which the un-altered factory Ruger cylinder is very well known for) it is usually necessary to ream these throats to an even size, generally .432" will take care of most Ruger cylinders, but about half can be evened out using .4315" throats. The boolits should then be sized .0005" to .001" below throat diameter.

Unless your revolver has a severe thread choke where the barrel screws into the frame, it should be a decent shooter once the throats are inspected and/or worked over so they are 1.) even with each other, and 2.) larger than groove diameter.

It generally does not take much to get a Ruger to shoot. Cylinder throats corrected, forcing cone cut to 11° and a lighter trigger return spring swapped in is about all you need to do to the revolver. The rest lies in the shooter's skills at the loading bench AND how well he/she can shoot a single action revolver.

[Ickisrulz]

Those seem like a lot of really big numbers. Are you sure you measured your cylinder and bore properly with a micrometer? I think most people size their 44 bullets to .429 or .430 and just shoot them (I know I do). Have you tried that? I have tried sizing my bullet to .432 and then they did not fit in the cylinder, so they I went smaller. Keep in mind, Ruger makes their guns for jacketed bullets not cast lead. We have to make lead work.

[DougGuy]

I have tried sizing my bullet to .432 and then they did not fit in the cylinder, so they I went smaller.

Your cylinder has tight throats. A .432" boolit is in itself a pin gage, and can be used to measure with just like a hardened ground gage pin.

[Ickisrulz]

Your cylinder has tight throats. A .432" boolit is in itself a pin gage, and can be used to measure with just like a hardened ground gage pin.

I cannot argue with you. But I just go with the .430 and it works fine for my level of shooting. There is no real leading to speak of and I am happy.

[g20gunny]

I used a dial caliper. I assume this is how most people measure. I updated the original post with photos.
I started originally with .430-.431 boolits but leaded to the point of pulling lead cornflakes out with my jag. A .431 bullet will fall out of the cylinder freely.

[Walkingwolf]

Slug your barrel/chamber throats, and then measure those. When using dial calibers it is important not to use pressure when measuring or you will receive false readings greater than actual. Personally I would use a micrometer to measure your slugs instead.

Rugers also tend to have chambers to spec exactly for jacketed bullets. But the throat will have some leeway for the ogive of a cast bullet, which is usually .001 larger. You will need to seat your bullets to where the ogive meets the bearing surface not extended to far into the lead.

If you have a quality jacketed bullet you should be able to push it through the throat with some force. If so you are on the money.

[DougGuy]

Dial calipers serve no purpose measuring across an internal bore. They give you just enough info to get in trouble with.

If you get even a cheapo but decent micrometer, you can clean and oil the cylinder throat, then drive a dead soft lead ball through it and mic that, it will be much more accurate but even with that the anvil will tend to make a small flat spot on the round lead slug which makes it also inaccurate. The way to measure a slug is to have a curved shim of a known thickness on either side and subtract that thickness from the reading. You can make these from a brass case.

Same with slugging the bore, clean it and lightly oil it, drive a soft lead ball through and mic the ball. If you got a ball not quite big enough just smack it with a hammer it will grow.

Pretty much slugging the bore isn't necessary, it most definitely will not be any bigger than .431" and I say that because this part is one thing Ruger IS known for.

This is why pin gages are the correct measuring method. You can use a boolit as well if you know what it's diameter is.

Will a .432" go into your throats? Some but not all of them?


As far as seating depth, load data has specific LOA data because it is critical due to the immense pressure of the .44 Rem Mag cartridge it is important to not vary from this given measurement because seating deeper to accommodate a tight cylinder throat only serves to compound things by creating a much more dangerous second problem as a workaround to the first. You can easily blow up a gun by arbitrarily choosing a shorter LOA or COA when the proper thing to do is have the cylinder throats reamed to accommodate the boolit you want to use.

Cylinder throats are a tool. A guide. They guide the boolit from the case mouth to the forcing cone. They should be snug fit but not smaller than the boolit. If they need to be adjusted or corrected, this is a common thing to do it's no big deal, it almost comes as mandatory in setting up a gun to shoot cast booolits. Fit the throats to the boolit. NOT the other way around.

[williamwaco]

Before you waste any more time, try a .430 diameter bullet. Bought my first .44 mag in1956. Lost count of how many i have owned. Ruger, Smith, TC. Never owned one that wouldn't beat 2" at 25 yards with a .430 bullet.


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[DougGuy]

OP one thing you CAN do with your bore that is useful, once you got it clean and dry, take a cleaning rod and a plastic or brass jag and patch it really tight in the bore. Push this through the bore and observe how much effort it takes to keep the jag moving. When you get down to the part where the barrel threads into the frame, if the jag gets really hard to move, you are feeling the thread choke. When Ruger torques these barrels to the frame, they use a compression thread that causes the inside of the bore to become squeezed down smaller than the rest of the barrel.

Depending on how bad this choke is, pretty much dictates how your gun will shoot. If the jag stops completely and has to be beaten through, it's severe. If it gets marginally tighter and you can still shove it through, it's not too bad and at the worst may need firelapping. IF you cannot feel a change in how hard the jag is to push, there is NO CHOKE and you should jump for joy because this gun is not limited to how well it will shoot because of a choke. If there is not change, your gun can be made into an excellent cast boolit gun.

[MrWolf]

Great info DougGuy, thanks.

[g20gunny]

Thanks for the info guys, lots of good knowledge here. I will try a few of the methods mentioned.
DougGuy, it did have severe thread choke, soo bad that it was visible with the bare eye so I had it Taylor throat reamed and that helped a lot.

[DougGuy]

Thanks for the info guys, lots of good knowledge here. I will try a few of the methods mentioned.
DougGuy, it did have severe thread choke, soo bad that it was visible with the bare eye so I had it Taylor throat reamed and that helped a lot.

Heh when they are that bad yes you can see it like a hazy ring about 3/4" in from the forcing cone. One of mine was that bad and I Taylor throated it too!

Send me the cylinder and you will get it back evened out and at least pinned so we can figure out exactly what we are dealing with. Something in the combination is not matching the rest of it. That gun outta put 6 into about an inch and a half at 25yds all day long. Mine will.

[44man]

You can NOT measure with calipers!
Listen to Douguy.
Pin gauges or pure lead slugs and you can't even measure them with calipers, need a good mike to .0001" readings.
You are WAY,WAY oversize with .437" boolits.
Never seen a Ruger groove over .430"

[spfd1903]

I have a Super Red hawk in .44Mag which has the correct cylinder throat dimensions and forcing cone finish to shoot cast boolits with accuracy. A New Model Vaquero, and a New Model Blackhawk, in .45 Colt, have both benefitted from work by DougGuy. I just sent the cylinder to him for the Vaquero, and fire lapped 40 rounds to date to smooth out the barrel crush. I sent the whole Blackhawk revolver in to have the cylinders honed, and the forcing cone recut to 11 degrees. It is amazing how much these pistols have improved for cast boolit shooting! They both shot Hornady HP/XTP's very accurately before, but had dismal performance with boolits. Not anymore, thanks to DougGuy.