Cylinder reaming = accuracy

[Bluerock2000]

Had DougGuy ream the cylinder throats on an older baby Vaquero 32 mag and a New Vaquero 45 colt I just bought. I’d say it worked. Thanks Doug!

25 yard groups.




It’s also amazing to me how much more I prefer the Bisley grip. I’m more comfortable shooting full house Blackhawk loads in my 7.5” Bisley than +P loads in that 5.5” plow handled NV. But it sure does point well! Think I’ll keep it at 800fps; most critters in central TX don’t get much bigger than a Labrador.

[dondiego]

Had DougGuy ream the cylinder throats on an older baby Vaquero 32 mag and a New Vaquero 45 colt I just bought. I’d say it worked. Thanks Doug!

25 yard groups.




It’s also amazing to me how much more I prefer the Bisley grip. I’m more comfortable shooting full house Blackhawk loads in my 7.5” Bisley than +P loads in that 5.5” plow handled NV. But it sure does point well! Think I’ll keep it at 800fps; most critters in central TX don’t get much bigger than a Labrador.

You've never met my dad's Brahman Bull!

[Bazoo]

It looks like two inch group or so to me. What did it measure and what was it before?

[fredj338]

I have a Ruger BH/ss. The throats were coming in 0.4505" avg. The groups were not terrible, but I was getting leading in the first 2" of bbl. After having the throats reamed to 0.452", accuracy was about twice as good with virtually no leading.

[Bluerock2000]

It looks like two inch group or so to me. What did it measure and what was it before?

Yes both groups around 2”; I’m not done with load development for either yet. The 32 throats were .309, reamed to .3125. The 45 throats were around .451, reamed to .4525.

[Bluerock2000]

I have a Ruger BH/ss. The throats were coming in 0.4505" avg. The groups were not terrible, but I was getting leading in the first 2" of bbl. After having the throats reamed to 0.452", accuracy was about twice as good with virtually no leading.

Yeah some of mine were smaller than .451 as well. I didn’t even shoot the gun; sent it straight to Doug for reaming. It’s not fun to me to use a tool that doesn’t serve it’s only purpose for existing.

[fredj338]

Yeah some of mine were smaller than .451 as well. I didn’t even shoot the gun; sent it straight to Doug for reaming. It’s not fun to me to use a tool that doesn’t serve it’s only purpose for existing.

I am lucky to have a buddy that owns a grinding shop. He showed me how to use his honing machine, set it up for me & I did my own in about 20m.

[Larry Gibson]

Be nice to see some "before and after" groups with the same ammo at 25 yards?

[DougGuy]

Be nice to see some "before and after" groups with the same ammo at 25 yards?

The average improvement is about half. If you are getting 5" and 6" groups at 25yds, and cylinder throats are either undersized or different sizes, which the majority of Ruger cylinders I get in are one or both of those, you can expect about a 50% reduction in groups.

In addition to uniforming and sizing cylinder throats, taking the creep out of the trigger ala Bradshaw (reducing hammer pad height) and using a Wolff 30oz. trigger return spring, you can normally get 2" ~ 2 1/2" @25yds in most single action Rugers, it's not caliber specific it works for all of them.

[Bazoo]

I’m interested in the improvement if all the throats are already over bore diameter. My flattop 44 special has throats between .4312 and .4325. My bore is .4292. I’m getting 2.5” groups or so. So if I had my throats reamed to 4325, and sized bullets to .432, what could I expect?

Course none of my moulds drop .432. Most are .431. So I’d have to divest 5 moulds and buy all new from a custom maker. And I’d have to fine tune my expander plugs for that size. Would it be worth all that trouble?

[6thtexas]

DougGuy has done several cylinders for me and I have been very happy with all of them. He just did both cylinders of a Ruger Buckeye 32-20/.32 H&R for me I hope to shoot it tomorrow.

[DougGuy]

I’m interested in the improvement if all the throats are already over bore diameter. My flattop 44 special has throats between .4312 and .4325. My bore is .4292. I’m getting 2.5” groups or so. So if I had my throats reamed to 4325, and sized bullets to .432, what could I expect?

Course none of my moulds drop .432. Most are .431. So I’d have to divest 5 moulds and buy all new from a custom maker. And I’d have to fine tune my expander plugs for that size. Would it be worth all that trouble?

Shooting from a rest?

Uneven throats cause variations in pressure. It makes the gun recoil differently from shot to shot, having throats all honed the same lessens the variables which usually improves groups.

The only thing that can be done in your case is to hone them all the same, then size to fit the throats. The other thing you can do is use a soft alloy, like 50/50 and soft lube and if you are shooting over a magnum load, they will obturate to fit the throats before boolits even exit the front of the cylinder, so you may be assembling a .431" boolit but upon firing it bumps to throat diameter. It's not written in stone that you have to statically size to the throat, but best results happen when you size to fit the throats so, maybe use the biggest mold you have, and let pressure do it, won't take long to see how that works out.

You could send the gun back to Ruger sans cylinder and let them replace the cylinder, see if that doesn't give you an alternative that might be easier to live with.

My own experience when I first started reaming throats, I had a 70s SBH that had 3 pairs of throats, two at .432" two at .431" and two at .429" you would think I was shooting a shotgun when shooting cast. XTPs are jacketed with a dead soft lead core, they would very happily bump to fit the throats then swage into the bore at the forcing cone, and they took a LOT of game like that.

I ended up taking all the throats to .432" and then I was using some Lee C430-310-RF boolits cast in 50/50+2% so I final honed the throats to one of the boolits, and it shot like a million bucks! Then after about 4 or 5 months, I went to shoot it and most of the rounds I had loaded wouldn't chamber. Boolits had grown .0003" or so while they age hardened. At this point in time I figured out that a little "wiggle room" was needed, and .0005" to .001" over boolit diameter would allow just a little tolerance for some out of rounds, age hardened, bigger across the parting lines, etc, it needed room to accept my handloads and sizing too close didn't give any tolerance. I honed all the throats to .4325" and haven't had nothing but great results out of it since. I haven't cleaned the bore in that gun in years. There is no leading, it leaves a blackish gray residue that is lube and powder residue, but no leading. I call it "pre-seasoned" and the subsequent shots now have lube in the barrel that lubes the front of the boolit as it travels in the barrel.

I also recut the forcing cone, as this SBH was spitting a bit of lead out the barrel/cylinder gap, that went totally away and groups shrunk even more.

Sounds like your cylinder is pretty close to what mine was when I started on it.

Edit: I will add this as well. My avatar is a Uberti Old West model in 45 Colt. I was and am still VERY impressed with their attention to detail and how faithfully they replicated an 1877 Colt "Civilian Model" SAA. Only thing they didn't nail was the bore diameter, it is a modern .451" groove but cylinder throats were a faithfully copied .4565" and quite consistent. I shoot the 454190 in 50/50+2% sized to .456" and it is a fly's worst nightmare at 10 yards. Both this Uberti and the SBH are fed a diet of 50/50+2% boolits that I can scratch with a thumbnail. The SBH got Felix lube, the Uberti get SPG on the 454190. This is another one that I never have to clean. It just works. And yes I recut the forcing cone on this one as well. That's the ONLY work that got done, and I swapped in one of the coveted "cobra" Colt mainsprings while I had it on the bench.

[Bazoo]

Shooting position is seated back rested with left knee for support.

If you have consistent throats, at say .4325, but .430 bullets, why won’t it also be accurate? The pressure would be consistent for all of them.

[DougGuy]

Shooting position is seated back rested with left knee for support.

If you have consistent throats, at say .4325, but .430 bullets, why won’t it also be accurate? The pressure would be consistent for all of them.

If your boolits are soft enough they will work. If they are hard, going to get considerable gas cutting along the sides.

Oh wait you said bullets. Jacketed .430?" Try and see, they likely will bump up and won't even know they are being fired out of a .4325" throat.

[Bazoo]

Bullets of lead.

I forgot about gas cutting.

[Bluerock2000]

Be nice to see some "before and after" groups with the same ammo at 25 yards?

I don’t have a “before” for the 45 as I hadn’t shot it prior to sending it to Doug, but below is the last session I shot before sending the 32 off. The groups are numbered by powder used and are a fair representation of what the gun was shooting before. It’s not exactly apples to apples, but it’s close. I’ll also add that both guns would do better in the hands of a better shot; I’ve developed a bit of a flinch the last couple of years, mainly from a lack of shooting. I can call my bad shots every time. I intend to rectify that this summer.

Edit: this picture is load testing after reaming:



This picture is load testing before reaming:



And as Doug mentioned, he also honed the hammer on the .45.

[Larry Gibson]

The average improvement is about half. If you are getting 5" and 6" groups at 25yds, and cylinder throats are either undersized or different sizes, which the majority of Ruger cylinders I get in are one or both of those, you can expect about a 50% reduction in groups.

In addition to uniforming and sizing cylinder throats, taking the creep out of the trigger ala Bradshaw (reducing hammer pad height) and using a Wolff 30oz. trigger return spring, you can normally get 2" ~ 2 1/2" @25yds in most single action Rugers, it's not caliber specific it works for all of them.

Would still be nice to actually see the groups

[DougGuy]

Would still be nice to actually see the groups

Larry, there isn't another individual in this group any more scientifically qualified to do an A/B report on a shooting related subject than you. From pressure tracking to testing loads and noodling out the minute differences in powder, primers, you have a way of presenting facts that earns you great respect among your peers and yep I would count myself in that crowd.

I would suggest pick one of yours that you know could stand to be improved, shoot some groups with your control loads and send the cylinder this way. If it has creep in the trigger, send the hammer too, swap in a Wolff 30oz. trigger return spring and see how you like the results.

Pick one with uneven and undersized cylinder throats, this would accurately represent tens of thousands of factory made cylinders, guns that are daily drivers that people just do their best with because of the shortcomings in the manufacturing process.

[Mal Paso]

My learning gun was a S&W 629 with .428" throats. It was an intentional thing S&W did to improve jacketed performance which they seem to have dropped. The time frame was after Cylinder Smith but Before Doug and I wound up talking to Dave Manson and bought his .431" reamer. Performance went up as in actual fps over the chronograph and barrel maintenance went way down. I would say accuracy was better but that is opinion as so much depends on the operator. I tested 44 Mag in a Ransom Rest and don't think it is up to testing at that power level, I shot better groups and I am average.

[Bazoo]

I found an interesting thread https://castboolits.gunloads.com/sho...linder-throats where Larry offers some insight.

My interest is not in the reaming of throats that are undersized. That’s obvious. My interest is in with oversized throats. Why does everyone say size to the throats but there is Larry saying he doesn’t and has good results. But not just Larry, there are plenty of folks that get good results sizing to bore diameter, then when they measure their throats they are surprised that their throats are oversized. Those folks just don’t come on the forum and speak up because it’s not popular to size to bore diameter.