Should I Slug My Ruger #1 Barrel for Cast

[Billy Jack]

This forum taught me the importance of slugging my revolver barrel and cylinder throats before ordering cast boolits and that knowledge has served me well.....THANKS

I had planned to slug the barrel of my Ruger #1 in 45-70 also, but my bullet guy says it should be .458" and I will be fine with a .459 bullet.

Based on my revolver experience I was leaning more toward a .460 bullet for the 45-70. BTW I am planning to use 400-500gr in old fashioned loadings, not hot Ruger loads, my shoulder is at least as old as I am!

I'll probably go ahead and slug the barrel anyway as I am a "nit-picker" by nature, but I would love to hear comments on others experiences.

 

[Silent Sam]

I wouldn't bother unless you end up w/ "issues". You don't have the same situation w/ a rifle as you do w/ revolvers. The throat is part of the barrel and there isn't the possibility of a restriction from screwing the barrel into the frame.

 

[jerkface11]

You might as well slug it. Poorly sized bullets will lead the barrel worse than correctly sized ones.

 

[mavracer]

My understanding is that any gun made in the US since the late 50s has to meet SAAMI specifications for chamber size and bore diameter. bore diameter is held to .0005" so I'd follow your bullet guy's advice.

 

[dprice3844444]

go ahead and slug it.save having to reorder the correct bullets if your wrong

 

[Lloyd Smale]

mine does a bit better at 461 but its not a huge improvement.

 

[Jim Watson]

A cast to get the throat diameter would be helpful.
I didn't do it for my Browning .40-65 and had to work my way up in sized diameter til I got to .411" (in a nominal .408" barrel) for best accuracy.

 

[Billy Jack]

I used #8 egg sinkers to slug my 44 barrel and they are too small for the 45-70 so I assume just buy the next larger size. Anyone know off hand what size egg sinker that is?

I have not researched doing a casting of the throat diameter, but it makes perfect sense. Is it a simple home shop job or does it require special expertise?

 

[jerkface11]

Just buy some cerosafe and follow the instructions.

 

[Billy Jack]

I have slugged the barrel and it is about .4585 as best I can measure. However I can definitely feel the tight spot at the front sight, the barrel band for the sling swivel, and also at the rear sight. This makes me think that the rest of the barrel is slightly larger. If I fire lap or shoot a bunch of hot jacketed through the barrel it should all be slightly above the .4585.

At the .458" spec for the Ruger, my bullet supplier recommends a .459 cast bullet; but I am thinking I might should try a .460 bullet and plan on taking out the tight spots.

When I bought the used (but almost never shot) Ruger it came with 6 boxes (120 rounds) of jacketed bullets. Some std load 405gr 1330fps, some std load 300 gr 1810fps, and some hot PMC loads at 350gr 2025fps. If I concentrate on shooting all that jacketed stuff up for the brass will it smooth out those tight spots to some degree or do I need to order some of Veral Smith's lapping bullets to get the job done right?

 

[Jim Watson]

I don't think shooting jacketed bullets will even out tight spots in a barrel.
I have done fire lapping with the Tubb outfit and cannot tell that it made much difference other than making the barrel a bit easier to clean, but that was on a bolt action with nothing done to distort the bore.
With three detectable tight spots, it might require hand lapping which is way out of my experience.

My Ruger No 1 .45-70 was quite accurate with jacketed bullets but I never got good results with commercial cast bullets.

I'd go ahead and shoot some .459 and .460" cast as is and see how they go. Get all the copper fouling out of the bore before shooting lead.

 

[ultramag44]

Lead is a dead metal. Once it passes a tight spot, it will not "slug up" to fill the larger area. A gliding metal jacket will spring back a bit.

Be glad the muzzle is tight. That is the most important spot as far as accuracy is concerned in a rifle shooting lead alloy.

If the chamber/leade will permit it, .460 would be nice. If not use the .459 the dealer recommended.

The Ruger single-shot is not a Benchrest gun. Don't expect a zero group from it.

A tight fit of the threads in the receiver can and will restrict the leade. As you learned, the bands will restrict the bore. The restrictions in the leade and sling band can be lapped out by an expert. NEVER remove the tightness @ the muzzle. Read Bill Calfee's book. It explains this in great detail.

 

[Billy Jack]

Good points about the muzzle being undersized and a good thing.
So as it is now there is a good chance that the bullet will size to the first restriction then be at that size at it leaves the muzzle, but very very slightly loose in between.
Sounds to me like I should order .460 bullets and skip the fire lapping step and just go with it.
It is all academic and just for fun anyway as with my 68 year old eyes (five times operated on) and iron sights, I'll be shooting "minute of Hog" at 50 yards anyway. I just like to "get into the process".

 

[Skylerbone]

The only way to accurately hand lap a barrel is to do so when in blank form before either end is cut to ensure consistent pressure. Doing so afterward can ease cleaning considerably and IME, gives better consistency between shots. I prefer a constant diameter bore (or as close as possible) but if there is to be a "tight" spot then yes, the muzzle would be the best place, assuming it's concentric and not simply a deformation caused by the front sight. For your purposes, I'd recommend fire lapping it and re-cutting the crown.

 

[Lloyd Smale]

Most ruger 4570s do best with bullets sized 460-461. One thing to keep in mind too is youll get your best accuracy with the bullet seated out. Most were throated real deap. Not as much so as the 458s were but still pretty deap.