Did some barrel slugging last night

[AtlLaw]

As well as some throat measuring.   

Since I had the SAA's out I after I took their picture with my new Winchester (Uberti) '73, I figured what the heck.  I'd never checked their bore/throat measurements before, I'd just put whatever rounds I could get cheapest down their snouts... and that hasn't been many over the years!      I've long said my pistolaro days were over, old eyes and all that, but now I find myself getting back into it with a vengence!  Something else to thank GBO for!   

Anyway, the bore on the oldest one, an EMF Dakota over 30 years old, slugged out at .4522.  All the throats measured an even .456.

The other, a much newer Uberti, slugged .4517.  Interestingly enough, the throats were a uniform .455.

I say interestingly because it struck me that the newer revolver's .001 smaller bore, say .451 vs. .452 just for the sake of argument, was accompanied by  a correspondingly smaller (.001) set of throats.   

I figure I'll just use .453 diameter, 250 gr. RNFP's for all my shooting with these two and call it close enough!     I ordered a hundred last night.  Unfortunately I could only get ones sized .452.     But the good thing is when I do get the .453's I have something to compare them to!     If I can ever get any LP primers that is... 

[Glanceblamm]

Interesting indeed!

All of my revolvers are six years old or newer cept for a couple of rimfires along with single shot & cap n ball black powder that I have owned & shot for several years.

The centerfires are as you say though, Slightly smaller bores but with correspondingly smaller throats. At least it is good to see that my barrel slugs are a perfect slip fit in the cylinders. Gives one something to work with.

[AtlLaw]

If I had my 'druthers I'd Like to see the throats a couple of thousanths smaller.     But what the heck!  I don't even remember how these pistol guns shoot!  I may be pleasantly supprised!   

[44 Man]

Atlaw, my old EMF Dakota (Jaeger) had the same issue.  The barrel was 451 even, but the throats were from .458 to .460!  It would pattern 18" groups at 15 yds.  I finally got it to shoot by useing .250 gr 'unsized' bullets made for the .458 bore of a 45-70.  It would shoot very well with those, BUT it would also shoot 8" high.  I obtained another cylinder for 45 acp and that had .452 throats and shot excellently and right to the sights.  I should have bored the acp cylinder out to 45 lc, then put a higher front sight on the gun.  It was engraved and very beautiful.  But I got tired of messing with it and sent it down the road.  Knowing what I know now, I wish I had that one back.  You should have good results using the soft lead Remington bullets that they use in the factory loads.  Those are available as a reloading componet and you might give them a try.  Or obtain a cylinder with the proper .452 throats, those are available for a reasonable price and are easy to fit.  Good luck with her.  44 Man

[AtlLaw]

An interesting note in Brian Pearce's Q&A column of the August issue of handloader.  This person had a Colt SAA with a .452 barrel and .455/.456 throats!     Sound familiar!?   

Anyway, he wanted to know if he could use cast bullets sized .455 without pressure concerns.  Pearce basically told him to go ahead and do it.

I wonder what the writer's problem with smaller (I assume .452/.453) bullets?     Accuracy?  leading in the forcing cone?

Any ideas?

BTW, sure is nice to know my "clones" are right there dimension wise with jen-u-wine Colts!   

[44 Man]

You said it; Accuracy!  When my bullet fit the barrel but not the throats, they would pattern.  It seems that the bullets have the opportunity to rattle or tip in the throats and may hit the forcing cone at an angle.  Not much, but enought to ruin accuracy.  Try it both ways, but I'm sure you will find that with the bullets sized .454 will be much more accurate.  Pressure with lead bullets is not an issue.  44 Man

[Hank08]

Same thing I've found, bullets need to be sized to the cylinder throats, not the barrel.  Seems that at one time or another every manufactuerer has made some cylinders with oversized throats.  Ruger had some large ones but shooters have complained until now they seem to be
making they the correct size.  I once had a 32/20 that was rebarreled with a .308 barrel but it still shot best with .313 bullets (.313 throats).
H08

[AtlLaw]

I took the 2 SAA's to the range yesterday - along with 4 rifles!  At least I was very pleased with the way the revolvers shot... 

I didn't expect much as I was shooting up a bag of Georgia Arms cowboy ammo I've had for years; 250 gr RNFP's in Starline brass.  But at 25 yards both shot nice little groups (little for me anyway), albeit not to point of aim.     However, I'll worry about that problem after I settle on a bullet and load.   

Actually, they both shot way better then my 2 inch Taurus 44 Mag shot before I opened the throats up on it!     I can't help but wonder how well they will shoot if I can get some bullets sized to .455!?   

BTW, velocity from my 3.75 inch and 5.5 inch barrels averaged 728 FPS and 734 fps respectively.

[Flint]

Beyond accuracy, the worst effect the large throat had had in my experience is leading.  I have several Colts, whose throats are all in the 457 diameter range, which would be appropriate for the pre-war bore of 454, but Colt never changed the chambers when they changed the bore after WWII to 450/451.  The chambers themselves, as well as the throats are oversize.

I think the oversized throat alllows propellant flame to get around the bulllet base before the bullet is past the forcing cone and overheats the lead, and leads the bore.  The only cure I've seen is to use Moly coated bullets, such as Bear Creek brand, the flame doesn't seem to affect the bullet as much, at any rate, they don't lead the bore. 

Another, expensive cure would be a new cylinder, rechambered with a smaller throat, no more than 453 or so.

[jandbn]

Something to keep in mind with cast bullets is that if the lead is soft enough, case tension might decrease your diameter during seating. You might think the bullets are a .001-.003 larger than barrel grove when you cast or purchase lead bullets, but by the time soft lead bullets are seated and crimped in the case, they might not obturate in the barrel and "rattle" through the barrel creating shotgun patterns.

[S.B.]

If I had my 'druthers I'd Like to see the throats a couple of thousanths smaller.     But what the heck!  I don't even remember how these pistol guns shoot!  I may be pleasantly supprised!  

I agree with this thought. Far too much attention is being payed to printed advice instead of how a certain gun shoots? Every gun is an indivigual unto it's self.
Steve

[AtlLaw]

And they both shot just fine thank you very much!      Matter of fact I'm gonna take them out again today and work on a GP load.  Got some 250 gr RNFP's loaded up and am looking for a handload that will do as well as... or better  , then the old coyboy action loads I tried in them!

[huntswithdogs]

When I got my Ruger 45LC, it came with around 300 of those GA Arms rounds. 250 gr bullets in Starline brass. Didn't shoot worth a piss! Went bang and sometimes found the paper at 20-25 yds. I'm currently loading the same brass with a 255gr LFP that a friend molds for me and pushing them out at around 900fps. Accuracy is there now and the leading has stopped.


HWD

[AtlLaw]

I'd had those laying around for quite some time and was just shooting them up for the brass.  I got to say I wasn't real impressed either with the accuracy out of the rifle .   

Yesterday was the first chance I have had to try some of my own loads in the SAA and M-73.  I'm much happier now!  Trust me!   

I'm using a 250 gr. - .452 - RNFPPB, Starline brass and 2400.  Got a hunting load right now but I'm gonna play some more and make sure it's as accurate as I can make it.