500 S&W, Cylinder throats too tight

[Joe C]

I have been trying the search function , but not having any luck .

I have a 500 SW , and I think I need to try to open up the throats on the cylinder a bit .

I'm getting some leading , starting about 2" down the barrel.
These are not heavy loads, mostly 1100 -1200 fps. using wheel weight metal,(starting low, and working my way up)

The cylinder throats are .4995" diameter(slugged) ,and the groove diameter averages .5012-.5014
The cylinder will not take a .5002 pin gauge , and "just" takes a .4992 gauge .

I'm looking for some info on either buying a throat reamer . or finding someone who can cut the throats for me .

I am going to experiment with it a bit more before having the throats opened up , only have about 100-150 rounds thru it so far .

I did not see any leading at first, when I was shooting some light trailboss loads at 800 fps . (475gr bullet). but when bumping them up to 1100 fps or so (using 4759 powder) , I started to get some leading partway down the bbl .

I doesn't show up much in the forcing cone area , starts further down .

I am shooting a plain base NOE / John Ross design 475 gr bullet ,cast of wheel weights, with LBT blue (soft) lube .
They were sized to .501 but guess it doesn't matter , they are .499+ after coming out of the cylinder .


When I slugged the barrel , I did not notice any tight spots after pushing it thru the muzzle , not even at the forcing cone area .

Just looking for some info in advance , as my searches didn't turn up any reamers , at least not listed on the manufacturers web sites ( I know that doesn't mean they don't actually have them) , or any one doing the
500 SW cylinder I could send it to .

thanks in advance

Joe

[DrCaveman]

My 460s&w also has very tight throats, and i considered having some work done to open them up. Unlike your gun, however, my bore was even smaller than my tiny throats.

I tried loading boolits sized .451" (compared to normal .452") and still got a bit of leading, and worse accuracy. And neck tension sucked, i had boolit pullout all day

Next thing i tried was a different boolit profile that allowed a .452" to chamber freely, and MUCH harder boolits. Water dropped wheel weights at first, then water dropped 50/50 Pb/WW. And, i moved to a better lube than i had been using. Specifically, lithi-bee. I dont have any good Felix worked up, i screwed up the soap portion every time and dont have castor oil.

Leading went away, accuracy improved, and sticky cases are fairly rare now.

I still think these smith x frames are very tight...maybe too tight, i dont know. But better to get a difficult chambering round than one out of time that splatters lead all over the place, right? Im actually not sure, because some say that the cylinder will pull into alignment when the lead hits the cone, and i trust those who say it.

This may or may not help you. Good luck in any case, have fun with that monster!

[Porterhouse]

Do some serious casting, loading, and accuracy test first. Ideally longer than 50yds. With scope, if it's possible. Not just one or two groups, but as many group as possible. This may take awhile but don't look for quick answer. After doing this and you don't get any satisfactory result, then it's time to think about throat issue. If you get good accuracy for your definition, then I will ignore leading unless it's really bad.

[44man]

Open throats to .5015" to .502".