how much force to push cast bullet through cylinder throats???

I have known that having a good fitting bullet matters. However I just learned how to check if you have the correct size bullet in a revolver by placing the cast bullet in the throat end of the cylinder and see if you can push it through. And if you can do it with a little force then you are probably good to go as it is roughly .001-.002" bigger than the throat of the cylinder and that's what you want.
Well I went and grabbed my Ruger SP101 and some bullets I casted and gave it a go. The bullets I used were tumble lubed and resized. When placing them in the throat of the cylinder it took some force for me to get them to go through. I really don't know how much force but it took some. I pushed them through with the back side of a ball point pen. How much force should I be using to know its not to tight? I didn't need to use a mallet or anything just a good grip on the pen and applied good pressure till it pope through. I even tried it with the ones I powdercoated and it felt the same as the tumbled lubed ones. I dont know the exact size of the bullets or the resizing die I used as they are at a buddys house right now.

tightgroup tiger said:

I figure I should be able to push them through with one finger and not have any discomfort doing it. It should fairly easily go through there. The throats should be about a .001 bigger than a bullet of a correct diameter for the barrel which doesn't make an interference fit.

Yours sounds like their sized right and the tumble lube is making it a little more difficult for you. That is normal, the stuff is sticky.

You will just have to shoot them and see if they are accurate and your not getting leading.

I tried to beat a tumble lubed bullet through the barrel of my SP 101 once so I could mic it. I couldn't get it to start so I added about 5 gr of titegroup to a primed case and shot it into a bucket of water.
That worked, so I pushed that bullet through my throats and it just about fell through. I figured that was good enough. Barrel smaller than throats.
I shoot that SP101 3" barrel 327FM with reduced loads, with those tumble lubed bullets, at 25yds and get about 6" groups, standing and shooting off hand. I expect the load is a lot more accurate than I am.

I think your on the right track.

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Thanks tiger. I will have to get them to the range to see what happens. Next time I cast some and before I add any type of sticky lube I will try to push them through my cylinder to check fit, good idea thanks .

usmc0811 said:

Thanks tiger. I will have to get them to the range to see what happens. Next time I cast some and before I add any type of sticky lube I will try to push them through my cylinder to check fit, good idea thanks .

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Oh yeah I love my 3'' sp101 in .357 Mag.

edwardware said:

I don't think you can size a lead bullet down by pushing it through a throat by hand. If you can push it without pounding, it's not too tight.

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Your probably right. I will take one of my Lee liquid Alox tumbled bullets and clean off the lube with acetone to see how they then push through the cylinder throats without all that sticky lube on them.