i have a puzzle for people who shoot 30 M1 blackhawk revolver.

[mozeppa]

i cast 110 grain 30 carbine boolits, they leave the mold at .311 ...then the are powder coated and sized to .311

all good so far.

i have new starline brass for the m1...good.

i have dillon dies for it and a custom "M" expander die that expands to .312 ...(note that there is barely any expansion going on.)
as a mater of fact i can put the expanded case in the cylinder and
it nearly goes all the way in except 5/32"nds of case doesn't quite go in.....this was expected.

i can start a boolit into the case with my thumb pressure and almost seat it by thumb pressure alone.

once i seat a boolit and crimp it to 1.635" they look great!.......except....they won't go all the way into the cylinder.
they stop right at that 5/32"nds area.

so i wondered what my bore size was....cylinder size....and throat size even the forcing cone.

i have a set of precision ground gauge pins to check this with and here's what i found...

first i tried to put my sized boolits into the front of the cylinder and at .311 they sit on the hole but wont go in.
i used my pin set to find out the throat size .......its .3085 on all 6 throats.

well that explains why a .311 boolit won't go in!

now for the real problem.... i used a gauge pin the find the size of the barrel bore ....its .3025":veryconfu

the forcing cone is maybe 2 thousandths bigger (.3045" )

HELP! ........what am i missing?

here are some pix.

[BK7saum]

Bore size doesn't tell you what you need to know. Slug the barrel to get the groove diameter. Your groove diameter needs to be the same or smaller than you cylinder throats. If you find that the groove diameter is larger than the throats you can send it to Doug guy to have them opened up.

Brad

[BK7saum]

If your groove dimension is 0.308, you'll need to size your boolits to 0.3085 to fit the throats. Or get a different mold that is 0.308 forward of the crimp groove.

[mozeppa]

these are taper crimp....no crimp groove ...and these cases head space off the case mouth.

[BK7saum]

Sorry, I didn't catch that. Regardless I think you need to size to 0.3085 or go with a different mold that is smaller ahead of the crimp location.

[Echale3]

I'm The extra few thousandths bullet diameter (.311 vs .3085) sticking out the front of the case is what's hanging you up from seating in the cylinder completely--the bullet diameter doesn't get down to .3085 on the ogive until ~5/32nds beyond the end of the case at the seating depth you have set.

Size the bullets to fit the cylinder throat (.3085 is achievable by buying a .308 sizer and polishing it evenly using a drill, a split rod and some very fine grit emery paper wrapped through the split and around the rod enough to fit snugly and used to lap the die until the sized bullet hits just under .3085) and you should see it seat fully. Then all you have to worry about is the bore diameter being smaller than the throat diameter, which, if it's not, is an easy enough fix with a properly sized reamer, but that would necessitate a new die sized to the new throat diameter.

[Le Loup Solitaire]

A workable alternative to get around too much OAL or the round going too far into the cylinder is to load 32-20 cases. A whole writeup is on or in the cast-pics section, done by Beagle a long time ago. Accuracy is good according to his tests and extraction is no problem as the 32/20 has a rim. I size my bullets to .310. I use the RCBS RN with GC. LLS

[44MAG#1]

Simple, size the bullets .309" seat to the correct OAL, taper crimp the correct amount, try the cartridge. If the OAL won't work seat slightly deeper and try again until the cartridge does seat correctly. That is your working length. Start low and work up the load.

[Silverboolit]

Seat bullets to where the taper starts, like a .45 acp.

[Larry Gibson]

Simple, size the bullets .309" seat to the correct OAL, taper crimp the correct amount, try the cartridge. If the OAL won't work seat slightly deeper and try again until the cartridge does seat correctly. That is your working length. Start low and work up the load.

Bingo!

The 30 Carbine Rugers throats are for .308 bullets. I shot a lot of 311227s, 311316s and 311359s all sized .309 through a couple Ruger 30 Carbine revolvers w/o a single failure to chamber and with excellent accuracy.

Larry Gibson

[mozeppa]

Thanks 44mag#1 and Larry gibson!

NOW I do feel silly.
after posting my problem last night i thought on it all night long.
today i check my load book for boolit size...yup , it even says "lead bullets sized to .308".

i bought the wrong mold! ...not too wrong that i can't still use it tho.

then i bought the wrong push thru sizer.... .311 :veryconfu:groner:[smilie=b:

so ....today i made a .308 boolit and installed it into a case and crimped it it!

dropped it into the cylinder ......we have joy![smilie=w:


now i just have to wait on Lee to send me a .308 push thru sizing die!

[DougGuy]

Slug the barrel. Get the barrel nice and clean and lightly oiled and slug it. SEE if the slug will then go into the cylinder throats. If it won't then the boolits are coming out of the throats at whatever throat diameter is, but if the slug won't go into the cylinder, the throats are too small. They can be reamed of course, but see what the slug does first. If the slug goes from the barrel and through the throats, and they are all even I would leave it alone.

[rockrat]

Seat your boolits a bit deeper in the case, to where they will fit and function in your gun. Shoot them and see what results you get.

I did this with mine w/.311" boolits, using 32-20 cases trimmed, and it shot very well.