.30 Carbine Bullet Diameter?

[jski]

I reload a lot for my .30 Carbine hogleg (Ruger Blackhawk). I’ve always used a .308” diameter bullets but I thought I’d try a .309” diameter bullet this time. So I ordered a batch of .309” diameter bullets from Montana Bullet Works.

When I got my .309” diameter bullets, I tried pushing them thru the cylinder. They wouldn’t go thru without a chopstick I sometimes use plus some gentle tapping (using a mallet) on the chopstick. The .308” just needed an ever so slight push (no mallet) from the chipstick.

Both when loaded into a cartridge sit equally well in the cylinder. But which is better? Which is preferable?

[Rizzo]

I reload a lot for my .30 Carbine hogleg (Ruger Blackhawk). I’ve always used a .308” diameter bullets but I thought I’d try a .309” diameter bullet this time. So I ordered a batch of .309” diameter bullets from Montana Bullet Works.

When I got my .309” diameter bullets, I tried pushing them thru the cylinder. They wouldn’t go thru without a chopstick I sometimes use plus some gentle tapping (using a mallet) on the chopstick. The .308” just needed an ever so slight push (no mallet) from the chipstick.

Both when loaded into a cartridge sit equally well in the cylinder. But which is better? Which is preferable?

I'd start with slugging your barrel to determine the groove diameter, then choose a bullet diameter that is .001" - .002" larger.
....or, just shoot them and check for accuracy and for any leading.

[jski]

Keep in mind that the chamber diameter in the hogleg cylinder has an abrupt change as it goes further in. This is because the .30 Carbine is rimless and hence headspaces on the case mouth.

[Outpost75]

Most Ruger .30 Carbine Blackhawks have cylinder throats of barrel groove diameter or up to 0.001" smaller, which are optimized for factory ammo loaded with jacketed bullets. If yours happens to match barrel groove diameter or a wqee bit larger, then size cast to that and call it good. If tighter than groove diameter and you want to shoot lead, send the cylinder to Doug Guy and have throats uniformed to .312" and you will be much happier. You can then use jacketed bullets intended for the .32 H&R Magnum and .327 Federal.

[jski]

Most Ruger .30 Carbine Blackhawks have. Cylinder throats which are of barrel groove diameter or up to 0.001" smaller, which are optimized for factory ammo l Ioaded with jacketed bullets. If yours happen to match barrel groove diameter size cast to that and call it good. If tighter than groove diameter and you want to shoot lead, send the cylinder to Doug Guy and have throats uniformed to .312"

1. Who exactly is Doug Guy?
2. And wouldn’t reaming the cylinder chambers reduce the ledge in the chamber used to headspace the .30 Carbine on the case mouth? Possibly to a point where it might not headspace properly?

[gwpercle]

Load the .309" boolits and shoot them before you go paying a buch of money to solve a problem you probably don't have . They might just shoot just fine and dandy ...but you will never know untill you make some gunsmoke and look at a target .
If .308" size works ... I would bet money .309" will do just as well ...maybe even a slightly bit better ...but you need to be a good shot to tell the difference .
Load Em and Choot Em ...the Blackhawk will tell you the story .

DougGuy is a member and gunsmith who does a good job fixing revolvers with throat problems . He also likes to cook and is good at that too , he posts some good recipes .
Gary

[Outpost75]

1. Who exactly is Doug Guy?
2. And wouldn’t reaming the cylinder chambers reduce the ledge in the chamber used to headspace the .30 Carbine on the case mouth? Possibly to a point where it might not headspace properly?

DougGuy is well known on this forum and adjusts cylinder throat diameters in revolver cylinders with great precision using a Sunnen hone, which produces a mirror finish with perfect roundness. Enlarging the cylinder throats does not affect the stop surface used for headspacing on the case mouth because the .30 M1 carbine chamber is .337-.339" diameter at the mouth and the small adjustment is of no consequence except for the positive effect of eliminating trailing edge failure with cast bullets are used in the carbine chamber. I will send you a PM with his contact info. Doug has done numerous cylinders for me and I have been well satisfied with the quality of work, moderate cost and fast turnaround.

[Wayne Smith]

Do you have Doug's current information? I gather from a recent post he's moved.

[Larry Gibson]

If the Ruger 30 Carbine BH has been shooting well (most all of them do) with the .308 diameter bullets then I'd suggest sticking with those. In several Ruger 30 Carbine revolvers I loaded for .308 and .309 sized cast bullets gave excellent accuracy of which better could not really be expected. The .309 will also swage down in the throats and shoot well in the .308 barrel. The original 30 Carbine military rounds were loaded with both .308 and .307 bullets. Current commercial ammo will have .308 diameter bullets. That is what your revolver was made for.

If it ain't broke, don't fix it.....

[Outpost75]

Do you have Doug's current information? I gather from a recent post he's moved.

PM sent

[LJBrennan007]

Hello Outpost. I just joined the forum (but have been reading articles here for some time). I've been playing with an OM BH .30 carbine for about 6 months now and am getting OK, not great results with the Lyman 311008 mold using 12.6 gr of 4227. At first I was sizing .310" but most of the rounds would not chamber fully so I just got a .308" sizer and now they chamber better. .308" factory bullets will just fit through my cylinder mouth and the .310" bullets I cast would not fit at all, so I figured .308" was my next step. I may be interested in communicating with DougGuy if you can send me his contact info also? Most of what I know about loading for this round is from the excellent article by John Goins aka Beagle who I would also like to thank personally if I knew how to get hold of him too.

[mehavey]

See https://castboolits.gunloads.com/sho...=1#post4301584 for Doug...

[Larry Gibson]

Hello Outpost. I just joined the forum (but have been reading articles here for some time). I've been playing with an OM BH .30 carbine for about 6 months now and am getting OK, not great results with the Lyman 311008 mold using 12.6 gr of 4227. At first I was sizing .310" but most of the rounds would not chamber fully so I just got a .308" sizer and now they chamber better. .308" factory bullets will just fit through my cylinder mouth and the .310" bullets I cast would not fit at all, so I figured .308" was my next step. I may be interested in communicating with DougGuy if you can send me his contact info also? Most of what I know about loading for this round is from the excellent article by John Goins aka Beagle who I would also like to thank personally if I knew how to get hold of him too.

The problem may be that 12.6 gr of 4227 is pushing that PB'd 311008 too fast or is too slow burning for that cast bullet in the 30 carbine in the Ruger. I got much better performance with 4227, 2400 and H110 when a 115 - 120 gr GC'd bullet was used. With the 311008 I had excellent results with Unique powder.

[PositiveCaster]

…I've been playing with an OM BH .30 carbine for about 6 months now and am getting OK, not great results with the Lyman 311008 mold using 12.6 gr of 4227. At first I was sizing .310" but most of the rounds would not chamber fully so I just got a .308" sizer and now they chamber better. .308" factory bullets will just fit through my cylinder mouth and the .310" bullets I cast would not fit at all, so I figured .308" was my next step….

First off, you haven’t given us enough information. Which 4227 - there are two different powders called “4227” and they are not the same. If you are using H4227, 12.6 grains is below Hodgdon’s starting load for a 110-grain bullet, so it’s probably not too fast. If the loaded cartridges will not chamber fully then the bullets are too large and will not release easily when fired, potentially increasing pressures. What are “OK, not great” results - 4” groups at 25 yards? 10” groups? What are your expectations? What kind of accuracy do your other handguns exhibit?




.

[LJBrennan007]

My post may have been a little premature since I haven't really tested the load properly yet; I was mostly interested in getting the contact information for that DougGuy in case I do decide to have my cylinders trued up. So far in this gun I've loaded Hornady 110 FMJ's (.308") with 14.9 of H110 and get 1499 fps and 3-4" groups at 25 yards. I also loaded 115 Missouri bullets RN .309" with 12.0, 13.0, and 14.0 of IMR4227 for 1127, 1246, and 1338 fps and similar 3-4" groups with that load. I only loaded about 20 of the 311008 bullets sized at .308" (after I realized sizing them to .310" was not going to work) and got the load of 12.5 of IMR4227 from John Goins AKA Beagle article on loading cast in the .30 carbine. Mine weigh right at 115 grains using wheelweights with a touch of tin added. I have not even chrono'd the load yet but it is supposed to a mild load at 1170 which is what I am looking for. Initial groups from a not great rest on a windy day with my 66 year old eyes were in the 4" range but again this is preliminary. If I can get a load with this bullet that shoots 2-3" at 25 yards with open sights I will be happy enough that I will cast a couple thousand of them and call it a day. For all the other handgun calibers I load I keep a scoped gun on hand for load development and testing (.357, 41, 44, 45 colt) so I know for sure the accuracy is there. .30 carbine Blackhawks aren't easy to come by and I am not going to scope this old 3 screw so whatever I can do with open sights is what I get. I will load 50 or so of these today and get to the range with my chronograph and a proper rest and report back. FYI, no signs of leading but with low round count so far that doesn't tell me much yet. I like the idea of Unique and will try that too. Thanks guys!

[Thumbcocker]

I size to .311 same as for other U.S. .30 calibers.

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[Cherokee]

I get the best results with bullets sized to 309 for my Ruger 30 Carbines. 231 for light loads, AA9 for heaver loads.

Gun

[358429]

I size to .311 same as for other U.S. .30 calibers.

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Thems some shootin grips!

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[mehavey]

Starline 32-20 Case / 7" Ruger 30_Carbine
RCBS 30-115RN(GC) / #2 / Sized 0.310" / Lyman 50/50 Lube
PwrPstl / 6.5gr / 1.610" OAL / Oehler V= 1,244±04fps

25 Yards_Barrel_Bag-Rest


32-20 case -- with a rim -- makes this cartridge a breeze to load

[Thumbcocker]

Starline 32-20 Case / 7" Ruger 30_Carbine
RCBS 30-115RN(GC) / #2 / Sized 0.310" / Lyman 50/50 Lube
PwrPstl / 6.5gr / 1.610" OAL / Oehler V= 1,244±04fps

25 Yards_Barrel_Bag-Rest


32-20 case -- with a rim -- makes this cartridge a breeze to load

Did you have to trim the brass? I tried .32-20 brass and it seems to be a bit long.

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