Question for RCBS 30 caliber casters

[PBSmith]

What RCBS .30 caliber rifle molds are you using and what diameters do they drop for the alloy you're casting?

[Outpost75]

My experience with RCBS .30 cal. molds is that they all cast undersized in common alloys and they are suitable only for new .30 cal. barrels if you use linotype or Lyman No.2 to get them to cast marginally large enough. For the poor fellow with a worn barrel and access only to wheelweight alloy they will run 0.002" undersize.

With the easy availability of precision lathe-bored custom molds which cast true to size with your specified alloy, I don't understand why anyone would spend good money on a cherry cut mold based on 19th manufacturing technology and then have to roll the dice in hope that the bullet might fit, or that he could monkey with it by Beegling or other means to make it work.

Buying a new off-the-shelf RCBS .30 cal. mold and depending upon Voodoo spells and witchcraft to make it work is embarking on a fool's errand.

THIS is the only RCBS .30 cal. mold I own. It started life as a .30-180FN which I wanted to use in a .30-30. Problem was that in hunting alloy it cast exactly at .308", not the .310+ I needed. SO, I sent the mold off to Erik at www.hollowpointmold.com and had the GC heel bored out to make a .312" base band, plainbased bullet, which I could size to fit any rifle I wanted to use it in. I also had the slightly too long to feed nose truncated to enlarge the meplat from .187" to .25" and had both cavities cup pointed so that the mold drops a pair of 174-grain hollowpoints which shoot well in my .30-30 at 1450 fps using RL7 power and have killed seven deer.

Cost, $125 to fix a $65 mold...
155992

[Larry Gibson]

Outpost75 is correct in that if you want a mould that casts oversize with range lead or even COWWs then the RCBS moulds for modern centerfire rifles is not what you should get. If we bother to read RCBS's literature we find their philosophy is that cast bullets should be no more than .001 over groove diameter and should not be sized more than .001. RCBS states their testing has indicated both are a detriment to accuracy. If you look at their chart of cast bullets they recommend the sizer diameter. They also are partial to hard alloys such as linotype and that is the alloy they cut their moulds (excluding the BP and cowboy action moulds) for. Thus if you buy an RCBS 30-180-FN you can expect it to cast .310 +/- with linotype. I have 4 RCBS moulds for bottle necked rifle cartridges. They all cast right at .001 over the nominal listed sizing diameter with linotype. They cast right at the nominal listed sizing diameter with COWWs + 2% tin and in between with Lyman #2 alloy.


I find the RCBS bullets cast of a quality alloy that they are intended to be cast of shoot as well as similar bullets cast in lathe bored holes. Thus if you want a diameter with a different alloy than what the RCBS moulds are spec'd for then probably should spend your money elsewhere.

Larry Gibson

[PBSmith]

Thanks, Outpost and Larry. Both of you were reading my mind on this size issue. I'm looking for .310-.311 as-dropped or light-sized, in wheel weight material, so am out of luck here. Your excellent responses saved me buying the wrong mold. Appreciate you taking time to explain.

[Hickok]

I am glad I read this post. I was really looking at the RCBS 30-180-FN. You fellas saved me some money and misery in the future. I will just go to Accurate Molds when I get ready.

[Scharfschuetze]

When I started using RCBS moulds in the mid 1970s, the usual complaint about Lyman moulds was that they cast too large. Perhaps RCBS was responding to those complaints when they settled on their "as cast" size.

That said, I've had excellent results with RCBS 30 cal moulds (30-110, 30-150 and 30-180) in the 30 Carbine and 30/06 Springfields and the 35-200 mould in the 358 Winchester. Using my usual sizing dies, the boolits are barely touched and the sizing dies usually just lube 'em and crimp the GC on. Accuracy in .308" diameter barrels has been as good as any other brand and often better.

[Le Loup Solitaire]

The only 30 cal mold from RCBS that I am using is the 120 grain RN GC. It casts using ww at .310 and I shoot it as cast in the 30 carbine. No leading or other problems. It is an older mold that I have had since the eighties and has never given me any trouble. I have other RCBS molds in other calibers and no problems there either. LLS

[runfiverun]

my whatever alloy [3 parts ww's and 1 part softer stuff] in the 30-150-fngc pours out a click over 310 and I size it to that diameter it has enough resistance in the star size die to get checks on smoothly and squarely.
it is by far my number one 30 cal rifle mold and is the only one I would keep if life got tough and I had to make the choice.
now if we were talking lyman molds then your gonna get horribly undersized boolits suited perfectly for powder coating right from the box no matter how much tin you put in the alloy.

[Ford SD]

What RCBS .30 caliber rifle molds are you using and what diameters do they drop for the alloy you're casting?

I have -30-150-fn
30-165-sil
30-180-sil

Under size drop .308 -.309 with ww

Lapped mine a bit larger but hard to do only the base as the nose is ok

2 cav Mold --------? Slow
best casting was with 2 of the above moulds and after they heat up you can drain the pot with out a bad bullet (unless nozzle gets dirty)

you need at least a 4 cav mold so have switched to noe moulds --also have better selection

and better yet

[tomme boy]

I have had a couple of the 200gr SIL RCBS moulds. They both casted at 0.3095ish with range lead and WW's. Lino they went to 0.3102" for the largest. They did not like to go much faster than 2000 fps. Main reason was the 10 twist of my barrel. You have a very LONG un supported nose on this design. It can slump and get off balance very easy.

But if I drove it at 18-1900 fps, I could shoot golf balls laying on the ground at the range all day.

I have had other RCBS moulds and they all have casted very well.

[tmag97]

Outpost75 that is great looking expansion on those bullets. I have been casting pistol bullets for a while, and just now starting to cast rifle bullets. I use coow and a little tin added. What mix do you use to get them to perform like that?

Thanks Mike

[Hardcast416taylor]

Knowing what dia. they drop as cast at I use my RCBS 30-180 FN for the base core for paper patching for my Mosin and LE rifles.Robert