RCBS 115g RN success

[Jal5]

Bought this 9mm mold from a member here and its one of the easiest molds that I have to cast with. I had to mod the Lee 6cav handle to fit, which took forever since I don't have a proper grinding wheel but once that was done I heated it up on the hotplate and away we went. Boolits dropped out of both cavities easily and cleanly right from the start. Out of about 200 boolits I only threw back 4 I think. I am happy! :bigsmyl2:

I will weigh some and mic them to see where I am at for reloading, but so far so good.
Joe

[barkerwc4362]

I love my RCBS molds. Even though they are only two cavities I can get high production numbers out of them. Almost all of mine are many years old and continue to give great service. The mold blocks just seem to retain the right amount of heat and are very stable. I have many Lyman molds also, but none of the two cavities come close to the RCBS. Only the SAECO molds are close to the RCBS. I have been reluctant to go to another venders 4 cavities if I have an RCBS of the same basic design. I prefer the later thick sprue plate RCBS molds when buying a used mold.

Bill

[Jal5]

I liked that heavy sprue plate too. Weighed 10 of them and they are right around 120g only varying a couple of tenths heavier 120.1-120.8. They mic the largest at 0.360 and the smallest at 0.356 of the sample of 10. Joe

[Le Loup Solitaire]

All of the 9mm molds currently offered by RCBS are good performers. They cast easily and are of the right size and feed well according to many users. I have the conical truncated nose version. It has never ever failed to feed even one single time in a Luger, Baretta or S&W. I have also successfully used it in different 38's and a 357 Mag. One lube groove, two broad bands to hold the rifling and a flat base, it has been a real workhorse bullet that has never leaded and has shot accurately. LLS

[Jal5]

I sized them to .358 and lubed them with a homemade lube I use in other applications. Hope to load them and try out the tests this weekend if the weather isn't too bad.
Joe

[Jal5]

Well test driving this boolit didn't workout too well today. It was windy, around 35 deg. and my hands were freezing. Shot 5 rounds each from 4.0-4.3 Bullseye using 1.125 OAL and taper crimp of 0.376. All cycled, none FTF but the accuracy was poor at 10yds. and this out of my WWII era P38. That gun works well with 115 gr plated Berry's bullets over Bullseye and this is the first trial with cast boolits. The best trial was the 4.3 BE but even they were all over the paper 8.5x11 with a 3" shootnc target in the middle. Some of that could have been the cold weather and my freezing hands, so I will try another go with the 4.3 anyway and may bump it up slightly. I didn't try the full max load because I don't want to stress this old gun. Joe

[Jal5]

I decided to try a test at the lower end of the range for these with this gun: 3.7-4.0 BE and gave it just a little more TC. The rounds fit just right now in the chamber where before they were squeezed in more. Will see if I can get to the range this week to try them. If these are no good I will try some Unique since I have that available and I don't really want to have to get another powder.

[Jal5]

I tried them at the low end of the powder range for BE with not so great results. Some keyholing and not good accuracy at 10 yds. but no FTF and very slight leading in the barrel. My next trial will be repeating the 4.3 gr BE, but I think I will have to switch out to Unique. Maybe a slower powder like that will suit this gun more? Joe

[nanuk]

I liked that heavy sprue plate too. Weighed 10 of them and they are right around 120g only varying a couple of tenths heavier 120.1-120.8. They mic the largest at 0.360 and the smallest at 0.356 of the sample of 10. Joe

is this normal to have 0.004 between the largest and smallest from a 200 boolit batch?

are you concerned with the 0.356dia leading?

[dubber123]

I haven't done a lot of fooling with cast in 9mm, but some things I found: Water dropping worked better, (harder boolit), and the P1 I was using, (P-38 made from left over WWII parts), had a very large bore, as I recall, it slugged .358", I ended up sizing to .359". I was surprised they chambered, but no problems. Try selecting some of your fatter boolits and hand lube them, (don't size), and make a few rounds to see if they chamber. If some are coming out of the mold at .356", those are likely your fliers and leading problem.

[Jal5]

Thanks for the input guys. Yeah the .356 dia on some of them is probably an issue, but only very slight leading that is removed easily with a brush. I agree that those are possibly the fliers in the groups. This is a relatively soft boolit too made from range scrap + tin. I could water drop some or just use straight WW for another trial = harder boolit. Not sure if this is normal to have .356-.360 range in dia. since this is the first time I used this mold. What do you suggest would help to shrink that variation?

The difference between the first and second set of rounds for the reloading was slightly more of a taper crimp using the Lee TC die- on that second batch those rounds easily slid in/out of the chamber whereas the first batch cycled in the pistol fine but I noted that there was some resistance as I pressed on one to chamber. To me that seemed to indicate that the TC die was swaging the round slightly in the second batch. Does that make sense? And which is better the slight resistance chambering or the easy chambering?

Joe

[dubber123]

.004" variation is quite a bit. Just pouring too slowly can turn out an undersized boolit, but they usually won't have sharp edges, and the bases will appear more rounded. When you get one that measures .356", see if it exhibits these traits, if they do, then it may just be your pouring technique. Assuming it's a 2 cavity, I suppose the cavities could be cut off, but I wouldn't expect that from RCBS. A spot of lead may also be holding the blocks open on one end of the mold, which would produce fatter boolits on that cavity. I'm actually more surprised that you get some at .360" than .356". .356" is far more common in 9mm molds.

Too much taper crimp will swage a lead boolit down to a smaller size, not good. I prefer to just straighten out the bell on the case neck. If you are using mixed brass, you'll have to find a happy medium due to length/case wall variations.

[Jal5]

Thanks dubber. I will check out those .356 ones more closely.
Joe

[Jal5]

As I examined the boolits more closely and mic measured more of them there was an out of round problem with this casting batch. A lot of them show good bases and grooves but the measurement of the base is out of round measured by micrometer e.g. .355 to .359 it was like you could see a bump slightly on one side of the base diameter.
What caused this?

I will try sizing the biggest ones to 358 and see what difference that makes.

The experiment continues...

[dubber123]

I would suspect the mold is not closing fully. When you hold it tightly together, with no oil on the mold, ( oil can block light transmission), and hold it up to a strong light source, can you see any space between the block halves? A mold thats held apart for some reason, (burrs, lead splatter), will cast out of round boolits that are fatter 90 degrees to the smaller diameter.

[Jal5]

Dubber I will check that out tonite and let you know. Thanks.

[Jal5]

I inspected this mold and did find some tiny lead splatters, and removed them as best as I could. But I tried pouring 3 separate batches with the clean mold and varied the speed of pour, the temp of the pot, even how I poured and the same thing happened: boolits dropping with clean crisp bases, look filled out, and out-of-round measuring them by mic 0.355-0.359 at the base on the same boolit as I twisted it taking separate measurements. Here are some pics.
If I was just shooting these at .355 in a 9mm I would size them down and be done with it. But the P38 needs a larger boolit. 0.004 is too much variation I would think too.

Any ideas what I should try next?

Joe

[runfiverun]

lapping....
you need to determine which direction the variation is in.
i am gonna guess the parting lines are bigger.
any ways lapping will round things out for you.

[Jal5]

Prior owner is a member here and never needed to lap it-they were consistent .357 with his alloy.
I am wondering if its the Lee 6cav handle that I modified to fit? Maybe the blocks aren't free enough on the handles and that is affecting how they close or how tightly they keep shut.
Would that result in an out of round problem?

[Jal5]

Continued...
I checked the Lee handles and took just a little more off so that the blocks are definitely free on them now.
I checked the blocks and removed some tiny lead splatters and got them to close good.
Still the boolits drop out of round .355-.358 spinning the boolit around and taking those measurements by mic.
You can almost see the difference in the base looking directly at the base: there is a little hump on one spot, that would be the high spot .358 dia. and you can see that in the last picture in my post #17.
Not sure what else it could be, unless the alloy somehow causes this, but I can't understand how that would be possible.

The barrel for this P38 slugs at .357 so I should use a .358 boolit I think.

Joe

[Lloyd Smale]

proably the best 9mm mold out there for accuracy. Nice thing is my two cast out at 359 so i can size to 358 and even shoot them in the 38 specials.

[Jal5]

Any other ideas on what I should try to fix the out of round problem?
Joe

[dubber123]

You might check with Erik. I think his web addy is "www.hollowpointmold.com" I think he offers cavity alteration as one of his services.

[Jal5]

I may try to have a buddy cast some with this mold using his alloy and see if that variable is making any difference. He could do another trial using his handles and my alloy and see if there is any difference there too.

I am determined to get to the bottom of this!
Joe

[Jal5]

Update-
had a friend check it out and he cannot figure out what is wrong either.
I contacted RCBS to ask for help by email today. Will let you know what they advise.
Joe

[Love Life]

I bet it was the fact that the post office used it as a step ladder for a 400 pound employee.

[rintinglen]

Those boolits do not look well filled out to me. The bases are rounded and the edges don't appear to be crisp. Try a pressure fill, either holding the mold closer to the spout and letting in flow longer, or holding the ladle to the mold alittle longer and making a bigger sprue puddle. I suspect that the out of round is in part a function of the incomplete fill out, and partly due to incomplete closure of the mold blocks. I occasionally get this sort of a problem as I get fatigued after casting for an hour or two. I end up with oblong boolits that are a smidge heavy.
However, sizing them makes them round, and the minor variance in weight makes no never mind for all but the most demanding of uses.

[Jal5]

RCBS asked me to send it back to them for repair/replacement. this mold came to me via USPS and the small flat rate box looked like it had been run over.
We'll see what happens.

Joe

[Jal5]

Glad I was persistent with this mold. RCBS rep notified me today that they will ship me a new mold, much better service than I ever expected.

Joe

[Jal5]

Updated:
Finally got the RCBS mold back. Looks like they just replaced the sprue cutter bolt and poured half doz. boolits that look to be the correct size diameter. I will try it and see if I have the same results.

[Love Life]

Jal5- I am glad RCBS did right by you. I apologize for how the package made it to you, and hopefully you will be casting nice round boolits soon.

[Jal5]

Thanks Dick I am looking forward to trying it out this weekend. Will let you know, maybe you will hear the yahoo!!! from your house. LOL

Joe