RCBS Sprue Plate Screws Loosening

[Ken in Iowa]

I have found myself with 5 RCBS moulds. They all work well for me with the exception of the sprue plate screws. :-|

For the worst offender, a call to RCBS quickly brought me a new plate, screw and washer. That worked wonders.

I use use the plate lube that NOE supplies, but have not applied it directly to the washer. Perhaps I should....

You quickly learn to keep excess over pour away from the screw head. The lead 'wrench' that this creates loosens the screw immediately. :shock: One wonders why RCBS uses a hex head. ...

The washer supplied is cupped. I have been putting the cupped side down and the domed side up beneath the screw head. I suspect that there is a little spring tension to the washer that repeated heating /cooling spoils the temper of the washer.

The washer also digs in to the plate with use. Perhaps this adds friction, causing the screw to loosen. A replaceable flat washer on top of the plate beneath the cup washer might help.

A wave washer has been suggested as some other mould makers use them. I found the proper size at my hardware store, but it's plated. I haven't tried one yet.

One would think RCBS would have perfected this by now. Perhaps I am doing something wrong.

What are your experiences in this area?

[country gent]

Under the set screw for the sprue plate screw drop a piece of soft lead shot and tighten this gives more friction on the sprue screw ( a short length of copper wire works also) It also gets past any dead area that may not be tapped in this hole. Another thing I have done is install a 3/16"longer set screw here tighten set screw on shot then a jam nut on back of set screw and tightened up against the block, this helps lock the set screw itself.

[DLCTEX]

Are you using the set screw to lock the sprueplate screw in place? I didn't see you mention it.

[Ken in Iowa]

Are you using the set screw to lock the sprueplate screw in place? I didn't see you mention it.

Yes I am.

[leadman]

Did RCBS send along a tiny piece of brass small enough to go in the sprue plate lock bolt hole? They have this part and it goes against the threads of the sprue plate pivot bolt and the small allen screw is tightened against it to lock the pivot bolt in place.
Also using a tiny drop of 2 stroke oil on the pivot bolt helps keep the bolt in place.

[Ken in Iowa]

Did RCBS send along a tiny piece of brass small enough to go in the sprue plate lock bolt hole? They have this part and it goes against the threads of the sprue plate pivot bolt and the small allen screw is tightened against it to lock the pivot bolt in place.
Also using a tiny drop of 2 stroke oil on the pivot bolt helps keep the bolt in place.

They did not leadman. Easy enough to clip one from a scrap case or a copper wire. I'll give the oil a try too.

[gwpercle]

They did not leadman. Easy enough to clip one from a scrap case or a copper wire. I'll give the oil a try too.

#10 or #12 copper wire, works well. If you don't have any lead shot around.
I was in a hurry the other day for a thread saver and just cut a small piece of lead from a sprue that was lying on the bench..., that worked too.
Gary