Loose gas checks

[jasdebcr]

I have been trying to install some 270 GC's on some boolits that i casted. The GC's will not stay on even when i run them thru the sizer. I aslo tryed buying that lyman GC intall tool and that did not help. Has anyone had this problem? if so how did you resolve the issue.:castmine:

[44man]

Lap the GC portion of the mold until checks fit tight before crimping. Trial and more trial until you get a good fit. Take some out and cast a few, if not enough, take more out.

[grumpy one]

Just be careful you aren't trying to fit off-brand gas checks. I've got some that don't fit anything - some brands too small, some too big. I have found that both Lyman and Hornady are standard size though - if those don't fit, I suggest you take 44man's advice.

[badgeredd]

I have been trying to install some 270 GC's on some boolits that i casted. The GC's will not stay on even when i run them thru the sizer. I aslo tryed buying that lyman GC intall tool and that did not help. Has anyone had this problem? if so how did you resolve the issue.:castmine:

If you have a pair of calipers, you can check the shank of the cast boolit and check the same area in the mold too. Ther shouldn't be very much difference between the two measurements. Maybe a couple thousanths of an inch at most. What mold is it and who made it? What alloy are you using? And what brand GCs do you have?

If all is as it should be, then 44man gave you the best advice.

Edd

[No_1]

All of the posted information is good. If you need to increase the size of the gascheck area but do not have the tools / skills I am sure there are many here that do. One that comes to mind is our own resident machinist: Buckshot
If you are considering him doing some work on this you may consider having him HP it. I am sure that if it is a single cavity mould he can make 2 pins so you can have the best of both worlds.

Robert

[docone31]

Loose gas checks are why I learned to paper patch.
I had this vision of molding my own, lubeing, checking, sizing, loading, and getting stellar results.
Phooey! I made a fool of myself, time after time. I could feel the checks fall off in the case.
I took up paper patching and got the results I wanted.
If all else fails, paper patching.
It works.

[XBT]

The gas check portion of the mould can easily be lapped larger as 44man suggested by simply taking one of the boolits cast in the mould and adding a very small amount of fine valve grinding compound to the gas check area only. Turn the boolit upside down and spin it by hand in the mould, just inserting the gas check area into the mould of course.

This is easy to do, just go slow and measure often.

[runfiverun]

do you have the old style lyman's by chance they didn't crimp on and fell off at random times.
you can put a spot of super glue on these also.
but the advice above is sound,unless your nose and body is a tad too small too, then you can either beagle the mold or polish out the whole thing.

[stubert]

I had to open up the gas check shank on a Lyman mold last year. took a peice of 180 grit emery paper and rolled it into a tube and just turned it back and forth.until I had the size I wanted. Cleaning all the grit out of the mold took longer than opening up the hole.

[Will]

The non-crimp type will fall off and spin off at about a 30 degree angle and can cause real dammage to chrony or anything else. If you decide to open up your mold be careful of how much you remove especially if it is a Lee or other AL mold. It doesn't take much and you can't put it back.