Gas checks will not stay on base of bullet after sizing

I have been casting for years, 7 different Lee plain base bullet molds in numerous calibers all of them 2 cavity. I just bought 2 new 6 cavity Lee molds 148 grain tumble lube wadcutter and a 158 grain swc gas check design. I use wheel weights for my casting and both molds cast beautiful bullets. I use a Lee .358 push thru sizing die. I lubed the bullets first using 45/45/10 from White Label Lubes and let it dry overnight. Then I pushed the Sages gator gas check squarely on the base of the bullet and then through the sizer. Did 10 each and I was able to easily pull the gas checks off of 9 of them. If anyone has any idea why my gas checks are not being crimped well enough to stay on please let know. With the same mold in 2 cavity I used the same checks but I powder coated those bullets first before gas checking and they stayed on tight. Thanks for any advice.

Try seating them before lube. Lee Alox is REALLY good stuff. You are probably getting a nice layer of lube under the GC and it keeps the GC from getting a good crimp on the lead.

The Lee bullets I have used with GC's have slightly smaller shanks than my other cast bullets. Yours may just be a smidge too small. The layer of PC is just thick enough to get a good bite.

You don't need to lube the bullets before sizing in a Lee push-through die.
Try GC/size w/o lube 1st.

Failing that...PC it 1st as you find things work best.
(Luck of the draw here -- Luckily you have options)

"Cast beautiful bullets"? carefully examine the base of the gas check shank. If not fully filled and with sharp edges, you probably have an undersized shank. This will be especially true if you have shiny bullets instead of lightly frosted bullets. Another thing to check with 6 cav molds is the tendency of some to just pull the mold through under the flowing nozzle. This can create another issue as the alloy splashes off the sides of the sprue hole and the cold plate cools the alloy a little too much. This can be corrected by a stop and pour, stop and move on and pour. It will look like a decent welding bead and not just a strip of alloy. The bead is the sprue puddle that feeds the casting as it cools.

Have you contacted Lee customer service about the problem? Other option is to slightly enlarge the gas check shank portion of the mold.

As I poured the bullets I did modify my technique to use the pour stop pour method because I was having the molten lead run over the sprue and into the cavity that I had not reached yet. When i sized my bullets probably 10-15% slid thru the sizer without a lot of resistance, and some had a lot of resistance. You could look at them and tell the sizer had sized all of them, just some more than others. After reading your ideas to help me, it was probably my technique casting with a 6 cavity for the first time. I went to Lee's help videos and they said to tumble lube first and then size and 45/45/10 doesn't go on thick at all, but maybe too slick for the gas check to take a bite or the shank could be undersized because of the mold or my technique. After I cast it all depends on my mood whether I powder coat or lube them. Sometimes straight alox and sometimes 45/45/10. This is why I love this forum because people are helpful and want to see you make good bullets. Thank you for your responses and I think it may be my fault from being new to 6 cavity casting. I do love shooting the 148 grain wadcutters though. Thanks again.

Tilt the mould down & away, and fill the caviities working up...
even if some slops over in next cavity, just immediately go
ahead and fill it right then too.

Notwithstanding Lee's instructions, lube is 99% never needed.
(Even if it is, just use greasy-fingers w/ a little case-lube on bullet sides)

.

great thread, from the OP and the responders. Looking forward to seeing if an altered pouring/casting technique or changed sequence of sizing/check resolve the problem.

welderboy, I once bought the Sage gas checks thinking I could save money. I bought 22 caliber, 30 caliber, and 45 caliber checks. Loaded some 38 special loads for testing. I did notice that on some of the loaded bullets I could pull the checks off with my thumbnail. Anyway, I set up the chrony to do some testing. After about a dozen shots I noticed something looked funny on the face of the chrony. Closer inspection showed two round dents on the face of the chrony. Fortunately none had hit the glass plate so the chrony wasn't seriously damaged. The cause was obvious that the checks were coming off as the bullet traveled down the barrel and had hit the face of the chrony. You can install the checks and then powder coat and the checks will remain on the casts but whether or not they still come off in flight is a guess. Your problem is not your mold but the type of checks you're using.

Unlike the Hornady checks which have a ring inside the check which digs into the cast and remain solidly hooked on the sage checks do not have that ability. My Sage checks have been sitting on the shelf for about ten years now and I'll never use them again. The Hornady checks are more expensive but they are far superior to the Sage checks in my opinion. I even tried applying a drop of super glue inside the Sage checks before seating then on the cast with no joy. I know some people use the Sage checks and swear by them and some even make their own checks out of soda cans and also swear by those but not at my reloading bench.

I'm a big Hornady crimp on gas check fan too.

For filling the mold:
I run a fast flow from the bottom pour spout.
I tilt the mold block a little bit down at the front, fill the front cavity, then the rear one.
Any overflow will go off the front of the sprue plate.
Any spillage from the rear hole goes onto the sprue of the front boolit.

Try annealing the checks to reduce spring back.

Might just add 2% tin to your COWWs for a much better casting alloy.

my method is same as winger ed

Quote:

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Originally Posted by welderboy44

SNIP>>>
When i sized my bullets probably 10-15% slid thru the sizer without a lot of resistance, and some had a lot of resistance. You could look at them and tell the sizer had sized all of them, just some more than others. After reading your ideas to help me, it was probably my technique casting with a 6 cavity for the first time.

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If you haven't figured this out already, when pouring alloy into a Lee 6 cav mold, you must hold the two mold block handles together tightly, BUT NOT the third handle for sprue lever.

What happens when the sprue lever handle is gripped with the two mold block handles, the cam of the sprue lever handle will slightly open the molds blocks. This will give you inconsistent boolit diameters, causing the problem you mentioned above.
Good Luck.

The new 6 cavity mould is just throwing you a curve ball ... try winger ed's method of tilting the blocks and filling from the low front to higher rear cavity . Any excess sprue flows over filled sprue and not into unfilled cavity .
Be sure and leave a generous sprue puddle for the base / GC shank to draw and fill out completely .
This might be some of the problem and will help that base fill out completely .
Sages checks and Lee's GC shanks usually go together just fine .
Keep at it ,
Gary

Every point made is well taken. I did start tilting the mold downhill so the molten lead did not run into the next hole closest to me because I saw I had some bases not filled out completely with squared corners. Yes I did try to save money buying Sage copper checks instead of Hornady. I cast a load of both wadcutters and the SWC. I felt like it might be my fault for being new to 6 cavity casting, but now I have some "Sage" advice about correcting operator error. I will probably load the gas check bullets without the gas checks and just keep load them mild and then start from scratch on the next batch I pour. When I cast some soon for my 45 colt I will pull that mold out and try to incorporate my new knowledge. Thank you for all the answers to my problem, each and everyone of them was good information. That is why this one of my favorite forums. By the way, I tried to save money on Harbor Freight black before learning Eastwood Powders worked great and threw the black powder away. Sometimes being a tightwad is not productive.

You powder coat ? (It appears so)
Just PC before mounting the gas check, mount the gas check, and Lee size as normal.
I do it as req'd myself depending on situation.

I once had a problematic Saeco mold that wouldn't hold checks. They asked me to return it with 3 lots of checks I had tried, 10 sample checks and copies of the end flaps from the check boxes. Return time was three weeks and I have been happy with it.

SO what did I learn? Try different brands, check my casting methods and measure the shanks with a good micrometer, not calipers. If the shanks are varying diameters, change technique.