Applying gc to a Lee tumble lube bullet

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  • Last Post 21 July 2014
csparks1106 posted this 19 July 2014

What method is best. Just cast some up last night. Haven't done anything except lube and size, so far. Below is the mold I have. Lee 2-Cavity Bullet Mold CTL312-160-2R 7.62x39mm (312 Diameter) 160 Grain Tumble Lube 2 Ogive Radius Gas Check Thanks.Charlie

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Larry Gibson posted this 19 July 2014

Put the GC on the shank, make sure the shank is bottomed inside the GC and run through sizer again. That will size and crimp on the GC if they are crimp ons?

LMG

Concealment is not cover.........

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csparks1106 posted this 19 July 2014

They are Hornady 30 caliber copper gas checks. I think they are just press ons.

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bliksemdonder posted this 19 July 2014

csparks1106 wrote: They are Hornady 30 caliber copper gas checks. I think they are just press ons. All of the Hornady GC's is have used in the past few years were crimp on. Measure their diameters to make sure what you have.

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onondaga posted this 19 July 2014

http://www.castbulletassoc.org/view_user.php?id=7953>csparks1106

It doesn't matter if they are press on or crimp on gas checks. They are all oversize in diameter compared to the correct bullet size for your rifle or your gas checks are the wrong size. The Lee Lube and size kit you have does an excellent job. It will bottom out the check, size it and crimp it in place unless your bullets are too small to be sized. If you have checks that are smaller in outside diameter than your desired bullet diameter before installing them, you will discover that you have the wrong size gas checks and accuracy will stink along with checks falling off in the barrel or air.

Just pushing on gas checks and not sizing them leaves them larger in diameter than your bullets. Then seating bullets with a large GC on them will push the brass out and leave a loose bullet in the neck fit. That situation can leave checks in the case detached from the bullet when you fire or the check will be pulled off in the barrel. Either of those scenarios is a safety concern and definitely an accuracy subtractive.

I have Hornady 30 cal gas checks in hand, They measure .320” outside diameter and that is large enough to be used on 30 or 31 caliber bullets but too small for 32 caliber bullets.

You would be following Lee directions best by lightly tumble lubing your as cast bullets lightly and then putting the checks on and running them through the lee push through die in your kit. After that size/check, then apply 2 light coats of tumble lube and then you have followed Lee instructions so that bullets are ready to load. So:  Lube, size/check, lube twice more then load. I follow Lee instructions and this works great for me.

Gary

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mrbill2 posted this 19 July 2014

You crimp on the check and size and lube the bullet at the same time if you are using a lube and sizer. If using the Lee sizer system you crimp the check and size the bullet at the same time, then lube. Don't size and lube the bullets before installing the check. You don't want bullet lube under the check. The check needs to grip the bullet base in order to stay tight on the bullet.

mrbill2

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onondaga posted this 19 July 2014

http://www.castbulletassoc.org/view_user.php?id=1659>mrbill2

What you are recommending is against Lee instructions. The OP is using the Lee Lube and Size Kit. For this kit, lubing with tumble lube before size check is recommended by Lee to avoid leading up the inside of the die and as a preventative against sticking a bullet in the die. That is sensible stuff and it is more than reasonable to just follow instructions from Lee.

 Lube under the check will not affect check fit or grip to the bullet unless your checks are too large because the bullets cast with an undersize check shank area for the caliber of check you are using. That is a bullet mold or casting problem, not a check problem.

Gary

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mrbill2 posted this 20 July 2014

I have checked thousands of bullet the way I said in my posted. And have never had any leaded die problems or stuck bullets. I like to do it that way to insure that the check is seated tight and square to the bullet base. I admit it takes a little more push to get it done but it works for me.

(That is sensible stuff and it is more than reasonable to just follow instructions from Lee.)

If the OP indeed has a Lee sizer, perhaps reading the instructions would have solved the problem. mrbill2

mrbill2

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TRKakaCatWhisperer posted this 20 July 2014

Both approaches have 'face validity'. It makes sense to follow the directions and it also makes sense to firmly seat the gas check.

This raises the question, do the the gas checks NEED to be FIRMLY seated? 10,000 psi will have SOME effect on seating them!

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Vassal posted this 20 July 2014

I have never had any trouble using the push through dies dry either. I also like the the idea of the extra tension on the check while seating. Of course if everything is perfect you don't NEED the extra tension,,, and the producer's needs and liabilities manifested and expressed in the instruction manual are in perfect harmony with ALL the needs of every end user..> 

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OU812 posted this 20 July 2014

My Lee sizing stem (CUSTOM HOLLOW GROUND TIP)works verygood at installing Gas Check square with base of bullet, especially if base has raised sprue cut area. I size all my bullets dry to increase resistance for better seating. Then lube afterwards.

Or you can size bullets upside down in your Lyman or RCBS sizing machine. Use a hollow nose punch to seat outer edges of Gas Check flush. Lyman dies work best because of shorter sizing stem.

  • Ultimately sprue cut should be perfectly flat on bullet's base. Opening sprue plate using gloved hand with downward pressure against mould block helps cut sprue more flush with base of bullet.

Bumping our bullets in a bump die works verygood also. This requires lots of pressure and a custom made bump die.

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csparks1106 posted this 21 July 2014

Ok, so what I am reading is that I should be using my sizing die to install the gas checks. The mold is .312, and my sizing die is .311. Obviously that isn't much to shave off, so I don't know if there would be enough resistance. I slugged my 300 Savage at .310, hence the .311 die. I need to check what diameter the mold is dropping, but it feels close to .312.

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jhalcott posted this 21 July 2014

ONE of my Lee molds drops a “fat” check area on the boolit. This causes the checks to “flare” out IF I try seating them with the Lee push thru nose first. They seat fine when I push them base first, though.! If in a hurry, and do not want to set up the other seater lubri/sizer unit, this is what I do.

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