What's going on here?

[Ohiopatriot]

I'm having issues with gas checks on these.


As you can see if I seat them nose first they dish out and create a rim.
If I run them through base first they are a little convex and as seen in the 3rd picture flatten the nose.

It's a Mihec mold and is producing nice castings.
They're Sages gas checks and easily started with thumb pressure before running through sizer. I've tried both the copper and aluminum.

Used a Lee sizer initially and because of the "rim" on the check maybe the stem was undersized so I then tried the NOE. Same with either.

Not sure where to go from here. Any help appreciated.

*Edit : Looking at the pictures enlarged on the screen, the nose first ones aren't seated all the way to the base on the bullet.

I have further tried to tap them on with a hammer. Press them on with channel locks. And use an arbor press all in an attempt to preseat them, all to no avail.

I've also tried chamfering the base with the NOE tool. No joy.

[Winger Ed.]

That's a lot of nose and even base damage.

If they're unusually hard to push through:
I'd guess the sizer is trying to shrink them down too much, as in the boolits are too fat or too hard for that size of a die.

[Dusty Bannister]

Are you pushing them through dry? Polish the entry taper a bit more. Perhaps a little lube on the check area will reduce the friction? Still think the push rod is undersized to the sizer die.

[JWFilips]

Well yes they do not look normal but I bet they will shoot fine if they are sized and look like that! Not sure what is ging on the one on the left looks like the pusher stem is too small for the die... The one on the right is domed but both are seated well. I would shoot them and keep good notes

[Ohiopatriot]

That's a lot of nose and even base damage.

If they're unusually hard to push through:
I'd guess the sizer is trying to shrink them down too much, as in the boolits are too fat or too hard for that size of a die.

Doesn't really seem like excessive pressure needed to push through.

I've run them through the NOE .226 then the .225 with the same results. They drop from the mold at .226

They're water dropped and 18bhn with my alloy.

Boolit drops at .226
Shank measures .212
GC inner diameter .215
GC outer diameter .235
GC .010 thick

[Ohiopatriot]

Are you pushing them through dry? Polish the entry taper a bit more. Perhaps a little lube on the check area will reduce the friction? Still think the push rod is undersized to the sizer die.

I've tried dry, lubed and PC.

That was my first thought on the push rod and why I got the NOE setup. Both the Lee and NOE push rods do it.

[Ohiopatriot]

Well yes they do not look normal but I bet they will shoot fine if they are sized and look like that! Not sure what is ging on the one on the left looks like the pusher stem is too small for the die... The one on the right is domed but both are seated well. I would shoot them and keep good notes

Accuracy has not been good...... but....... I'm just at the start of load development for this rifle. Just trying to eliminate obvious issues early on.

If anyone has a good starting point (powder etc) for the Mihec .225 62 grain in an AR platform, I'm open to suggestions. I know it's a glorified 22 mag, but my 12 year old daughter likes it. I bought her a dedicated cast boolit upper in these panic priced ammo times to keep her shooting.

[tomme boy]

Show a pic of the base of the bullet before you put a check on. Looks like you have a nub on the base from the sprure. That makes it impossible to seat the checks. You will need to cast faster to not let the cutoff harden all the way.

[billyb]

Have you tried flaring the gas check before seating? Looks like the lip of the check is hanging up on the die as you insert the bullet nose first into the die. Looks like base first is the way to go.

[Cosmic_Charlie]

You might try annealing your copper checks. I do mine on the glass top stove. They change color and you push them off the burner with a spatula. TB's thought on the sprue nub seems good too.

[Ohiopatriot]

Show a pic of the base of the bullet before you put a check on. Looks like you have a nub on the base from the sprure. That makes it impossible to seat the checks. You will need to cast faster to not let the cutoff harden all the way.

I think they're alright......

[Ohiopatriot]

Have you tried flaring the gas check before seating? Looks like the lip of the check is hanging up on the die as you insert the bullet nose first into the die. Looks like base first is the way to go.

I have, with similar results.

[Ohiopatriot]

You might try annealing your copper checks. I do mine on the glass top stove. They change color and you push them off the burner with a spatula. TB's thought on the sprue nub seems good too.

I will try that today.

[Lloyd Smale]

usually the dished gas checks come from using to small of a punch. At least using a star or a lee sizer set up. Go to a lee sizing die. there push through so your nose doesnt bump up against anything. Its the only way to size if your using pc.

[Larry Gibson]

That doesn't look like a normal GC shank design.

What is the diameter of the GC shank as cast?

[brstevns]

Had this happen when bullet shank where gas check is to fit is too large , also when a gas checks inside diameter is just a few thousands to small. In my case those showing the cupped in effect worked just fine. This was on a 7mm bullet shot in a Ruger 7x57

[Bird]

Looks like the gas checks were not seated all the way before sizing. The shank does look kinda odd.
Try tapping the bullet into the gas check rather than just finger seating them. Use a rubber mallet or even a piece of wood as a test.

[Conditor22]

try putting your bullet seating/crimp die and lee pushrod (from the push through sizing kit) for that caliber on your press

raise the die and back off the seating stem

set a boolit with a gc on the lee pushrod and raise the ram

lower the seating stem to where it touches the boolit then adjust it down until the GC is seated to the depth you want.

after fully seated the bullets will need to be sized and GC crimped on

[JonB_in_Glencoe]

Had this happen when bullet shank where gas check is to fit is too large , also when a gas checks inside diameter is just a few thousands to small. In my case those showing the cupped in effect worked just fine. This was on a 7mm bullet shot in a Ruger 7x57

Like brstevns, I've had this also. A undersized GC shank will allow the GC to get smooshed back and dished, like the one's in your photo. One thing to try, is to size the boolit without a GC, then install the GC, then size it again.
Why do this?
Sometimes, sizing a boolit with a undersized GC shank, the shank will expand a bit, most of this depends on how much force is needed to push the boolit through the die the first time.

[Ohiopatriot]

usually the dished gas checks come from using to small of a punch. At least using a star or a lee sizer set up. Go to a lee sizing die. there push through so your nose doesnt bump up against anything. Its the only way to size if your using pc.

Used Lee then NOE. Both push through sizers.