Seating gas checks with powder coat

[Landshark9025]

I just started loading the Lee 312-155 2R bullet with Lil Gun for 300 BO. With a 1:7 twist barrel, I was able to find a load that returned about 1.5 MOA with my AR pistol, so happy with that. Now it's time to move to volume.

For my test loads I:

1. Cast
2. Installed gas check
3. Powder coated using the "Shake, dump, bake, water drop" method
4. Sized with Lee Push Through die that was opened to about .3095-.310

This worked well but for those bullets that the check didn't seat well, I banged it on the bench a few times to make sure it was seated well. This isn't going to work with trying to make 500-1,000 at a time.

Here's a photo of a gas check that popped right on:

It might go on more by rapping it on the bench, but it is straight and mostly seated.

Here's on that is straight, but does not bottom out:


Here's one that no matter what I did, it just wouldn't start straight (looks worse in the picture than in real life):


My questions are:

1. Knowing these drop at about .314, if I powder coat as is, will the second two seat properly when going through the .310 sizer die or will the powder coat keep the check from fully seating?
2. Do I need to "pre-size and seat" the check using a .314 sizer die prior to powder coat? I'd really like to avoid this step if possible.
3. Last option- Anyone shoot volume (like 2-300 in a single range session) of gas checked, cast bullets loaded with BLL? If so and with success, I could look into switching to that over PC

Thanks,

[Beagle333]

If the check fits tight, then gas check and size before coating. If it fits loosely, powdercoat first and add check later. It won't take but two or three boolits coated and baked to see if the check is going to still go on there later.

[swheeler]

Annealing the checks might let them seat better as would your suggestion to presize and seat to .314". I preseat the gas check on some bullets in 4500 Lyman with gas check seater before push thru sizing to powder coat, then size again when done! I know that's a lot of screwing around but some bullets need it, some don't.

[RU shooter]

I would anneal the checks (if copper) put them on and size them first . My one mould drops bullets with a slightly oversized shank and are troublesome what I do is use an old seater stem from a 30 cal die put it over the bullet nose and give a little tap on a hard flat surface with this little hammer I got . I only have Lee sizers so it's about the best solution for the problem I came up with . It's an extra step but really don't take that much extra time

[wnc435]

I used to seat my checks with the Lee push through die for these bullets I used my RCBS 30-06 seating die took seating punch out screwed nut on punch then screwed into die the wrong way used it to seat checks on went pretty fast I you hit to hard it would leave a ring on the bullet Just an Idea

[Landshark9025]

Thanks, gents. These go on too tight to try installing them after powder coating. I will pop the crooked ones off and try annealing them and see how that works.

Thanks!

[Kraschenbirn]

If you've got a Lyman lubrisizer available, Lyman makes a gas check tool that seats and crimps in conjunction with a standard sizing die and top punch. I use one to install GCs before coating then full-length size after PC.

Bill

[Thumbcocker]

I tap the stubborn ones with a Harbor Freight plastic faced mallet while they are sitting on the bench. Squares them right up.

[tomme boy]

The simplest way if it is not a pointed bullet to seat using a Lee push through is to take a flat piece of metal and put under the die and raise the bullet up like you are going to size. Then lower the ram and send it through the die. I use a piece of flatstock I had laying around.

I do the same thing with my RCBS lube sizer for the pointed bullets. Just have to find a nose punch that fits. Then just lay the same piece of flatstock over the die to seat, Then remove and size it.

[DAFzipper]

If you are powder coating shoot them without the gas check. I've pushed a NOE 130 RN to 2000 fps without any problem.

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[GARD72977]

If you are powder coating shoot them without the gas check. I've pushed a NOE 130 RN to 2000 fps without any problem.

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I'm going to try this. I have never shot a GC design without a GC

[Minerat]

I'm going to try this. I have never shot a GC design without a GC

Check out this sticky. It has a bunch of info on that subject.

http://castboolits.gunloads.com/show...-the-gas-check

[Lloyd Smale]

pretty heavy casting line on that bullet. Id bet the tough ones are because your mold isn't closing right.

[tomme boy]

They won't lead at 2K fps. But the accuracy might not be there either. Having the check on there will help the accuracy.

[Taterhead]

pretty heavy casting line on that bullet. Id bet the tough ones are because your mold isn't closing right.

This is good advice, and was my experince exactly. When I paid attention to give a bir of a squeeze on the handles, the gas checks fit better.

[charlie b]

Seat AND crimp the gas check either before or after PC.

Seating a GC square is key to good accuracy. I know at least one who made a die to keep the bullet straight as he seated the GC. I use a Lee sizing die. Run the bullet with GC up until I just feel it touch, then use a rod from the top and tap it down with a sharp rap or two. I use round nose bullets (Lee 309-180) with harder alloy and get about 1/10" flat spot on the bullet. After seating the GC firmly and square then run through the sizing die.

I have seated before and after PC. I do not have firm test data to say if one is more accurate than the other.