Plain base gas checks, who here uses?

[gloob]

Never would have thought of it. Thanks! I'll sock that away for a rainy day.

Today, the sun shines! I finished my check maker, and it came out good.

Checks push/snap on firm and level by hand with just a firm push. Then a run through the sizing die NOSE UP, like normal. And just look at the results. The check is flat and level on all of them. There's a bit of variation in height, on my homecast. But they had already been through my sizing die twice, so no resistance.

It might look like some of the checks are not symmetrical, that they're real thin on one edge. They're not. They're almost perfectly symmetrical. It's lube. The checks consistently pinch in a bit at the mouth, forming a tiny lube groove.

Seating and sizing is same as doing normal checks on bullets made for it. EZ peezy. Just had to stone the mouth of my sizing die a wee bit to smooth out the little sharp ledge.





And my press reaches TDC on this one, too. Utterly smooth. No jams.

[gloob]

Hmm. I'm starting to see some of the finicky nature of seating thick PB checks. Now I see why you might size in steps.

I made up a fresh batch of bullets, and the checks won't go on the unsized bullets, at all. To get them on straight, I have to size them, first. So I still have a huge variation in OAL after crimping them on, and it may be due to the lack of resistance.

The problem I have going base-first, the bottom of the check ends up convexed rather than flat, and it might just be esthetic, but I don't like it. My button is maybe 4-5 thous smaller than what they're using in the sticky, and that might be why I get the cupping, base-first. (So if you want to get flat checks when going nose-first, you might want to try a smaller button; it seems a common complaint that the checks end up concave, when sizing nose first, but not with mine).

I may just leave my check dimensions alone and buy a second sizing die. Size, add check, size smaller. For pistol bullets, I'm sure they'll work fine, even if this doesn't improve the consistency. But hopefully the OAL tightens up closer to what I get with my MBC bullets. The presized MBC's take the check perfectly, and the 18 BHN hardness gives a lot of resistance going nose up through my sizing die.

It looks quite challenging for a PB die/check seller to get a customer exactly what they want.

[Soundguy]

Your setup looks great. Thanks for posting. Loving the discussion and all the ideas and info being bounced around. Thanks

[gloob]

Thanks. I'm glad some of it is useful.

I found a potentially better and certainly cheaper way for me to pre-size just the base of my bullets. I found the opening of my Lee 9x18 Makarov expander die is right on 401. A bit of polishing of the mouth and fabricating a couple new parts, and she's right.

I made a .556" circle of 1/8" steel plate to slip into my ram for a "push thru stem" but with negative height. The nose of the bullet sits partway into the hole in the ram, this way. So I can get full leverage without having to set my sizing die way up into space. Then I set the die so I can go all the way to TDC, sizing the base of the bullet deep enough to clear the height of my checks, plus a smidge extra.

I put a knob on a 1/4 steel rod to sit in the die as an ejector. It fits through the power-thru expander plug. When I size the bullet, the base of the bullet pushes the rod up. After lowering the ram, I give the knob a smack with my hand, and the bullet drops out.

It's a bit tedious, but the check will fit on there fully by hand. And the rest of the bullet is still unsized, so the checks get crimped on nice and consistently, now.

[gloob]

Top to bottom:
1. bullets as cast after tumble lubing
2. base-sized with mak die
3. checks placed by hand
4. nose-first sized to crimp check in place.



Here's the mouth of the mak die. I shortened a spare expander plug to sit on the base of the bullet. The die is set to TDC of the press, but I think a positive base will help to ensure the bullet finishes straight.



I added a spacer. And the ejector rod. That's pretty much it, beside some polishing. And the little paddle slips into the ram, with that little handle to easily take it back out. You can see a spot of lube in the middle from use.



You can see the result of the sizing better in person. The sizing is very minimal, and it is not even visible all the way around. Just where the bullets are larger than 401, which is only some of the not-so-round bullets.


Place bullet nose down

Ram reaches TDC

Lower ram. Smack the ejector knob.


I also made a base-sizer just by drilling and sanding a hole in a 1/8" thick piece of steel. It works fine, tapping or pressing a bullet in. But when I got round to figuring out how to attach it to the press, I discovered I could just use the mak expander die!

[gloob]

I finally got to test my 401 bullets. I shot some unchecked bullets with just tumble lube. Some "greaseballs" that had the entire lube groove filled in with beeswax and motor oil. And I shot some checked bullets, mostly with just tumbled once, before checking/sizing.

Tumble lube bullets were the worst of them. They left patches of pretty thick fouling in both 40 and 10mm. Not full length layer of lead, but clearly not good. The greaseballs worked obviously better, but still a bit more fouling than MBC. MBC bullets are much harder than my bullets. Mine might be too soft for 40 cal.

My checked bullets with 9 thous roof flashing worked great. They cleaned the fouling out of the bores, just like jacketed bullets. Accuracy was good out to 50 yards, at least. Couple caveats. One of my guns has a groove size that is evidently larger than my sizer. Even my checked bullets left some fouling in the grooves. But even jacketed bullets did not clean out that lead.

After realizing how improper seating left some of the checks barely clinging on, I fixed most of them. But I went ahead and loaded up about 25 of them, just to see what happened. I found 9 detached checks, all from 5 to 15 feet away. They are obviously from the ones that weren't seated flush enough.




I also made a new base-sizing die. My mak die only just touched the bases, leaving them about 401. My new die takes them down to 395 or so. I found the gas checks seat a few thous flusher when using my new die. And you don't have to push to get the check on. Just touch the bullets into the check, and it fits good enough to hold the check as you put it into the sizer.




place bullet in
[Imgur](https://i.imgur.com/JiCu1rj.jpg)
lift to TDC
[Imgur](https://i.imgur.com/4aXUk3t.jpg)
lower ram, and the bullet autoejects, using the primer arm.
[Imgur](https://i.imgur.com/8Ap4TUn.jpg)
https://i.imgur.com/Wa37CAu.jpg

I screwed up my measurements, and I had to glue a brass slug into the primer cup to get it to eject the bullet.


Edit: I also discovered that the checks were going on consistently nose-first with the hard MBC bullets, but consistently bad, like Larry warned of. There was a large air gap between the bullet and check. These 18 BHN bullets appear to take checks better sizing base-first. Even after base-sizing, I had to push on the nose with a rod, to get them to seat well when going nose first. I bet that could be sorted with yet a smaller base-sizing die.

I also found the checks were going on near flat to slightly concave when crimping nose-first on these hard bullets. Pulling the checks off, there was a rim of lead sticking up around the entire rim of the bullet, contributing to this effect. Base-first, the checks were convexed, but if I pressed hard on the back of the check to "remove the air," they also become slightly concaved, due to that rim of hard lead.

When seated good (for me, so far) the length of the bullet grows by the thickness of my check plus 20 thous. The badly seated ones can grow by the thickness of the check plus maybe 60 thous. This is the same with my super soft bullets and the MBC (the softer ones are just more easy and automatic to seat nose-first to +20). Maybe thinner or better checks can be seated even flusher than +20.

I'm still a noob at this, but my favorite way to do this so far with my fat checks is using soft bullets, base size the bullets, add check, then size nose-first. My checks seat almost as flush as so-far possible this way; they shoot great; and they look the best, with perfectly flat and perpendicular checks.

My die won't make soda can checks. A bigger button would probably help. Or maybe my die is too soft/dull or too loose in the tolerances. I might be shopping for a 6 cavity TL groove mold. My bullets seem way softer than anything for sale. And pouring two bullets at a time just doesn't do it for me, other than in a pinch.

edit:
I tried sizing the bases of these hard MBC bullets down to 390. It works ok, but even if I use my 395 die, first, this leaves a huge flange of lead sticking out the side of the bullet. If I size the bases extra high, that leaves some space for this lead to fold into, when crimping nose first, and the flange adds resistance in the sizing die, even if the bullets were already sized. So it might work ok if I make a new die. The lead flange kinda messes up the looks a little, because the flange breaks off in some spots rather than filling back in. But the checks come out flush and flat, nose-first.

[gloob]

My apologies to the OP for taking over the thread. I have tweaked my "base-sizing" die a bit with a more progressive taper and a high polish, and I think the results are quite good and consistent, now.

I tapped the die for screws, so I can easily play with the dimensions without worrying too much about going too far. I can also use different inserts for different bullets or check thicknesses, or size down in steps. Here are some of the hard 18 BHN bullets that were run through the base sizer. The rim that pushes out of the base when you squeeze the check on an unsized hard bullet barely occurs when base-sizing with my die. And by setting the press to slightly "oversmush" the bullets, it somewhat flattens out what little rim occurs.

The flange that I was getting out the side of the bullet is pretty much gone, too, just from better tapering and polishing.

The OD of the sized portion is 388-390, well below anything you can do with a normal sizing die without destroying your bullet, but leaving a decent amount of lead left to be displaced/swaged by the check.



As you can see, I am now getting the checks on there more flush. Length of this bullet grew by less than 17 thousandths, including the ~9.5 thou thickness of the check, itself. Sized nose-first with no rod/pressure on the bullet. And the best part is the consistency...





... They all measure that. This entire lot of GC'd bullets varies in OAL by only 2 thousandths of an inch extreme spread, just run through the sizing die nose first. That's the same variation in OAL of the bullets before adding the checks.

[northernlead]

Just what I wanted to here.

[Soundguy]

Neat.

[gloob]

Thanks. I guess I'll add some new data for those interested.

I made another insert for 358 bullets. I'll probably post some pics, soon. But here's what I found.

It took two tries to get it right. My first one only sized the base to 350, because that was the size of my closest drill bit. I got a bit of variation when crimping them on, unless I pressed on the nose with a rod in the sizing die.

Second try, I went down a drill then opened it out. I ended up at 346. Results appear to be just as good, now, as with the 40. At least regarding flush-ness and consistency. The checks end up very slightly concaved, though.

So with the 40 cal, I ended up at 12 thous under bullet size. And on the 358, I am also pretty happy at 12 thous under. Same thickness of checks, about 9.5 thous.

[gloob]

358 bullets with 9.5 thous checks.


Here's a better angle where you can see the slight concave check base. The two on top are already base-sized. You can maybe see the actual base of the bullet is very slightly concaved by the displaced lead.



These checks add ~18.5 thous to the OAL of these 12 BHN bullets, consistently to a thous or so. About 2 thous more length than the 40 cal checks, maybe due to being taller and displacing more lead.

I needed to use a good fitting top punch to get these fine-pointed bullets into the base-sizer. I converted my Mak seater die into a universal top punch.


I am posting a new thread on this, in Reloading Equipment.

edit: here are some mixed bullets, 4 before base-sizing, 4 after sizing the base down to 345-346.



The base-sizing adds a step, but it's pretty easy to execute once the dies are dialed in. Lube builds up and makes the primer arm stick in the die, so after ejecting the bullet the primer arm is sitting up in the die, forming a flat surface. Just place the bullet roughly over the hole in the die, and it will sit straight with the top of the primer arm supporting it there, so no worries about the bullet tilting or falling over while raising the ram. The top punch will easily catch and guide the nose of the bullet, and the bevel on the bullet base will guide it into the mouth of the base sizing die. Everything stays straight. No hiccups or malformed bullets with a decent top punch. This step goes fast and smooth!

[pt4u2nv]

Been awhile since I have been on here but I have many PBGC dies that I bought from Pat Marlin and they have worked flawlessly . Nobody has mentioned him that I saw on this thread . Is he still around ? Nobody buying from him ? Whats up ?

I use his checkmaker for 9mm, 10MM, 40 , 45, 38, 357, 44 Mag ,357 Sig and they have worked great . I also PC all my boolits with no lube and barrels are very clean when i finish

[Larry Gibson]

Guess I should have given Pat credit as it's one of his GC makers I use to make PB 45 cal GC's.......my apologies to Pat. I also have one of his regular GC makers which I make 35 cal GCs with.

[TD1886]

Here's what I do and have been doing it for decades. I make my modified version of what the call a freechecker. I make thick washers that fit inside the nut that retains the H & I died in Lyman and RCBS Luber/Sizers. I make those washers for each caliber I'm going to freecheck. I then cut a small recess in the base of that thick washer to hole the aluminum disc that will become my gascheck. The purpose if this washer is to guede the bullet straight into the sizing die. The only thing I do to the H & I die is to radius it's open more and polish it up with good. This aids in the transition of the aluminum discs and the bullet entering the die. You have to make a discs cutter to the correct diameter. So here is how it works: You take the thick washer, put a discs on that bottem recess cut for it, and it was stay there from the little lube that area gathers, place the washer with the discs in it into the inside of the die nut. Next place the bullet to be sized, lubed, and gaschecked gently into the washer and then lube/sizer as normal and when you eject it you have a sized/lubed gaschecked (in this case "freechecked" bullet) bullet. No having to size the shank area of the bullet down. If the discs are made of soda cans they can withstand up to 2100 fps. Lot simplers making them and using them than explaining them. Like I said l've been using them for 20 years.