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View Full Version : Gaschecks and "Goo"....



BruceB
08-08-2006, 02:35 PM
The current batch of Hornady .45 gaschecks on my bench are a loose (VERY loose) fit on no less than three different .45-caliber rifle-boolit designs which I use.

The fit is so bad that the checks are chopping the bejaysus out of my chrono screens and their diffuser supports, located just ten feet from the edge of my van's benchrest. EVERY gascheck imprint on the chrono assembly is a .45, in spite of my having fired thousands of rounds of other calibers over the screens. They are obviously leaving the bullet as soon as they hit open air.

I found that I can firm-up the attachment by sizing just the bases of checked boolits in a .457" die, but that sort of ruins the whole purpose of sizing to fit the bore, which in my Shiloh is .4575 or so. (My customary sizing diameter is .459", which works well in this rifle.)

After arriving home from work last night, and not having to arise at 0330 on my day off, I cast up a few hundred 457483s, a roundnose 390-grain gascheck design. On sizing a few, I naturally encountered the same loose fit with the checks. After a bit of searching, I found my 50ml bottle of red "permanent" LocTite, and treated a couple dozen gaschecks before placing them on the boolits for sizing. They were still loose, of course, some pulling off while still in the die, and some partly coming off as they were removed from the sizer. I just pushed 'em back in place and left them overnight.

This morning, they are TIGHT. I can't move them at all with any force I can exert with my fingers. So...it may just work!

To avoid the mess associated with LocTited checks coming off in the sizing die, I now have a hundred or so naked boolits on the bench with checks LocTited in place. The bottle says, "Fixtures in 30-60 minutes, full cure in 24 hours". In an hour or so, I'll see if they're secure enough for the sizing process. I'm quite hopeful about this, even though it's an extra step. What I do is lay out a dozen or so checks mouth-up on the bench, and place just a small drop of LocTite in the center of each one. On removing a freshly-applied check from the bullet to have a peek, I find that there's an even coat of the stuff on both base and gascheck, but none escapes around the edges to foul the die. Of course, a nice flat boolit base helps here, too.

Shooting tests of these bullets should be fired on Thursday, if not before.

StarMetal
08-08-2006, 02:47 PM
Bruce,

I was looking at some new 30 caliber Hornady gaschecks and noticed two things, one they are the shinest and polished I've ever seen them, and two, they fit loose, real loose. Hornady changed something.

Joe

Dutch4122
08-08-2006, 03:41 PM
Noticed the same thing with Hornady .45 caliber gas checks on the Lee C457-500-RF that I have been working with in my .450 Marlin H&R single shot. I shoot these unsized at .459" (the bore slugs .4575") as dropped from the mold. Gas checks were a loose snap on fit, so I used a dab of "Krazy-Glue" and let them set for 24 hours. Tight and no more spin; also no flying saucers hitting the chronograph.

Bass Ackward
08-08-2006, 05:00 PM
I suspect that lose fitting checks is more of a problem than a lot of people suspect. Peopleused to hate Lyman checks for that very reason although they seemd to have gotten away from the lipless check. I don't notice it because my chrono is protected from "direct fire" these days. :grin:

What is strange in Bruce's account is that if he sizes his bases in a 457 die, the check stays much better than if his barrel sizes it to .4575.

I suspect that because of material costs, Hornady is cutting costs where ever it can either in saving energy in the anneal process, material costs in the sheet thickness, or chemical composition of the sheet material. Looking at gas check prices, I can see they must be going broke. :roll:

RANGER RICK
08-08-2006, 05:22 PM
Hornaday was also giving me fits .I changed over to Gator checks and no more problem .
Plus gator checks are less expensive than all the others from what I have seen.

RR

jhalcott
08-08-2006, 10:29 PM
if it is true that Hornady is making lyman and hornady checks ,they may only be using the lyman machinery. Less steps to produce and just dump them into any box on the line.

madcaster
08-08-2006, 10:37 PM
If the little thingies weren't so slow to make I think we could all do better at times,just because we care to.

BruceB
08-09-2006, 07:09 AM
I sized-and-lubed the boolits to which I'd attached the checks with LocTite.

Out of perhaps 150 bullets, only five checks came off, which gave me a chance to inspect the "insides" of the job. It seems like I was a bit too stingy with the stuff, as the bases of the bullets and the gaschecks were not well-coated. I changed the system a bit for the next bunch, now setting-up on the bench.

For this new group, a finishing nail was used to ensure that the fluid reached all over the cup, including right into the corner between side and bottom. When the check is pushed onto the boolit, a bit of the stuff oozes out around the top of the check, so at least I'm sure of good contact on the shank.

LocTite, epoxy and Krazy Glue all set up as "brittle" bonding agents, and I'm wondering if something a bit more flexible might do as well or better. A good rubber-based cement might be worth a try, and I'm also thinking about Gorilla Glue, which has a bit of an expansion factor as it sets up. This expansion should ensure good base-to-gascheck contact, as long as it doesn't push the check away from the base as it expands slightly. The danged stuff grips like iron, too.

Bass Ackward
08-09-2006, 07:18 AM
I sized-and-lubed the boolits to which I'd attached the checks with LocTite.

Out of perhaps 150 bullets, only five checks came off, which gave me a chance to inspect the "insides" of the job. It seems like I was a bit too stingy with the stuff, as the bases of the bullets and the gaschecks were not well-coated. I changed the system a bit for the next bunch, now setting-up on the bench.


Bruce,

Did this add anything to the accuracy depeatment? Or is this strictly a chrono protection trial?

JDL
08-09-2006, 07:48 AM
BruceB, Have you tried annealing the checks? I did that on some and it helped by reducing springback. -JDL

Bucks Owin
08-09-2006, 09:06 AM
I find the same thing as you Bruce regarding loose checks, I'll try the loctite approach!

Thanks,

Dennis

(Although I haven't had any problems with them hitting my chrono, maybe it's because I set it 3' from the muzzle. That way it gets spattered with bullet lube!) :roll:

9.3X62AL
08-09-2006, 11:39 AM
Gas check fit can be an exasperating factor in cast boolit shooting. In a couple examples--my Lyman #311291 and #257420--the GC shanks on the castings are too big, so I have to flare the edges out slightly with a punch to get them to fit on the shank.

On the other extreme--and this is not a recent development, it dates from the 1980's--my #454490's shank was too loose on the shank when sized to .454". All was well when sizing to .452 for the now-departed S&W Model 25-2 and its EXACTLY MATCHED .4515" throats (GROAN, WHY did I let that one go.......), but when sizing at .454" for the 45 BisHawk's .453" throats, things wouldn't stay together. Annealing the checks didn't help, either.

One other thing noticed when sizing the boolits in the .454" die........the drive bands weren't always "cleaning up" evenly like they had in the .452" die. The ever-present Lyman Curse of "UNDERSIZED BOOLITS" reared its head yet again! Micrometer work confirmed The Curse's presence......what to do. I lapped the cavities with soft/unalloyed lead slugs and automotive polishing compound, going slowly in two steps, with test casting taking place after each lapping session. I was a first-timer, kinda learning as I went along. After the second lap, boolits fell out at a fat .454", almost .455". I continued casting, pouring about 200 boolits. This mold had previously been kinda balky about boolit drop-out, and that quirk had disappeared. Nice. When the castings cooled, I tried the Hornady 45 checks--a nice snap fit. VERY nice. The trip through the sizing die produced even drive band contact, .454" boolits, and good fit in the Ruger's throats. With luck like that, I should have taken my paycheck to Santa Anita or Las Vegas, but I digress.

I don't have enough molds of any maker to make a blanket statement, but the only maker's products I have that produce loose or tight gas check fit are Lyman molds. NEI, MM, RCBS, and a smattering of other makes all seem able to get shank diameters correct--although RCBS falls down a little on 45 rifle drive bands, while getting the shank right.

All in all, if I can get a rifle or handgun to produce reasonable accuracy and meaningful velocity without use of a gas check design, I'm all about using plain base boolits whenever possible. Gas checks have become for me a necessary evil restricted to venues where their capabilities are required, otherwise a plain-based slug gets the nod.