Gaschecks slamming into chronograph

[Marlin Junky]

I had several gaschecks separate from boolits today and would like to get some input.

What I can tell ya:

Rifle is a .35-366A made in '51 with deep grooves... about .005" or slightly deeper in places (near the chamber).

Boolit is SAECO 352 that drops from the mold about .3605" to maybe .361" max. Boolits are slightly out of round 'cause the mold is shimmed to cast a wider boolit.

Gaschecks are Hornady and were annealed on a red hot electric stove for 15 to 20 minutes in a skillet.

Gaschecks were applied with a .360" Lyman 450 die that was polished out somewhat and just barely touches the boolits above. The checks were all inspected before boolit seating and all seemed to be tight.

Boolits were loaded into .35 Rem cases and seated so the checks were below the shoulder in order for the rounds to chamber.

Velocity was 1950 to 2000 fps. Powder was AA2520 and DP-74.

MJ

[arkypete]

Marlin
I've not had any indication of the gas checks coming off with my any of my rifles.. But I don't have a chonograph either.
An idea, check the gas check shank diameter on a handful of the bullets, to see if there is any variation.
I use the Lyman sizer like an arbor press for seating the gas check on the boolet. I put a piece of flat steel over top of the sizer die and use the nose punch to force the boolet into the gas check. Once I've finished seating all of the gas checks I size and lube.
Like you I anneal all of the gas checks as soon as I get them.
Jim

[Glen]

Nice rifle and a good bullet for that rifle. It sounds to me like you're not getting the GC fully crimped onto the base of the bullet. What does your GC shank measure? A friend of mine was having this problem with this exact same bullet and it turned out that his GCs were too thin (he was using some Hornadys that dated back to the early 70s). I measured some of my new Hornadys for him and convinced him that the new ones would work, and he went out an bought a new box of Hornadys and the problem disappeared. You might also try sizing them .359" to crimp them a little harder (I shoot CBs at .359" in my Marlin .35 Remingtons, and they shoot great).

[MT Gianni]

MJ, I bought a new Saeco 352 3 years ago. No checks would stay on unless sized at .356 in which case 1/2 stayed on. I talked to Saeco & they told me to try another lot. I tried the 3 I had on hand and returm\ned it to them with 3 examples of the 3 lots I had. [LY & Horn.] They reamed it to fit the checks, No charge each of us shipped at our own expense. I am very happy with the results. Be prepared to give check diameters as well over the phone. From this I would try a couple of different lots of checks and call them. Gianni.

[Marlin Junky]

OK... just a couple of thoughts/concerns at this point.

I have next to no experience (just a few range sessions) with .35 cal checks in bottle-necked cases and am wondering since they are so much thinner than .30 cal checks (unless otherwise noted, my checks are only from Hornady) I was thinking that it's not a good idea to be annealing the heck out of them. I don't think the problem is associated to the diameter of the GC shank because the checks appeared to be on tight. Of course, that doesn't mean a few boolits with marginally crimped on checks couldn't sneak by my inspection; but, my chrony was hit a half dozen times out of 60 rounds.

I have about 5K Hornady checks that I bought recently from Midway just before the price skyrocketed (to help pay for the war, I guess) and I'm hoping they'll stay on the shanks of my boolits cast from my .360-220 GB mold (when it gets here) 'cause I was planning on shooting them hard from a new .35XLR (when they become available). I think the next time I crank out some SAECO 352's for the .35 Remington, I won't anneal the checks. My chronograph took a beating today but I didn't notice how much of a beating until I packed it up at the end of the day. At one point a check clipped the cable leading from the chrony to the remote display and I think I should probably to replace it... anyone know if Staples or Office depot carries these phone cables? The cable is larger than the standard 2-line phone cable but does not have an RJ-45 connector as the cat-5 ethernet cable. Maybe it's a 3 or 4-line telephone cable.

MJ

[Bigjohn]

Marlin, wayward checks can be a problem and if you do a search of this site you will find references to screens to prevent the check from hitting the screens.

As you have the remote display version you may need to shield the leads. Not knowing what materials are available to you over there I will refrain from making a suggestion. In Australia we use a flexible electrical conduit.

Best of luck

John.

[Bass Ackward]

I have about 5K Hornady checks that I bought recently from Midway just before the price skyrocketed (to help pay for the war, I guess) and I'm hoping they'll stay on the shanks of my boolits cast from my .360-220 GB mold (when it gets here) 'cause I was planning on shooting them hard from a new .35XLR (when they become available). I think the next time I crank out some SAECO 352's for the .35 Remington, I won't anneal the checks. MJ

MJ,

Now you know why the Gator buy was so popular. I was once told that 35 caliber checks are the thinest checks of any caliber.

But I think anneal is actually helping. It stops springback. That is a good thing. My guess is that you didn't anneal long enough or hot enough. Best to use an enclosed method, so that heat is 360 degrees.

A threaded pipe with caps on each end allows you to chuck it in a fire and walk away. Just because you heat, doesn't necessarily mean you annealed evenly unless all checks were one layer deep with their bases flat against the skillet. Maybe you did, but I never had your problem after anneal.

But checks coming off will play havoic on the target too. And when your base is oblonged from beagling, the check is not going to make the same 360 degree contact all around so correct anneal is even more important in your situation.

Other options are more antimony in the bullet for a larger base or polish out the bases in the mold or use something like super glue or lock tite as a space filler to fill the space and support the check.

I like rifle checks to BE TIGHT!!!

[Jon K]

MJ,

I think you may want to see how easy it is to pop one of those GC's off, and check your brass. As the brass flows with firing, it will build up a ridge at the neck, on the inside of the case. Now this may attribute to the GC seperating. Also I have had trouble getting the GC to crimp firmly on the boolit, when sizing the boolit large. I have the Saeco 316 the GC criimps tight @.309, but @.3105 it is not always tight, alloy is WW/12% lino.

Good Luck & Have Fun Shooting,
Jon

[Marlin Junky]

Bass,

My sentiments exactly... on all accounts.

I guess the Gator GB is history, huh? One of the reasons I took a shine to the .35 was because I liked the price of the Hornady checks! Now I feel I was bamboozled

When I anneal checks on the electric stove I lay them out flat, one layer deep, with the bases down. The last time I annealed checks I turned the range-top down a little and cooked a bit longer 'cause the time before that I ran the range-top at its highest temp for about 20 minutes and my wife freaked out 'cause the stove top was warping. Next time I'll lay my casting thermometer in the skillet to see how hot the surface gets. Perhaps I should lay the checks cup down? Using my method .30 cal checks have come out so soft I can dent the sides with a finger nail. I've never tested a .35 check for softness 'cause I use the same method for the heavier, stronger .30 checks; however, my .30 checks always come out an even color while the .35 checks I've annealed so far have an uneven case-hardened-color-like appearance.

Without more testing, I believe you've hit on the essence of the problem which should be resolved:

MJ,
But checks coming off will play havoic on the target too. And when your base is oblonged from beagling, the check is not going to make the same 360 degree contact all around so correct anneal is even more important in your situation.

I've also noticed that the .35 Hornady checks don't seem to have the aggressive crimping lip at the top like their .30 checks and perhaps need a harder boolit alloy to hang onto; i.e., the 14 to 15 BHN metal I'm using is allowing the checks to be stripped off. How much are those Gator checks? Are they less than Hornady .30 checks?

MJ

[Marlin Junky]

MJ,

I think you may want to see how easy it is to pop one of those GC's off, and check your brass. As the brass flows with firing, it will build up a ridge at the neck, on the inside of the case. Now this may attribute to the GC seperating. .

Jon,

Brass has only been fired twice. I don't know what to think about your sizing comment but my checks are definitely bottoming out before I crimp them on and they won't loosen no matter how many times I chip my thumbnail or try to rotate them with finger pressure. I sure hope Lee cuts that .360-220 GB boolit so it casts .361 on the body and has a wide enough shank to hold Hornady checks on tight. I probably should find a .361" die somewhere 'cause I'm running the SAECO bullet into my polished out .360" die only down to the top of the lower driving band (see picture of SAECO 352 below) so my checks will end up near .361".

MJ

[Marlin Junky]

There's a couple things I can try but I think I'll heat treat the next batch of 352's to about 20 BHN and see what happens. I will need some Gator checks though if I want to use the .35 on a hunting trip with an alloy that'll expand down to 1500 fps.

Thanks to everyone for the input.

MJ

[grumpy one]

Like most of us I don't know how many of my checks come off in flight, but it is possible to look at this as a simple engineering problem. Consider a standard Lyman check without the crimp-on feature that the Hornady has. That check is only held on by the stretching that occurs when it is seated, and if the free diameter of the check (i.e. OD before fitting) is larger than the sizing die, the whole exercise is doomed to failure. The check will be squeezed down by the sizing die, the lead bullet shank will be permanently deformed more than the check will (less spring-back) so after sizing, the check will be loose (whether or not you can pull it off with your fingers). Such checks need to be annealed so they won't spring back - there is no other way to keep them on the bullet after sizing. Even annealed, they will just barely be retained, with negligible clamping force due to the softness of the check. For that situation you don't really want annealed Lyman checks, you want annealed Hornady checks with a crimp-on feature.

Now consider a check that has a free OD that is smaller than the sizing die. It won't be squeezed down below its free diameter, and while the bullet shank may be reduced in diameter slightly by sizing the bullet will still be gripped tightly after sizing because the gas check is still springing in the smaller direction, not the bigger direction. It would be really dumb to anneal the check under those conditions, because you would just be sacrificing all the spring-back tension that is the only thing holding it onto the bullet.

FWIW, the free OD of my old Lyman 30 caliber checks ranges from 0.308 to 0.310. I size my bullets from .0311 to 0.313, depending on which rifle and how I happen to feel at the time. Hence all of my Lyman checks end up gripping the bullet shanks after sizing, and have a good chance of staying on. They'd have less chance if I annealed them.

Of course if I were sizing to 0.308, I'd need to anneal those checks, or they'd fall off.

[Marlin Junky]

I just read that copper annealing takes place above 761F. I've got an oven thermometer sitting in the skillet I use for annealing and I've got the burner turned up all the way. It managed to reach 500F but it took a few minutes to get there. Perhaps I didn't anneal my .35 checks at all last time... also evidenced by the funny coloration I mentioned earlier.

MJ

[No_1]

MJ,
The GatorChecks are less expensive than the Honady across the board on all sizes. I have also noticed that the thickness differs on the gc's. The 35's are thinner than the 30's or the 323's. The last GatorCheck GB I ran had a minimum buy in of 5000. You may find someone out there that will part with a couple of K's OR if you are willing to do a little work for some I have an idea that may be up your alley and I think a deal can be made. If you are interested, send me a PM.

Robert

[Marlin Junky]

...The 35's are thinner than the 30's or the 323's.

Robert,

.35 checks are usually thinnest/cheapest check available, no matter what the brand. Probably because there's so many cheapskates shootin' .357/38 wheelguns. PM sent.

MJ

[Marlin Junky]

I'm almost convinced I didn't get my .35 checks hot enough the last time I annealed them. I just finished annealing a new batch on the electric range top and the checks came out with better, more even coloration. This time I maxed out the range top's burner and cooked them a half hour plus on the glowing orange hot burner after they became covered with carbon. Next step is to shoot 'em with a screen placed in front of the chrony to see if the checks stay on. I also shimmed my 352 mold a little more and ought to get another .0005" to .001" out of the next batch of boolits.

MJ

[Griff]

Boolits were loaded into .35 Rem cases and seated so the checks were below the shoulder in order for the rounds to chamber.

Load some so thr check is inside the neck. Load singly and see what happens. Only thing I'll seat below the shoulder is a boattail.

[Marlin Junky]

Load some so thr check is inside the neck. Load singly and see what happens. Only thing I'll seat below the shoulder is a boattail.

Griff,

The chamber won't allow it.

MJ

[jh45gun]

I never heard of annealing gas checks before. do you do this with all calibers or just the 35? Most of my use of gas checks will be 30 caliber sized to 309.

[Marlin Junky]

I never heard of annealing gas checks before. do you do this with all calibers or just the 35? Most of my use of gas checks will be 30 caliber sized to 309.

I started annealing .30 checks years ago because of the spring-back factor. If the boolit's shank (the groove diameter part) ends up slightly smaller than the gascheck after sizing and the lip of the check is below the shoulder/neck junction of the cartridge case, problems can result. Even if the check is not below said junction, if the check opens up the neck while seating to a diameter larger than the boolit's shank, accuracy may take a beating.

MJ