GC removal in 44 mag molds?

[jmsj]

Hey guys,
I've got a question for those of you that have removed the gas check step in 44 magnum molds intended for full power loads. Is this a good idea or bad idea.
I have a Lee 310 RF-GC and I am not really fond of paying for gas checks or installing them. I am getting for Father's day the Lyman 429640 HP mold and that is a gas check mold also.
I want to shoot a cow elk and possibly a black bear this fall w/ my new Bisley SBH Hunter. So I want to use full power loads and wonder if I'm better off staying w/ the gas checks or if removing them will hurt or improve performance. I have slugged my throats and bore and I'm getting no leading on the Lee bullet now using FWFL for lube.
I would appreciate anyone who has done this modification on these molds to chime in and give me their opinion.
Thanks once again, jmsj

[BABore]

With your wheelgun and a 310+ gr boolit, velocity issues with a plain base is not a worry. While a GC design can sometimes be easier to get to shoot well, I have no problems with PB in the 44. My Ruger SBH Hunter actually shoots PB design better than GC ones.

That said, I see a couple potential problems that may or may not come up. When removing the GC shank there's a couple ways to do it. One would be to simply ream out the offending area. This creates a very long based band. The longer the base band, the harder it is to upset for oburation. It also increases the bearing length. Lee designs are not known for their excessive lube capacity. With more bearing you will need even more lube than before. This can be remedied by using a more high tech or slippery lube such as LBT. Another method of removing the GC shank is to machine off the top of the blocks til its gone. Depending on design, you may now end up with too short of a base band which has its own set of problems. Finally, you can bore the shanks out to create a long base band and then machine the block tops to get a perfect band length. That would likely be 0.090 to 0.120 with a full house load. The lube groove depth and configuration, above the base band, is one of the determining factors on base band length.

[Ben]

I had Erik remove the g/c shank on a Lyman single cav. 431215 mold and HP the mold providing 3 different HP pins also . It shoots GREAT in my .44 Special Lipsey model Ruger.

You can reach Erik at : http://www.hollowpointmold.com/

I highly recommend Erik for this kind of work. Here are photos if you'd like to see the results of his work :

When this link opens look in the top right hand corner for a red tab marked " SlideShow "....click on this and sit back and look at the photos :

http://smg.photobucket.com/albums/v494/haysb/431215%20%20HP/

[Dale53]

Ben;
Nice mould, nice bullets, and excellent pictures with slideshow.

Thanks for sharing with us...

Dale53

[Ben]

Dale:

You'd like to fire off a few of these in you Lipsey 44 Spec. ! !

Ben

[MtGun44]

I find no real reason for GCs in pistols. Not that they won't work, just that they are
an additional cost and effort without any payoff for me. It is no problem getting full max
magnum velocities out of a good pistol with a normal barrel and throat dimensions with
no leading and good accuracy, like 2-2.5" at 50 yds.

Keith called them diapers for boolits to keep them from making a mess. I read that decades
before I ever tried a magnum pistol with cast boolits. I have tried a number of them like
429215 and 429244 and found them to give much poorer accuracy than various PB Keith designs
from different makers. I gave up on them years ago and maybe today I could make them
work, since I know a lot more about it. I have no desire to try since I already have .44 and
.357 mag loads with various PB designs, Keith and LBT styles that work just fine.

[Dale53]

MtGun44;
I couldn't put it better, myself!

Dale53

[MtGun44]

Thanks, Dale.

Bill

[JIMinPHX]

When you get the mold, cast some up & try them as-is with no GC & see how they do. If you don't like the performance, they get someone to ream out the GC shank on 1 cavity. That way you can do comparisons between plain base & GC without loosing the ability to make both types. If you're still not happy with the performance, then get some gas checks.

At least, that's what I would do.

In my experience, I've gotten up to about 3/4 of full house loads on a .44mag before I saw an improvement from adding gas checks. Certain powders that burn hot, like H-110 will really chew up the base of a PB boolit. Anytime that I use H-110, I use a GC. Heavy loads of H-110 have given me my best top end loads in the .44 mag, but I always use GC or jackets with it. Unique has done well with plain base in that caliber up to moderately warm loads. This includes gas check design boolits without GCs. I haven't tried a true Keith design in that caliber. A true Keith may work better with heavy loads than the ones that I was using.

[MT Gianni]

I like a GC on a HP bullet. It allows me to use a softer alloy with good accuracy.

[jmsj]

JIMinPhx,
Thanks for your response. I have mostly used 2400 in 357 and 44 magnum loads, how does that compare to H-110 as far as tearing up PB bases?
I have admired your posts showing your machining skills. I have used machining tools on and off for the last 30 years but I am no machinist. But I know enough to know when I see good work.
I have a 13"X36" import lathe and boring bars. On the Lee 429-310RF-GC, if I decide to go the machining route, what do you think about trying to leave a little of the gas check step inboard to try to make another small lube groove?
Your expert advise woould be appreciated.jmsj

[JIMinPHX]

Just off the top of my head, I believe that 2400 is a little less harsh on plain base boolits, but I haven't done side by side comparisons at the same velocity, so please take that statement with a grain of salt.

H-110 is a little harsh on the boolits, but it gives spectacular results in the .44mag. I see 10 shot strings with total extreme velocity variation of less than 50 fps & I get accuracy that is better than I thought I could shoot. 2400 is a good powder & I use it in a lot of places, but H-110 is something special in high end .44 mag loads. It's just a super good match for hot loads in that caliber. I'm told that 296 is almost indistinguishable from H-110, but I haven't tried it myself. 2400 may be better for more medium range loads.

If you're going to try to peel the shank out of that mold on a lathe, than you might want to take a look at the fixtureing tricks that I pulled in this thread - http://castboolits.gunloads.com/showthread.php?t=45741.

Personally, I think that either a lathe with a boring bar or a vertical mill with a boring head are the best way to approach that kind of a job.

I like the idea of adding an extra lube groove. I often lube the area of the shank above the gas check when I load GC boolits. I think that you've got something there.

[JIMinPHX]

The top left picture in post #40 of this thread shows the effects of H-110 on a plain base compared to the effects of Unique or Bullseye. http://castboolits.gunloads.com/showthread.php?t=41033&highlight=H-110&page=2

[JIMinPHX]

I did a little fooling around with the .44 recently & was surprised to find that with the particular boolit I was using, I needed a tougher alloy for the .44 than I did for my .30-30 which pushes 'em out at about 75% faster. More on that here - http://castboolits.gunloads.com/showthread.php?t=81258

[jmsj]

JiminPhx,
Thanks for the response.
I'll have a pound of H-110 in the cabinet, I'll have to give it a try.
I am leaning towards machining off the gas check on the Lee mold, I like your fixture for indexing the mold. I think that fixture would be a fun shop project. I have been wanting to get a boring head for the mill/drill but I have been spending all my play money on casting gear.
If I go to gas checks I'll have to back over the gas check maker threads and figure a design out. I really like the idea of making as much as I can myself.
I'm still reading your thread on bhn, got to go help my daughter w/ her "new math" homework. Man they can take something simple and make it confusing.
I just want to say thanks again to you and all the others here at castboolits for all the help and patience you've shown me. I'm no expert caster but you guys sure have quickened the learning curve for me and probably others. jmsj

[JIMinPHX]

If you're going to make your own gas check maker, then here's a twist that you might want to consider -

Instead of reaming out the gas check completely from one of those cavities on your mold blocks, ream out just enough to leave the GC shank .007" below the diameter that you plan to size your boolits to. That way, you can set up your gas check maker to use .004" thick soda/beer cans as a raw material. Cans are a lot thinner than standard checks, but if you had a fatter shank on your boolits to accept them, I think that they might work very well. I haven't tried that yet myself, but it's on my list of things to do when I get time.

[jmsj]

JIMinPHX,
Leaving a thinner gas check step to use single thickness soda cans is a great idea. If I can get away not using GC's would be preferable. The Lee 310gr mold I have is a dual cavity so I think I can afford to experiment w/ it.
Thanks again,jmsj