Where do you get Plain Base Gas Checks and can they be crimped with a Lee sizer?
Thanks
Where do you get Plain Base Gas Checks and can they be crimped with a Lee sizer?
Thanks
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
That explains why I'd never heard of them. I saw a post in cast boolit with a pic of one, looked interesting. Don't think I'll invest that much money right now. Thank for the reply.
"Some times it's just better to smile an walk away."
-161
"Think ya used enough dynamite there, Butch?"
-Butch Cassidy & the Sun-dance Kid
If you put a gas check on a bullet that was not designed for it not only will it be harder to size the bullet causing distortion but the metal that is displaced from not having a gas check shank will also distort the bullet even more. Not to change the subject but have you ever wondered why shooters wanting to get the best accuracy pan lube their bullets. It is because the bullets do not get distorted buy being sized in a sizer die. When a bullet is larger then a sizer die and is pushed through, it swages the metal in the path of least resistance making it as round as the sizing die is. The best combination is a mould that casts a bullet of the right size, and is round that needs no sizing and can be pan lubed or put through a sizer die that does not size but only lubes the bullet. This is why it is great that we have group buys here at Cast Boolits getting a mould that drops bullets that fit our guns and require minimal sizing or non at all. When a new shooter asks questions somebody always says we need more information like what kind of gun, is it for light plinking loads or heavier hunting loads and what about extreme target shooting.target Then you will also be asked did you slug your gun. Then you will get a flood of answers.
Now you got me thinking. I too have a 45PB on order for a long period now. I see your point on distorting the base of the bullet. I heard the 35PB is working out ok.
Unless the "As-Cast" size isn't a whole lot bigger than the size you're sizing down to, the distortion effect should be of no consequence; even with one of the gas checks in question.
Of course, if you're sizing down from say .434 to .429 or .430 all at once you may very well impart some distortion. (44 caliber example)
Since the inside diameter of your PB gas checks should be constant before installation, pre-sizing your cast bullets to the inside diameter of the gas check before you actually install it will mitigate the chance of distortion when you install your PB gas check onto your pre-sized cast bullet.
That's basically what you're doing even with a cast bullet that's designed to accommodate a gas check.
In a case like this, you may want to size down in steps till you reach your desired size.
I use lee sizer dies and I've not had any noticeable distortion on any of the bullets I've sized down.
Maybe I'm just one of the lucky ones.
HollowPoint
Last edited by HollowPoint; 04-24-2011 at 03:04 PM.
The thickness of the gas check say is .010" which means .020" all around on the base of displaced metal which will distort the bullet, and this is not even counting how much smaller you are sizing the bullet under it's cast size to begin with. It cannot be good for accuracy especially after doing all that work to cast the bullet in the first place. If it was a good idea it would be in the mould manufacturers catalog and all the moulds would be made with out the gas shank to save money.
I can't argue with that logic.
I just know that since I broke down and made my own PB check maker I've had none of the distortion or accuracy problems that are eluded to here.
I use aluminum flashing from HomeDepot that measures a little over the numbers you've mentioned above.
When I pre-size my plain bast cast bullets before installing them, any deformity-causing resistance that is present, is usually just on the gas check itself as it's being swaged into position onto the base of my bullet.
Since the gas check itself is hair under 1/8" in width, it offers little resistance for me as I push it through my sizing die. The rest of the bullet is just centered by the inside diameter of my sizing die because it had already been sized to that diameter.
Any accuracy problem I did have with these same bullets were experienced before I started installing these PB gas checks; and that was done as an afterthought.
If I hadn't gone the PB gas check route I would have lost money by buying a mold that wasn't working for me before the gas checks.
Of course, I'm only referring to one plain base bullet mold shooting out of one specific gun. Everything stated about possible in-accuracy caused by possible deformities caused by installing these PB gas checks may very well be the case with someone else's bullet mold and gun setup.
HollowPoint
I fail to see where making a cast boolit round and moving a small amount of base metal to add a check will hurt its accuracy. After all we expect the throat and barrel to change the shape, size, and fit of the "perfect boolit". Melt, mold temp, and alloy all can change our boolits more than adding a check, even to a PB boolit.
mold maker:
I failed to see the logic in that as well but, I figured that offering up an argument to the contrary would have only opened up a can of worms.
When I was casting .224 bullets, (before I gave it up) I actually did manage to deform several of them while sizing; and they were made with the gas check shanks on them so, I guess in some sense it is possible to run into deformation problems; which in turn would lead to accuracy problems; if you were inclined to shoot those deformed bullets anyway.
The only plain base bullets I cast and add these PB gas checks to are the .44 caliber round nose bullets from my Lee six cavity mold.
Since adding those gas checks I've never had a problem. I really must be one of the lucky ones.
HollowPoint
I am not saying you cannot get some accuracy with doing what you are doing for close range, but if you were trying for small groups at 200 meters for silhouette shooting it would become apparent. The bullet on a revolver should fit the cylinder throat. If you had a 44 mag and the front of the cylinder/cylinder throat measured .432" to get the best accuracy your sized bullet should measure at least .431" to a max .432" and hopefully this is larger then the barrel.
HollowPoint, if your LEE mould was casting undersized your gas check would help in this case. The real problem is you are fixing a mistake that should not be there in the first place. But you did make something that was not usable to something you can get by with.
Here is an article on the original Freechec tool.
http://www.lasc.us/TaylorFreeChec.htm
longbow...a great read...
Doc,
one use that I seek with a .004 popcan PB gas check is,
I have a PB keith style HP that I like to cast with a
softer alloy...a gas check will let me bump up the pressure
for a given alloy.
Jon
~~~~~~~~~~~~~~
“If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun.”
― The Dalai Lama, Seattle Times, May 2001
If you want to size it on using a lee sizer (my route also) stay with the thinner can material ,They go on nicely sizing the proper nose in first way on 35 cal plain base bullets. the thicker .008 and .010 material would actually turn inside out unless I sized reverse base first. And dont worry that thin material works just fine I loaded them up to full power jacketed levels in my 35 Rem. with good accuracy using a saeco #351 bullet.
If you find yourself in a fair fight, your tactics suck!
JonB_in_Glencoe, I agree that a soft alloy is a good reason to use a gas check especially if they are for hunting and some practice where you do not shoot a lot of them. I have some moulds just for this, I just bought two moulds from MiHec 462122 one plain base and one gas check. I want to use 30:1 to 40:1 alloy and I will be able to shoot both side by side to get the accuracy I want.
Perfectly formed bullet bases are generally accepted as an aid to good accuracy hence the production of nose pour moulds for this purpose. If gas checking a bullet then the same reasoning will apply to gaining accuracy i.e. a nice square and properly sized base gas check.
I run a shoulder for a .429" (44 cal) gas check on my plain base .423 cal bullets in a lathe. Can process these quite quickly and simply with the set up I have. They crimp on perfectly in the Lyman 450 with a good flat concentric base resulting in a poor performing bullet becoming a great shooter with the addition of a gas check.
I guess that it is time for me to comment on the plain base gas checks.
I have been using one of Pat's 35 PB Checkmakers. My experience has been limited to using them in a .357 magnum. I have tested two different boolits in three different guns with the same results. The guns are a S&W model 27, a Merrill Sportsman, and a RPM XL.
My tests have been to use the same load of 2400 with each boolit with and without the PB checks. Each gun shot smaller groups with the PB checks.
I have been surprised at how easy the PB checks go through my Star sizer.
I have used .004 pop can through .010 copper for the PB checks. I did not see that the copper material checks took much more effort to size than the pop can stuff. My favorite PB check is the .008 lith plate material.
G'day.
What is the dia of the disks used to make the 35 cal GC?
I'm thinking of trying some in my 357Sig on a Lee 356-125-2R.
Thanks.,
Hooroo.
Regards, Trevor.
Australia
Best WAG: .4531 using a 29/64 drill rod and .016 aluminum material.
Machinist drill sizes: http://www.engineersedge.com/drill_sizes.htm
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BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |