Undersized bullet shank.

Q

Quigly

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Southern Ontario
I was wondering of someone with more experience could help me out. Gas cheks are not crimping to the cast bullet, because the bullet shank has been cut to small to hold the gas check after sizing.
As I understand it I have a few options including, opening up the mold diameter by about 2 thousandth, powder coatint to increase the diameter, and try a check other than Hornady, though Hornady is usually the standard. Does anyone have any experience with these fixes, or other fixes.
Thanks
 
If this is first go with that mould and those gas checks, might be the alloy that you are casting with? Several references point out how harder / softer alloys or mixes can cast different size from same mould. If you think you need 0.002", that might be the issue?? I know that Accurate Molds does specify what alloy their dies are cut to use - I can only assume that other mould makers must make that same information available?

If you have thin enough foil, might read up on "beagaling" - a way to gain a few thou on bullet diameter from the same mould. I have never had to do it, so can not comment how well it works or not.
 
Potash has good advice.

Casting temperature can also have an effect on size but not as much as alloy.
Powder coating is quite easy and something you might want to explore anyway if you are driving cast bullets with enough pressure to warrant gas checks.
 
OP - you had not mentioned what cartridge you are casting for?? Many cast loading references will point to the free-bore diameter in your barrel - just ahead of the neck area of your chamber and before the leads - typically want to size your cast bullets to fit that free-bore area snuggly - then work backwards to whether that will work with your brass in your chamber. That free-bore area diameter is often .001" or .002" larger than your groove diameter. I think Veral Smith thought that was so important, he sold a kit for "lead packing" that freebore area to get a measurement on it. Same can be done today with a Cerrosafe cast of the chamber neck-to-leade area.
 
By the way - was just too obvious, so I overlooked it - you could indeed have an improperly made mould that was incorrectly cut for a gas check. If that is true, all the rest is kind of waste of time? Would need mould replaced or repaired, if that were the case.
 
Potashminer said:
OP - you had not mentioned what cartridge you are casting for?? Many cast loading references will point to the free-bore diameter in your barrel - just ahead of the neck area of your chamber and before the leads - typically want to size your cast bullets to fit that free-bore area snuggly - then work backwards to whether that will work with your brass in your chamber. That free-bore area diameter is often .001" or .002" larger than your groove diameter. I think Veral Smith thought that was so important, he sold a kit for "lead packing" that freebore area to get a measurement on it. Same can be done today with a Cerrosafe cast of the chamber neck-to-leade area.
Click to expand...

45-70 Marlin 1895 lever.
 
Potashminer said:
By the way - was just too obvious, so I overlooked it - you could indeed have an improperly made mould that was incorrectly cut for a gas check. If that is true, all the rest is kind of waste of time? Would need mould replaced or repaired, if that were the case.
Click to expand...

I agree the base where the gas checks attach has been cut to the wrong diameter. Too small so the check won't crimp to the bullet. I think I will try to icrease that diameter with emery cloth. It only needs about.002 more to make it right.
 
Marlins often like .460 and maybe even .461 bullets.
Powder coating could solve both problems and avoid sticky lube.
Also, if your mould gives a smooth flat base, a gas check may not be needed in a .45/70.

If you get your own gas check maker, you could vary the thickness of the check and how much it will bite into the base.

As well, carefully opening up the shank area of the mould is a final option.

Many years back, my crimp on checks would bite into the shank lightly. They could be rotated with the fingers, but stay in place.
However, when a friend was chronographing some loads, a check came off and busted the readout screen of my chronograph.

I think powder coating would be the solution.
 
Quigly said:
I am using wheel weight alloy. I am using a .459 sizer. If I go to a .457 or .458 sizing die, I think that may help.
Click to expand...

I think this approach will just compound your problems. a slightly tighter sizer will crimp the checks on tighter but in the end it will just reduce the gas seal you are trying to achieve with the gas checks
in the first place...barrel leading may be the result. If you must use GC, increase the mold GC shank dia ....but my suggestion would be to take the "powder coat" route that some have already suggested .

Don't be afraid of learning powder coating...probably the cheapest single segment of reloading there is and makes using cast slugs as easy as using jacketed at 4 times the price.
 
Quigly said:
I was wondering of someone with more experience could help me out. Gas cheks are not crimping to the cast bullet, because the bullet shank has been cut to small to hold the gas check after sizing.
As I understand it I have a few options including, opening up the mold diameter by about 2 thousandth, powder coatint to increase the diameter, and try a check other than Hornady, though Hornady is usually the standard. Does anyone have any experience with these fixes, or other fixes.
Thanks
Click to expand...

You could try Gator 458 rifle checks. They're a bit thicker than Hornady, give you an extra 1-2 thousandths.

What mold is it? Bullet shank diameter measurement would help.
 
jethunter said:
You could try Gator 458 rifle checks. They're a bit thicker than Hornady, give you an extra 1-2 thousandths.

What mold is it? Bullet shank diameter measurement would help.
Click to expand...

The mold is a RCBS 45-405-FP. It drops slugs that are .459.
The shank diameter is .426. I've ordered a box of Gator checks from DL.
 
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fingers284 said:
I think this approach will just compound your problems. a slightly tighter sizer will crimp the checks on tighter but in the end it will just reduce the gas seal you are trying to achieve with the gas checks
in the first place...barrel leading may be the result. If you must use GC, increase the mold GC shank dia ....but my suggestion would be to take the "powder coat" route that some have already suggested .

Don't be afraid of learning powder coating...probably the cheapest single segment of reloading there is and makes using cast slugs as easy as using jacketed at 4 times the price.
Click to expand...

Thank you for the advice. The mold is an RCBS 45-405 gtain flat point. It drops bullets at .459 with wheel weight alloy.
 
fingers284 said:
I think this approach will just compound your problems. a slightly tighter sizer will crimp the checks on tighter but in the end it will just reduce the gas seal you are trying to achieve with the gas checks
in the first place...barrel leading may be the result. If you must use GC, increase the mold GC shank dia ....but my suggestion would be to take the "powder coat" route that some have already suggested .

Don't be afraid of learning powder coating...probably the cheapest single segment of reloading there is and makes using cast slugs as easy as using jacketed at 4 times the price.
Click to expand...

I think you are right. Reducing the vullet diameter at the base could complicate things. I will definately give powder coating a try.
 
Quigly said:
The mold is a RCBS 45-405-FP. It drops slugs that are .459.
The shank diameter is .426. I've ordered a box of Gator checks from DL.
Click to expand...

.426" is about right for a 45 rifle bullet. Gator makes two 45 caliber gas checks, 45P is for .452" pistol bullets. 45R for .458" rifle bullets and it has a heavier wall.



Depending on your velocity you may need a gas check even if you powder coat. Try it both ways and see.
 
jethunter said:
.426" is about right for a 45 rifle bullet. Gator makes two 45 caliber gas checks, 45P is for .452" pistol bullets. 45R for .458" rifle bullets and it has a heavier wall.



Depending on your velocity you may need a gas check even if you powder coat. Try it both ways and see.
Click to expand...

Thank you gor the advise. I hope I can make the problem go away. It may just be the gas checks that are the problem. Yes, I ordered the 45-70 checks.
 
Good news. The Gator gas checks work great. They're on there as tight as can be. Since the gas checks work, there isn't any need to powdercoat at this time. Though, it's definately something I will try at a later date. Nonetheles, I want Thank Yomomma for the offer to powdercoat a few of the bullets to see if that would help with seating the checks. I think it would have worked. So for anyone, in the future having an issue with gas checks not seating try Gator checks, or powdercoating. Both, I am confident will solve most of the problems.
 
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