New caster with gas check fit problems

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  • Last Post 07 August 2008
Lillard posted this 02 August 2008

I have been reloading since 1988 but new to casting. I have a saeco sizer and pour with a ladle. I use WW to cast 44s from a RCBS 240 gr. swc size to .430 with no problems and they shoot well. I bought a RCBS .458 405 gr. fp gas check for 45 70. I also use WW and size to .459 the gas checks fall off after sizing. Thought about using a .40 cal. case and fine valve grinding compound to enlarge gas check area of mold. Please help. Thanks

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billwnr posted this 02 August 2008

what brand of gas checks?

What's the diameter of the bullet shank?

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Lillard posted this 02 August 2008

Hornady

.424 .425

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CB posted this 02 August 2008

Those sizes are within spec so I'd try some different checks or look for some other problem before grinding on the mould. If the problem persists call Hornady and see what they say. 

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billwnr posted this 02 August 2008

I doubt .424 and .425 are the shank diameters of your .458 mould.  That's the one your gas checks are falling off I presume?

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CB posted this 03 August 2008

billwnr wrote: I doubt .424 and .425 are the shank diameters of your .458 mould.  That's the one your gas checks are falling off I presume? I could be wrong but think .426 is the max shank dia. on 45 caliber moulds.

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billwnr posted this 03 August 2008

Pat,  I was expecting something much larger for shank diameter.:shock:

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CB posted this 03 August 2008

billwnr wrote: Pat,  I was expecting something much larger for shank diameter.:shock: Seems small to me too until you think about the 30 calibers whose shank diameter is .284 max. Getting back to the original post I read that Gator makes two different 45 caliber checks, one for rifle and the other for pistol with the rifle check being a bit thicker. A call to him might be something to look into. 

Bullet Swaging Supply 303 McMillan Road West Monroe, LA 71291 (318) 387-7257 Fax (318) 325-7034

 

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LWesthoff posted this 03 August 2008

Your problem with .45 cal. Hornaday checks is interesting.  I had the same problem with a couple of boxes of Hornaday .30 cal. gas checks.  Same bullet molds, same alloy (lino) as I had been using for several years, so I'm certain it was the checks.  I rigged up a little tooling to open the checks up very slightly, and have almost used the off-size supply up now.  At a match a few months ago, some of the other shooters were complaining of the same problem - with .30 cal. checks.   Just recently purchased a couple thousand new .30 cal. Hornaday checks from either Cabela's or Midway - don't remember which, and they are O.K.  (I opened both boxes as soon as they arrived and checked.)  I figured they had some kind of worn tooling problem with their .30 cal. check making machinery,  which they seem to have fixed.  If they had/have the same problem with a different size, maybe there was some other cause.  Let's hope they do actually have it fixed - I like Hornaday checks.

  WES

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giorgio de galleani posted this 03 August 2008

I have a rcbs 405 gr flat nose with the same problem,that I solved  at once  using a 4 cavity LBT bevel base mould for lighter loads in my 45-70 marlins.

My rcbs was a bit undersize,not more than 459,Microgroove marlins love 460-461 bullets.

When I  acquired  a Ruger77 in 458 lott I ordered a 450 gas check 4 cavity mould from Veral Smith,  and  he makes bullets that are perfect match for the Hornady gas checks I have recently bought.

I have found that the various lots of gas checks  may have little dimensional variations,if they are too tight I open them with a punch  If the bullets have a too slim gas check shank they are hopeless.

Do not waste your time with incorrect diameter moulds.

I like to anneal my gas checks.

Giorgio.

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Lillard posted this 03 August 2008

Update.

I tried a freind's hornady checks same problem he took my bullets to his .459 sizer same problem. I used a fired .40 S & W with fine valve compound to hone shank area. At first case was very tight I honed a little then cast a few and tried gas checks for fit. It took three times before checks stayed on when sized .459. The jury is still out on how well they shoot. The reason for buying this mold is because my freind has same style mold that shoots well in my gun and he will not part with his.

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310Cadet posted this 07 August 2008

The problem with GC fit was covered very well in an article in the FS #41-26 by C.E.Harris. It included Hornady's factory drawings and dimensions. The .45 GC's dimensions are given as : O/D .460” + or - .002” , ID .428” + .000” - .003".  Therein lies the problem. If the OD is .460” there is only .002” reduction when sized to .458” and that is why GC's can be such a loose fit on .45 Rifle Bullets. The variables of (a). Alloy used which can vary the bullet GC shank diameter by at least .0025” between soft lead and linotype. (b) the tolerances which are a necessity in manufacturing allows for up to .003” variation on the ID and  +or- .002” on the OD, although I have found Hornady usually manage to hold much closer than this to size. I'm not sure why there is so little margin on the OD to allow for sizing on Hornady's .45 Gas Checks but possibly it is due to the fact that they are meant to be used on rifle and pistol bullets covering bullet sizes from .452” to .458” ? I prefer a GC heel on my .45 rifle bullets to be .426” to .428” as this seems to give the best fit . I have made reamers with a tapered lead which I use to open out the GC shank on moulds I find to be a bit loose.

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