Help need some info

[Oklahoma Rebel]

I have designed a boolit for the 9.3X62 but I haven't got my rifle yet, I have about a month or so of saving, and wanted to get a start on things. does anyone know how I could find the chamber dimensions of the CZ550FS in 9.3X62, I mainly want to make sure that I can crimp in the crimp groove and still be able to close the bolt.202431 that's the bboolit, hope it shows up. mainly, how far in from the mouth of the case does the rifling start? I think I can figure out if it will work from there. so to anyone that can help, I would really appreciate it! thanks-Travis

[Oklahoma Rebel]

sorry its blurry, oal= 1.12, length to end of crimp groove is .370,groove width from base to .670 ,radius 1.250 from .670 to meplat of .20

[waksupi]

I would wait until I got the rifle first.

[RED333]

I would wait until I got the rifle first.

I agree 100%, then do a chamber cast.

[Oklahoma Rebel]

is there a way to get the measurements I kneed without doing a chamber casting? I don't know how to do that and it will be brand new out of the box. I mean I know the basics of it but that's it so far, according to measurements from several accurate boolit designs, my boolit will fit. the only thing I don't know s how far I will be from touching the rifling. I know it will be close. and it will weigh 291.6grns with cow. according to auto cad, and about 3 measurement conversions! I am going to take .015 out of the middle of the boolit to get it to about 285-286grs.

[smoked turkey]

I am not a machinist or a gunsmith but I have an uneducated opinion on this question. Manufacturing tolerances provide a certain amount of +/- to a SAAMI chamber. A chamber reamer gets a little smaller with each use due to the cutting required in order to cut the chamber. Let's say that the same reamer is used on two different actions on two different days. The work is done on the same machine by the same person with the same reamer. Both chambers will be within the SAAMI specification. One could be on the plus side and one could be on the minus side. That is in part why some rifles will shoot the lights out and the next one may not be quite as accurate. I am sure that a real gunsmith will chime in here with the facts. It all points to the need for you to make a chamber cast of your rifle. Then you will know the answers to your questions and more importantly your boolit design will be made for your individual rifle.

[waksupi]

is there a way to get the measurements I kneed without doing a chamber casting? I don't know how to do that and it will be brand new out of the box. I mean I know the basics of it but that's it so far, according to measurements from several accurate boolit designs, my boolit will fit. the only thing I don't know s how far I will be from touching the rifling. I know it will be close. and it will weigh 291.6grns with cow. according to auto cad, and about 3 measurement conversions! I am going to take .015 out of the middle of the boolit to get it to about 285-286grs.

Short answer, no. If you go ahead, you may end up with something that isn't going to shoot, and it is money down the drain.

Keep in mind, these are cast bullets. You are moving towards graduate work here, and half arsed doesn't do the job.

[KCSO]

Chamber casting is SOO easy. Just a dab of cerrosafe or sulphur melted and poured into an oiled chamber. Wait a few and poke it out. Shrinkage for sulphur is available but I put my chart away after someone gave me a pound of cerrosafe. I just use a couple cotton balls to plug the barrel so I can get the chamber and leade. Start to finish maybe 10 minutes. most of the casting material is reusable.

[Oklahoma Rebel]

do you take the action out? or is there a way to protect the wood from burning it with cerrosafe?

[RED333]

How about some reading?
http://castboolits.gunloads.com/showthread.php?218414-FYI-This-is-how-I-do-a-pound-cast

[Rcmaveric]

I also recommend waiting for the riffle and using a pound cast. Read the link above and watch a few youtube videos. Its scary the first time, but perfectly safe I promise. Just make sure you use lube so the cast doesn't get stuck (I use the RCBS case sizing lube). I also have tried the Cerosafe but I *****'ed it twice, in a row, same day. I ended up with a blow torch and a dental pick cleaning it out and scared as hell I messed it all up. Pound cast is easiest by far, I even made a pound cast of my Grendel AR.

[KCSO]

You use a funnel and pour it directly into the chamber. I clamp the gun in the vice and pour till the cerrosafe fills the chamber. I use a tin can with a lip bent in if I have enough room to pour. It won't hurt to take out the barrelled action but it is not necessary.

[Oklahoma Rebel]

so just a light spray of an aerosol gun oil? and what do you plug the barrel with? I assume I would want to get some of the rifling with it so I can check that too, or would the cerro get caught in the rifling? I picture putting the stopper ( whatever it is supposed to be?) about 1/2-3/4 into the barrel?

[Oklahoma Rebel]

i'll read that link now

[Oklahoma Rebel]

ha! that link says you need a mould to do their way, and you guys are saying wait to buy a mold till I do a chamber cast! I cant afford to buy a mold just to do a pound cast. so I guess my only choice is cerrosafe, and wait til I get the gun to buy a mold. that means I will be shooting prvi partisan jacketed for a while. oh well I guess it will help smooth out the barrel

[EDG]

There is really no way to mess up a Cerrosafe cast unless you use the wrong alloy.
You can melt the metal using hot water from a faucet. If you have a problem remove the barreled receiver from the stock and warm it with a hair dryer and all the metal will melt and fall out so you can try again.

To plug the bore I have been using some foam ear plugs that got to hard to use.

To make the Cerrosafe better fill out your chamber you can remove the barreled receiver from the stock and warm it to about 110 to 120 degrees. Then the Cerrosafe will not try to freeze as soon as it hits cold metal. This will help prevent cold shut flaws and trapped air bubbles.


ha! that link says you need a mould to do their way, and you guys are saying wait to buy a mold till I do a chamber cast! I cant afford to buy a mold just to do a pound cast. so I guess my only choice is cerrosafe, and wait til I get the gun to buy a mold. that means I will be shooting prvi partisan jacketed for a while. oh well I guess it will help smooth out the barrel

[Texas by God]

I would get the rifle first. Shoot the Privis to get brass and marvel at the accuracy. Then do what these guys are telling you. Moulds for the 9.3 aren't cheap. Unless you get the Lee .366" Makarov 95gr- that would be fun city for plinking. My .02 from below the Red.
Best, Thomas.

[Tom Myers]

I have designed a boolit for the 9.3X62 but I haven't got my rifle yet, I have about a month or so of saving, and wanted to get a start on things. does anyone know how I could find the chamber dimensions of the CZ550FS in 9.3X62, I mainly want to make sure that I can crimp in the crimp groove and still be able to close the bolt.202431 that's the bboolit, hope it shows up. mainly, how far in from the mouth of the case does the rifling start? I think I can figure out if it will work from there. so to anyone that can help, I would really appreciate it! thanks-Travis

Travis,

Just to give you an idea of what you may be dealing with, I entered the 9.3 x 62 chamber and cartridge dimensions into the Precision Bullet Design ~ Ultimate (http://www.tmtpages.com/#ultimate) software then scaled out an approximation of your your bullet drawing in the Precision Bullet Design ~ Advanced (http://www.tmtpages.com/#advanced) software.

The Cast Bullet Design ~ Ultimate Overlay module (http://www.tmtpages.com/draw/HelpfilesUlt-5/hs130.htm) was then used to bring the three images together into a composite overlay. You can now visualize the fit of your bullet design in a SAAMI spec chamber.

As you can readily see, the specs call for a loooong shallow leade angle of less that 1/4 of a degree, This taper starts at the chamber end and reaches 0.24" into the barrel before encountering the groove diameter and then continues 1.1" into the barrel before it finally tapers down to bore diameter.

Your rifle chamber and throat may or may not be cut to those specs. Perhaps this will provide a better understanding of why everyone is advising to wait until you have the rifle in hand then do a Cerrosafe Chamber Casting (http://www.tmtpages.com/draw/HelpfilesUlt-5/hs30.htm) or a Chamber Impact Impression (http://www.tmtpages.com/draw/HelpfilesUlt-5/hs40.htm) to determine just what you need the first time around - Custom molds are expensive.

Hope this helps.

(Click for larger image)
202736

[Oklahoma Rebel]

no, I understand, I was just scared of screwing up a chamber cast. but I know more about it know, and especially how low of a temp this stuff melts at, I have no problem doing it! would cerrosafe even damage the clearcoat on the gun? if I spilled. and thankyou tom myers for giving me the visual! it helped a lot.