ultimate 30 is really a 303 supreme!

[nekshot]

I being of sound mind today with nothing in my body but flexaril have taken a swag(pure lead slug in case and pounded on to fill chamber area) of this win mod 70 featherweight barrel. When I picked up the casting I knew something was not right. After reading the slug I placed my smallest diameter 30 boolit a 311-466 in end of bore and it pushed straight thru easily and now I knew something was amiss. Here is a photo of the results, I am not complaining except I only have 2 molds that will work. The molds for 308 will have to be paper patched. This barrel I bought about 15 years ago, it looks brand new and I bet the guy who had this gun pulled the barrel because it didn't groub with factory rounds! I have a shortened case above to show how nice the long neck will work. I think I need to ream the neck to be perfect for the new case. I love challenges and this now is one. I have some 303 brits with almost identical throats and bores.
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[nekshot]

I forgot to add the twist is 1-12
nekshot

[Marlin Junky]

.006" tall lands! Wow, it should shoot like a champ once you get things figured out. Only problem is, what reloading dies will you be using after opening up the neck to .342"?

[nekshot]

the same 308 dies I am shortening to match the chamber I will ream out for the neck. Thank goodness every thing is bigger rather than smaller. It still is weird but I am happy.

[Marlin Junky]

the same 308 dies I am shortening to match the chamber I will ream out for the neck.

I wasn't aware that could be done, given the hardness of a good die set.

MJ

[Green Lizzard]

i annealed a lee an reamed it out,being 70 yrs old i dont think i will wear it out

[303Guy]

I'm not sure I understand the need to ream the neck area. Isn't it large already? Remembering that the smaller the neck area the better. For paper patch there is no need for any clearance at all - I've tried it. For cast? Well there I don't know but I'd have thought only a bare minimum to allow the neck to expand then spring back. I do know that if the friction between boolit and neck is too high it will take the neck with it! [smilie=1:

72898

That was supposed to be a fire-lap round. Do not embed fire-lapping compound on the patch area that gets seated in the neck. It didn't do all that much to the pressure.

[338RemUltraMag]

Why do you always shoot "groubs" what is a "groub"? Is it a fancy group? Does it differ in some way?

My curious mind wants to know!

[nekshot]

303- I guess I should shoot it first before taking any metal off.

338ultra, give me a break, I am from Pa. dutch country. We say many funny things, you know!

[mroliver77]

Willbird made me some brass for my 22-250 from .308 match brass. He turned the necks till there is .002 clearance of the loaded neck in the chamber with a loaded round. When fired the brass expands enough to let bullet go but not enough to stretch the brass. Fired cases measure the same as before they were loaded. They can be reloaded with NO resizing at all. Thought this might interest you.
J

[nekshot]

Thanks for all your input. This morning I took another cast just to be sure of all of this. It came out identical to first cast. Then I expanded a 308 case in a 303 neck expander and placed a lee 303-185 boolit in it and chambered it. The outside neck is .342 and the boolit seated in case perfect as it engaged the rifling. I could not have done this better if I purposely tried(I think). In the photo is a lee boolit, then the proto type case with boolit seated at lands and last this mornings cast which is same as yesterday. So onward I go with project.
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nekshot

[338RemUltraMag]

303- I guess I should shoot it first before taking any metal off.

338ultra, give me a break, I am from Pa. dutch country. We say many funny things, you know!

I wasnt trying to bust your nutz, but I was really confused!

[nekshot]

absolutely no offence on my account! I really did get a kick out of thinking about it and I don't know why I call it groub or groubs except grandpa said it like that and now we say the same thing. Tradition, tradition, tradition!

[mroliver77]

Do I understand you right? Are you saying the chamber neck area is .342 and the loaded round is the same?
J

[338RemUltraMag]

absolutely no offence on my account! I really did get a kick out of thinking about it and I don't know why I call it groub or groubs except grandpa said it like that and now we say the same thing. Tradition, tradition, tradition!

I do lots of things like the old old man, carry on!

[nekshot]

moliver, yes the dummy rounds neck od is the same as the cast comes out. With a little tap the dummy went in and seated the lee boolit against the lands. It is a tight fit which can be dealt with in future. As of now with the surprise that this 308 barrel is not a 308 I am happy things are looking as normal and workable for me. I do wish I knew this was a 303 from the beginning, I would have put it on a smle with a bad barrel.
nekshot

[Wayne Smith]

I believe you gotta have some room in there for brass expansion to release the boolit.

[nekshot]

Wayne, you are right. I will be using 307 brass for the rim and they will be shortened substantially and I assume the neck will be thick and there allowing me to turn them to the dimension needed for proper fit. So far so good,
nekshot

[303Guy]

Just curious, has it been demonstrated that cast boolits require expansion room in the neck area? Or is a case for having a margin of safety for the odd one that may be too tight? That one of mine was due to the abrasive compound - normally a tight one would shoot out just fine (that's for paper patch).

[nekshot]

Kinda makes necksizing only seem that it could be dangerous! :)

[truckjohn]

People forget that when you look at SAAMI specs for US 30 caliber stuff (308).... that 308 is the MINIMUM allowable bore diameter... There really isn't a published maximum... but generally it's around +0.002" or +0.003".... so that would put your 311 barrel right in spec......

That's why you gotta slug....

Thanks

[9.3X62AL]

What Truck John said. My current 30-06 (an early 1950s Husq Mauser) is the ONLY '06 I've ever owned with "minimum" dimensions--.3085" throat, .308" grooves, .300" lands. Rems, Wins, and a Ruger had throats up to .311". Grooves were better, usually somewhere between .308" and .309", and bores somewhere between .300" and .301". All of these barrels shot both j-words and castings well enough for hunting purposes, and some bullets/boolits with SUPERB accuracy. Never say "never" in this hobby field, and never say "always".

That said......the barrel under discussion by Nekshot is a little out of spec for a 308 Win/30-06 application, but is still quite usable if you're willing to do the work to "match the hatch".