303 Brit .315 groove size.Will it bee to big to chamber?

[multifasciatus]

Hi


I have a SMLE Mk III Enfield 1912.
Measured the groove size to .315" Orderd me a CBE mould (.316")
But then i got to think about the chamber measure ,is this bullet going to give me problems ,new sized cases comes out .305" throath,fired cases .315" Do i need a lager expander button?.
Sorry for my bad English ,but i guess im better speaking Norwegian than most of you:razz:

Regards Alf

[Larry Gibson]

I would suggest you slug the chamber neck with a soft lead slug. Then size your bullets so when loaded in the case there is a .001" clearence (less diameter).

I also suggest you neck size only. Use either a Lee collet sizer or a Bushing die. Adjust either die so the inside neck diameter is .002 - .003 less than the sized bullets.

At minimum with the die you have you should use a .31 cal Lyman M Die to expand the case neck and flare the case mouth.

Larry Gibson

[herbert buckland]

Measure the mouth of a fired case from your rifle it will tell you how big a bullet you can go to

[Char-Gar]

Your English is far, far better than my Norweigan. My GGGrandmother came from Norway.

If I had to guess, a .315 bullet will give you no problems in your rifle. I use .315 bullets in my 1944 Longbranch MK V with no problems.

But you could measure the inside diameter of a fired case and see if it is .315 or larger. Even it is is not .315, all is not lost. You can neck turn some cases to reduce their thickness and get a few extra thousands that way.

However, I am a practical sort, I would just load a dummy round with a .315 bullet and see if it chambers freely. Doing something is really the only way to know if it can be done.

[multifasciatus]

I have measured the inside neck .315"+
Thanks for all the good advise.
Char-Gar ,come to Norway and visit!!!

[462]

Alf,
You, sir, have a far better command of English than the vast majority of American high school students.

[303Guy]

My Grandmother came from Norway.:drinks:

I favour zero sizing and fitting the boolit to the neck and throat. 303 Brit cases have a way of developing a 'dough-nut' at the neck/shoulder junction - very handy for seating the boolit up against.

[9.3X62AL]

Multi--

Your English is excellent, sir. I have a SMLE No. 1/Mk 3 (1918 BSA) with similar dimensions. I neck-size halfway down the neck, then use a custom M-die spud made by Buckshot @ .314" to fit my .316" boolits. These shoot quite well to 300 yards.

[multifasciatus]

Hi!


Now i got loads testing to do during winter.
Well with my interests there is no way around the english language.
Guess i picked up a thing or to...
Cant wait to begin casting my 303s.
Norwegians in Kiwi land ,i like it.
Thanx guys Alf

[NuJudge]

See if a .316" bullet is at least a slip-in fit in a fired case, and if not, then see if a .315" bullet will fit. Use the biggest that will fit.

It should not be a big job for a gunsmith to ream your chamber neck a few thousandths of an inch, if you can not get any to fit.

[303Guy]

You know, I've been loading boolits that are a snug to self holding fit in unsized case necks in my rifles and have not observed any sing of raised pressure. As long as the loaded cartridge fits they seemed to work just fine. I should stress that I do not load anywhere near max for any load let alone cast or paper patched loads (although the paper patch loads are at a higher loading level than plain cast).

I wouldn't do that with j-words!

[multifasciatus]

Hi


Now casting ww water quenched,bearly 314"sized,found out that my RCBS sizer button is just 306",going to replace it with a Buffalo Arms M type expander 312"-315".
Would it be smart to use a Lee factory crimp die?Ever so gently :p
Not very impressed with the way the RCBS is doing crimping/de belling.

[leadman]

I don't crimp any of my cast boolit loads for rifles as long as there is enough neck tension to hold the boolit tight. I have even shot the 1903a3 rapid fire with no crimp.

[303Guy]

You might find those slightly undersized boolits will work just fine if you use a granular filler.

[multifasciatus]

You might find those slightly undersized boolits will work just fine if you use a granular filler.
Hmm, what do you use for filler.

[303Guy]

I use either wheat bran (sieved) or wheat germ. I have tired Grits (course ground corn) but not in the field. I compact the wheat bran or wheat germ slightly so it remains firm between the powder and boolit.

[Multigunner]

It's fairly common to find a milsurp rifle chamber neck choked down by hardened fouling, if theres enough of this fouling it can cause even factory rounds to show excessive pressures.

I had this situation with my No.4.
The fouling was hard and shiny and when scraped out looked like pencil lead graphite.
The shiny surface made it difficult to spot the fact that it was a thick layer of old fouling.

I made a scraper from brass tubing, cutting a angled slot in the side and filing teeth in the rim.
After each pass turning the tube to cut into the fouling I'd expand the end till it was again a tight fit.
Solvent did little to soften this fouling, likely due to it being an agregate of carbon, atomised lead, and resinous neck sealant. Additives used in military propellents, like graphite and calcium flash suppresants, would also be present.

[303Guy]

My patched boolits have a diameter of .319. They do compress slightly on seating and with my thick walled cases, there is virtually no clearance in the chamber. I'm not sure that it's safe to fire a plain cast with no neck clearance but it seems to do nothing to the pressure with patched boolits.