Got another Lyman mould.....

[Larry Gibson]

Longbow

My bad on that. I was referring to cartridge specs not the "groove diameter" I stated. (sometimes the fingers don't type out what the brain is thinking, especially when thinking of both) Looking at SAAMI's specs for the cartridge we find the MMC is .3125" for the bullet. Since we were talking bullet diameters that was what I meant. My bad........

The commonly held .312" bullet diameter comes from that. An example would be the .311 - .312 jacketed bullets for the ".303 British". You won't fined any .314 - .316 bullets from Speer, Hornady, Sierra, Winchester or Remington......they all will be .311 or .312. Also take Lee for example with bullet moulds; his C31-185-2R is the "303" bullet. Also Lyman for years made to use any of the .311 cast bullets and only in the recent past came out with the 314299. So with the 314299 I quess maybe we matter a little bit to Lyman. Lyman used to cater to the whims of us "knowledgeable" bullet casters but our share of the market is very small and as long as the major cast bullet internet site (this forum) badmouths Lyman's products.....guess what?

I guess maybe that is my point; Lyman has been the hand that has fed us for 100+ years so maybe we should bite that hand? They do have a good customer service and will replace any defective product. I've had nothing but very good service for many years. Those that have bad experiences might want to take a double check on their attitudes a bit when they call Lyman or any other customer service. Probably not going to set the stage for a good relationship if the 1st thing one does is badmouth the product.........Lyman is like any other manufacturer....sometimes a poor product will slip through.......I have found they will replace one that really does. Just my thoughts is all.

Larry Gibson

[longbow]

Larry:

Yes, you are right on with the factory bullet diameters for .303. That is what surprised me when I looked up the SAAMI info. I had always thought that .303 British used a 0.311"/0.312" bullet (which is maybe what has been loaded all along) but when I see the SAAMI info showing 0.314" to possibly 0.316" it makes me wonder why.

I had some Federal factory loads that shot poorly, very poorly. I pulled bullets and found the miked at 0.311". I knurled them to 0.313" and lubed them then re-seated and shot. Accuracy was very good.

Oversize military bores do not seem uncommon but this is more of a case of undersize bullets based on SAAMI specs.

Regardless, Lee Enfields and some other guns do tend to require "fat" boolits which are not commonly available, at least from the big box places.

Longbow

[Larry Gibson]

Regardless, Lee Enfields and some other guns do tend to require "fat" boolits which are not commonly available, at least from the big box places.


Longbow

Definitely some strange goings on with the .303 Brit in ammo and barrel sizes over the years. Before I got the oversize GB Lee mould 311291 I would size down 323470s. I would size at .325, lube and GC and then push through a .318 Lees sizer (.314 honed out). Those always did very, very well in the oversized 7.62x54R MNs and .303 Brits, much better than any .312 or even .314 sized bullets would do.

Larry Gibson

[Three-Fifty-Seven]

.....

[Larry Gibson]

Shawn

I've included the results part of our PM's as now I seem to have a question ... Is the "80/20 lino/lead" mentioned what is recommended by the manufacturer?

No but it casts almost identical to Lyman #2 as to diameter. Subsequently tried straight Lino as I believe that is what RCBS uses(?) as per their manual. That one cavity still was .0005 short of .277. Wouldn't take much to lap it out but I've no .270.......

Larry Gibson

[nanuk]

Probably why in most Lyman CBHs they recommend slugging the barrel groove diameter and sizing to .001 over?
Larry Gibson

what makes me laugh about Lyman, is they will post a barrel diameter that is larger than the nominal boolit size, and they show it being sized to a size SMALLER than the groove diameter...

I wonder why they even bother?

[Larry Gibson]

what makes me laugh about Lyman, is they will post a barrel diameter that is larger than the nominal boolit size, and they show it being sized to a size SMALLER than the groove diameter...

I wonder why they even bother?

Lyman has done that one or two times in the past but they always give a good explanation as to "why they bother" in the cartridge preamble. I've seen quite a few sized to groove diameter in the #4 CBH but haven't found any undersized, have you? I'm just interested to know is all.

Another thing to understand is Lyman no longer tests for accuracy by shooting on target, even at 50 yards. Like most everyone else with reliable published cast bullet data they rely on measured internal ballistics to determine not only min/max loads but what loads should give accuracy based on consistent internal ballistics with in known parameters of accuracy. Reason is, and I'm sure you'd agree, it is up to you the reloader to find what shoots best in your firearm.

Larry Gibson