314299 Proper Sizing Question

[Shiloh]

I have some 314299 boolits I recieved from one of the members of this forum.
I thought that I would size to .312 for the '03 Springfield and the Krag. The '03 has a new barrel. I re-examined the boolit and the nose, .302 is slightly engraved from the rifling. The posts here and at other forums suggest 2 to 3 thousandths over bore diameter. Will 4 or more thousandths cause an excessive pressure spike? These will be over 19 gr of surplus 4759. These are quenched WW boolits.

My 311299 mold drops a .310 boolit and accuracy could be better. The 311299 at 19 grains has an AV of 1725 with an ES of 21.03 and SD of 6.24. The accuracy however is 3.00+ at 50yds and about 7 at 100yds. Is 1725 fps too fast?

The nose of the 314299 engraves the rifling slightly while the 311299 will turn in the barrel about 1/4 turn. I have heard of fine accuracy with both boolits but the 311299
isn't rally performing for me.

Any help from those in the know would be appreciated. I'd really like to find a good combination for my rifles. Thanks in advance.

Shiloh

[Buckshot]

"My 311299 mold drops a .310 boolit and accuracy could be better. The 311299 at 19 grains has an AV of 1725 with an ES of 21.03 and SD of 6.24. The accuracy however is 3.00+ at 50yds and about 7 at 100yds. Is 1725 fps too fast?"

Nope. not too fast at all. Something else is happening

"The nose of the 314299 engraves the rifling slightly while the 311299 will turn in the barrel about 1/4 turn. I have heard of fine accuracy with both boolits but the 311299 isn't rally performing for me."

That may be part of the problem. That quarter turn may just be the parting seam coming up against a land. A bore rider really must RIDE the lands in order for it to guide. I actually prefer to see a bit of light engraving

http://www.fototime.com/16FA4CC02947384/standard.jpg

This is obviously NOT a 30-'06 but it's the best photo I have clearly showing nose contact. As a routine I treat all my bore riders to a trip in the Tumble Lube container, regardless the type of lube they'll get later. It sure seems to help in the ease of chambering and has made no ill effects in shooting. I figure the long bare lead nose might just benefit from it, and it takes no big extra effort.

When I got a rifle in 40-65, I'd also ordered the Lyman 400gr 'Snover' mould for it. While it was a really nice looking slug, the nose at .398" didn't give me warm fuzzy feelings, having a rifle with a .400" bore. It dropped with bands at .410", so that was fine for my .408" groove. In one way I was happy to see it didn't shoot :-) as I figured it wouldn't with a non-bearing nose. As an experiment to further vindicate myself I bumped the noses on 20 boolits. Actually I had to bump more boolits then that, but due to bending some were obviously not going to do well.

I loaded 20 of the regular ones and 20 bumped ones over the same load, and then fired them into 2 ten shot groups. The difference was remarkable to say the least. And mind you these 20 bumped ones weren't what you'd call superlative as some had just a bit more bulge on one side of the nose then the other. I shucked that mould and got an RCBS.

"I have some 314299 boolits I recieved from one of the members of this forum.
I thought that I would size to .312 for the '03 Springfield and the Krag. The '03 has a new barrel. I re-examined the boolit and the nose, .302 is slightly engraved from the rifling."

You should size the boolits to the throat, so long as they will chamber. My 1903A1 will not take a .310" cast slug. It has a Remington 11-44 barrel. The slug will get pushed back into the case or get all scabbed up. One or the other. I have to size .309" and they really DO come out at .309" (check your die, regardless).

"The posts here and at other forums suggest 2 to 3 thousandths over bore diameter. Will 4 or more thousandths cause an excessive pressure spike? These will be over 19 gr of surplus 4759. These are quenched WW boolits."

I'm sure you mean groove. I think you can get TOO fat as I believe the lead has to go someplace and that's usually to the rear. It may just cause problems with the GC, but that is just a theory of mine. As above, size to the throat as even the wartime Springfield '03 barrels were usually pretty well done. Besides, if you size .004" over the groove without checking, you might not be able to even chamber it.

...................Buckshot

[NVcurmudgeon]

I use the fatter 314299 version of the same boolit in several .30 and .31 cal. rifles. The boolits cast .314" in wheelweights plus 2% tin. I size .001" to .002" larger than groove diameter. That is .314 for the .3138" groove of the .303 British, .312" for the .311" 7.65 Argentine, and .310" for the .308" Springfield and the .309" Krag. Shoots accurately in all four.

[joeb33050]

I have some 314299 boolits I recieved from one of the members of this forum.
I thought that I would size to .312 for the '03 Springfield and the Krag. The '03 has a new barrel. I re-examined the boolit and the nose, .302 is slightly engraved from the rifling. The posts here and at other forums suggest 2 to 3 thousandths over bore diameter. Will 4 or more thousandths cause an excessive pressure spike? These will be over 19 gr of surplus 4759. These are quenched WW boolits.

My 311299 mold drops a .310 boolit and accuracy could be better. The 311299 at 19 grains has an AV of 1725 with an ES of 21.03 and SD of 6.24. The accuracy however is 3.00+ at 50yds and about 7 at 100yds. Is 1725 fps too fast?
__________________________________________________ _____________
It's too fast for me. I've always found 30 caliber accuracy at ~1400 fps, never had much luck at higher velocities. I shoot 311299 and 314299 sized from .308" to .314" with no discernable difference in accuracy. If only it were so!.
BUT, with 3" groups at 50 yards and 7" at 100 yards, your problem isn't in minor dimensional changes to the bullet-you've got something seriously wrong with the gun or load or bullets or your bench technique. With a new CLEAN 30/06 barrel and any reasonable cast bullet and 10 grains of Unique or 17/SR4759 you should be able to shoot 5 shot 50 yard group averages-5 groups-of 1 1/2" or less. If you're old, those sights may be part of the problem.
Let us know.
joe brennan
__________________________________________________ ____________
The nose of the 314299 engraves the rifling slightly while the 311299 will turn in the barrel about 1/4 turn. I have heard of fine accuracy with both boolits but the 311299
isn't rally performing for me.

Any help from those in the know would be appreciated. I'd really like to find a good combination for my rifles. Thanks in advance.

Shiloh

joe brennan

[Harry O]

I have had pretty good luck with sizing for the largest diameter that will chamber. I have a Krag with the usual "generous" chambers and a 0.314" bullet works best with it. Others I have work best at 0.313", but most newer commercial rifles work best with 0.312". The light engraving you see on the "bore riding" portion of the bullet is perfect.

[sundog]

I use the smallest sizing die that will barely smear the boolit while trying not to reduce the size. This assures that the GC is at least close to same size as boolit so that when loading it will not stretch the case neck larger than boolit size. Does it really make a difference? Who knows, but it works for me. If I can fit a bigger boolit into the throat, I cast a bigger boolit.

I'm with Harry. I like to see evidence of the rifling on the shank of bore riders. sundog

[Shiloh]

Thanks to all for the very in-depth and precise answers to my questions.

Shiloh