Does the direction of sizing effect accucary ??

CBA Member

RicinYakima posted this 02 November 2010

D: It depends upon the accuracy of the tooling.

My Lee .309 die does a good job, but the .314 die's lead in is so sloppy, it wil not seat gas checks square and sizes one side of the bullet more than the other.

After going through 8 lube/sizers, I found one that is square from the ram through the die holder.

HTH. Ric

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Standard Member

Wayne S posted this 02 November 2010

GOOD POINT, I'll check my “push through” sizing dies for roundness

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CBA Member

RicinYakima posted this 02 November 2010

It isn't roundness, but angularity. The hole in the bottom is about .340” and rough surfaced. The push rod is .306” and doesn't fit tight in the press ram. As it moves up, it just flops around. The small sizing area is round but doesn't appear to be in the middle of the die. FWIW, Ric

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CBA Member

billwnr posted this 02 November 2010

RicinYakima wrote: D: It depends upon the accuracy of the tooling.

My Lee .309 die does a good job, but the .314 die's lead in is so sloppy, it wil not seat gas checks square and sizes one side of the bullet more than the other.

After going through 8 lube/sizers, I found one that is square from the ram through the die holder.

HTH. Ric

Ric,

This makes me think it might be worthwhile to have someone true up the sizing die hole in a lubesizer.

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Standard Member

gunarea posted this 03 November 2010

Gosh Wayne

This thread will probably get some stuff going. All these variables combined with those encountered in the firearm along with reloading practices make for so many possible solutions there is not a single right answer.

My Rem Kodiak in 30-06 performs best with two of the forward driving bands sized at .310 and the two rearward bands left as cast. You would not imagine how many years of fooling around it took to come up with this mess.

Best of luck in coming up with the combination that makes your particular firearm a tack driver, I will anxiously await to read your progress reports. For sure there will be a wealth of information and opinions offered on this project. I will be lurking.

Roy

Shoot often, Shoot well

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CBA Member

RicinYakima posted this 03 November 2010

Bill, I thought of that, but would involve making new rams for the now oversized holes. It was easier just to sell the less accurate ones on E-bay. Ric

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CBA Member

billwnr posted this 03 November 2010

Ric, I have one that sizes bullets slightly offcenter and wondered if it would affect accuracy. I haven't noticed it on one rifle but have on another. Then I realized I'm using a bump die that trues up the bullet dimensions for the rifle that's not showing any effect.

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Standard Member

Wayne S posted this 03 November 2010

For the bullets with any sort of flat on the nose {Saeco RG-4 & 311} I plan to use a SWC top punch for conventional base first sizing with a flat area several times the size on the flat on the nose, that should eleminate any misalignment marks on the noses, linda SOL on the 311299 style noses.

Ain't it always something

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CBA Member

RicinYakima posted this 03 November 2010

I think you answered the question. Bump dies are almost always custom made with great care, so compressing the bullet would reform it to interior shape of the bump die.

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CBA Member

billwnr posted this 03 November 2010

One would think the chamber and barrel of a rifle would act similar to a bump die and true up the bullet. One would think....

I haven't seen that happen in real world practice.

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CBA Member

RicinYakima posted this 03 November 2010

Bill,

I think about it this way:

In the barrel the bullet has nothing on the front, just the open bore. It may (!) touch on a couple of lands and maybe the edge of one band. Then it gets 20,000+ psi applied only to the back end in 0.0001 second.

In the bump die, it is totally surrounded, either by the die or lube in the grease grooves. It has steady pressure of maybe 1000 psi applied over several seconds.

At least that is how I look at it.

Ric

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Standard Member

Wayne S posted this 03 November 2010

RicinYakima wrote: Bill,

I think about it this way:

In the barrel the bullet has nothing on the front, just the open bore. It may (!) touch on a couple of lands and maybe the edge of one band. Then it gets 20,000+ psi applied only to the back end in 0.0001 second.

In the bump die, it is totally surrounded, either by the die or lube in the grease grooves. It has steady pressure of maybe 1000 psi applied over several seconds.

At least that is how I look at it.

Ric PLUS, the bump die should conform the nose to the same Dem. and angles as the weapon's chamber, there for it is supported on all sides and if not already engraving the rifleing it is guided into them supported on all sides, VS the bullet that has a jump from the case to the rifleings,

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Match Director

DAMRON G posted this 03 November 2010

Wayne S wrote: Situation, as cast Dia. .313, need sized dia. .309.

For the best posible accucary would it be ;

A. Lube and size in .309 H&I die

B.Lube and size in .312 H&I die, then run through a Lee push through .309 sizing die.

C. IT DOSEN'T REALLY MATTER

Wayne

I vote for “B"

i have taken many .311-.313 diameter bullets and shoved them i my 309 lee die un-lubed with GC and have never had any trouble.In fact i think it helps seat the GC square due to the resistance when it first enters the die.

I have also taken a long 240g .324 diameter bullet and lubed them first in a .323 die (with 8mm check) and then ran them right into a Lyman .313 die base first.Accuracy was under 2 MOA out of a Russian Mosin Nagant and it shot as well as any other bullet tried.

George

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Does the direction of sizing effect accucary ??

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