Questions about the Foster Bushing Bump Neck Sizer Die?

The only sizing die I know of that's better than a full length bushing die is a standard full length sizing die whose neck is honed out to .002" smaller than loaded round neck diameter. Their necks stay in alignment with case bodies whereas bushing have a couple thousandths slop sideways. Necks are a tiny bit better centered on case bodies with one piece sizing chambers.

Forster will hone one of their die's necks for $12. I tried expensive custom match dies and they were no better than standard dies with honed out necks. Don't need expander balls with these dies; case necks are worked half as much and last longer.

Sized cases with straight necks let bullets seat very straight with most any seating die.

Bart,

when you have a die honed for that specific setup I assume you want to keep the components the same/very similar. for example you don't want to switch brass correct?

I have a 308, I've been shooting SMK's and 178AMAX with winchester brass. I have had success and will continue with my winchester brass for at least 400-800 more shots. after that i plan on upgrading to lapua. I assume that having a die honed for specific neck tension would require someone to commit to using only one brand of brass OR turn necks to a specific thickness correct?

z7 said:

I assume that having a die honed for specific neck tension would require someone to commit to using only one brand of brass OR turn necks to a specific thickness correct?

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Yes, but as long as neck wall thickness doesn't vary more than .001", turning necks is not needed.

And three bushings across .003" in size could take care of lots of different brass.makes.

Capybara said:

Do you also go as far as using a concentricity gauge, weighing and segregating your bullets by weight and or length or other more "extreme" steps?

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No concentricity gauge measures rimless bottleneck bullet runout like it will be in the chamber when fired. Commercial gauges don't hold cartridges headspacing on their shoulders like chambers do when they're fired. Make resized case necks straight on the case and you won't need a bullet runout gauge. Besides, if bullet runout is less than 1% of bullet diameter, that'll do well for well under 1 MOA at 600 yards; sometimes under 1/2 MOA if all else is just right.

Best runout gauge has its front reference a round hole the diameter somewhere on the case shoulder and the back reference at the case pressure ring. Those two places are the only ones the case touches the chamber with when fired. There's clearance around every other place on the round.

Weighing bullets and sorting them for length is best done when your worst groups at long ranges are no bigger than 1/10th MOA.

However, if you have some superstitions like people who touch slot machine screens at different places in the same order before each pull on their arm as their good luck ritual, then by all means, do them. You'll always know you did the best magic stuff possible.

The only sizing die I know of that's better than a full length bushing die is a standard full length sizing die whose neck is honed out to .002" bigger than loaded round neck diameter.

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How do the cases get sized down to "loaded round" diameter?

jmorris said:

How do the cases get sized down to "loaded round" diameter?

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By having the die's neck .002" smaller in diameter than a loaded round's neck diameter so their mouth is about .001" smaller than the bullet after springback.

Thanks for asking which enlightened me to my error stating "bigger" which was backwards. That was my first mistake this year. My other errors since Jan. 1 were just plain weak in being right.

Thanks for asking which enlightened me to my error stating "bigger" which was backwards. That was my first mistake this year.

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That's still a good record, I didn't make it to the 2nd day before my first.

From how I felt when I woke up later on the 1st, I am pretty sure my first mistake was staying up until it was 2017.

Regarding "competition" seater dies.....

While their precision adjustments may be in .001" increments, few of us size cases and push bullets into their necks that lets every round's bullet have that little spread in how far they move to touch the rifling. Three to four of them (.003" to .004") is more realistic when all the variations in case headspace and bullet ogive dimensions combine. If one must have the same jump distance for every bullet, soft seat them shallow enough to set back a few thousandth inch every time their chambered. Each bullet's jump will then be exactly the same; zero. Cut the powder charge a grain or two if you're already loading them hot.

Standard seater die stem threads are usually 20 or 28 per inch. Twisting them a tiny amount for each adjustment is good enough.

How many dummy reference rounds with different bullets, cases and OAL's can you make for the cost of a competition seater die?

How many dummy reference rounds with different bullets, loads and OAL's can you make for the cost of a competition seater die?

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I was going to say a lot but then realized I had more than a dozen presses just so I don't have to fiddle with adjustments.

I've used digital calipers to set seater stem's top some distance from the die's top. Not a micrometer system but works as precise as seaters with numbered marks on their adjustment thimble.

I have a Wilson chamber type hand operated, RCBS and Bonanza (now Forster) press mounted competition seater dies. The RCBS is best for me as it's easiest and fastest to use. Don't have to carefully guide a case with bullet aligned to and on its mouth up into the die; a slow and tedious process. The Bonanza best aligns the case mouth with the seating stem because it centers case shoulders in its die chamber a little better than the RCBS one does. The popular Wilson hand seater has a lot of slop in this regard. All seat bullets equally as straight as my conventional seaters as long as case necks are sized correctly and well aligned with case body and shoulder axis.

I started another thread with my "cheat" for setting dies from a known position.

I use the Forster neck/shoulder bump die along with the Forster Benchrest seating die. Both work well for me, and the Forster seating die is the same design as the Redding, but costs less.

Seating dies....

Measured my seven 30 caliber bullet seaters to get the bullet chamber diameters at the mouth juncture:

Wilson BR chamber type .308, circa 1966;.3105"
RCBS standard .308, circa 1966; . . . . . . . .3100"
RCBS standard .308, circa 1979; . . . . . . . .3115"
RCBS competition .308, circa 1980's; . . . .3107"
RCBS standard .300 Win Mag, circa 1999, .3104"
RCBS standard .30-.338, circa 1967, . . . . .3102"
Bonanza BR .30-.338, circa 1980; . . . . . . .3093"

Standard bullet seaters will benefit from a layer or two of thin tape wrapped around their seater plug so they center better in the die's bullet chamber.

One nice thing about the Bonanza seater is it centers the case shoulder in the die and aligns the case neck perfectly centered in the die's neck; providing the case neck is dead centered on the case shoulder and straight with the case body axis.

The RCBS Comp. seater uses a floating bullet chamber that centers on the case shoulder with a bullet funnel at its top. Good for faster operation and does well seating bullets straight.