I got the bug for a 6.5-284 heavy barrel long range rifle.

So, I sent one of my OM 70's to Bartlein to be barreled with a medium Palma contour barrel and FCH in late April. Their reamer is a JGS, for the original design, based on Winchester 284 brass. Neck it down .020 and the necks get thicker. Their reamer cuts a .297" OD neck chamber. LAPUA brass measures .291" out of the box, and is very consistent. .2905-.291", and case length is within a thousandth as well.

Sizing brass .006" every time kills brass, so I had JGS cut the neck at .293". They called this morning and the reamer is done. They are shipping to Bartlein this afternoon.

Meanwhile, Bartlein has everything ready to go, other than the chambering. In two weeks, it will be headed back to Idaho.

I am a very happy camper...

Rich

Sizing .006? Wow!

quote:

Originally posted by Idaho Sharpshooter:
I got the bug for a 6.5-284 heavy barrel long range rifle.

So, I sent one of my OM 70's to Bartlein to be barreled with a medium Palma contour barrel and FCH in late April. Their reamer is a JGS, for the original design, based on Winchester 284 brass. Neck it down .020 and the necks get thicker. Their reamer cuts a .297" OD neck chamber. LAPUA brass measures .291" out of the box, and is very consistent. .2905-.291", and case length is within a thousandth as well.

Sizing brass .006" every time kills brass, so I had JGS cut the neck at .293". They called this morning and the reamer is done. They are shipping to Bartlein this afternoon.

Meanwhile, Bartlein has everything ready to go, other than the chambering. In two weeks, it will be headed back to Idaho.

I am a very happy camper...

Rich

What does that Lapua brass case neck measure with a bullet seated in it?

My loaded Lapua brass with a 142 grain SMK bullet measures between .2957" to .2959" at the neck (as close as I can see on my 0-1" micrometer) so I had my chamber neck cut to .298".

I use the Redding S type sizing die with a .293" bushing in it because the brass spring back to .294" after sizing and I wind up with about .002" of neck tension.

Frank that is about right.

Slivers, et al,

four dummy rounds mike the same .291" OD. The cases were first run into an FL sizing die with a .263" mandrel. The dummy rounds are 3.228" oal per the specs in the Berger Loading Manual.

Case OD did not change from its' out of the box measurement.

My mistake. I didn't know "out of the box" ment out of the box, through a sizing die, and then into a seating die with a bullet.

the operations made no difference in outside neck diameter.

Taken directly out of the blue box and measured, they ran from .2905" to .291".

I just ran them thru the FL sizing die to double check. It made zero change in the OD. I did remove the decapping pin first. The expander button measured .264".

Using a mandrel made no difference in the OD.

Miking about sixty of the bullets, just to see what the tolerances were on diameter and oal left me with less than .004" difference in oal, and all of them were .264" exactly.

Seating a bullet made no difference in the OD from out of the box to dummy round OD.

All 120 of the LAPUA cases measured the exact same OD, with the exception of a dozen or so that were the .2905". Case length varied between ZERO and .0001".

The brass is almost boring in its' uniformity.

The steps just took them to .291".

I will be curious to see the tolerance the CBTO* is on the first twenty rounds I load.


Rich

* Cartridge Base To Beginning of Ogive.

Rich,

Are you saying that after sizing the brass case necks measure .291" in O.D., and when you seat a bullet in the case, the neck diameter doesn't change?

Yes. Seat a bullet that measures .264" into a case with an ID of .264" and the OD measurement of .291" does not change. At least not in this case.

quote:

Originally posted by Idaho Sharpshooter:
Yes. Seat a bullet that measures .264" into a case with an ID of .264" and the OD measurement of .291" does not change. At least not in this case.

That kinda flies in the face of all reason don't it?

quote:

Originally posted by Idaho Sharpshooter:
Yes. Seat a bullet that measures .264" into a case with an ID of .264" and the OD measurement of .291" does not change. At least not in this case.

Doesn't that mean that you have no neck tension at all? Wouldn't the bullets just slide around in the neck?

You're right Jim. I thought somewhere above he said he was sizing them .006" I'm lost.

quote:

Originally posted by Jim Kobe:

quote:

Originally posted by Idaho Sharpshooter:
Yes. Seat a bullet that measures .264" into a case with an ID of .264" and the OD measurement of .291" does not change. At least not in this case.

That kinda flies in the face of all reason don't it?

Rich, depending on your finished chamber, you may need another sizing die.

yes.

the rough reamer will do that if need be.

Take everything said about Winchester brass and reamers with .297 necks and forget it.
Nobody that is serious about the 6.5 x 284 is fooling around with necking Win. brass.

Focus on this.
Lapua brass in 6.5 x 284 is plentiful and also has the correct head stamp, neat!!

The Lapua brass is .291 + .0005
Richs' JGS reamer has a neck dia. of .293
That's a .0015 to .002 tolerance
chamber being bigger than brass.

Take a .264 bullet and seat it into a case with a neck ID of .263 as stated earlier, this is a .001 fit obviously.
This should create a final neck diameter of
.292 + .0005 bullet seated.

Simply said this is a snug neck 6.5 x 284 set up for Lapua brass.

Was the finish reamer made with any special throat? like the latest long range rage the
"bore rider throat"?

I agree with Stuart 100% without any question

nobody said the Timan was incorrect, but I question his thoughts about the original Winchester brass. A simple visit to the www.accurateshooter.com forum, and a click on the left panel where it ways 6.5-284 may prove enlightening. The design/reamer data dates back to 2005 or so.

They say .297" neck OD.
The standard JGS reamer print calls for a .297" neck OD.
The reamer that Bartlein uses is .297" neck OD.

I know this, because I asked them all before deciding on a tight neck reamer.

You are close, but the odd thing was that the loaded rounds mike that same .291" as a new case.

The .006" case expansion is not going to change with the brass and bullets I have. To me, it is excessive, and brass cannot be reloaded very many times, even if annealed, before case necks start to split. LAPUA brass is waaaaaaaaaaay too expensive for a poor man like me to have to replace it.

As an aside, most of you never experienced the initial NORMA 6PPC quality issues (too soft) and shortages. I am so old, Fred Sinclar still owned his company, and built me a LV rifle using a 40X action. After not being able to shoot much (for lack of brass), I got a call from Fred. His solution was to fit an extra bolt with a standard .308 bolt face. It let me get 220 Swift brass, and after much work, use it. The rifle shot as well. About that time a couple of noted gunsmiths from back East, Seeley Masker and Dave Tooley got the idea to combat the totally un-American PPC, based on the 220 Russian military that Palmisano and Pindell had introduced.

They came up with the idea of a 6MM SMW, Seeley Masker Wasp, using a 30-30 case and a bushed primer pocket to use small rifle primers. About 1988 they got together with Federal, and one weekend, the same small crew that made 222, 222 Magnum, and 308 Win Match brass they produced what is known as the 30 American case. Used the 30-30 case, built to match specs, and a small rifle primer pocket.

You must understand, the original PPC brass was so soft, that BR competitors would take ten new PPC cases, neck turn, uniform the primer pockets, and actually shoot them in a match on their warmup target. They then reloaded them and shot five 5-shot targets. A lot of them would be holding the primer in the expanded pocket between thumb and forefinger as they inserted the round into the chamber so as to be able to finish that match.

By the end of the BR season, there were a lot of people shooting the SMW. Cases lasted forever. Federal produced an initial run of 50,000. By the next month, they made a second run of 100,000, iirc. NORMA got the hint, and at the SHOT Show the next January, they introduced a stronger case alloy, and increased production to 500,000 or so rounds per year.

Back on task:I sent JGS a new case, and an FL-sized case, showing that was just .001" difference between the two. I also sent them a bullet (140gr Berger Hybrid) and a dummy loaded round. The dummy measured, on their optical comparator, measured the same as a new, out of the blue box, case. .291", and YES, there is some non-standard throating. I like the base of the bullet even with the shoulder/body junction, and hopefully about .010" jump to origin of rifling.

Like Berger's, and the rest of the people making them, the VLD design with its' long secant ogive is very sensitive to seating depth. According to Berger, the "Sweet Spot" is only about .030-.040". They generally require a bit of tuning to make them shoot accurately. Like finding that sweet spot.

Like most manufacturers, Berger offers boat tail designs that feature a more standard tangent ogive. It will NOT cut thru the wind like a secant ogive design will, but is much less finicky as far as seating depth.
They are almost as accurate as the VLD, but not as fussy.

Brian Litz is Berger's chief ballistician and bullet designer, as well as running his own company, www.appliedballistics.com.

I believe his biggest contribution to bullet design to date, is his Hybrid model. As bearing surface ends and the ogive is reached, the nose begins with a tangent shape. Easier to tune, but not as aerodynamic. As the nose continues, it morphs into a secant shape. More aerodynamic, but not as fussy as a true secant shape like a true VLD. It, in essence, combines the best design characteristics of both profiles.

Brian's expertise dates back to his work for the Air Force in air to air missile design.

I remain a bit skeptical about his SD valuation, and why he sees it so important. The concept is valid, but when it comes to "Confidence Intervals", the Bell Curve, and how a group's ES and size are not consistent as more groups are fired baffles me. It assuredly does not hold true in the case of the 6PPC from 100/200/300yds.

When I get my 6.5-284 back from Bartlein's in two weeks, I will be able to (hopefully) find some answers.

thanks to all for your input,

Rich

I guess if you have some issues you can always change the follower

sound advice.

I am still wrestling with whether to convert to single shot or not. I would like to send the barreled action to Carl Bernosky for one of his FT-R or Long Range BR laminated stocks over the winter.

I think I mentioned that my OM 70 came with a Kenyon trigger.