OK. NOW what am I doing wrong ? ? ?

[NorCal Hal]

I am loading 30-06 with 165 grain Nosler Partion bullets. Trying to get the correct OAL and best / tightest pattern I used a Hornady Lock-N-load straight OAL gauge and Hornady bullet comparator with the 8-30 insert. Pressing the sample case firmly into the chamber then the bullet snugly against the lands. I took eight measurements using eight different bullets from the same box and got eight different measurements ranging from 3.682 to 3.775, only two were the same; 3.773."

I could get this degree of accuracy by measuring off the bullet tip and not have spent the money on all the Hornady tools.

I expected ALL measurements to be +/- .002"..... What's wrong?

[Jim243]

I could get this degree of accuracy by measuring off the bullet tip and not have spent the money on all the Hornady tools.

I expected ALL measurements to be +/- .002"..... What's wrong?

You could have spent the money on purchasing better bullets and not blame the tools that showed you bought crap.

Jim

[PawPaw]

Originally Posted by NorCal Hal

I am loading 30-06 with 165 grain Nosler Partion bullets.

Partitions aren't noted for sterling accuracy. They're noted for being magnificent hunting bullets. Some rifles give great accuracy with Partitions, while other give only so-so accuracy. However, that so-so accuracy is okay for the game fields. They're great hunting bullets and the ogive might vary somewhat.

I could get this degree of accuracy by measuring off the bullet tip

Which is just exactly what I do when I'm loading hunting ammo.

[dunerjeff]

I take a fired case and just bump the tip of the neck with the sizer so the bullet I'm loading fits snug but can be pushed in with a couple lbs of force.Then I load the round in the chamber and close the bolt.When the shell comes out you have your max oal that fits in your chamber.You can measure off the tip, or like I do,the ogive.Pull the bullet out a bit and repeat to double check,then change to another bullet from the box and do it all over,now you will know if it is the bullets or your process.

[mrawesome22]

Cut a vertical slit down the centet of a case neck, now barely seat a bullet, now chamber it. Do this with a few bullets and your measurements should be much closer.

[mehavey]

I am loading 30-06 with 165 grain Nosler Partion bullets. ...Pressing the sample bullet firimly into
the chamber then the bullet snugly against the lands. I took eight measurements using eight different
bullets from the same box and got eight different measurements ranging from 3.682 to 3.775,...

If I read that right, it is nigh impossible to get those OALs -- 3.68" to 3.78". At those lengths the bullet
isn't even seated into the case. Were those the real measurements?

Second, you said you had a comparator. What were the comparator readings? (They ought to
have been 2.7-ish to 2.8"). Soft point bullets will, by their very nature, not give you a consistant OAL, but
the comparator will.

What did you measure?



postscript:

Pressing the sample bullet firimly into the chamber then the bullet snugly against the lands...

Third. You don't press anything "firmly" against the lands. You press lightly to contact the lands, and rock the bullet back and forth against them--lightly--using a cleaning rod down the barrel with one hand while pressing lightly back and forth with the rod through the modified case in the chamber.

Lightly -- to just barely contact the lands consistently from bullet-to-bullet -- then measure.

[NorCal Hal]

The 3.682-3.775" dimensions are from the micrometer with the Hornady bullet comparator body attached to the micrometer blade and the 8-30 comparator insert on the ogive. The actual OAL bullet measured to the point is 3.380" which means only about 1/4" of the bullet is in the case neck. I said "sample bullet" in my original post when I should have said "sample case" meaning the case Hornady provides with the threaded primer hole for the straight guage rod to screw into.

I thought that perhaps the sample case wasn't seating all the way forward accounting for the bullet being hardly seated in the case but I put the case in the rifle and closed the bolt completely so it has to be at least seating on the case neck.

The sample case is 2.482" long which is .010" shorter than my normal trim length which means the bullets would have .010" more neck support than the sample case shows but it's still to little to make a solid seat.

I know (now) that Nosler Partitions are not the most accurate bullets but I expected better consistency than what I got. I didn't realize that as Jim243 says that they were "crap".

Before I bought the Hornady equipment I loaded a batch to seating depths I established by measuring off the point as suggested by mrawsome22 and dunerjeff. Five rounds seated to 3.267" OAL gave me a 3/8" wide by 1 3/8" high spread at 100 yards. I was going to load more and shoot at 200 yards but I might be wasting supplies and time trying to tighten up the Nosler Partitions.

So I guess I will load my remaining 165 NP's to 3.267" as measured at the tip and use them up.

I have bought some Hornady Interlock 180 gr BTSP and Sierra 180 gr Spitzer and was going to try them for tighter groups.

[NorCal Hal]

OK, I can accept that the Nosler Partition 165 gr ogive manufacturing tolerances are such that I get a .010" variance in mamimum OAL cartridge length.

Based on my recent reloads and shooting results the 3.267" OAL (measured at the point) preformed best - most consistent and tightest pattern. That is .113" shorter than the maximum chamber length as measured with the Hornady equipment.

Is .113" a reasonable "gap" between a loaded 30-06 cartridge and the lands?

[William T. Watts]

Nosler Partitions aren't crap, they are some of the finest bullets made in this country. I have yet to shoot any group in several rifles (6) that are larger than 1 1/2", that's plenty good out to 300 yds for large game. One mature buck I shoot thru the brisket and recovered the bullet near the anus, it doesn't get any better than that!! William

[NorCal Hal]

Nosler Partitions aren't crap, they are some of the finest bullets made in this country. I have yet to shoot any group in several rifles (6) that are larger than 1 1/2", that's plenty good out to 300 yds for large game. One mature buck I shoot thru the brisket and recovered the bullet near the anus, it doesn't get any better than that!! William


That 1 1/2" group; how many shots and at what range?

[mrawesome22]

.130" is far but it will work. Most rifles will perform best when ogive is seated .050" to .010" from the rifling.

And I believe Barnes recommends a .060" inch jump. That could just be the lawyers talking however.

[NorCal Hal]

OK Thanks.. Mine is .113" not .130". Should I try working it out a few thousands closer or leave well enough alone? I shoot a Win 70 with the BOSS system so after I get the cartridge dialed in I will experiment with the BOSS.

I did shoot the exact same load the same day with the OAL length .020" longer or .093" short of the lands but the 3.267" did marginally better (tighter group).

[William T. Watts]

NorCal Hal The groups I alluded to were shot at 100yds, all groups were the typical 3 shot group. Another Nosler bullet I like very much is the solid base lead tip bullet that groups well in my rifles, when Nosler discontinued this bullet I purchased several thousand of them in several calibers. While I haven't tried every thing Nosler makes what I have used performed better than I expected so that makes me a satisfied customer! FWIW I usually seat my bullets .020" off the lands, the exception to this rule my Winchester model 70 in 270Win has a long throat, the magazine limits the OAL length of the loaded round and that rifle has approx .040!! William

[mrawesome22]

If the group is shrinking the closer you get to the rifling, then you should keep moving it out until the groups stop shrinking.

Then you will have optimal seating depth and can start tinkering with the charge weight.

[hooligan1]

Usually handloaders start with powder weights and then start "tinkering" with oal. NorCal, just make sure that the modified case is threaded properly down on the tool, then like Mchavey says, "LIGHTLY" kiss the land with the bullet, then push it back and do it again, with a little practice, that tool will become your friend. Jim.243 I disagree abouth the Nosler Partition being crap, maybe not your cup of tea but definetley not crap!

[F. Guffey]

NorCal-Hal, I am a big fan of standards and transfers, I like to take one measurement from the chamber to the press and back to the chamber, and I can keep up with two thoughts at the same time.

When I want to find the length of the chamber from the bolt face to the bullet contact point (bullet ogive/rifling) I drill the flash hole/primer pocket out to a diameter that will accommodate a cleaning rod/wood down on cases that have bullet hold, some call bullet hold neck tension, I don't, I call it bullet hold because I can measure bullet hold in pounds, neck tension can be measured ‘difference in pounds, some have pin gages, me? when I want a pin gage I make one.

After drilling the primer pocket/flash hole I size the neck for bullet hold, I then seat a bullet, remove the bolt, chamber the round and with a cleaning rod, I push the bullet out of the case until it hits the lands, then I use the test case to adjust the seater die to .000 off the lands, after adjusting the seater die to .000 off the lands I use the dial caliper to measure the seater stem height off the top of the die. This allows me to seat the bullet off the lands in thousands.

Then there is measuring the difference in length of the bullet when measured from the contact point between the bullet and and rifling, that to can be measured and then sorted.

F. Guffey

[F. Guffey]

but first a reloader should know how to determine the length of the chamber from the bolt face to the shoulder, when measuring off the lands, head space is an include measurement, when using your case screwed to the front of the tool remember the case is chambered and pushed forward, no bolt, no bolt face, again I have one rifle with .016 thousands head space, If I should do something so vain as to seat the bullet to the rifling with either method, head space would have to be added to the length of the case (COL-case overall length).

I am a fan of the jump start, I want my bullet to hit the rifling running, I do not want my bullet sitting still at the rifling when everything behind the bullet sets busy, time is a factor.

F. Guffey

[NorCal Hal]

I'm shooting a Winchester model 70, 30-06. Should I start with my starting point as 3.267" measured at bullet tip - as those have given me the best 5 shot group and move forward towards the lands OR start at someplace like 3.360" which is .020" shorter than the indicated maximum length of 3.380" and work back from the lands ?

I still don't understand why the Hornady tools are giving me a maximum chamber length of 3.380" as the bullet is barely seated at that length.

In what graduations do you move and how many shots at each size to establish a group / pattern? I was thinking increments of .010" and five shots in each size. Then when I get the best group I can try +/- .005" from that.


Does that make sense?

[mrawesome22]

The long measurement is because your rifle has a long throat aka freebore. 10 thou increments is what I do. 3, 5 shot groups will show you if you have a good load. I wait 15 minutes between shots. As a hunter, I only care about shots from a cold barrel. If you shoot rapid fire competitions, shoot groups accordingly.

[PA-Joe]

There are several issues here. 1. If you seat the bullet to the max COL or Ogive it may not fit the magazine or it may create feeding issues. Make certain that the COL you will be using will fit teh magazine and feed correctly. 2. The Hornady gauge should be giving you more consistent readings. There is a technique in holding the case firmly in the chamber while pushing the bulllet into the lands. Try using the same bullet and take multiple readings until you learn the technique of holding the case in the chamber while pushing the bullet into the lands. Once you get consistent readings then change bullets and take several more readings. You will, as noted, get different readings with different bullets even from the same box.

[mehavey]

The 3.682-3.775" dimensions are from the micrometer with the
Hornady bullet comparator body attached to the micrometer blade
and the 8-30 comparator insert on the ogive.

Got it. You measured the whole shootin' match: comparator body+insert+bullet. If you're running a digital caliper,
I recommend that you start by zeroing the reading with the blade against the assembled body/insert (no cartridge).
That way you'll measure (near) true Distance-to-Lands when you insert the cartridge itself.
For now, let's just subtract 1.000" inch from your 3.682 to 3.775" readings and you entirely normal range
D2L measures of 2.7"-2.8" (same as my Mod70).

As to "general" D2L for various bullets and the newer Model-70s, I'm struck that yours appears to have a longer throat than mine. As part of the game with my particular Model-70, I measured* Actual Distance-to-Lands (A-D2L) for several bullet types/weights I’ve got on the shelf. I then compared that data to the Reloading "Manual" OALs (M-OAL)for those same bullets.

* Stoney Point/Hornady gauge & comparator

Are you sure you aren't over-snugging the bullet into the lands, instead of just kissing them? That would explain the D2L variation on what are otherwise finely-made bullets.

Last. As to whether a large standoff distance is conducive to accuracy...

"Maybe." and "It's not as unusual as one might think."

See here:
http://thefiringline.com/forums/show...72&postcount=1


.

[hooligan1]

In the October edition of Handloader magazine there is an interesting article by John Barsness. Its called Handloading in the 21st Century, this by the way is pretty informative.....

[Unclenick]

A good rule of thumb with seating depth is that changes smaller than 0.010" are not normally discernible, though it is chamber and bullet dependent. Often changes are coarser than that. Stealing from Berger's recommendation for their VLD's, try working up your best accuracy load with the bullet touching or up to 0.010" into the lands, then use that same load with a bullet that is 0.010" off the lands, then 0.040" off the lands, etcetera, seating deeper in 0.030" increments until you run out of room for further seating. Pick the best result and if it one of the ones further than 0.010" off the lands, then see if going 0.010" either side of it does any better. Zero in on optimal that way.

As Mahavey suggests, I'd get in the habit of zeroing the caliper so your measurement reference numbers all stay the same. You may also find it drifts a digit or two over time, and if you zero, you can check for that between measurements by closing the jaws and re-zeroing if you need to. If you don't zero you won't be aware of the problem.

Before I make any other measurements, I start by measuring bullets alone from the lot. I usually measure a sample of 30 to get a good representative average, but 15 is actually pretty good. Just stir the box and get them out as randomly as you can. Put the comparator on the caliper and zero it with the jaw closed on the comparator by itself. Then measure the base to ogive contact length and average the result. Once you have that, try to find a dozen that have the average value within 0.001". Use one with the gauge and the others with your seating die to adjust seating depths.

If COL concerns you, also measure bullet lengths without the comparator adapter and find a few bullets that have the shortest base to ogive length, but the longest overall bullet length. These can be seated after you adjust your seating die to give you your worst case longest COL. That's the number that has to be in your magazine's comfort zone for reliable feeding. If you load singly, COL variation due to bullet overall length isn't really a concern.

As Mahavey suggested, measuring is delicate touch stuff, but before you even go there, be sure your chamber and bore are completely clear of oil or grease or dirt or fouling particles, as these will affect your result. Follow Mahavey's instruction on getting the bullet positioned. Also wiggle the caliper when you take the measurement off the gauge afterward to be sure the jaw is square with the head of the gauge case.

If you bought the case comparator inserts for the gauge, now's a good time to use them. Again zero with the comparator in place, then measure the head to shoulder datum (where the comparator hole will touch the shoulder) length. Wiggle the case a little to be sure the head is flat against the moving jaw of the caliper.

Subtract your cashead to shoulder datum reading from the casehead to beullet ogive reading you got off the gauge. If you have cases a slightly different length from the adapter case for the gauge, it is that difference in the two measurements that you want to keep constant. With a case that headspaces on the shoulder, that difference will determine how close the bullet gets to the ogive.