So..long story short, I've been reloading for 10+ yrs and had a major wakeup call this evening. I'm only posting my findings to help others from making the same mistake I did. This is not intended to bash any manufacture etc.
I bought and reloaded a box of 140 amax in my 260. Everything went well. Ran out of amax so I switched to 140 smk for the time until I found more amax. Obtained and Reloaded some of the new amax and went to range tonight. These rounds were loaded to the same specs as the previous load with amax.
Was shooting 1087 yards. Had both loads with (140 amax and 140 smk) 140 smk was the standard expected accuracy. The amax were shooting everywhere, several feet off in every direction etc.
Went to reloading room and gave the rifle a thorough cleaning. I then decided to remeasure the overall length to the lands with the new amax to compare them to the previous loads that were .020 off the lands, measured with Hornady oal tool to ogive. My findings were rather disturbing.
The previous lot of amax measured 3.311 to ogive when contacting lands with 25 cal insert in oal tool. Rounds were loaded at 3.291. The new amax however had an oal of 3.275-3.291 when touching the lands. (About 20 bullets measured). Meaning I was unknowingly jamming my rounds up to .016 into the lands when I thought I was jumping the same .020 as before (the seating die was adjusted so the oal of the rounds from new lot was 3.291).
I confirmed the smk measurements as well. Both previous and current measurements were 3.350. This was for 5 bullets all exactly 3.350.
Has anyone seen this big of a difference in bullet lot numbers? FYI each amax was measured several times to confirm each measurement was correct.
Last edited by hafejd30; 11-23-2014 at 01:23 AM.
Is there any possibility that you originally measured the first lot of Amax's with a different tool/insert?
I know that I have been known to measure with the wrong insert installed and was getting different measurements than what I was expecting. It takes me a minute to catch my mistake. If your original notes (6 months ago, for example) were based on a different insert, how would you know until you tried again?
Last edited by foxx; 11-23-2014 at 02:08 AM.
Negative. That is why I remeasured the 140 smk rounds as well. I was looking for any possible mistake but was unable to find one. The smk were to the exact measurements as before. It must be a different design in the amax or something. Because the same insert set to the oal of 3.291 puts one lot .020 off lands and jams another several thousandths into them.
Same micrometer, same oal tool, same insert, same case, same everything. Smk are the same as before, amax are not even close.
You said your 260. Please explain to this simple mind what numbers ranging from 3.311 to 3.350 represent??? ;-))
Thanks......Jim
Length from base of cartridge to ogive on bullet. This is total length using the oal tool and a 25 cal insert. Used 25 because that is what the set contains. Rather than buying a 26 cal insert. Everyone has different ways of measuring oal. This is the method I always use for mine
I agree with your method but suggest you get the 264/6.5mm insert. It's not the cause of your problem but it may have helped to identify it before you got to the range.
I've never experienced a variation of more than a few thousandths in bullets even from different lot numbers myself.
Hafejd30, I am with JTCrl, although it stands to reason that a .250 insert woodwork as well as any other as long as the hole is not bigger than .264 insert (whatever that is). It just makes no sense to me.
Grasping at straws, here, but maybe your original 140 A-maxes were not 140 A-max. I simply cannot believe there would be such a big difference from lot to lot. Even from decade to decade. I'd call Hornady.
I'm going to run more tests later. I do have the box from the first lot. Deffinately the same 140 amax. Same manufacture number etc.
I dont shoot Amaxes but do shoot 140g hornady match bullets and 142g smks. Ive only shot about 150 of the hornadys but have only had small differences in them. I just got a 500 box of the smks and they have up to .012 variation, .583 to .595 in bearing surface. I use 2 bodys and inserts to measure bearing surface 1 on the top and one on the bottom blades of my calipers and always use the same insert for the boat tail and the same one for the Ogive. Im just wondering how the longer bullets got jammed .016 if your seating die was set to seat the bullets .020 off the lands? Is the ogive shaped different or do the new amaxs just have a longer bearing surface?
Ordered a 264 insert. Will try that. I've never seen it either which is why I'm wondering what caused it. Of course I have no bullets from previous box to compare...
This is how I measure bearing surface the top insert is maked BT with a sharpe so they so they dont get mixed up.
I have a couple lots of 178 amax for my 308. Will measure with 30 cal and 28 cal insert later. See if that yields same results as 260 bullets using 28 vs 30 insert
I've had to adjust seating depth once when using a new box of Berger VLD's. They must have come off a different line or machine,definitely a difference between the two boxes.
"An armed society is a polite society"
"...shall not be infringed" What's the confusion?
Longrange, just noticed your question. The seating die was reset to seat the smk bullets .020 off the lands. I only adjusted the die to seat back to 3.291 when I reloaded the new amax. Had I not adjusted for smk I assume I would have noticed the difference when I seated the first amax.
I did test some bullets this evening. I had 2 lots of 178 amax. I measured from base of the boat tail to the ogive on the bullet (bearing surface, less the boat tail in the back). All rounds from each lot were within .001 of their counterparts from the same lot. With 30 cal insert the difference between lot 1 and 2 was .007. With 28 cal insert the difference was .003, same bullets.
I also remeasured the overall chamber length in my 260 with the 140 smk and amax with hornadys oal tool. Got the following measurements from 5 bullets from each lot.
140 Amax
1) 3.282
2) 3.284
3) 3.275
4) 3.287
5) 3.276
140 smk
1) 3.350
2) 3.350
3) 3.350
4) 3.350
5) 3.349
This again was the total length from casing base to ogive on bullet with oal tool and 25 cal insert on an rcbs dial micrometer.
So you did readjust you die for the amaxs from the smks...this still has me stumped as even if the bullets are longer or shorter if your die is set to seat the bullet(amaxs in this case).020 or what ever number the bullet off the lands should still be the same you would just have more of the bullet in the case as most seating dies seat just above the ogive of the bullet. What brand of seating die are you using?
Also do you check every bullet after seating?
Last edited by LongRange; 11-24-2014 at 12:38 PM.
Redding benchrest seater with micrometer. And I measure every round after the bullet is seated. That's why I'm confused to. The bullet is contacting lands .030 prior to last lot. Even tho the oal of the loaded round is identical as the last lot after seating, the bullet is being jammed...
Almost like the ogive is different...strange... ive never had an issue like this and would like to know whats causing it, maybe call hornday CS and ask what they think.
Yea, I don't get this either ???
The seating die could be left in the same position to seat all bullets to the same jump only if the bearing surface of the seating die were of exactly the same diameter and profile as the throat in the rifle being loaded for. Seating dies typically contact the bullet at a point significantly ahead of the ogive or even at the tip of the bullet and therefore need to be adjusted for different bullets and even for different lot numbers of the same bullets.
If we had a comparator insert that was made with the same reamer as the chamber in the rifle we're loading for we could at least load all our rounds to the same BTOL but, that unfortunately is not the case. Here's an article by Berger Bullets that I think explains the situation pretty well.
http://www.bergerbullets.com/effects...e-cbto-part-2/
this makes sense...if the tip to ogive is different then it would change the seating depth.Originally Posted by JTCrl
isnt that what he is saying he thinks changed between batch #'s of the same bullet?
Correct. That is my conclusion as I've tested several lots of 308 amax and smk and found little variation in them. The 6.5 amax are also varying quite a bit in the same lot. .016 from 20 I tested. The smk are within .001. Wish I had some left from 1st lot but unfortunately I don't.
I think the op was looking for an answer as well. Personally ive never had this happen or even heard of this before and im still not 100% sure what caused the seating issue but it does make sense...I could see a bullet being longer or shorter but the ogive to tip being different is kind of odd and not normal.
Once had some 9mm that wouldn't chamber in my pistol all the way. When I went back to my bench I measured and remeasured and found several rounds were longer than what should have been. I drove my self crazy checking differences in lot numbers and measuring chamber. Turns out my seating die had come loose in the press and backed out ever so slightly, but just enough to give that extra length.
Check your dies for any loosening. Just a thought.
Good Luck.
If everything else is constant--that's the only possibility I can think of.
[B][COLOR="#FF8C00"]Shooting--it's like high-speed golf[/COLOR][/B]
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