Question about conflicting reloading data

[BradF]

This is my first post on the forum, and I thought I'd give a little background before I ask my question. I am far from being a master reloader. I started reloading back in the early 90's, and did reload quite a bit before the family came along. I bought a Hornady reloading manual in '92 and used it exclusively for my reloading data. Fast forward to now. My kids are now old enough to shoot with me, we now live on a farm where I have my own range, so a month or so ago I got out the old Rockchucker, dusted off the Hornady manual and proceeded to load some rounds for a 30-06 I now hunt with. I checked in the manual, decided I would load with IMR 4831 since I could use that same powder in my 7mag. I bought a new lb. to use. Here's where the problem came in. I was pressed for time and I admit that I cut a few dangerous corners on my first load. I didn't start at the lowest listed load, I started 1 1/2 grains below the maximum load listed in my manual. I loaded up 15 rounds and head out to the range. To shorten an already long story, there was no consistency from shot to shot, and primers were flattened. I didn't look at the primers until after I shot all the rounds. I know that was stupid and dangerous.

After that experience, I decided to try and find an alternate source for load data. I looked on the Internet and found the IMR load data center. It doesn't even list a load for an 06 in IMR 4831. I now have a new lb. of IMR 4064 to try. The old Hornady manual lists the MAX load with IMR 4064 at 49.9 gn. The IMR website lists the STARTING load with IMR 4064 at 49 gn with the max load being 52.5 gn. Why is there such a large difference between the data from one site to another? Has the powder changed since the Hornady manual was produced? Since I just ran 15 rounds of too hot ammo through my MKII, I would like to avoid doing that again. Thanks for any advice and assistance.

Brad

[snuffy]

First, reading pressure by primer appearance is like reading tea leaves to predict the future. Of little value. Your load might have been perfectly safe.

Then you didn't list bullet weight or who made it. Too little info to be of any help with your loading problems.

The hodgdon website lists both H and IMR 4831 for heavier bullets, above 175 grains.

http://data.hodgdon.com/cartridge_load.asp

[Slamfire]

Can't be of any help until you list bullet weight, type.

[BradF]

Hey Snuffy and Slamfire1 thanks for the reply. I will give all the info I have, so you guys can help me. The bullets are 165 grain Hornady BTSP's. The primers were completely flattened, with very little distinction of where the primer stopped and where the case started. Something was bad wrong with the loads, I don't fully know what it was. All the cases had been fired once in my rifle, partially sized, trimmed, chamfered, etc. I seated the bullets just short of touching the rifling. I had moved my scope so I knew it wouldn't be sighted in just. I got the scope close after the 3rd shot. I continued to shoot 3 shot groups, if they could be called that. After each 3 shots I allowed the barrel to cool for 10 minutes. The temp outside was in the 30's, so the barrel got cool, but not cold before shooting again. If I had measured the groups, which I didn't, they would have been in excess of 6 inches. The next day I shot a sub 1" group with factory ammo in the same rifle. I have never had any handloaded ammo perform so poorly. The cases all have the same headstamp, and are all from the same lot. The powder and primers were new. Each powder charge was weighed on my Hornady scales. Thanks.

[ForneyRider]

There is a great article in current Handloader Journal about how the various components affect accuracy.

Quality of bullet had a huge impact.

Interestingly, an appropriate powder with charge in a good range was important to a lesser degree.

Make sure your brass prep and bullet seat depth is consistent.

Hodgdon has loads for IMR 4831 for the heavier bullets in .30-06 (175gr to 220gr). Which is appropriate. If you are using a smaller bullet, you may want to go to a faster powder like IMR 4350, IMR 4320, or IMR 4064.

[snuffy]

I seated the bullets just short of touching the rifling.

That right there COULD be one reason for flattened primers. There's NO REASON to load out so far as to touch the rifling,(or be just short of it), for a hunting rifle. Most likely those rounds would not feed through your magazine, so you would, in effect, be hunting with a bolt action SINGLE shot.

[BradF]

Thanks for the replies. I have always considered Hornady bullets to be a quality bullet. They may not be as good as I think, or perhaps something else is to blame. The bullets did feed through my magazine with no problems. In my MKII 7 Rem mag there is quite a bit of freebore. Seating the bullets just short of touching the rifling makes a huge difference in accuracy in that gun. In the 06 there is not much freebore, the bullets are seated only a few 1000th's longer than a factory load. I may never know what caused the poor performance as I have no plans on replicating that load. I am interested in knowing what your opinions are on the differences in the data from the IMR website and the data from my old Hornady manual. Since the minimum load listed on the IMR website is so close to the maximum load listed in the manual, should I start out working the load up considerably lower than the minimum load listed in the old manual, or do you think the new information on the website is more reliable? Is that about as clear as mud?

[Al Norris]

BradF, just comparing Lyman's 48th, Hornady's 6th, and Hodgdon's website, I've come up with the following for 165gr bullets:

IMR-4064
47.0gr to 52.0gr. Lyman's using a Nosler ballistic tip. COAL: 3.285" Win Cases
41.8gr to 50.2gr. Hornady's using Hornady #3045 BTSP. COAL: 3.230" Hornady/Frontier Cases
49.0gr to 52.5gr. Hodgdon's, using SIE SPBT. COAL: 3.300"

IMR-4350
52.5gr to 57.0gr compressed. Lyman's. COAL: 3.285" Win Cases
48.1gr to 57.0gr. Hornady's. COAL: 3.230" Hornady/Frontier Cases
56.0gr to 60.0gr compressed. Hodgdon's. COAL: 3.300"

IMR-4831
54.0gr to 59.0gr compressed. Lyman's. COAL: 3.285" Win Cases
50.6gr to 59.5gr. Hornady's. COAL: 3.230" Hornady/Frontier Cases
I checked several back issues of Hodgdon's and they all agree, no Hodgdon load data for this bullet.

I've just started loading for 30-06, but I can say that for the powders I have, I like IMR-4350 the best. Um, so far. Since I load for hunting, I try to stay with the published COAL.

[BradF]

Al, thanks for the info. I haven't tried IMR 4350, I may end up trying it if the 4064 doesn't do what I want it to. One thing I like about the 4064 is that I can use it in my .223, .243 and in my 06. I haven't loaded it in the .223 so I hope it performs okay. I like to use powders that I can load in several calibers. I know there are many other powders besides the 4064 that will do that also. I may end up trying Varget, as it will work in all the calibers I listed too. I don't shoot enough in any one specific caliber to buy powder in bulk unless I use the same powder in several calibers. I primarily load for hunting too. I know I don't need sub moa accuracy to take a deer or yote, but I still like that performance when I punch paper.

[wncchester]

"The primers were completely flattened, with very little distinction of where the primer stopped and where the case started."

Brad, that degree of primer flattening is much more often due to "excess" headspace due to overly setting back the shoulder and less likely to have anything to do with an over pressure charge. We create that excess head space by the method we adjust the sizer. Try the load again but set up the sizer differently.

FL size a fired case, one with a flattened primer, with your size die backed out a quarter turn or so from where it is now. Try to chamber the case. It should be very tight and the bolt is unlikely to close, that's what we want for now. No sweat, just size it again after moving the die DOWN but no more than 1/16 th of a turn! That will move the shoulder only a little over .004". Then try the chamber fit again. If it goes, fine, if not do it again. Keep it up until you get to a point that lets you chamber the case just snugly. Lock the die ring there to maintain the adjustment.

Complete loading that round and go fire it, into the dirt. Check the primer. bet it will look normal. If so, load the rest of your ammo and smile.

Setting a sizer the "factory way" typically sets the shoulders back a lttle too far, sometimes a LOT too far so doing it with the chamber test is much better. That's why so many people toss cases after five firings, they are stretched to the danger point if we size after touching the die with the shell holder the way the "instructions" say to do it.

A faster way to adjust size dies is to have a case length tool that measures from the case head to the shoulders. They we can just adjust the sizer for a couple thou shorter than fired length and be good to go. Hornady's LnL gage is good, so is the RCBS Precision Case Mic but the gages are really not necessary if you just use the chamber as a gage. FL sized right, we can safely get a dozen or more firings from our brass.

[rg1]

Years ago my shooting buddy and I started loading at the same time. We followed book data. He read an article on 7mm Rem Magnum in a magazine that printed data a grain or two higher than book max data. He tested those loads and while it showed that it was warm it did not cause any problems. Later he read another article saying seat bullets to touch or nearly touch the lands for better accuracy. With the same loads that were posted in a magazine and with bullets nearly or touching the lands, pressure sky-rocketed. While I didn't know what he'd done with his loads I did know something was wrong when the rifle was considerably louder. The case was so tight in the chamber that it took pounding on the bolt handle to get the fired case out of the chamber. A strong rifle and luck with the case not separating prevented a disaster.
Some of Hornady's bullets profiles have changed a little since 92. Some rifles prefer flat-base bullets rather than boattails for accuracy. I've noticed some factory and some load data has bullets seated as much as .050" off the rifling in a few of my bolt rifles. A couple of my hunting rifles prefer bullets .030-.040" off the rifling to show a little increase in accuracy.
Hornady's 7th Edition manual shows:
165btsp overall length---3.230"
using Frontier cases and Fed 210 primers
IMR 4064---41.8--2400fps
---max 50.2--2800fps
IMR 4831---50.6--2400fps
---max 59.5--2900fps
A change of primers from the one's tested can boost pressure with max loads that could cause pressure signs. Wnncchester has a good point too about case sizing.

[maggys drawers]

I had the exact same problem loading AA 2520with my M1 in 30-06. The Hornady manual listed a load range (and the groups were terrible throughout the entire range), and the NRA service loads listed another, it started about where Hornady said max, and went up 5 grains over Hornady's max. I called AA, got their recommendations (which were the same as NRA) and loaded up a few rounds and headed for the range. About a grain and a half over the Hornady max, and barely out of the NRA/AA lower range, the groups tightened up remarkably. No signs of overloading, and well within the NRA/AA specs.

I don't know why Hornady was so far off on the AA2520 range. Their specs for Varget worked like a charm.

[BradF]

Guys, thanks so much for your replies. One thing is for sure you guys sure know your reloading. I just found this website today, and have been reading old posts for several hours on and off during the day. The content of this website, knowledge of the member base and the freedom with which you guys share it is amazing. I can see now I won't have to stumble around in the shop trying to figure out all this alone. You guys are good! Man, what did we do before the Internet came along? BTW, my Hornady manual is the 4th addition, printed in 1993.

[Centennial]

I had the same problem comparing 06 loads from the Hornady #3 and #7 manual. Years ago I worked up a great load based on info in the #3 and when I looked at #7, it was all of a sudden 3.2 grains over max. For IMR 4350 the #3 lists 56.6 as max and the #7 lists 51.8 as max with a 190g bullet. That’s a 4.8g difference! I called Hornady to find out what was up. I thought that maybe they had changed alloys and were now using harder bullets or that IMR had changed formulas and the characteristics were different.

The Technician said that the new data represented the testing they did for the #7 manual. He said that if I had worked up a load that was safe in my rifle then I should be okay. BTW, I have never had any problems or any pressure signs with my load based on the info in the #3 manual. My (+3.2g over max according to #7) load mikes less expansion at the ring in my rifle than factory loads. I sure am glad im a data geek and have kept records. Based on all of my experience with this load, im am gong to keep it. I still find the huge swing in published data un-nerving and confusing.

[BradF]

Centennial, I still don't understand the discrepancies. I don't guess I ever will. I guess I can see a difference from one companies tests to another depending on the equipment used, but changes from one decade to another all from Hornady is suprising. Maybe there are more changes in powder from one year to another than I thought there was.

More on my problem. I went back and looked at everything I could on my end. It looks like snuffy was right all along. I have always relied on chambering a round with a polished bullet, looking for rifling marks, polish the bullet between each chambering, seat a little deeper each time until the marks disappear. I did this rifle the same way, but apparently didn't notice the last set of light scratches from the rifling. I took my dummy load tonight and colored the bullet with a black sharpie. There were small but distinct marks where the lands had lightly scratched it. With the black marker on the bullet, it showed up crystal clear. I changed the die and am now seating them .03 short of touching the lands. That oughta reduce the pressure back down to a normal level.

[LHB1]

Quote: "Centennial, I still don't understand the discrepancies. I don't guess I ever will. I guess I can see a difference from one companies tests to another depending on the equipment used, but changes from one decade to another all from Hornady is suprising. Maybe there are more changes in powder from one year to another than I thought there was. "

Brad,
It is possible that powder composition or burning rates have changed over the years but my first thought would be that BULLETS have changed. Perhaps the makers are using different jacket alloys which would have different friction coefficients and thus different pressures with same loads. Or perhaps they have changed the bullet shape, curvature, length, hardness of lead core, amount of rounding or tapering on base, etc. Any or all of these could affect the pressure with what we might think of as the "same" bullet I used to shoot without any problems using this load. Would suggest you get a current edition loading manual from the maker of your favorite bullet brand and go with their latest recommendations. Good luck.

[BradF]

LB, that is good info. Thanks.