I spent a few hours yesterday preparing another 100 cartridges for my 6mm Rem. I was going through the normal 10 step routine of prepping the brass for loading. It occurred to me that I have been performing this routine over and over again during my 30+ years of reloading. My father took me under his wing when I was a wee tadpole and taught me the nuances to reloading. Since this time, I have faithfully followed the same steps over and over again.

Over the past 30 years, reloading principles have not changed to any great degree - segregating cases, trimming brass, turning necks, annealing, deburring flash holes, seating bullets just off the lands, checking run out, etc, etc. The only big changes that I have found have been the quality of the reloading tools, the quality of brass, more powder options, better primers, and the quality of bullets. There are a few new ideas like moly coated bullets, cryo treatment, sifting powder, substantially better cleaning tools and solvents, but at the end of the day, the principles have remained constant.

What has been the biggest �EUREKA� in your reloading knowledge? Was there any one reloading skill that you learned which made a considerable difference at the range or in the field?

I've been reloading for 30 years also. Last year I came upon a solution to handle case runout caused by oversized chambers in military rifles(Mausers and a French MAS 36)and thus solve the inevitable decline in accuracy it causes. After 2-3 reloadings accuracy went to pot and I had to start with new cases again.
I observed that on initial firing, a pronounced expansion ring would form on the case head as expected, but only in rare cases would this ring be co-eccentric. Most often, one side of the case would "blow out" and form a large bulge, thereby setting the runout. This was especially true when I tried fireforming domestic 6.5 Swedish to 7.5 French in my MAS 36. I nearly had case head separations.
It occurred to me that if I could hold the undersized cartridge head in the geometric center of the chamber at the moment of firing, it would force the brass to expand evenly around the circumference of the case head and result in a uniform expansion and a case with little or no runout.
How did I do that? The solution came to me one day at the range while I was scrounging for brass. I picked up a Rem 7mm Magnum case and looked at the "belt" and the idea hit me - why not create a shim around the case base like a belt on a magnum cartridge that would center the case head in the chamber?
The problem was finding a material that would be able to withstand the pressure and be easy to apply to the cartridge case. The answer was aluminum duct tape. When peeled from it's backing this 100% metal tape is about .002 in in thickness and is moderately compressible. By measuring the difference between a fired case and a new case and adding about .002 I calculated how many turns of tape I would need for a snug chamber fit. Small adjustments were made by rolling the prepared case on a hard, flat surface if the diameter was a bit too large.
When wrapping the case heads, I had to make sure I did not overlap joints because this would have built up a ridge. Instead, I would stop short, tear the tape, and start a new turn offset from the previous one. The tape width need not be more than 2 mm and should be placed just above the extractor groove cut.
The proof is in the pudding they say, so I loaded up 20 newly formed 7.5 French cases and applied my tape belts. Eureka! Firing revealed my theory was correct. Each and every case came out with a perfect expansion ring and little/no runout. Accuracy was excellent even with the fireforming loads. The best news is that the effect is permanent. The tape can be removed and the cases full-length or neck sized and they will remain straight thru repeated firings. The "rebated head" look takes a little getting used to, but the results make up for it.

PS: I learned I could salvage previously fired cases with runout by full-length resizing and applying the tape as above. They straighten right out when fired.

Two things I've learned, one by "osmosis" from Hornady and Sierra techs, the other by perusing load data manuals.

First, if you're loading light varmint bullets in 22 and 24 caliber, you will be far better off if you seat the bullets deep in the case, with no regard to distance from the lands. This increased bearing surface appears to limit bullet deformation on firing, and probably has some benefits for rifle's whose chambers aren't perfectly concentric with the bores. I have noticed that by seating these lighter bullets deep you can go to max charges without losing accuracy.

The max charge thing brings me to the second thing I've noticed. It's what I have named optimal charge weight, or OCW. This is the amount of a given powder in a given load recipe which ignites and burns most consistently. For instance, the OCW for the 270 Winchester using a 130 grain bullet and IMR 4350 powder is 55 grains. If you deviate more than about half a grain either way from that charge, you're leaving the "accuracy groove."

I have found that you can identify the OCW by something like, but not exactly like, the Creighton Audette method. Ideally, with larger capacity cases, you would load +.3 grains and -.3 grains (above and below) the test charge. Use .2 grain deviations with .223's, etc...

I began testing for my 270 with 53.5 grains, a charge suggested by a Sierra tech. I loaded some of that charge, and some with 53.2 and 53.8. I then fired two of the 53.5 grain load, and into the same group, two of the low charge. I shot another group consisting of two of the 53.5 grain charge, and two of the high charge. I noticed that the 53.8 grain charge came closer to the 53.5 grain pair than the low charge (53.2) did. This indicated the direction I though I should go with the charge. So I moved up, and tested again. This time, I used 53.8 grains as my normal group, and 53.5 as the low charge. The high charge was now 54.1. The 53.8 grain pair (mean charge) was met closer with the high charge pair again.

I continued this routine until I came to a mean charge of 55.1 grains, and noticed that 54.8 grains and 55.4 grains all grouped in about 1 1/4 MOA. I knew that the "accuracy groove," or OCW, was right about 55 grains of IMR 4350 for this recipe.

Then I found out that I hadn't discovered anything new... It seems that Winchester used to use exactly that powder and charge in its factory 130 grain 270 ammo. Oh well...

Anyway, I have tried the same method with other calibers, and it seems to work. By locating the OCW, you can worry much less about the minor intricacies of loading. I have noted that loads loaded with the OCW can tolerate brass case differences and other "no-no's" much better than non OCW loads.

How can you fine tune your load for optimum performance in your rifle without deviating too far from the OCW? After I identify what I believe is the OCW for a particular recipe, I then try different primers to see which ones might tighten the group. Another variable is OAL, or distance to lands of the bullet. Hone in on a primer first, then "super fine tune" with the OAL.

I used to do this in reverse order, deciding what distance to the lands to use first, choosing a primer, and then developing a powder charge which would work within those parameters. Often times if not most, the OCW would not be reached. (I have discerned this from looking over my old load data).

Anyway, those are my EUREAKAS! Perhaps some folks will disagree with me, but I would ask that they give these two tips a try. They may work well for you, too...

green 788

seems that most of my eurekas have been discovering that some of the things I have been doing are really "monkey see, monkey do" things that don't really contribute to accuracy nor safety. weighing cases comes to mind as a biggie.

Kinda like when some of the experienced loaders here have posted experiments with worn out brass--even mixed brands. In these experiments they took proven loads with decently accurate guns. They used a mix of brass--some needing annealing bad. Didn't pay attention to concentricity either. What happened--groups varied only by 10th's of an inch! If you are shooting matches it matters, if you are hunting the animal won't know the difference.
YET its still the Love of Labor that seems to keep most of us going doesn't it. Seem's like it's even "the beginning of the hunt" when we meticulously make up those magic rounds for our hunts!! We'd be better off spending the time at the range or improving our stalking skills in all honesty!

For me it was case trimming, on pistol cases.
I have one of those cross-breed guns.
A Coonan 357 mag, picture a stainless 1911 on steroids, just a little heftier on every dimension. Well, It was always a finicky gun
sometimes it would work great other times it wouldn't get three rounds out without a jam.
What I started doing was trimming the cases down to minimum length. I use range pickup brass so it's a mix of different headstamps. and sometimes the cases are long even after a first firing. Trimming them down made a huge difference in how the gun worked, can't say I saw a huge improvement in accuracy but I think it helped a little. My method is to resize, and then flare the brass ever so slightly, this will make them truly round again and then run them on the trimmer to nip a bit off the top.

Although I like to do all of the "case prep" stuff, I am finding that *I* am the limiting factor in my shooting endeavors.

Just yesterday, I was out shooting my Hornet seriously for the first time. I had prepped the cases in the normal fashion and the 70 shot well off a rest. Then I simulated field conditions and sat down with no rest involved other than my shaky frame. The groups opened up naturally, but more than I like to see. I kept all 5 in the black but the nice little cluster was gone.

I will still prep the cases in my normal fashion as I tbink having confidence in the load is important without a doubt, but as mentioned earlier, the part of my game that needs the most work is ME!

Good thread!

Tim

------------------
Protons have mass? I didn't even know they were Catholic!

NETim, you made an excellent point. You read post from guys that shoot hundreds and hundreds of hunting rounds a year and hold long debates on whether brand x bullets or brand y bullets can reduce their groups by an eighth of an inch, etc,etc. And every bleeding round they fire in practice is from a bench. Many years ago, I was shooting a 30-06 that would shoot nickle sized groups often enough for me to know the rifle was more capable than I was. Just for giggles and laughs, I posted a 6 inch bull on the 100yd frame and fired 10 rounds at it offhand. I did not keep all ten rounds on the FRAME! Since then a certain amount of my range time has been allotted to practice using real world shooting positions.

[This message has been edited by beemanbeme (edited 03-19-2002).]

quote:

---

weighing cases comes to mind as a biggie.

---

I just can't stop weighing. I even mark the different weight ranges with various colored Sharpies in the extractor grooves to keep them separate Is there a Case Weigher's Anonymous help group?

My "Eureka" was a chronograph. It showed that some of the factory's loads weren't what they claimed, nor were some of mine what I thought.

R-WEST

------------------
"the spotlight of truth will cause the cockroaches of deceit to run for cover every time"
Rush Limbaugh

Yea, I got rid of my chronograph years ago. I'm not out to impress anyone with speed, just little bitty groups. And, I learn the true drop of my loads by shooting, not from some 'program'.
I learned how to watch for pressure signs and when to stop fiddling with one powder and move on to the next.
On most of my rifles I seat the bullets so they fit the magazine, because if I seat just off the lands, they won't fit.
And, I pay attention to others on these forums who know what they are doing and pass their knowledge on to us.
I've been reloading since 1964 and I'm still looking to learn more.