Which book to trust

[0321jarhead]

Here I have (at this time) two reloading books. My first book is the LEE Modern Reloading 2nd Edition. The 2nd is Sierra Rifle & Handgun Reloading Data.

I noticed (after I reloaded) that the two books give different data. For example, LEE shows (page 336) .308 Win. using IMR-4895 for 165 grain jacketed bullet, start grains at 42.7 and the Sierra book (page 538) using IMR-4895 #2140 (Game King) .308 165gr. HPBT at a starting load at 38.3. What gives? I used the Sierra data.

FWIW, I am still a green horn at reloading since I started in April this year and have only load 200ish rounds so far. I only have reloaded (per LEE book) 7.5X55 Swiss and all have cycled just fine. On this subject I have only loaded 50 of the .308 and yet have not tried them out.

[ElvenSoul]

The one that enlightens you to the Great Old Ones!

[0321jarhead]

The one that enlightens you to the Great Old Ones!

Perhaps I should of mentioned Sierra is the one I trust at this time. Thanks!

[5.56Geo]

These reloading book are like cook books full of recipes. They are all a little different but work. Thats why its important that you start at the lower end of the powder charge and work your way up. What may work well in your 24" barrel my work marginal in my 18" barrel. ...another thing, many powders have very similar burn rates and can be substituted at a lighter/heavier powder charge.

[ElvenSoul]

I think your ok with either one.

Use one as a starting point...then fine tune for your gun.

[Bastard]

and the lyman book will say something different as will the hornady....

there is no one book to take as gospel.

all I can say is that where you are working up loads, just watch for pressure signs.

[0321jarhead]

Recipe books for sure. As I had started out with LEE I have only used the lower end of a charge. The same with the Sierra. And will with any.

[Bastard]

oooh don't forget, since you are using IMR powder, to check their website to really confuse you... err I mean as another reputable site for load data

[0321jarhead]

I even printed out that info months ago. Thanks!

[meaty-btz]

Various books have various data generated from various sources. Some old, some new. There are actually few companies that actually run complete testing like they did in the old days. Like Speer used to, in house.

Even more loads varied downward over time for two reasons:
-Advent of piezoelectric pressure testing which revealed new "fast" pressure events that the old crush testers could not detect.
-Lawyers, which should be self explanatory.

Unsurprisingly the "old" loads are usually fine and were used for decades without major issue. However combining the new pressure data and lawyers and you get reduced loads. I wouldn't shoot an "old" max load in a firearm in disrepair or dubious quality but otherwise it would be safe.

Many of these books still have old data lurking in obscure calibers that no one tests for. One particular caliber's load data was generated not from testing but from essentially historic "hearsay" without any concrete testing done. Turns out it was ok.. but still.

Most of us keep multiple sources for load data and then interpolate based on our own feelings.

Reloading is not for everyone

Oh yeah, and powders change over time. H4895 is about to undergo a revision, which makes me nervous. Old Red Dot is today's Promo and current Red Dot is not old Red Dot, they have different burn rates.

[OpenSightsOnly]

I use the Sierra and Hornady manual (I use their bullets) as well as the IMR website (I use that powder). I use that for cross check as well as min and max charge based on bullet weight.

Gives me a ballpark idea . . .

[0321jarhead]

You guys are sure filling me in with some great info. I feel a bit relieved now.

The only powder at this time that I have is the IMR-4895. I'm in no rush to try experimenting. I am enjoying reloading. It's relaxing to me. And when at the reloading bench I think SAFETY. I just take it slow. I'm in NO rush to screw up.

[RandyD]

Hey 0321, I am a fellow Recon Marine. I have been reloading ammo since the mid 70's. There is lots of good advice above and I won't counter any of it. You can trust both Sierra and Lee manuals, as well as the powder manufacturer's manual. There are reasons why each publisher has slightly different data; they could have been using different brass, a different bullet with the same weight in grains, different powder lot, different ambient conditions ect.

Safety is foremost. If you use a starting load, the chances of experiencing an unsafe condition is minimal to non-existent. As you fire your reloaded ammo, check the primers for indications of excessive pressure. If there isn't any indication, the load is good to us.

As you progress in reloading, you may want to invest in a chronograph, and verify the muzzle velocity of your ammo. To maximize your reloading skills look up ladder test and review the reloading section on 6mmbr.com and you will find a wealth of information there to guide you.

SF Randy

[meaty-btz]

For the safebet, jarhead, take the highest min and the lowest max as your guiding light.

That will prevent squibs (too weak a charge)
and KBs (over charge). So the safebet can be interpolated from the various data to find your "safest" window to work in till you get more confident.

[0321jarhead]

Great advice guys!

"I really appreciate it".