Why are factory loads usually decent?

[stillsteamn]

Hi guys. I am a handloader and try to use OCW and/or ladder type testing to short load development curve although I only caught on to those methods in the last few years. Anyway my question is why do you suppose that in general, factory loads tend to be pretty decent in a wide variety of rifles, while in the process of finding a good handload I often find numerous horrible grouping loads?

This is not a perfect example, but I've wasted a couple years (very intermittent) trying to find a good 130gr bullet load for my wife's .308. I finally pulled out two 30-year old 150gr factory loads and they shot like magic. It's not a perfect example because most likely what I've learned is this rifle likes 150gr SP bullets.

 

[1moaoff]

Testing!

 

[salks]

In the interview with Mark Gordon on the summit he talked a little bit about it. What I got at least from what he said about Hornady was they found just the right jump. Hornady in cartridges like 6.5CM created the SAMI spec for the chamber free bore and a jump that would work well in a variety of barrels. Yes they didn't just pull numbers out of the air they did alot of testing. Mark even talked about pulling bullets on factory ammo and finding the charges were not all that consistent but because they were in that jump sweet spot they work. I found that interview very interesting.

 

[Snuby642]

Those old bullets are probably a tangent ogive / Spitzer design.

You may have been trying secant ogive bullets (eld / vld) .

Is it a ruger tactical 308?

Try some smk and berger hybrids.

 

[DellaDog]

Don't know the physics, but even with hand loading, there’s common loads that shoot well for most, and most of us waste innumerable rounds testing to end up close to these loads. Something the manufacturers have already done.

223 77SMK 24 gr. Varget
6 BRA/Dasher 105 Hybrid 31ish gr Varget (about a grain less w 4895)
6.5 CM 140 Hybrid 41.5 H4350

I’d bet many factory loads are similar to above.
(Hornady loaded their 140s at 41.5, powder unknown)

With Hybrids (and SMKs) jump really doesn’t account for much. (my observations)
As noted above, my guess is bullet design really helps.

 

[Dthomas3523]

1: lots of testing by ammo companies that show what loads do well across the most barrels with a particular chamber and such

2: loading ammo isn’t as much vudoo as people think. Consistency in the loading and components is more important than the fine tuning the individual rifle (as far as accomplishing satisfactory ammo)

 

[isofahunter]

When you go into the basement of Hornady (sure others are same) you get to see a sliver of what they do. Hornady has a vault of guns (350 when I was there) that they test ammo in to make sure it works in a broad selection. They have a reloading room and a range right there too with all sorts of cool testing tools. $$$, time and smart people.

 

[LostInJersey]

I mean, if you pay me my currently salary, I'll invest the same time Hornady and other factories put into it. If I could shoot on my own property and could do 8 hours of loads per day with the funds for the test equipment needed, I'd test every 0.1gr load on my 6.5CM from 38-42gr H4350 at varying seating depths and find that perfect load. Wish they'd let me test some of my powders on the calorimeters though so I could get EXACT pressure amounts per piece of propellent based on gas production.

But yea. it all comes down to how much are you willing to invest into finding perfect loads? Big companies can afford a lot of man hours and equipment the average person can't.

 

[smoothy8500]

Consistency in the loading and components is more important than the fine tuning

Federal GM Match is one of those factory loads that work well universally. What's interesting is that there have been more than a few individuals who have broken down some 168gr 308 Fed GM Match and weighed the charges and found sometimes a 0.4gr variance from high to low. I'm sure their testing found a node that is wide enough and "plays well with others" to accomplish what is expected.

 

[Dthomas3523]

Federal GM Match is one of those factory loads that work well universally. What's interesting is that there have been more than a few individuals who have broken down some 168gr 308 Fed GM Match and weighed the charges and found sometimes a 0.4gr variance from high to low. I'm sure their testing found a node that is wide enough and "plays well with others" to accomplish what is expected.

Or .4 isn’t as big a deal as people think for practical shooting.

 

[Snuby642]

That fgmm 168 works well in about every 308.
Probably the best factory round ever.

 

[Deleted member 113831]

If you were to chrono most of those loads, you would find them just a bit slow compared to what is possible with that combination.

There is a point in any optimal load combination ladder where the powder is just on the edge of optimal burn. It hasn't reached anywhere near high pressure and isn't causing the gun to vibrate like a tuning fork near as much....the whole system upon firing is relatively sedate. This is the zone where a lot of factory ammo lives.

If you were to take a bunch of random powders and bullets (appropriate combinations of course), and load them about 5% off max, and load them to SAAMI overall length, you would find that very many of them shoot extremely well. The only downside is the loss of speed and a little more soot.

When you cross the threshold of high pressure you can actually see on the paper where the gun becomes much more "active" in it's response to firing.

 

[smoothy8500]

It hasn't reached anywhere near high pressure and isn't causing the gun to vibrate like a tuning fork near as much....

I guess that explains what the OP was referring to: Quality components and good powders where certain combos cause bizarre groups.