155g Amax in a 308

Load the Amax about 20 thou off the rifling. With 4895 start at 43 gr and load up in 0.5 gr increments to 46.0 gr. Shoot 5 of each and see what the rifle likes.

be prepared to not shoot the hotter loads. Depends on your rifle. Each is quite different.

I loaded 40,000 of them one summer. Seemed to work well in many different rifles.
 
rnbra-shooter said:
Wow, sounds like a really hot load! Do your primers get loose after one firing?

(FWIW 44.5 grains of IMR 4895 in a 165 grain case, under a Sierra 155, giving 2925fps in a 30" barrel, was considered a hot load back in 1992. With Varget and other powders it is possible to get well over 3000fps in a 30" barrel. But I am surprised at you getting nearly 3000fps in a 24" barrel!)

I wonder if you have a long throated chamber? What is your loaded round's overall length?
Click to expand...

No I haven't had any loose primers after three reloads, not sure about the throat. the OAL is 2.800". and I have never a stiff bolt on ejection at all.:)
 
FWIW 44g of 4895 gave me 2850fps out of a 22" bbl. Accuracy was poor as expected due to bedding issues...first 3 shots went .5 though...A bedding job then my tesing /experimenting begins.:D
 
Last edited:
"What were you doing cranking out that much ammo? Were you doing it commercially? "

My son owned an ammunition company and supplied ammo to the military and police forces. He supplied match ammo at cost to the DCRA and vistiting rifle teams for about 50 cents a round.

I was the technical director. I had to test ammo from time to time. Terrible job, but somebody had to do it.

I filled garbage cans with empty 308 (7.62) cases just testing at 200 yards. Some ammo got tested 1000 yards, which is the real test for match 308 ammo. The bigger caliber (50 BMG) was tested at 1500 yards.

The most interesting things I discovered were that:
- all rifles shoot well with the bullet well off the rifling and only a few shoot best with the bullet close to ot touching the rifling.

- increased neck tension improves accuracy a lot.
 
FYI, if anyone wants to pick up (for free) the results of thousands of rounds of testing match ammo in a number of different rifles, go back and read "ganderite"'s post carefully. In two sentences, he hands out information that would literally cost you thousands of dollars (and hundreds of hours of work) to replicate yourself.

Let's see if I can set him up, and pull a third vital tidbit out of him and his ammo testing experience... if I succeed in this, the lazy reloaders in all of us will be amply rewarded:

"ganderite, is it possible to load really good match ammo (i.e. capable of winning a national Target Rifle match) using relatively crappy brass?"
 
Hey Ganderite, Redding has revised its recommendations for bushing neck tension to only 1 thou rather than 2 or 3 as previously recommended, and my personal experience with Berger VLD's is they shoot best jammed as much as 25 thou past first land contact.

Do you think this affects larger calibers differently?

Interesting how even very experienced experts can have such differening perspectives.

I have read many Ganderite posts and found them great reading!
 
The nice thing about a bushing die is it is real easy to experiment with various neck tensions.

The experience I have is based on target rifles, not benchrest. A lot of difference between loading virgin brass and brass with turned necks. Big differnce between production bullets and custom benchrest bullets.

My advice is aimed at guys loading fairly routine calibers, components and rifles. Or, phrased another way, what is best in a benchrest rig may not be best in an ordinary rifle using ordiary brass and bullets.

For example the critical dimension in a laoded round is the distance from the back of the case to the ogive shoulder that would first engage the rifling. This should ideally be a constant. But most loaders measure OAL. The Sierra match bullet can have a 20 thou variation in a box of bullets from the bullet tip to the ogive shoulder. The OAl may be constant but the ogive shoulder will vary a lot.

This is why loading 20 thou off the rifling gives consistant results. The Hornady tolerance is half that of Sierra. I would not be surpized if Lapua is even less.

I found I got the best groups (virgin brass) by sizing the neck with a neck sizer with no expander plug. That made it real tight. This only works with boattail bullets. A flat base bullet would not get started in such a tight neck.

Again, this is an easy experiement to run. Quality brass might work better with less tension.

As for gettting better results out of "crappy brass" (military brass and primers, loaded by the thousands on a Dillon) the tricks were more neck tension, bullets well off the rifling and ball powder that would meter very accurately. Typicaly, plus or minus a tenth, with about 7 out of 10 being bang on.

Velocity Standard Deviation was between 10 and 15 fps. This was also due to the use of a Berdan primer. SD is inversely proportional to the size of the flash hole. Berdan cases have very small flash holes.
 
You must log in or register to reply here.
Back
Top Bottom