Which "weight" is more important??

[singleshotbuff]

Gentlemen,

I loaded my first 20rds of 308 Norma ammo tonight, nothing special, just want to fireform the brass for a good chamber fit so I can neck size it and hopefully extend the life of this pricey Norma brass. The load is:

Case: Norma
Primer: Fed 215
Powder: 59grs IMR-4895
Bullet: Military pulldown 150gr FMJ

None of which is relevant to my question [smilie=1:

Anyway, my typical procedure when loading rifle rounds is to set my Lyman 55 measure to drop the appropriate amount of powder, then I drop each charge and weigh it on my RCBS electronic scale. If the charge is within +/- .1 gr (.2gr total variance), I dump the charge into the primed case. If the thrown charge varies more than .2gr, I dump it back and drop another. FWIW, both of my Lyman 55s drop charges so consistent (with most powders) that I normally only reject 2 or 3 charges out of 20, even fewer with ball powders.

As I stood there at the bench tonight, following normal procedure, it occured to me that I am using PULLDOWN military FMJ bullets. These bullets typically vary a grain or more in weight, which finally leads me to my question (and sort of ties this to cast boolits).

Which (in your opinion) is a bigger factor in consistency and accuracy? Exact powder weight or exact bullet/boolit weight?

I realize that different applications will produce different answers, so let's say when seeking good or better accuracy from a 30 caliber rifle, particularly with cast boolits, which would you pay more attention too? Would you spend your time weight sorting boolits or trickling powder charges? Maybe both??

Thanks for indulging my ramble and for any input.

SSB

[45 2.1]

Which (in your opinion) is a bigger factor in consistency and accuracy? Exact powder weight or exact bullet/boolit weight? SSB

Benchresters use thrown powder charges and bullets that are about as perfect as they can make them. Does that answer your question............................

[dubber123]

Benchresters use thrown powder charges and bullets that are about as perfect as they can make them. Does that answer your question............................

It was for this reason, when Ross Seyfried decided to try and shoot a M.O.A. group at 100 yards with a .45 Colt revolver, he made as perfect a batch of boolits as he could, but dropped all of his powder charges.

[racepres]

FWIW The best group I ever shot in my life, was w/ dropped [thrown] charges!! If I did have a load that required exact weighing of powder... I would call it Bad, and develop a better one!! MV

[Calamity Jake]

Benchresters use thrown powder charges and bullets that are about as perfect as they can make them. Does that answer your question............................


Benchresters don't us stick powders eather and there measures are top of the line.

[45 2.1]

Benchresters don't us stick powders eather and there measures are top of the line.

I didn't say what discipline of benchresters (there are several), but some do use stick and flake powders and do quite well at it also. Several normal powder measures do very well at dropping uniform charges with proper manipulation.

[felix]

Case quality and fit (shot to shot consistency) is most important when the gun shoots in the ones, and the gun still can be tweaked further. The powder weight has been the least problematic, then the bullet, and finally the case as the most important. The Houston Warehouse experiments back in the 80's brought all of this to light, proving that ignition is first and foremost. ... felix

[45 2.1]

The Houston Warehouse experiments back in the 80's brought all of this to light, proving that ignition is first and foremost. ... felix

After proper boolit fit with cast guns..........................

[felix]

No doubt...boolit WITH case must allow next to zero gas escape, or at least be extremely consistent if and when doing so. ... felix

[singleshotbuff]

Thanks for all the replies gentlemen.

It seems the consensus is that bullet/boolit weight is more important. Maybe I should adjust my procedure, with powders that I know to drop consistently, and eliminate weighing each charge.

In that light, what is an acceptable weight variation in a 30 caliber boolit in the 170-200gr range?

Thanks

SSB

[Bret4207]

An old timer once told me, "Powder is hygroscopic". Once I looked the word up I realized what he meant. Powder can vary from day to day. With that I mind I vote for the boolit.

[runfiverun]

the bullet is definately the most important
in terms of construction and quality

i know a lot of ballistic labs do not weigh powder they use a volumetric measurement
as do quite a few b-resters.
and lee disk things, and shot-gun reloaders[ponses warren] dillon etc
we just use weight so every body knows what we are talking about

if we did it the other we would discuss everything in volumetric case fill
not powder burn rate, would be kinda cool but then we could only discuss one case
at atime

[felix]

Bullets seldom weigh the same, but the feel of the custom bullet as it is being swaged is most important. This means the pressure ring towards the base is most consistent and that is what will give the most consistent ignition. Boolits must weigh the same because that would indicate hopefully that all the air holes are the same size and equally distributed about the center line. However, the only check is to rotate the boolit at some "safe" RPM looking for runout/imballance. ... felix

[lovedogs]

Felix beat me to it... a little variance in powder charge probably isn't significant. But get some bubbles in your bullet and you're in trouble.