Does a diffrence of 1 or 2 tenths of a gr. really effect the accuracy or a round at say 100 yards. Would it make a big diffrence in a .270?

Probably not. However, the answer is dependent upon a variety of factors including, but not restricted to, burn rate of the powder, bearing surface of the bullet, and primer choice. To answer your question, you will need to provide information on powder, bullet and primer, I should think.

quote:

Originally posted by marquezlc:
Does a diffrence of 1 or 2 tenths of a gr. really effect the accuracy or a round at say 100 yards. Would it make a big diffrence in a .270?

No.....and heck no!

Even a full grain isn't likely to be noticed by very many experienced reloaders!

In rifle cartridges, especially the larger ones, a tenth or two-tenths is a very small percentage of the total charge weight. One-tenth of a grain is only .167% of the total charge weight.

Pistol and very small stuff (.22 hornet, for example) would be different.

LWD

In a factory rifle no---in a BR gun yes it can and does in fact. Different needs and requirements. In my hunting rifles even using the same tubes and reamers as the BR chamberings .2 or .3 is not that noticable ALL Things being equal which they seldom are...

Changing primer brands would probably have more of an affect in that large a cart.

The smallest increments in which I make adjustments is 1/2 gn. If I were to make an exception it would only be for pistol loads.

Usually I work with 1 gn increments and that is when Im getting close to good..

quote:

Originally posted by Wstrnhuntr:
The smallest increments in which I make adjustments is 1/2 gn. If I were to make an exception it would only be for pistol loads.

Usually I work with 1 gn increments and that is when Im getting close to good..

X 2 roger

I appreciate everyones input good to know there is such a wealth of information here. Thank you

Creighton Audette's load development shows that in caliber .270 even a difference in everage charge of one grain does not effect the wanted accuracy. So weighing every individual charge to eliminate tenths of grains does not seem a necessity!

Nice day,
Jan.

quote:

Originally posted by marquezlc:
Does a diffrence of 1 or 2 tenths of a gr. really effect the accuracy or a round at say 100 yards. Would it make a big diffrence in a .270?

No.

Well...

1/2 grain can most assuredly make a difference in accuracy. In a 270 it's less likely than a small caliber, but a difference of ~1/2" in an '06 when working loads up with 1/2 grain charge change is not unusual. It doesn't usually make all that much difference to find the exact best, but it can.

I have seen guns that really did like a charge to be +- .2 grains to deliver their best., but that tends to be more common in smaller (.308 size cases and below).

Does it matter? IMO no, because you cannot control temperature and that will have every bit as much effect as that small a change in charge. But, when I notice a gun & load that is sharply focused on specific charge weight I do try to find the middle of it because it buys me a little insurance for temperature change in either direction, and any mistake I might make loading. Just remember that the next lot of powder and/or bullets and it's a whole 'nother do-over.

1 or 2 tenths of a grain are probably not going to make a noticeable difference in the .270

From others
No
Heck no
Probably not
etc. etc...

Yup .1 or .2 grain variation will not be noticed at 100 yds.

Many benchrest records were set by shooters who load with a culver style measure. They just "dump powder" and shoot. A plus/minus 0.1 grain accuracy is what they deliver. That translates to a spread of 0.3 grains (30.0 ,30.1 and 29.9)
That is not to say you don't ever need to weight your charges. It is prudent to weigh several charges on a calibrated scale or balancebeam to verify your measure's settings and your throwing technique befor you ever charge a case. Also depending on the number of rounds being loaded, a periodic check to see that nothing has changed.

muck