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Apollo
02-13-2009, 09:02 AM
Question dealing with the time between resizing - loading - shooting. When going to a match or practicing - how much time, in advance, can you load your rounds (1 day, 1 week, etc) before the dimensions start to change? Or do they change at all?
I would like to try to go to matches (100/200 yd score shooting 30BR) preloaded or at the very least resized, but no use in doing that if the brass changes.

Thanks for your time

Stanley

Dick Grosbier
02-13-2009, 09:06 AM
My best finish ever at an IBS score Nationals (4th) I was shooting loads loaded a month before . I believe it is one of the beautiful things about the 30BR how well it stays in tune even with pre-loading.

Dick

abintx
02-13-2009, 09:20 AM
Here is something I always refer back to when this subject comes up:

Hall of Famer Jim Borden: "I have my ammunition already loaded for [major matches]. It's working, both rifles are Agging in the 'low Ones', with a load of about 29.0gr N133, running about 3300 fps."

"Loading to conditions on match day can kill you. All you can do is go by memory and guess-timates. If your rifle has good vibration control, you'll typically have an accuracy window of 100-125 fps."

"I set preloads for velocity in the middle of the accuracy window which lets me shoot in any conditions. Studies by Jack Jackson convinced me we could let ammo sit for as long as a year and accuracy will hold."

Source: http://www.6mmbr.com/6ppc.html

jackie schmidt
02-13-2009, 09:33 AM
I have gone to the range, and fired rounds that had been left over from a previous match, and more times than not, they shoot really well.

One major thing that keeps me from pre-loading is it requires too many cases for a Two Gun Event. Especially a Unlimited Match. Plus,you have to find time to do it.

I rarely change the powder charge, I work with the tuner to keep things competitive.

The only time this can bite you is if you are shooting 133, and the bottom falls out of the humidity, and the Rifle goes .300 verticle. That will put you back in the middle of the pack real quick.

Per-loading makes a lot of sense, but for every successful shooter who pre-loads, you will find 30 that wouldn't dream of it. .........jackie

Randy J.
02-13-2009, 10:11 AM
I don't go pre-loaded but I go with pre-weighed charges in glass vials. When I went to this past year's 200-300 score national, neither of the two charges/bullet combinations would work because of vertical. If I had gone pre-loaded, I would have spent two miserable days. With switching of components, I did fine. I am from Maine and the weather in Thurmont Maryland was 95-99 with very high humidity, at least high humidity for a Mainer. What shot well before leaving home didn't when it came time to shoot. I was fortunate to arrive a few days earlier than the event for me to determine my load wasn't going to work. Randy J.

Dick Grosbier
02-13-2009, 10:21 AM
I don't go pre-loaded but I go with pre-weighed charges in glass vials. When I went to this past year's 200-300 score national, neither of the two charges/bullet combinations would work because of vertical. If I had gone pre-loaded, I would have spent two miserable days. With switching of components, I did fine. I am from Maine and the weather in Thurmont Maryland was 95-99 with very high humidity, at least high humidity for a Mainer. What shot well before leaving home didn't when it came time to shoot. I was fortunate to arrive a few days earlier than the event for me to determine my load wasn't going to work. Randy J.

Randy was most likely to modest to mention that he won the match he is referring to. And in doing so beat some of the top competitors in the game.

Apollo
02-13-2009, 11:46 AM
Thanks for the quick replies, but maybe I need to reword my question. I am not asking if one should go preloaded or not. I would like to know (assuming I go preloaded or "preresized") how long before the tournament can I load or resize? Example; The Webster City match is May 23-24th. If I go preloaded, how long in advance can I resize or load?
Reason for asking = I've been told that your brass will change, after resizing, if you let it sit "awhile". Just wondering what "awhile" means. 1 person above mentioned a month. Just wondering if anybody else has some experience or research on this also.

Thanks again
Stanley

zippy06
02-13-2009, 11:55 AM
This is a good question.
Brass changing dimensions.
I have heard of/seen powder, move a bullet, out of seated position. On compressed load.
Seen primers move. In a really tight pocket.

Randy J.
02-13-2009, 01:43 PM
I can't speak to the brass changing. I resize and then shoot shortly thereafter. I do however seat my bullets long so I can reseat them before going to the line if my rounds were loaded the day before. I do so because all my testing is done immediately after loading, not the day or week after loading. A very veteran top quality shooter, sadly now deceased, once explained to me that seating depth can change under a compressed charge, of which I am usually shooting. The other factor that he took into consideration was that the release of the bullet from the brass may be inconsistant and/or different than when freshly loaded. So in my quest to keep everything as similar/constant as possible as when I tested, I reseat before I go to the line. I have not done any quanitative study on this however but he was winning and I was new, so I listened and followed the advice. Randy J.

Bob Kingsbury
02-13-2009, 05:06 PM
If cases were made of aluminun, I might get concerned. This of course
would not work at common pressures. Any material is relative to
temperature, 68 degrees being the common reference in tool work.
Brass will not change sufficiently to be a problem unless you need
to put 2 feet on your bolt handle to close it. Even then , they will
all be changing at the same rate. Seating depth is a different issue
not really related to changes in brass. I will not believe that brass
changes are anything that will change your scores and tune.

alinwa
02-13-2009, 09:17 PM
Stanley,

If you're going to let the loads set around for more than a day or two then you need an extra half-a-thou on everything. I ran into this immediately upon having to preload 150rds at a time for 600yd matches. I'd always just loaded/shot as I went.

Brass starts moving back the instant you pull it from the die, it's not really noticeable for the first day or two but within a week it will have grown/relaxed/moved maybe a half thou. (purely guessing here...)

This is really only applicable if your sizing die setup and fit is REALLY persnickety! MOST people shove the shoulder back a thou or thou-and-a-half to begin with...... if you do this you'll never notice the tightening up effect.


hth


al