Load testing

Cheech · Posted: Tue Mar 10, 2009 6:37 pm Post subject: Load testing

Hi Folks, I was wondering about opinions on number of rounds fired to determine a viable new load. Some say 3 rounds are sufficient others say no less than 5. I've been using 5 but with the costs Shocked

and availability of components rising daily it is a concern. I'm looking for opinions because I don't want to short change myself one way or the other. Thanks.

Cheers Cheers

minerfile · Posted: Tue Mar 10, 2009 7:17 pm Post subject: Re: Load testing

I always use five shot groups determine the accuracy of a new load. If the initial groups looks good I will try three or four more groups with the same load to confirm the initial results to make it was not a fluke.

Pumpkinslinger · Posted: Tue Mar 10, 2009 7:29 pm Post subject: Re: Load testing

To get arough idea how a load might work I shoot 3. To really test it I shoot 10.

RePete · Posted: Wed Mar 11, 2009 6:46 am Post subject: Re: Load testing

3 rd groups are good for hunting rifles but anything else I use 5 rd groups, but have recently - the last 2 weeks - read about 10 rd + groups being more representative of consistant accuracy.

Once in a while I will do a 10 rd group but that's only for my satisfaction.

gelandangan · Posted: Wed Mar 11, 2009 7:15 am Post subject: Re: Load testing

I shoots 5 rounds - at least at 3 different times/temperature.
sometimes, I shoots extra groups depending of my moods..

But then again, I always looking for excuse to shoot some more.. Very Happy

chambered221 · Posted: Wed Mar 11, 2009 7:30 am Post subject: Re: Load testing

If your load puts 3 at 100 yards touching one another, it is capable of making 10 shots touch !!!
The next 7 depend on the gun, reloader, and the nut behind the butt pulling the trigger to also be capable !!!

Vince · Posted: Thu Mar 12, 2009 4:35 am Post subject: Re: Load testing

Good reply Chambers...I have to agree with your comment.

Like Punkin, I shoot 3 rounds to get an idea of the viability of a load, but to test it properly I shoot 5 round groups. I also allow the barrel to cool down pretty well between shots.

I can see where firing a 10 round group might prove consistency, but if every one of your loads are carefully handloaded, then the consistency should be there anyway. The one variable that we always seem to have problems with is the "nut behind the butt". Find a way to tighten that nut and you have the battle won.

Cheers, Vince

wncchester · Member Joined: Apr 08, 2006 Posts: 160

"If your load puts 3 at 100 yards touching one another, it is capable of making 10 shots touch !!!"

Not always, the laws of chance come into play quite often with less than ten rounds.

The "ladder" method is the quickest way to find good the charge ranges worth pursuing more closely.

RePete · Posted: Thu Mar 12, 2009 5:44 am Post subject: Re: Load testing

I received the monthly newsletter fron Longrange Hunting and lo and behold there is an article on accuracy.

Worth the read.

www.longrangehunting.c...oups-1.php

chambered221 · Posted: Thu Mar 12, 2009 8:41 am Post subject: Re: Load testing

The laws of chance are exactly what I’m referring to !!!

Chances are the gun itself is not capable of repeatable accuracy.

Chances are the re-loader is not capable of producing consistent ammo.

Chances are the nut behind the butt !!! Insane

This is my favorite.
Can’t even begin to tell you how many times I’ve heard and watched guys make comments and mistakes and blame everything but themselves.

Fact is, if the load is capable with 3, its capable with 10.
Its all the other influences that cause it too not happen !!!

Remember the question was about the load, not the gun, shooter or the re-loader.

As for the article on groups !!! Sorry I can’t buy it. The whole thing was based upon a computer simulation, not real world.
Ever hear the saying “It looked good on paper” Deal

Dawgdad · Posted: Thu Mar 12, 2009 10:24 am Post subject: Re: Load testing

Figures lie and liars figure... BUT statistics are useful if you know how to use them.

A three shot group is better than a single bullet down range, 5 is a clearer representation and 10 is even better ...Statistically.

The other factors involved in external and internal ballistics add error to every shot which is why we get groups and not single bullet holes. The Chance of that true error being seen is better with more shots.

When I am developing a load for my service rifle slow prone 600 yard matches I am shooting 20 shots in a barrel that has already had 68 shots fired down it. I am trying to get 20 rounds in 20 minutes in a 12" 10 or 6"X ring so I test that load with more rounds.

When I am developing a load for my scoped bolt rifles, I want to know what the group is when the barrel is clean and cold or fouled and cold. The best group for one of those rifles could take me a month or two to get as it would be the first shot of the day at a target made on several different days (shooting at the same target). This would be the condition most closely simulating how the load will be used in hunting.

This link to Optimal charge weight gives a sound scientific porcedure for testing a hand load.
OCW page

fnuser · Posted: Thu Mar 12, 2009 6:22 pm Post subject: Re: Load testing

I think we all agree that the more you shoot a load the more experience you have, the more experience you have, if it's positive, the more confidence you have, the more confidence you have the better you shoot, the better you shoot the better the "load". I seldom return from a day at the range without learning something. You didn't say but I'm guessing from your language you're working up a hunting load and 3 would probably be adequate unless the range is extreme. Pet loads often include this for hunting guns 1. the ammunition feeds flawlessly from the magazine. 2. it's components that you can readily get. 3. 100 f.p.s. more won't decide if it lives or not, so go easy on your brass. thats why they call it reloading not just loading. having said all that I just like to shoot so i usually shoot at least 50 rnds a trip and 5-10's or 10-5's cost the same. I usually luck into a load before i shoot more then 5 different ones that meet requirements 1-3. be careful, have fun, live to repeat.

Grumulkin · Posted: Thu Mar 12, 2009 7:36 pm Post subject: Re: Load testing

I shoot 3 shot groups for starters. When I find the load that appears optional, I will shoot at least 2 or 3 three shot groups to see if the accuracy is repeatable.

Handloader · Posted: Fri Mar 13, 2009 12:00 am Post subject: Re: Load testing

Assuming centerfire rifle, 7 shot groups @ 200 yds are often far more telling than at lesser ranges. Bullets can stablize or destablize between the 100yd and 200 yd distance. 7 shot groups are usually a good statistical proof of standard deviation. Like some have noted, initial development can often give good indicators with three shot loads.

A nice tool in load development are manuals that list load densities. Nosler and Barnes, for example, will show load density information for chosen poweders. In general, powders that give 90%+ density and high velocity often give best accuracy. This correlation can be seen as you flip page to page, cartridge to cartridge. Much of today's computer load development programs are based on the solid research of Homer Powley and others that promote high density loading.

Cheech · Posted: Fri Mar 13, 2009 7:45 pm Post subject: Re: Load testing

Thanks guys. I guess I'll use three to see if five is necessary and go from there. Lots of good opinions here. thanks again.
Cheers