# Need help with load development...



## toasty (May 15, 2008)

So I have been developing loads for a couple custom rifles this spring. A 260 Rem, 243 win. I clean the gun, shoot a single fouler shot and then I'm getting excellent groups on shots 2-5, they start to open up from there. With the great groups I decide on my load, the problem is when I shoot them again 10-15 shots after cleaning the group size usually doubles or more. Here is the question, are you guys doing development on fouled bores? Can I expect my best groups on shots 2-5 to be my best groups when the bore is fouled? I feel like I'm chasing my tail.

100 yard 4 shot group - 260 Rem 123g Lapua Scenar IMR 4350









100 yard 3 shot group - 243 Win - 80g Berger Varmint - IMR 4064


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## DallanC (Jan 13, 2009)

Barrels can be finicky... I was reading a article recently where the author mentioned he was only getting a handful of shots before the groups started opening up. Other barrels were more forgiving and allowed more. IMO, finicky barrels are usually rougher and can stand from some careful polishing / lapping.


-DallanC


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## sagebrush (Sep 8, 2007)

I do all of mine in a clean barrel. I clean the copper out of the barrel all the time, I can get around 15 - 20 shots before it starts to open up, but we all have set standards to what we call good and bad groups. also we all clean our rifles different too. some people don't bother with the copper. btw I shoot a factory barrel Remington sps.

the reason I start with a clean barrel is that I like to keep it clean when its just sitting around and I'm not going to run out and shoot a couple of fouling shots to go hunting or shooting.


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## Bax* (Dec 14, 2008)

Be cognizant of barrel temps too. Cold bore shots vs warmed up barrels can change groupings too.


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## toasty (May 15, 2008)

sagebrush said:


> we all have set standards to what we call good and bad groups.


Agreed, my groups open from sub .2" groups to .4" or .5" groups, which is good for the majority of rifles out there. Not trying to be greedy, I was just hoping to get a longer shot strings of .2" groups. These rifles are varmint rifles and will see between 50 and 100 rounds a day without cleaning and I'd like them to maintain accuracy for the duration of the shoot. Guess I will shoot some varmints and shoot a group after 50 rounds and see where I am.


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## Springville Shooter (Oct 15, 2010)

How are the rifles bedded. In my experience, pressure points created as the barrel warms are the biggest culprit when it comes to finicky grouping.----SS


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## longbow (Mar 31, 2009)

DallanC said:


> Barrels can be finicky... I was reading a article recently where the author mentioned he was only getting a handful of shots before the groups started opening up. Other barrels were more forgiving and allowed more. IMO, finicky barrels are usually rougher and can stand from some careful polishing / lapping.
> 
> -DallanC


True words right there! I can shoot my 6mmAI 100+ times before I see any change in group size. My 300Wby is good for maybe 10 shots before I have to let it cool down. I have a Kimber .223 the never quits shooting sub-minute groups. I usually clean the barrel out of guilt rather than necessity. My .338 Edge shoots 100+ fps faster than any Edge I know of and shows no high pressure signs. Barrels are different.


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## longbow (Mar 31, 2009)

By the way Toasty, you missed that dime on both your targets.


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## jungle (May 10, 2008)

To paraphrase an African PH, a barrel that requires such babying is worthless. An accurate rifle is one that can be fired numerous times all day, in 110 degree heat, in a endless dust and still drop an impala at 250 yards at the end of the day.

This is an accurate rifle barrel.


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## Huge29 (Sep 17, 2007)

I always start with a thoroughly cleaned barrel and seem to do ok; as I would be hunting with a clean barrel. Although, I may have to look back at my first groups, it does make me wonder if there is something to the first shot not grouping well. I clean with two patches between each group too. My thought would be to watch the heat too. I usually take a few rifles to shoot, by the time I have run two patches and shot three the barrel is generally cooled back down.


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## Nalgi (Apr 16, 2010)

Im in to consistency! I never clean my barrel so I never get disappointed in the 3' groups!!!!

Seriously, I saw a show on Shooting USA that shocked me. The US Army shooting team stated that it takes 75-100 rds to "settle a rifle down" and they dont use copper solvent until they get very large groups maybe 300 rds if I remember. I never heard that before but I figured they would know.:shock:


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