I just worked up 5 different loads (of 5 rounds each) for my 06, all with 180gr NPs and either IMR 4350 or IMR 4831. My question is - how important is it to thoroughly clean the barrel between shooting test groups? Do I need to give it the full brass brush, bore cleaner drill, or should I just run some patches thru the barrel between groups. Please tell me how you do it when you are trying to find the best load. Thanks

It may not be the best way ,but I just let the rifle cool a little between groups. If I get a group I like, than I try to get repeatability data buy shooting a round and really letting the bore cool.

The cold bore repeatability is more important to me in a hunting rifle tha small groups shot in succession.Since you are talking 06 I presume it is a hunting rifle. roger

I usually take some rounds for fowling. First I shot one fowler. Then take my time to shoot the five shot group so the gun doesn't heat up to badly. After the group I clean the rifle and let it cool down. Then I repeat the process.

Yes, but how well to clean between groups?

Another idea is to shoot "round robin". For example if you have five loads to test, put up five targets (one for each load) and fire one shot at each target and repeat until you have five five-shot groups (or whatever). Theoretically, that will even out the effects of fouling, barrel heat, shooter fatigue, etc. On the other hand, it's easy to get confused and fire the wrong load at a given target.

I run a boresnake through my .223 three times between groups.

A couple of my reloading manuals say it is very important to thoroughly clean the bore every time you change powders. They call it "powder compatibility". "Powder sometimes reacts very badly to a second powder being fired in the same barrel without cleaning".

After every 6 rounds (1 for fouling, 5 for record) I run a wet bronze brush down the barrel and then a dry clean cotton patch followed by another dry cotton patch.

Time between shots in a group is 2 minutes.

Time between groups is 10 minutes.

Another vote for the occasional pass through with a bore snake. It also seems to make cleaning the gun when back home easier if I take a swipe or two before leaving the range when done shooting.

It's been said that to be ultimately fair to each group, and differnet powder, to shoot your 5, then thoroughly clean the bore between groups.

I've read that some precision shooters believe that the moment the powder is different, like 4350 to 4831, then it can skew your results. I do not know that I believe it.

I prefer to shoot the 5 identical rounds, then clean the bore (yes, the "drill"). And I make sure that the bbl, is COLD before the next group.

I've got several off the shelf rifles, there is quite a bit of difference on how they react to cleaning. I've pretty much taken to cleaning them after 20 fired rounds. When working up loads I generally shoot three shot groups. I know a lot of people are shooting five, but for hunting accuracy I don't see the need. Besides, I don't have the patience to sit and let the barrel cool between shots. I don't know if it matters statistically what you do, as 1 5-shot group won't show you a lot. That being said, I find it much more difficult to group 5 shots well as there is more chance of a flyer. I load up 6 rounds and shoot 2 3-shot groups on different days and if they both go good, which doesn't always happen even if the first group looks good, I'll consider it worth pursuing.

Thanks so much for the responses. I am somewhat surprised at the different methods people use. I'm just a hunter who is trying to get the best possible load with the NPs. I think I'll do the 5 shots, clean completely, then shoot another load. The barrel should cool rather quickly as it is expected to be 37 degrees here tomorrow AM. Thanks again. There is a wealth of info here.

Good luck on your shooting. One other powder that works extraordinarily well in the .06 with 180 wt bullets is IMR4064. 2 of my best loads ever were with this powder in my .06.