I'm trying to see what loads will shoot best out of a couple of rifles and want the evaluation to be fair. For you guys that develop or test loads, what is the process you use for cleaning a barrel between test groups? How long do you let a barrel cool between groups?

Not trying to be a knowitall but YOUR rifle will let you know far better than us rifle loonys. Calibers&rifles your using? Scoped long range or woods ranges?

When I work up a load for my or my brother rifles we load up 1 grain differences through out the load data and usually dont use the max load. We load 3 each load when we shoot we shoot one gun 3 shots swab it out and let it cool while we shoot another rifle and repeat till we get every load shot then take the tightest groups which are usually 1 grain difference in load data. Then we load up 1 tenth of a grain difference between the two tightest groups. Say our tightest groups from the first round 40gr and 41gr the next time we load 40.1gr.,40.2gr.,40.3gr. etc till we get till 41gr then take the tightest group and that's what we load for that rifle. It takes several days to do it but thats how we work up powder charges. If you doing store bought stuff just buy several brands in several different bullet weights and go see what it likes. None of it's cheap but it is what it is. We try to take all human error out like using a lead sled, barrel cooled, etc. I like loading my own and doing all that for hunting rifles is probably over kill but I enjoy it and when you get a load in your gun that it likes and will drive tacks its just a sense of accomplishment and when you shoot a deer with your loads its satisfying

I clean with a copper solvent, like patch out-wipe out, until all the copper is gone. I then use a carbon remover. Then I use a bore paste polish,followed by a cleaning solvent. If I am going to let it sit a while I add a light oil.

Some guns will walk when their barrels get hot. A properly stress relieved barrel won't change from it's normal group size until it is hot enough to droop. It will take a 10 shot group to show you the average of what your rifle will do on any given day.

I usually load up in half grain increments and don't fool with cleaning until I reach about a hundred rounds down the tube or accuracy fails. The fouling, from what I see, actually helps up to a certain point. If you want to be as precise as to clean it every other load then to me your still doing injustice. You mine as well clean it every shot fired if you worry about it that much.

This is the answer. I'm not a benchrest shooter but I load for accuracy in my hunting rifles. Some of them will shoot great with a clean, cold bore, some of them need 2-3 fouling shots before they group well. Some will have a small shift in POI after fouling. I have one rifle, an old tang safety Ruger M77 7X57 that will not group well until it has at least 12 fouling rounds. Groups will be 1-1/2"+ and go under an inch after fouling.

Unless you know the amount of fouling your rifle requires before it can achieve its potential accuracy, don't waste time and effort to clean the rifle between test loads. I used to do this and finally figured out it was a waste of time. You will have to re-foul the barrel after each cleaning before you shoot each test load. You just need to know how many rounds it will take before too much fouling causes accuracy to degrade. A quality barrel can take many more rounds than most people realize before accuracy begins to fall off.

I've got an older A-bolt .270 that's the same way. Clean bore will spray shots so bad you'll swear it needs a new barrel and yet after 12-15 rounds it will start coming around and after 25-30 rounds will absolutely stack them on top of each other.

Look these two guys up on YouTube. You will get great info and proof from what they do and why they do what they do. Panhandle Precision is a hunter first and foremost.

TiborasaurusRex
Panhandle Precision

I do not clean any rifle that is getting good accuracy, other than a pass or two with an Otis Ripcord with a small amount of oil on it, and I never "break in" a barrel with a cleaning process. It may have been needed at one point, but not with today's rifles.

Unless it is a used rifle that is really nasty, I never use a bore brush at all, and any brush I use is nylon, bronze or copper, not stainless.

Custom bores are hand lapped and really smooth, so they don't foul much.

Factory bores are rougher, and foul, but the fouling smooths them out.


Those black streaks you get on patch #12, or #37 ain't fouling. It's actual barrel material that you are scrubbing off.

Shilen makes some of the best barrels available. Here's what they say - "Break-in procedures are as diverse as cleaning techniques. Shilen, Inc. introduced a break-in procedure mostly because customers seemed to think that we should have one. By and large, we don't think breaking-in a new barrel is a big deal. "

My method is hardly scientific, but I have been able to work some sub MOA magic on all my rifles. First of all, I usually clean my barrels good about every 500 rounds (copper and carbon). I've watched and read enough barrel makers say that unless you have a peculiarly finicky rifle, acceptable accuracy usually can still be achieved within this parameter. My initial testing involves a standard bullet seating depth 0.015" off the lands, then from the supporting manuals, load the medium loads through the max listed load in 0.5 grain increments, usually 4 or 5 rounds per trial. Then go to the range. I try not to let the barrel too hot (as in, I can touch it and hold it throughout the process) and shoot the groups. The results usually give you an idea of were to concentrate the next rounds of tests.

If there is a clear winner from those tests (around or sub MOA), I then load more with the exact same bullet seating depth, going below and above that best charge the initial test proved. I usually go 0.2 grains increments, and usually go two increments below and two increments above (along with a replication of the initial charge that gave me the starting point). Back to the range I go, and do it over again. Very seldom have I had to do a third round of testing, as most of the time that second round has provided a winning combo. If the resulting best group still isn't quite what I'm looking for, I then either load up a third round of tests with the identical charges and try again, hoping that it was just an off day for me holding the gun steady, or I start monkeying with bullet seating depth... making test rounds with the exact charge that provided the best accuracy on the second round of testing, yet having the test groups have incrementally shorter seating depths. I think I've only had to go to the bullets seating depth twice over the years to help nail down the accuracy I wanted in a rifle/round team.

For my long range rifles, I make sure to have a chrono, and often times I go well past the max load listed in any reference material, working up the loads in that 0.2 grain increment, looking for the accuracy I want, at the highest velocity I can make those pills go, carefully looking at the standard deviations the chrono gives me, as well as keeping an eye on what the spent brass is telling me. Maxing out a cartridge can be done safely, if you take your time and watch what the gun does. Both my 308 and 243 reached another accuracy node above max listed loads from the reference material, and didn't begin to stress the brass with the classic over-pressure signs. The result is HOT rounds that make up a good bit of ballistic advantage way downrange that the average loader would never be able to achieve just sticking to what the *lawyer reviewed and influenced* manuals say. Every rifle has it's own max that can only be found with careful testing.

To add further confusion some rifles like medium speeds others full maximum. Far as Barrell break-in it really is a nonissue with QUALITY tubes.

Just to be clear,I don't clean between loads,just when I think it need it,or accuracy seems off.

First thing I do is pick a bullet I want to shoot. For a new gun I usually fire a few factory rounds over the chrono just to see what it will do and to foul the barrel, break it in or whatever process you want to do there. That also gives me an idea of how fast a load is running in my particular gun compared to published factory data. I have a mountain of my own data but I also like the Nosler manual. You can go there and see the most accurate load tested. That is usually my starting point. You've got a twist a bullet and a speed considering barrel length of the test rifle. I find it to be a pretty good starting place. I'll go to several loading manuals and I'll load up 3 rounds each with various powders all trying to match something close to that "most accurate" speed with the same bullet or at least close to the same weight. Then I'll go test all those. Most of the time you'll see something that is going to group from this first round of shooting. I pull my better targets write the load data on them.... pack it up and head to the house. I have a backboard that will hold about 10+ targets on it at time and I only shoot 3 at each so I go through a lot of targets this first round. This is a long morning at the range usually.

Next time I go to the range - I go back shooting more 3 shot groups bumping those charges up a little and see what happens when i start pushing it faster with those powders that appeared to give good accuracy. I usually go up until the bolt handle get's stiff or the primers start telling me to stop. The whole time I'm shooting over a chrono and recording the data.

Most of the time by the end of the second trip I have found the powder/charge that gives the best accuracy, the one that give the best speed and then I have to sit down an decide for myself what gives acceptable accuracy for my purposes and how much speed I really want.

After that I start weighing cases and taking all kinds of extra steps to improve accuracy. Third trip to the range. Shoot for tight groups.

Then decide if I am satisfied. If not it might take a 4th trip to the range. The intent is to get at least 1 load I am satisfied with.

After that if I swap bullets of a similar weight I can usually narrow down and get results pretty quickly just shooting over the chrono and looking at the data I've recorded from this exercise.

After that I might play with new powders or different loads/bullets for the next 20 years but I've got my hunting load figured out.

On the cleaning thing - I don't clean mine to the extent of getting all copper fouling out of it during load development. I do clean it removing the copper after I find the load I want. Then I start shooting that particular load and it might take 10-20 rounds to get it dialed back in after a deep clean. Then I don't worry about copper, etc. until I start to see accuracy falling off.

On the seating depth thing - I seat mine all to where they are just snug on the lands. It is just a feel thing for me. I check to make sure it is in spec that's about it. It is rare that I have had to mess with the seating depth much to get a rifle to shoot. It has happened but I'm usually pretty frustrated at that point. I will adjust this when on my first range trip described above I'm not seeing acceptable accuracy. It is rare that I have to repeat that first range trip described above but it has happened.

That's the CliffsNotes without getting bogged down in details. The details are why after 40 years I still work on load data for 7 mag at least once or twice a year.

Noticed nobody mentioned seating depth I usually find the most accurate seating depth using a lite charge before working up a powder charge

I’m trying to remember the last time I cleaned the bores of my bench rifles. My 6.5/284 has about 300 rounds through it and is 4 years old. It has NEVER been cleaned (Bore). It still shoots sub 1/2” at 100 yards (5 shot groups). I’m liable to shoot the barrel out before I clean it.