Fouling Your Barrel

[Patriot_1776]

Is it a good idea to shoot a fouling shot first then let the barrel cool back to range temp before testing groups from a magnum rifle?  I've heard about this before, but I still believe it is always good to start with a CCB shot first, then two more to complete a 3-shot group.  After one lot has been tested, cleaning the barrel thoroughly before trying each new load/lot would follow.  What process should I follow when testing loads for best accuracy?  Please let any answers be considered in the "3-shot group" format, not 5-shot or otherwise.  Thanks.   Patriot

[ricciardelli]

I alsway fire a fouling shot before going for a group ... only I use 5-shot groups.

My technique...

Fire a fouling shot, wait 2 minutes.
Fire 5 shots for record, 2 minutes between each shot.
Clean barrel.
Wait 15 minutes.
Fire fouling shot...etc...

This is for all rifle calibers.

[Patriot_1776]

Thanks ricciardelli,  thats just want I wanted to hear.  Also, that info went to my file so its easier to access for future use.  As for the 5-shot/3-shot group thing, that was just in case there fewer shots made for magnums only due to their extra heat generation.  But I'll go for 5-shot groups from now on since I now know that's ok for all calibers.  Again, thanks for the info.     Patriot

[KYsquirrelsniper]

I always fire at least 1 or 2 fouling shots and then let the barrel cool before testing for groups, because just about every gun with throw the first shot or two from a clean bore. Of course I always hunt with a fouled barrel to avoid that first shot flier.

As for 3rd versus 5rd groups. When testing different loads or testing different types of factory ammo, I first start off with 3rd groups, with each shot 2 minutes apart. If a 3rd group isn't worth a crap then it isn't going to get any better with 5rds and there probably isn't any use in messing with that load any more. After the 3rd group testing, I should have a few loads that are showing some promise, so then go to 5rd groups to figure out which one is truly the best.

FWIW, I no longer use group testing to find the proper powder charge. I've resorted to the OCW and ladder methods for that purpose, but group testing is the only way you can compare factory ammo or two completely different handloads.

[Duffy]

I have three  that wont shoot worth a crap after a cleaning and will take up to 6 shots to settle down. One is a S&W 38 spec revolver, a 708 Encore bbl and my 270 rifle. The 708 will pitch the second shot and then settle down after the third the other two just pattern until they decide to shoot.

[Patriot_1776]

because just about every gun with throw the first shot or two from a clean bore.

I had a feeling that holds true most often.  The first shot or CCB shot does not have any real extra friction to go through.  Whereas the second, third, and so on shots have the fouling and residue to go through; hence, firing a fouling shot presents a more uniform pressure environent for the group shots.  

I've resorted to the OCW and ladder methods for that purpose

How do they work?  Do they prove more reliable and foretelling of which is the better load out of a lot?

 

I have three that wont shoot worth a crap after a cleaning and will take up to 6 shots to settle down. One is a S&W 38 spec revolver, a 708 Encore bbl and my 270 rifle. The 708 will pitch the second shot and then settle down after the third the other two just pattern until they decide to shoot.

Duffy, sounds like you need to either teach those guns who's boss, or maybe feed 'em what they like!
 
 
Patriot

[KYsquirrelsniper]

The Optimal Charge Weight (OCW) and ladder (AKA Audette ladder) methods will only help you find the best powder charge for a given type of powder with the components you're using. Although you can get a good idea of the performance of a given rifle and load, these methods do not necessarily tell you which bullets, powder, primer, etc will be most accurate, you may still have to use group tests to determine that.

I'll post a couple links below where you can read more, but here's the overall idea...
The OCW and ladder methods rely on the Optimum Barrel Time (OBT) or "Shock Wave" theory. This "Shock Wave" theory says that when a round is fired, a shock wave begins at the chamber, travels to the muzzle, then back to the chamber, back to the muzzle and so forth. If the bullet exits when the shock wave is near the muzzle, the load probably won't produce good accuracy, and if it does, it will be extremely finicky and any slight change will cause a loss of accuracy. What is preferred is to have the bullet exit when the muzzle is most stable and the shock wave is back near the chamber. The OCW and ladder methods basically show you where your powder charge needs to be for a given load to have the bullet exiting at the best time. What you're looking for is a place where incremental powder charges tend to cluster together. This gives you a load that is consistent from day to day and slight variations in components or enviromental conditions don't affect the load as much as it otherwise would.

I believe just about everyone has had a load that would shoot amazing one day, but then if the conditions changed even slightly, the groups opened up quite a bit. The OCW and ladder methods are aimed at reducing or eliminating this inconsistency. However, an OCW load doesn't always produce the smallest groups possible (they're usually very good though), but it will give you a load that will shoot consistenly in a variety of conditions. I'm not a BR shooter who is constantly tuning my load for varying conditions, so I prefer the OCW method to help find a load that will perform well throughout the year in a variety of conditions.

There is somewhere on the net that describes the ladder method, but I don't have the addy. You can probably find it if you do a web search for "Audette ladder."

You can read more about the OCW method at http://www.clik.to/optimalchargeweight

You can find the OBT theory at http://www.speakeasy.org/~cdlong/shock%20wave%20theory%20summary%20explanation.htm

[KYsquirrelsniper]

I have three  that wont shoot worth a crap after a cleaning and will take up to 6 shots to settle down. One is a S&W 38 spec revolver, a 708 Encore bbl and my 270 rifle. The 708 will pitch the second shot and then settle down after the third the other two just pattern until they decide to shoot.

If you're cleaning and scrubbing until the bores are absolutely spotless, that may be part of the cause for it taking so many shots, especially if you're using moly coated bullets or lubed lead bullets. Factory barrels have imperfections that will have to get re-filled (is that a word?) before accuracy gets back to normal, and if you clean them until tehy're perfectly clean, it can take several shots to get back to normal. Of course cleaning is a necessary part of shooting, but you can actually clean so well that it may take several shots to get the POI and accuracy back to normal.

[Daniel]

I've shot my rifles enough to know that they shoot their very best groups (3 shots) out of a pristinely clean barrel. This is assuming I'm shooting a known accurate load for each rifle. Then the groups start opening up for the next 3 or 4 groups. After that, the groups settle back down and the next few are almost as good as the very first. So, one or two fouling shots does me no good at all. I've either got to shoot out of a clean barrel or one that's had about 5 groups shot through it if I want to shoot for tiny groups. However, my worst groups are still plenty good enough for any kind of hunting I do, so this is not something I worry too much about during hunting season because the general point of impact is pretty much the same for my rifles whether the barrel is clean or fouled.

[Redhawk1]

My guns are shot in with clean barrel's. When I go out hunting I have a clean barrel. I never use a fouling shot.  

[james]

I like to hunt with a clean barrel like Redhawk.  But I know where the first shot will go. I have an encore 6.5 x 55 barrel that throws the first shot 3" high and 1" left then will make a clover leaf.  I had a Browning BAR .270 that would put the first CCB into a 1" bull but the group would then open up to 3-4".   Different barrels are individuals and must be treated differently (in my opinion).
james

[Duffy]

KY,
Yeh I went through the extreme cleaning for a while and now just brush a bit to remove the crud and then a couple of patches. The 38 shoots mostly lead and it will fall off after several hundred. Once cleaned it just takes about 6 rounds and it's good as new. The 270 is just a piece of crap that never did shoot.

[roper]

Since I use my mag rifles for hunting I'm real concerned about the first shot.  I've always left alittle copper in the barrel so not having to worry about fouling shot and I use Sweets so I've learned over the years about how much blue on a patch I want left.  All my hunting rifle have SS select match grade barrels those being hand lapped helps.  Between groups I use a wet patch (GM top Engine Cleaner&Kroil) and that takes care of everything but copper and cools the barrel down somewhat. After about 9 shot I'll take a brush with cleaner and use Sweets.  One of the things I do Is use Choke Cleaner on my brushes no use always running dirty stuff up and down the barrel.  When I'm breaking in a barrel when that brush goes thru the barrel I use that cleaner on the brush before I bring it back and  pour my cleaner mix on the brush.  I'm not one to over due it with a bore brush can wear out a bore just cleaning it.  I'm lucky and load at the range so some of my test loads may only have 2 shot.  Once I have a load that show promise I stop and come back another day I want to see where that first shot goes then follow up with 2 more and if the group holds I'll come back another time and chronograph that load and if the velocity is there then I'll start shooting that load I'll take it to the 200/300 yd range may shoot another 50 or so rounds over the  next couple months and there is a state range pretty close to where I elk and deer hunt so I'll take it over there for some shooting also.  I like to start testing a new rifle say in early spring so have enoght time to get use to everything.   I figure with the barrels I've got 3 shot should hold less than 1/2" and 5 about 1" and since they are 30 cal velocity with 180 gr bullets should be over 3000fps and 165gr at 3200fps my 180gr rifles have 1/10twist and 165 gr rifles have 1/12 twist so I pretty much know where I'm headed with those rifle even before I pull the trigger.  Well good luck.