moving impact of clean barrel

[bigdog454]

OK! am shooting a persuit 50 cal, cast 310 gr .45 cal boolit in a sabot, (tried 3 different brands of sabots), 80 gr of RS Pyrodex. Here's the problem, clean barrel at 50yards it's dead on, the following 3 shot hit 6 inches high. I would think that it woudl be the other way with the first shot from a clean barrel hitting high and then the rest hitting low, and I woulden't think that there would be that much difference in the point of impact. I cleaned the barrel and tried it 4 times and got the same results. Any Ideas why, and what the cure would be?

[Underclocked]

Try some JB bore polishing compound and give that barrel about 100 good long strokes with the JB on a patched bore brush.

I'm not familiar with the Pursuit's lock up or forearm arrangement but take a look there so see if you can spot uneven rubbing points/contact points. A bit of sanding inside that forearm might help alleviate any uneven pressure points.

If the barrel has an "easy load" section at the muzzle, wipe that clean after each shot. Allow several minutes between shots for the barrel to cool.

If all else fails, clean the bore after each shot.

[SPRINGFIELDM141972]

BigDog-

Are the follow up shots grouping well, just high? If so, I would suggest that you foul the barrel before loading your first round. I sight all of my hunting rifles from a fouled barrel. I load a charge of BP without the projectile and touch it off, prior to hunting or sighting in. In the field, this verifies that the ignition path is not blocked or fouled with oil that might impede firing. At the bench, it places the barrel in a condition that all subsequent rounds will see and keeps the POI the same.

Let us know what you find out.

Regards,
Everett

[Lead Fred]

What he said, no petrolium based oils, they slow the next round going out, building pressure.

[Baron von Trollwhack]

Why not simply accept the fact that your first shot out of a cold, clean barrel will be on because you set your sights that way and live with it. You know where the next three hit. It's not an unusual thing. It is repeatable. If you don't want to shoot that way change your sight setting. But hey, the hunting kill shot is the first one.

Do you think that any of the shooters that proceeded us for centuries did any other thing?

Now if you are target shooting, you get at least one fouler in many cases and shoot for score these days, with the next shots.

So it's where you set your sights and why you are shooting. I hunt and shoot target and my choice is to shoot high first shot at target range. I can compensate for that in hunting. I can see better for target using a 6 o'clock hold after the first high "fouling"shot , then going for ten ring. BvT

[northmn]

When I chronographed several laods I found that the first round out of a clean barrel always had less velocity than the followup shots. The most consistancy came from not swabing between shots but using a cleaning type lube. For a hunting gun I would suggest that one would sight in with a clean barrel.

Northmn

[twotoescharlie]

fouled barrel-more friction-more pressure-more velocity-?

TTC

[bigdog454]

Thanks guys, what you said makes sense, especially the part about clean barrel having more friction. I'll try your suggestions and if I find a work-around I'll post.
again a big THANKS.
BD

[StarMetal]

Old Ross Seyfred said it best I think. He said take the rifle you want to hunt with and the ammo. With a clean cold barrel take it out and shoot one shot.....save your target. Go home, clean it, put it away. Go out the next day with the same target, repeat the scenario. Do this for five days, or however long you wish. You will get a very very good ideas of where that rifle will put it's first shot under the cold clean barrel conditions. I would imagine this would work for cast bullets too.

Joe

[Digital Dan]

First shot counts unless you got deer that stand still for a group.

[bigdog454]

Here in Ohio your allowed 6 in the southern half, and 6 more in urban areas, and sometimes they stand around wile you reload. Only one can be a buck, and We can't eat that many deer, but it's allowed.
BD

[northmn]

For most of us it is not common to have a deer stand while we reload. I have had young ones watch for a little bit to see what the racket was, but about the time I was reloaded they were gone. Last year I shot at one and cleaned the barrel with soaked cleaning patches I carry in a plastic bag for that purpose. A muzzleloader is usually a true single shot rifle in that you get one shot. More fouling means greater resistance and higher velocity and an increase in the total projectile powder mass which also increases pressures and thereforevelocities. Sighting in a cold, clean barrel is a very good idea. However it seems like some guns are more "touchy" on this issue than others. I think it has to do also with the obsession people have with the idea that a deer hunting load should be "easy" loading. While I shoot patched ball, I have come to the conclusion that a good short started tight load is good for the filed as well. A small game gun where more shooting is involved may be nicer with a looser load, but for deer I do not feel so. Sabots I cannot speak for but don"t they tend to load harder after a couple of shots?

Northmn