Dam I hate when things like that happens throws all the theorys out the window. Good luck keep up the good work.

Saeed try changing to a very slow powder. If the thrust is complete before the bullet reaches the muzzle, the crown may have little effect.

Whate if you damage it by introducing some corrosion or rust?

That would be fairly even and random.

Kind of reminds me of an episode of "WKRP in Cin." Where Johnny Fever is drinking shots and a cop is giving him a test on reflexes. The more he drank the better and faster his reflexes got.

Saeed, This is very interesting. I wish I had seen it earlier. I did the same experiment several years ago with a 30-06 I had and found that the damage to the crown had absolutely no effect on accuracy what so ever. I chipped it with a hack saw, pounded it with a hammer, let the last 1/4" sit in salt water and rust for three weeks and finally drove a punch into it with a hammer. After each abuse I fired it and cleaned it and went to the next without un-doing the previous abuse and at the end I found statistically no difference in groups. The post-abuse groups were .004 smaller than the pre-abuse. Of course nobody believed me so I don't talk about it much. There is only so much being called a liar one can take. Conventional "wisdom" is so hard for some to let go of.

Good luck with yours. I wish I had pictures of mine to post.

Gentlemen,

here is the result of the groups shot after that chunk was removed from the muzzle.

52 grain Sierra Match King - boat tail

0.666
0.731
0.466
0.402
0.376
Average - 0.5282

52 Brawand - flat base

1.571
1.036
1.288
1.414
1.385
Average - 1.3388

I am going to take the barrel off, recrown it, shoot it, then will try to cause some rust to form inside it at the muzzle, in the final 1/2 inch or so, and shot again.

For best results, use a Lincoln Idealarc and weld the little hole at the end shut. It leaks out most of the pressure needed to get the bullet downrange. This huge pressure loss is why most of todays rifles are only good for 300 to 500 yards...........

I have taken off the end of the muzzle that was damaged, and tried a sort of "home brew" crowning job.

We took a Dremel tool, and put a round stone in it, and used it to crown the new barrel as it were. We thougt this is the sort of thing someone might do at home, if he did not have access to a lathe to correct a damaged crown.

I will shoot it in this present state, and post the results.

[ 07-17-2002, 15:52: Message edited by: Saeed ]

I have 95 mauser in 7x57 that wouldn't shoot in 6 in at 50 yards the last in of the barrel was shot or worn out cut it off used a round stone but did in my lathe. It shoots them into one hole at 50 yards now. Roy dunlap recomends the round stone in his gunsmithing book.

Notice that the average of the second two groups is actually .04" better than the first two groups! "Where's my Dremel tool..."

[ 07-18-2002, 18:05: Message edited by: savageshooter ]

Gentlemen,

I will post the latest results in the morning.

Next is the rust test.

I ran an oiled patch through the bore, stopping about 1/2 an inch from the muzzle, and leaving it there.

We then took a small piece of cotton wool taken off a Q-Tip, put into the end of the muzzle, and soaked it with sea water.

Rust began forming a couple of hours later, as teh cotton was becoming brown!?

I am going to leave it like that for a few days, and shoot it after it has developed some pits at the muzzle.

I had a Rem 700 in 222 and the barrel looked like a rat tail file had been used for a cleaning rod with 60 grit paper for patches. 5 shot groups around 3/4" were common. Go figure.

As you can see, the rust is coming along very nicely!

You had better keep the "improvement" with the crown damaged quiet!!! It would be ashamed to see some of these theories we have been fed for years go down the tubes.

Gentlemen,

We kept about 1/2 an inch of the end of the muzzle soaking in sea water. We had a small piece of cotton wool in it for a day, then we removed that, and just put some sea water as the previous lot evaporated.

A couple of days ago, I put a plug of sea sand in the muzzle, and soaked that in sea water.

Today I removed it, cleaned the barrel, and looked at it through a bore scope.

Plenty of damage was done. There are pits and scratches everywhere in that part. I think this must have been caused by the sand.

We will shoot it and report the results that we get.

Geez, those pictures give me the willies. What were the groups like following the "dremmel crown"?

Gentlemen,

Here are teh groups shot after the "Dremel Crown".

Sirra Match KIng

0.505
0.922
0.906
0.531
0.607
Average - 0.6942

Brawand bullets

0.962
0.939
1.121
1.032
0.837
Average - 0.9782

I will shoot it now that the rust has done its job of pitting the last 1/2" or so of the barrel, and report the results.

Saeed,

John Y Cannuck mentioned a few postings back about slower powder.

To go one step further, I am wondering if calibers with bigger case capacities for the bore size, like 257 Wby, 264 etc will be affected more because of the much higher pressure at the muzzle.

I suppose it would not amke much difference because whether 223 or 264, the muzzle pressure is very high in either case.

Perhaps one other test is to cut across the barrel at an angle, but only a few degrees.

Mike