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What are your thoughts on shooting paper patched bullets in a gun with a muzzle brake. I here people say "O No you can't do that" but thy are just quoting what read no practical experience. I shoot paper patched 500gr bullets out of my 50 RazorBack and it has a muzzle brake and I have never had any issues. The onley thing I'm wondering is if it's affecting my accury using paper patched with a brake. When I shoot the paper blasts out the ports of the brake in small bits. So any thoughts? Thanks
I make and install a lot of muzzle brakes. Not many people have tried to shoot cast boolits through them, but those that have had awful results. Just to see what was happening I tried several on different guns. Uniformly bad results. Nothing catastrophic, but poor accuracy. Brake off, sub MOA groups. Brake on, 4 MOA groups.
I know IPSC guys shoot through brakes all the time, but with much lower powered cartridges than used in rifles and at handgun ranges, so they may not notice any difference.
I haven't tried PP through a brake, but based on what I have seen with naked boolits I don't think I want to.
The only "comped" firearm I have is a 1895G with factory ports. Over 3000rds of paper patched and no problems yet. 1.75 three shot groups at 100yds, must not bother things too much.
Yep, big difference between a ported barrel and a muzzle brake. I guess my M1 Garand counts as a ported barrel - it works fine with PP!Quote:
Originally Posted by pdawg_shooter
Most interesting. I wonder what might be happening with your 'breaks, Nobade. I had never considered the possibility of a break or a suppressor affecting cast or paper patched boolits. Why would a break be any different to a suppressor? We know that a suppressor has no adverse effect on a 22lr (unless there is a problem with the end bit of bore being worn and the baffles being out of line).
I gave the rifle I did for my great-nephew very close tolerances - like 0.2mm clearance (5.6mm boolit through a 6.0mm baffle) and it shoots one hole groups. Although the barrel is pretty short, muzzle blast is not great. Perhaps it's the effects of muzzle blast on slower projectiles?
303 Guy, you're right about 22LR suppressors - they work just fine. But again, muzzle pressure is a lot lower than centerfire cast boolit loads.
I would love to have some high speed photography of what is happening when a cast boolit goes through a muzzle brake. But without that, I have two possibilities. One is that the gas is hitting the baffles ahead of the boolit, rebounding off them, and chewing up the sides of it. We do know that at the moment the base of the boolit uncorks the muzzle the gas overtakes it, and will hit the baffle before the boolit gets there. We also know the same thing happens to copper jacketed bullets, based on the amount of copper fouling that accumulates in muzzle brakes. It just doesn't seem to hurt the copper bullets or their accuracy. I also have tried reaming brakes for cast boolits bigger to see what happened. I got a 30 cal. brake up to 338 cal, and it still wouldn't shoot. But it didn't do much work anymore either so I stopped there.
The other possibility is the base of the boolits are getting expanded enough on exit to touch the baffles, but I don't think this is the case or we would see evidence (lead smears) on the baffles, which we don't see. But something awful is happening to those boolits, because lead is getting deposited some places like the crown of the barrel. My most recent experiment with this involved a Contender pistol chambered for 7mm TCU. I shot it maybe 50 times with a brake and cast boolit loads, and when I removed the brake there was a heavy layer of lead firmly stuck to the crown. I couldn't get it off with normal solvents so eventually had to scrape it off with a razor blade. Since removing the brake, accuracy has returned to normal and no lead build up anymore with the same loads. You wouldn't think something 3/8" away from the muzzle (the first baffle) could do that but it does. It's got to be vaporizing or powdering the boolit to allow material to re-deposit on the crown.
I modified one of my .458s for a muzzle break...with it off the rifle still shot less than one inch off the sandbagged benchrest at 100 yards.....with it ON, the groups opened up to THREE inches! Same day, same loads.
I have wished for years to get hold of a high speed camera to investigate just what happens to the patch and how it sheds...it would answer so many questions that have raised tempers in the BP and smokeless communities.
Some think that the combination of centrifugal force and the air slipstream past the just launched bullet strips the patch.
Another school of thought has that the muzzle blast when the bullet base clears the muzzle starts stripping the patch off the bullet from the rear. In the open air the patch sheds cleanly...in a muzzle brake the shedding paper (my theory) fills the gap between a tight break and the bullet and possibly this contact may push the bullet off course...causing larger groups and fliers.
On the silencer issue, being in the good old USA it is a hassle getting one with the fees and paperwork. But a friend has one on a rifle chambered for .308 Winchester and once I got him to shoot some PP loads......it was terrible.., the patches shed INSIDE the baffles and even damaged some of the outer ones with bullet strikes as the bullet tipped in flight inside the 'can'. Bullets were key-holing at 25 yards!!!
303guy said he had one, have you tried it with PP?
Yeah, nearly all my PPCB's have been fired though a suppressor. I'm having trouble getting the patch off, let alone coming off inside the suppressor! Well, with lighter loads anyway.
I can't even claim the muzzle blast as having too much effect as it doesn't blow off the patch tail ring.
http://i388.photobucket.com/albums/o...3Guy/001-2.jpg
That ring followed the boolit into the sand trap and was still attached to the boolit base. It looks clean as it was washed off with water and a toothbrush. It was a 206gr over 40gr H4350 from the short barrelled pig gun with suppressor. That load did not perform in the field. I can't say how badly it performed as I could not hit anything to to get a group!
I wonder whether my baffle design is what makes the difference?
yes i will agree with the bad leading problem with brakes and comps. all my brakes and comps get very thick lead build up on the baffles and the barrel corwn/muzzle. i have wondered how this coudl be hapening. its eather hapening all the time with or with out the brakes and the brake just captures it. or the brake is eroding the boolit.
Its been a while but last I heard you were using a 'glue' on your patches that made them hard and able to stay together even into your bullet trap. Or making 'sleeves' to fit over the bullet? My patches are either plain paper or waterproofed with Rooster Lube or JPW and shred/shed right at the muzzle. If you are still using the same patching method, I can understand why none of your patches have come off in the silencer.Quote:
Originally Posted by 303Guy
On the leading, in both the silences and muzzle brakes the hot, high pressure gas is basically trapped from expanding and has to flow alongside the bullet. We know that gas cutting of lead bullets and bore leading does NOT come from contact or scraping action but instead is a jet of high pressure gas trapped between the barrel and bullet side that cuts/erodes the lead and is deposited in the bore (or break or silencer) ahead of the bullet...in fact. the gas curing would be worst case onside a properly tight tolerance d muzzle break.......that's my theory and I'm stickin to it!
The glue is pretty dilute and is used on the tail only. There does need to be enough power behind the boolit to shred the patch. The use of filler is what protects the patch tail ring. It also protects the boolit base.
I'm leaning toward gas erosion within the bore. I've recovered a 44 mag boolit that had the groove ridges eroded level with the land impressions. No skidding in the bore and the bore stayed clean. The alloy was too hard to obturate.
My pig gun developed a problem with gas cutting when the bore roughened. I didn't know what I was looking at initially. My baffle design didn't allow for internal inspection and now that it's out, I can't find it in the long grass.:roll:
Here is a slow boolit showing patch failure (the lead has rubbed on the bore).
http://i388.photobucket.com/albums/o...igGun004-1.jpg
Here is the gas erosion.
http://i388.photobucket.com/albums/o...kirttails2.jpg
A patch that survived the bore before it roughened.
http://i388.photobucket.com/albums/o...574_edited.jpg
Apples and oranges example . I have a High Power clone 9mm,maybe I've been lucky. I've never had major bbl leading except with some lube/copper issues in my 1st attempts. The bolt face was recently found impacted full of lead. I'm thinking "gas splash" . I don't have a better name for it. Similar thing happens around the cylinder gap .
I just looked at the sks,its all I have w/ anything resembling a comp/flashhider or the like. No leading .som powder fouling and freckles that look like paper impacts. The muzzle has been bored back about .2in none ther either . The loads are making confetti w/full tilt 160gr 4895 loads and full case compressed loads w 200gr spire points and 4350. Now that the bore is smoothed out I don't get any lead in the gas port either my last run was about 40 rd but the bore,action,bbl,and muzzle and grenade gizmo haven't been cleaned more than a swab in 150 rd or more.
I offer the load info as another variable. Also the muzzle and extention are recessed at 360 vs the 316 muzzle. . The extention is drilled w/5 ports per row at 9,12,3 o'clock points.
More usless info from a probably uncomparable example.
It does throw a predictable round related to case volume variations and fast twist 30s in my expirence . Another useless thought as to twist rate having some thing to do w it as well . Maybe the fast twist negates the gas vent. Food for thought. Use what you can ignore the rest.