barrel porting for minor revolver

[longbarrel]

I think bountyhunter is right on the way the blast force works to reduce recoil. He sure is right that the ports/magnaport type holes make them louder, some quite obnoxious. I was referring to how the magazine gun writers always talk about how you cant reduce recoil but just divert it or redistribute it.

This is always an interesting conversation.

Troy

[seanc]

I think bountyhunter is right on the way the blast force works to reduce recoil. He sure is right that the ports/magnaport type holes make them louder, some quite obnoxious. I was referring to how the magazine gun writers always talk about how you cant reduce recoil but just divert it or redistribute it.

This is always an interesting conversation.

Troy

My 2011 with the super comp barrel which has 3 large holes in it is very definitely obnoxious with 9.8 grains of 3n38 but the thing is incredible with that barrel, but the noise and concussion are both something that take alot of practice to ignore...

It is easily as loud as an 223 or 308.

The 9mm barrel I recently had fitted has no holes. It is slightly more dot movement but way less insane noise.

[bountyhunter]

Anyone have any good info on this? I see all manner of cuts and ports on open revolvers at the IRC but its unclear to me if there is any experience being applied to those cuts.

I don't know how good the info is, but here is some test data on magnaporting. It's the only test data I saw on ported barrel performance.

Recoil reduction ran from a low of 11% on the .38 to a high of 47% on the .44 magnum.

http://www.tsengineering.com.au/mag-na-port/

Which confirms my own experience on 9mm and .40 which are low pressure rounds like .38 as I saw no perceivable difference.

I have not found any published data on muzzle flip or G forces on the gun. Seems like that would be easy to measure using sensors like they use in football players hellmets attached to the gun.

Edited June 8, 2015 by bountyhunter

[pskys2]

Many years ago American Handgunner had an article that measured with a ransom type rest the recoil flip of different 1911 Comps. Yes 1911's it was back aways.

I seem to remember seeing one on Magna porting also even earlier.

Might try their archives, I believe it was late '80's and early 90's.

Edited June 9, 2015 by pskys2

[Nv45shooter]

I have two 627s, one with 5 hybrid holes and the other stock. Both are standard 5 inch slabside bbls. The ported bbl had the front sight removed so the holes start about a half inch from the muzzle. I was REALLY apprehensive when I sent the gun to my smith to drill the holes thinking, "Oh my God, what have I done?" I have been shooting both of these in ICORE matches for 4 or 5 years and can say from experience that there is a noticable difference. The ported bbl definitely has less muzzle rise. I shoot 158 gr. lead at medium velocities mostly but also do some pin shooting with 180 gr. lead at 1000 fps. It's a little more obnoxious with the pin loads but not that bad with the medium loads. I also have a shooting buddy that has the exact same setup and he has never regretted it.

I'm going to be at the IRC and you're welcome to try them out and compare them.

[Toolguy]

What is the hole size and spacing?

[seanc]

I have two 627s, one with 5 hybrid holes and the other stock. Both are standard 5 inch slabside bbls. The ported bbl had the front sight removed so the holes start about a half inch from the muzzle. I was REALLY apprehensive when I sent the gun to my smith to drill the holes thinking, "Oh my God, what have I done?" I have been shooting both of these in ICORE matches for 4 or 5 years and can say from experience that there is a noticable difference. The ported bbl definitely has less muzzle rise. I shoot 158 gr. lead at medium velocities mostly but also do some pin shooting with 180 gr. lead at 1000 fps. It's a little more obnoxious with the pin loads but not that bad with the medium loads. I also have a shooting buddy that has the exact same setup and he has never regretted it.

I'm going to be at the IRC and you're welcome to try them out and compare them.

thanks for that info. a 180 at 1000fps must be very obnoxious

[Nv45shooter]

Toolguy: They're a tapered hole and I'm not real good with the micrometer thingy but they're about .35 center to center, .25 at the top of the hole and .175 where they enter the bbl.

Seanc: They're not that bad really, I've shot Major 9 and safetyed behind many of them and I wouldn't put them in the same class. And I've chronographed them many times with the Ltd gun and I was really surprised at the small difference in velocity. Usually less than 25fps. Remember, I'm using lead bullets and I don't know if that matters. The lead is self cleaning in those hybrid holes, not so with a comp. You have to dig the lead out of a comp every 100 rounds. I'm just too cheap to buy jacketed bullets.