Barrel Ports and Cast Bullet question

[Char-Gar]

In a trade, I have come by a Marlin Guide Gun (stainless steel) with barrel ports. I can imagine the ports becoming problematic with cast bullets.. ie cloging up with lube and gunk.

Is this just my imagination or is this reality?

[nighthunter]

I have a Taurus 627 with a ported barrel and have shot nothing but cast in it and have no problem with the ports clogging. I think that as long as the bullet is sized properly it should not be a problem.

[imashooter2]

The pressure at those ports is on the order of 20,000 psi. They won't clog with anything.

[Blackwater]

How's the accuracy with the ports? I have a ported GG too, and haven't shot any cast in it yet, or at least none I've cast myself, and am interested in your reports. A buddy has a ported Taurus .45 LC and it won't shoot PB bullets at all well, and he blames it on the ports.

BTW, gas pressure at the ports is exactly what makes them work to reduce "muzzle flip" and the kind of pressure that takes will assuredly keep any potential buildup of crud blown out pretty effectively. The main question is whether those ports strip lead from one side of the bullet and upset the bullet's balance, thus affecting accuracy. That's my concern, anyway, and I haven't gotten my round tuit to test it yet.

[PatMarlin]

I've got a Taurus Raging Bull Cannon- 8 3/8" barrel in 454 Casull.

It shoots cast great. The ports have not plugged as yet.

[lar45]

I have a Tuarus Rageing bull 6.5" in 454 with the ports. I shoot notheing but cast in it. There is some residue in the ports, but not enough to worry about. I get very good accuracy with plain base and gaschecked bullets. I shoot water dropped WW.
Tell your buddy that he needs to load WC820 and then all his troubles will go away

[MTWeatherman]

I've got a Taurus .357 Tracker...4" barrel. No...the ports don't plug...they're self cleaning. However...with a plain base bullet there is significant gas cutting across the base into the ports. With a .357 class load, the result is lead build up on the barrel above each port and a grey lead wash on the front sight. It's very noticeable on the satin finished Tracker and I suspect it's occurring with other handguns but not noticed due to the port or sight location...the lead vapor simply blows on by without being deposited. Not nearly as bad with reduced .38 Special pressures, but its still there. Certainly can't help accuracy.

The solution is a gas check bullet. The problem is gone. That's the only bullet I shoot in it.

Pressures are a lot higher 3" down a .357 barrel than they will be at the ports in the Guide Gun. As a result, my guess is that the gas cutting would be minimal at the port of your Guide Gun but some would still be there. Since any deformation of the bullet base can affect accuracy, I'd still opt for a gas check bullet when I selected a mould.

[Bass Ackward]

In a trade, I have come by a Marlin Guide Gun (stainless steel) with barrel ports. I can imagine the ports becoming problematic with cast bullets.. ie cloging up with lube and gunk.

Is this just my imagination or is this reality?

Chargar,

Problems occur more when there are burrs from when the hole is made. There aren't supposed to be any you understand, they just find there way there by magic. But clean them up with some jacketed first and you should be fine. My only problems ever occurred with PB because one hole will be drilled sooner than the others. Then when the pressure breaks it is vented through a smaller area than an even crown. My guess is that high pressure venting of hot gas will notch the base. Regardless, can't be doing it any good.

Carborator cleaner works for clean-up.

[Bent Ramrod]

Chargar,

I have a Model 70 with the BOSS attachment which has a bunch of holes drilled lateral to the bullet's passage. It shoots well with cast bullets, but there is a gray deposit of lead vapor on the outside at the end of a shooting session. I've never seen any leading buildup, though, and the deposit wipes off with a Hoppe's moistened cloth.

[David R]

Only problem I have ever seen with a ported barrel was on a DAN Wesson. It has a barrel and shroud. The barrel has holes drilled in it and then it vents through 2 slots in the top of the shroud. Lead builds up in between and you can't get the shroud off the barrel, its almost soldered together. A real mess.

David

[BruceB]

My Savage .338 (Model 116) has the neat muzzle brake which can be selected "on" or "off".....and it REALLY makes a difference in the perceived recoil.

After a relatively-few rounds with cast bullets, the brake was seized in the "on" position, and I mean SEIZED. I haven't yet tried immersing the brake in penetrating oil for a day or three, because I'm practising with the rifle for an upcoming hunt.

If anyone else has such a feature on a rifle, I'd suggest doing the cast-bullet shooting with the brake closed, or "off", to reduce the chances of gumming up the works.

[Char-Gar]

Thanks for the input..I don't have my hand on the rifle yet and I will keep you posted. I have 4 45 cal rifle molds and they are all gas check designs except the 330 Gould HP. One of them is Hock 350 which is nothing but the Gould with a gas check shank.

I want a velocity of 1.4 - 1.5 K fps...That is about all the romp and stomp I want to put up with.

[Finn45]

One problem with Marlin porting is that holes are cut straight through the bore surface, mine wasn't very well finished and it slung the lead and even copper chips all over hitting the range roof etc. Some incidents have been reported them hitting bystanders as well.
Holes caused excessive copper fouling and lead fouling which always started immediately after first shot right from the rearmost hole resulting copperized or leaded upper half of the muzzle inner surface. No evident lack of accuracy though and there wasn't any kind of clogging or something because of the ports, but front sight hood got very permanent blasting marks right next to port holes.
These Marlins are very accurate and accuracy didn't suffer at all when I chopped the porting off. It jumps more, it kicks slightly more, it's not so screaming noisy anymore and there's no flying chips or lead build up anymore. 16½ inch barrel still gives near 1900fps with 400 grain cast, so I think it's not a big problem performance vise either. Very handy little big rifle.

[Beau Cassidy]

On my .450 Guide gun, I can assure you the ports don't affect accuracy. The only thing I have noticed is a little lead and lube buildup under the edge of the front sight ramp. No problem to remove.

1900 FPS with a 400 Gr. bullet in a 16 1/2 inch guide gun. Ouch!

Beau

[Finn45]

It's pretty much ouch alright. Last years hunting load was 1860fps with 400+ grainer burning N120, which is not even nearly ideal for highest velocity. Last year was my second season with high velocity cast and for this year I'm lowering it down to 1600 or just above. I've now seen that irrespective of the Internet truth that more velocity (or more penetration for that matter) always means better kill also with this caliber, I'm going to check out the possibility that it's not the velocity but something else... Besides, the Kick and general handling of the rifle is way much easier with 1600fps than 1800+fps, way much easier. Just let the moose cross my path... and without me driving a car this time.

[STP]

I had a SSK 14inch MagnaPorted 375JDJ for a few years. (900+ round history by me) I had no issues with cast using a Saeco DC #374 using WW alloy. Range visits with cast lasted a whole lot longer for sure!
I miss that caliber...

[MGySgt]

I am currently working up a load for my GG with Creeker 430gr GC (too bad I can't get more).

2 groups tonight hovered around MOA and still going up.

The only powder I use for heavy loads in the 45/70 is 3031 - I guess I am stuck in yester year for powders!

No sign of leading anywheres in the barrel to include around, in front or behind the ports!.

Drew

[BOOM BOOM]

HI,
I have/had 4 ported guns.
1) 444 marlin lever action mag-na -ported best cast bullet group I ever shot was w/ it. 11 shots Lyman 250 gr gc kieth style all holes touching 1 big hole. Better group than jacked bullets.
2) 44 mag Redhawlk mag-na-ported shoots the 250gr gc kieth just as well as any jacked. Lead spray deposits on side of front sight, this is w/ gc.
3) 7MM Mag rem 700, mag-na-ported shoots Lyman 168gr gc bullets squib loads ok but nothing to brag about. Does better w/ jacked 162gr hornady full house loads sub MOA.
4) 7MM/06 mauser markX action, shoots the 168gr gc squib & mid vel. loads ok but nothing to brag about. Does better w/ 145gr speer & full house loads sub MOA.
Have never noticed any lead on outside of the rifle barrels. Have fired several hundred rounds out of the 444 & 7MM Mag & porting made them alot more fun to shoot. Have fired thousands of rounds out of the 7MM/06 & 44 mag , no lead deposits on outside of 7MM/06, but there is on the 44mag.