looking for some input from the pros

[zenman223 460]

hey guys, hoping someone can chime in here and give me a little input.

 

so i just removed my gas block to find 3 very small ports. i havent bother to poke a bunch of bits in em but my 5/64 wont fit and its a good bit bigger than the ports.

now i know the recommended size for a 3 and 4 port gun and i know most people say to add a fourth port but the more reading im doing(double checking port size)

the more conflicted ive become. i originally planned on doing 4 @ 5/64 now im wondering should i do that our 3 @ 3/32

OR 3 @ 3/32 and 1 @ 5/64

OR 4 @3/32

OR........

 

it seems people have all the above combinations and they all work better than the factory pin holes but what do guys think is the best for an unstoppable gun with minimal crud build up in the gas block? im thinkin my original plan is the best, but im looking for input.

also need to know soon b/c im doing this TONIGHT!! bought to do a little reshaping on the gas block and then im tackling the ports!!

[JAldrich2008 28]

I upsized my 3 small ports to 3/32, and when that wasn't quite enough I went back and added a fourth @5/64. My gun runs everything now, and doesn't get too much crap in the block since the holes aren't any bigger than they should have been from the factory.

[Cobra 76 two 2,677]

It depends on how well, or how poorly it cycled before removing the GB...also if the ports are all completely uncovered.

 

If it cycled "so so" before then I would just add one additional port and leave the rest alone. It's not as big a deal the second time if you have to go back in there after testing.

 

[72Stick 0]

I'm not an expert, but my 3 port gun works so much better since I opened the ports up to 3/32nds. The trouble with drilling out the ports is removing the burs in the bore. I didn't try to buff or polish the burs and the nylon from the shot cup clogged the gas block up after it finally cooled off. I ran 125 rounds of anything and everything through it I had as fast as I could reload and it never failed once to eject all the shot cases and they flew a long way when they came out.

 

It was really hard to get the nylon build up out of the gas block.

 

I took some torch cleaning tips to the ports and used a brass cleaning rod in the bore to scrap the burs off. Then I used a brass brush on the cleaning rod with a drill to polish the bore. I think I've removed the burs, but I haven't taken it back to the range. I have a 3gun match I'm shooting this weekend and I'll try it there. Regardless of how much crud does or doesn't build up in the gas block, it's well worth the change in reliability.

[evlblkwpnz 3,418]

It depends on how well, or how poorly it cycled before removing the GB...also if the ports are all completely uncovered.

 

If it cycled "so so" before then I would just add one additional port and leave the rest alone. It's not as big a deal the second time if you have to go back in there after testing.

 

Hi Cobra,

Excellent advice

[zenman223 460]

hey thanks guys, i had a long reponse typed and lost it so lemme just say if you would take a look at this pic

 

it looks like this bottom port b/c of the angle is pretty much blocked by the GB, i know ive read not to mess with that end but it really looks to me like it would help. what do you think cobra? anybody else?

i was lookin at your pics cobra of the reshaping on the inside of the GB but i dont think it would benefit me any, i think it needs it on the other end. what do you guys think?

 

ETA. if i was to try and do anything to that end it would be very minimal of course. just a little more angle not makin it any bigger or takin the hole back any further.

Edited October 14, 2010 by big-J

[zenman223 460]

i just checked and a 1/16 bit will fit snug in the top 2 and the bottom has a little play, so i think i need to open the top 2 up at least!

[Cobra 76 two 2,677]

4 = > 3

 

[sapper1371usmc 107]

hey thanks guys, i had a long reponse typed and lost it so lemme just say if you would take a look at this pic

 

it looks like this bottom port b/c of the angle is pretty much blocked by the GB, i know ive read not to mess with that end but it really looks to me like it would help. what do you think cobra? anybody else?

i was lookin at your pics cobra of the reshaping on the inside of the GB but i dont think it would benefit me any, i think it needs it on the other end. what do you guys think?

 

ETA. if i was to try and do anything to that end it would be very minimal of course. just a little more angle not makin it any bigger or takin the hole back any further.

 

Looking at your picture, it appears your ports in in the right location and ARE NOT being blocked by the gas block. If you look closely you will see a circle on the barrel from carbon and what not. As long as your ports are within that circle your good to go. As for porting, and since you have the room above the top two ports, I would add a port at 5/64" and also run the 5/64" holes that you already have (but three holes at 3/32" is fine too). Just take you a center punch, make a divot, start the drill bit straight until it catches and then turn it to a 45 degree angle to punch through. After your done sizing all your ports, I would run a fine flex hone to remove any burrs created in drilling the new holes.

[sapper1371usmc 107]

Ohh, and i am no pro, so take my advice with a grain of salt. I have though, converted/tinkered with/worked on 6 different S12s, so I like to think my knowledge has progressed, especially with the information I have learned from this site and the hands on experience.

[72Stick 0]

hey thanks guys, i had a long reponse typed and lost it so lemme just say if you would take a look at this pic

 

it looks like this bottom port b/c of the angle is pretty much blocked by the GB, i know ive read not to mess with that end but it really looks to me like it would help. what do you think cobra? anybody else?

i was lookin at your pics cobra of the reshaping on the inside of the GB but i dont think it would benefit me any, i think it needs it on the other end. what do you guys think?

 

ETA. if i was to try and do anything to that end it would be very minimal of course. just a little more angle not makin it any bigger or takin the hole back any further.

 

Looking at your picture, it appears your ports in in the right location and ARE NOT being blocked by the gas block. If you look closely you will see a circle on the barrel from carbon and what not. As long as your ports are within that circle your good to go. As for porting, and since you have the room above the top two ports, I would add a port at 5/64" and also run the 5/64" holes that you already have (but three holes at 3/32" is fine too). Just take you a center punch, make a divot, start the drill bit straight until it catches and then turn it to a 45 degree angle to punch through. After your done sizing all your ports, I would run a fine flex hone to remove any burrs created in drilling the new holes.

 

That's what I need, a fine flex hone to remove those pesky burs!

 

Unfortunately, they're $65 at Brownell's. I took the cheap route and used a drill with a cleaning rod and a patch loop with some 2000 grit sandpaper. It worked like a champ. I made a top end run to the range and fired for effect. Darn if it didn't work perfectly. After 75 rounds no nylon from the shot cups and very little fouling crud in the gas block on setting 2. Man, this Saiga12 runs better every time I take it to the range.