brad cole 65 Posted October 22, 2013 Report Share Posted October 22, 2013 My friend shot my v12 and loved it so he went and bought one. the barrel has been shortened,and a perm atached CSS gko1 installed on it.the trigger is a tapco that appears to be locking up good. He is having FTE alot so he brought it over and it has 5 ports; 3 original that looks a bit enlarged and 2 about 1/16 in size. before we hog out some ports more, I was wondering if it could be over gassed and cycling too fast and causing malfunctions. He is new to firearms and I dont want him to be discouraged after I bragged about these veprs, so I hope to help him out on this. Thank you for any help guys. Quote Link to post Share on other sites
haugpatr 972 Posted October 22, 2013 Report Share Posted October 22, 2013 If there are 5 ports, I would look elswhere for your problems, 5 seems like too many to me. Has the hammer been reprofiled? Quote Link to post Share on other sites
brad cole 65 Posted October 22, 2013 Author Report Share Posted October 22, 2013 it looks great and that is what has me stumped, everything is smooth and no "catches " on anything.it is not polished, but worked over pretty good. I think I will help him polish the internals.Also the mainspring looks identical to mine. so we may try to polish then go from there. Quote Link to post Share on other sites
thebuns1 4,323 Posted October 22, 2013 Report Share Posted October 22, 2013 What kind of ammo are you guys running? Polishing key areas does wonders. Id do that prior to fucking with ports. Quote Link to post Share on other sites
Run and Gun 25 Posted October 22, 2013 Report Share Posted October 22, 2013 How short is his barrel? Quote Link to post Share on other sites
gunfun 3,931 Posted October 22, 2013 Report Share Posted October 22, 2013 If there are 5 ports, I would look elswhere for your problems, 5 seems like too many to me. Has the hammer been reprofiled? 5 is the normal number for V12s. They usually come with 5 small holes. If he is having FTE, then Over gas is not his problem. Undergas is possible but less common on those. Hard to say how much the chopped barrel would change this. I'd be more likely to look at some kind of hammer or trigger group vs bolt carrier interference issue before I messed with the ports more. Extreme over gas can cause rebound where the bolt bounces off the back of the reciever and outruns the mag. This would make an FTF, but the empties would be flying out with alacrity. 1 Quote Link to post Share on other sites
thebuns1 4,323 Posted October 22, 2013 Report Share Posted October 22, 2013 If there are 5 ports, I would look elswhere for your problems, 5 seems like too many to me. Has the hammer been reprofiled? 5 is the normal number for V12s. They usually come with 5 small holes. If he is having FTE, then Over gas is not his problem. Undergas is possible but less common on those. Hard to say how much the chopped barrel would change this. I'd be more likely to look at some kind of hammer or trigger group vs bolt carrier interference issue before I messed with the ports more. Extreme over gas can cause rebound where the bolt bounces off the back of the reciever and outruns the mag. This would make an FTF, but the empties would be flying out with alacrity. Exactly. Everything sits lower in the reciever than it does vs. the rifles. Its funny how the shotguns change the characteristics of the operation of the weapon of the same basic design. Quote Link to post Share on other sites
gunfun 3,931 Posted October 22, 2013 Report Share Posted October 22, 2013 Well, they have to deal with a huge variation in pressure levels which is far broader than anything rifles need. the cartridges have a great variety of shapes and sizes and resistance to insertion and extraction, which you will never find in a rifle.The propellant is dirtier and there is a lot of it. The change to a short stroke captive piston is the most dramatic and necessary change. Quote Link to post Share on other sites
ezveedub 2 Posted October 22, 2013 Report Share Posted October 22, 2013 My friend shot my v12 and loved it so he went and bought one. the barrel has been shortened,and a perm atached CSS gko1 installed on it.the trigger is a tapco that appears to be locking up good. He is having FTE alot so he brought it over and it has 5 ports; 3 original that looks a bit enlarged and 2 about 1/16 in size. before we hog out some ports more, I was wondering if it could be over gassed and cycling too fast and causing malfunctions. He is new to firearms and I dont want him to be discouraged after I bragged about these veprs, so I hope to help him out on this. Thank you for any help guys. I assume you have this issue with stock Molot mags, not SGM mags, correct? You never mentioned what mags were used. Quote Link to post Share on other sites
poolingmyignorance 2,191 Posted October 22, 2013 Report Share Posted October 22, 2013 If he chopped the barrel more than 2" he could have very well reduced the dwell time to insufficient levels of gas. If such is the case you can try enlarging the ports, or if chopped too much will have to move the gas system back. Quote Link to post Share on other sites
brad cole 65 Posted October 23, 2013 Author Report Share Posted October 23, 2013 the barrel length is 18 1/2 inches total. We tried wally winchester , federal, and estate 1 1/8 ounce shot, I believe all 3 dram. estate ran the best but the last round still caught. As far as mags tried sgm 12, 10, and one cut down to 8, and factory 5 rd. the factory provided the best results but still FTE often. Will try to polish internals and double check trigger this weekend if he can make it up.thanks for input everyone! Quote Link to post Share on other sites
supertex 242 Posted October 23, 2013 Report Share Posted October 23, 2013 I would try a lighter front recoil spring. 1 Quote Link to post Share on other sites
poolingmyignorance 2,191 Posted October 23, 2013 Report Share Posted October 23, 2013 the barrel length is 18 1/2 inches total. We tried wally winchester , federal, and estate 1 1/8 ounce shot, I believe all 3 dram. estate ran the best but the last round still caught. As far as mags tried sgm 12, 10, and one cut down to 8, and factory 5 rd. the factory provided the best results but still FTE often. Will try to polish internals and double check trigger this weekend if he can make it up.thanks for input everyone! Okay. 18.5" OAL... but if your sporting a tromix monster your barrel is really about 12" IIRC of tube, or if your sporting a Chaos warthog, then it's about 15" at the brake. So with the wart hog, you'll need larger ports with the monster, you might have to move the gas system back. Quote Link to post Share on other sites
WUNDERWAFFEN 21 Posted October 23, 2013 Report Share Posted October 23, 2013 I would love to see a picture of this cut/perm V12 Quote Link to post Share on other sites
ezveedub 2 Posted October 23, 2013 Report Share Posted October 23, 2013 the barrel length is 18 1/2 inches total. We tried wally winchester , federal, and estate 1 1/8 ounce shot, I believe all 3 dram. estate ran the best but the last round still caught. As far as mags tried sgm 12, 10, and one cut down to 8, and factory 5 rd. the factory provided the best results but still FTE often. Will try to polish internals and double check trigger this weekend if he can make it up.thanks for input everyone! You should have no issues with that barrel length. Make sure you lube the rails and carrier contact surfaces after you clean/polish the contact surfaces. On the SGM mags, make sure the rounds move freely, as they tend to also hang-up right below the very top of the mag, at least they did for me on my 12rd and 10rd, which I had to correct for them to function properly. Quote Link to post Share on other sites
Mullet Man 2,114 Posted October 23, 2013 Report Share Posted October 23, 2013 Did it have a cycling issue before the barrel work? Was anything else done to it at the same time? Quote Link to post Share on other sites
DresNightfire 39 Posted October 23, 2013 Report Share Posted October 23, 2013 Always try a lighter recoil spring and polishing the bolt and trigger face before messing with the gas system ports. Because you can't un-fuck gas ports once they are too large. Quote Link to post Share on other sites
poolingmyignorance 2,191 Posted October 24, 2013 Report Share Posted October 24, 2013 Always try a lighter recoil spring and polishing the bolt and trigger face before messing with the gas system ports. Because you can't un-fuck gas ports once they are too large. You can, it just requires a competent gunsmith. How do you think you move the gas system back? You weld up the old holes and machine blend it back into the barrel. Quote Link to post Share on other sites
brad cole 65 Posted October 24, 2013 Author Report Share Posted October 24, 2013 ok he bought it from a "guy" at a gunshow in OHIO so no info on performance before barrel work. And we will see what it does on sunday he is bringing it up then. the barrel length is 18 1/2 inches total. We tried wally winchester , federal, and estate 1 1/8 ounce shot, I believe all 3 dram. estate ran the best but the last round still caught. As far as mags tried sgm 12, 10, and one cut down to 8, and factory 5 rd. the factory provided the best results but still FTE often. Will try to polish internals and double check trigger this weekend if he can make it up.thanks for input everyone! You should have no issues with that barrel length. Make sure you lube the rails and carrier contact surfaces after you clean/polish the contact surfaces. On the SGM mags, make sure the rounds move freely, as they tend to also hang-up right below the very top of the mag, at least they did for me on my 12rd and 10rd, which I had to correct for them to function properly. what was done to correct the problem, if you dont mind sharing? Quote Link to post Share on other sites
Thor's Hammer 33 Posted October 25, 2013 Report Share Posted October 25, 2013 Maybe test some more powerful loads and see if there is an improvement. Quote Link to post Share on other sites
ezveedub 2 Posted October 26, 2013 Report Share Posted October 26, 2013 ok he bought it from a "guy" at a gunshow in OHIO so no info on performance before barrel work. And we will see what it does on sunday he is bringing it up then. the barrel length is 18 1/2 inches total. We tried wally winchester , federal, and estate 1 1/8 ounce shot, I believe all 3 dram. estate ran the best but the last round still caught. As far as mags tried sgm 12, 10, and one cut down to 8, and factory 5 rd. the factory provided the best results but still FTE often. Will try to polish internals and double check trigger this weekend if he can make it up.thanks for input everyone! You should have no issues with that barrel length. Make sure you lube the rails and carrier contact surfaces after you clean/polish the contact surfaces. On the SGM mags, make sure the rounds move freely, as they tend to also hang-up right below the very top of the mag, at least they did for me on my 12rd and 10rd, which I had to correct for them to function properly. what was done to correct the problem, if you dont mind sharing? On the SGM mags, there was a thread on issues with the Saiga 12 version, so I checked mine and sure enough, the rounds would hang up right in the area one round below the feed lip. I took two 5/8 spark plug sockets and inserted them into the mag like rounds and placed the mag into boiling water for about 10-15 seconds, then sat them on a rag top down to cool off. Once cool, they were now widened enough for the rounds to slide freely with no hang ups anymore. I would Make sure the rounds have no hang ups at all through the entire mag to make sure they work properly. Quote Link to post Share on other sites
brad cole 65 Posted November 3, 2013 Author Report Share Posted November 3, 2013 okay, we lightly smoothed all the edges and contact points on the trigger group, then polished all the contact points.Then we test fired and got a lot better results.Then we ran about 100 slugs through it and NO FTE, broke it down cleaned it. Then back to birdshotand it ran perfect with factory 5 rd mag and only 2 fte with the SGM mags so I believe it was just not broke in.Thanks for pointing to trigger group guys we will see how it goes in the future and may try a reduced front recoil spring later if needed. 1 Quote Link to post Share on other sites
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