james lambert 3,059 Posted November 21, 2012 Report Share Posted November 21, 2012 A number of people have contacted me about feeding issues with 10rnd and above magazines, this post should clear up questions about malfunctions related to feed ramp inconsistencies. The plastic lower receiver has a mold or parting line at the transition between the mag well and feed ramp. When this area is unchanged during clean up of this parting line, and a clear angular transition is still intact, the gun will usually feed from deep stacks. The evident malfunction of shells moving straight forward but failing to ramp up is greatly reduced or not present at all, but when the factory worker files this transition into a radius, this type of malfunction is common with hi cap magazines. This is due to the lower presentation angle inherent to higher numbers of shells in a stack, which lowers the impact point on the ramp. Factory 5rnd mags present the shell high enough to miss impacting this filed area, but factory and aftermarket 10rnd mags can be problematic, however, they will usually feed with an undisturbed parting line. I have found when magazines with capacities above 12 or 13 rounds are used the ramp geometry becomes very important, and most factory guns will start exhibiting the straight forward malfunction. At that point correctly engineered mag springs and magazine tuning can help greatly, but may not completely address the problem. In some guns the only way to address this problem is to replace the entire feed ramp. The pictures below show a filed transition, a clean transition and a replacement ramp assembly. Jim 1 Quote Link to post Share on other sites
Armand Willis 4 Posted November 21, 2012 Report Share Posted November 21, 2012 Nice looking ramp Jim. Quote Link to post Share on other sites
TonyRumore 1,332 Posted November 21, 2012 Report Share Posted November 21, 2012 Yeah, that replacement ramp looks a shit load better. Quote Link to post Share on other sites
xflowinA3 12 Posted November 21, 2012 Report Share Posted November 21, 2012 My receiver with the new ramp should be showing up today!! Now I just have to drill and tap for the chaos hk style sights..... Quote Link to post Share on other sites
FoxHound 3 Posted November 21, 2012 Report Share Posted November 21, 2012 Thanks for the info How much would it cost for those of us who dont have the time (or most likely patience) to do this ourselves? Quote Link to post Share on other sites
james lambert 3,059 Posted November 21, 2012 Author Report Share Posted November 21, 2012 Foxhound I am not yet a direct dealer on the forum, I may join but I am better at engineering and manufacturing than at retail.... My intent is not for work or sales, but more as a source of information pertaining to the MKA . As such I must refrain from quoting prices of work we do or parts we sell. The only reason I included the ramp in my post is that in some guns it is the only option to repair a broken ramp, or improve feeding if the factory ramp is causing problems. ARR ramps are not a do it yourself item, they require CNC machining and special fixtures to correctly install. Jim Quote Link to post Share on other sites
FoxHound 3 Posted November 21, 2012 Report Share Posted November 21, 2012 Foxhound I am not yet a direct dealer on the forum, I may join but I am better at engineering and manufacturing than at retail.... My intent is not for work or sales, but more as a source of information pertaining to the MKA . As such I must refrain from quoting prices of work we do or parts we sell. The only reason I included the ramp in my post is that in some guns it is the only option to repair a broken ramp, or improve feeding if the factory ramp is causing problems. ARR ramps are not a do it yourself item, they require CNC machining and special fixtures to correctly install. Jim Roger that, I'll give you a ring after the holidays Quote Link to post Share on other sites
scooter_x 0 Posted December 9, 2012 Report Share Posted December 9, 2012 Jim, I am interested in having you perform the feed ramp modification for me if you are interested. Shoot me an email at your convenience and we can discuss the specifics. tscottmatthews@yahoo.com Thanks, Scott Quote Link to post Share on other sites
OKC08GT500 1 Posted December 9, 2012 Report Share Posted December 9, 2012 My receiver with the new ramp should be showing up today!! Now I just have to drill and tap for the chaos hk style sights..... Where did you get the receiver with the new ramp from? Quote Link to post Share on other sites
duggr 13 Posted February 25, 2013 Report Share Posted February 25, 2013 (edited) Jim Took my new XN out today for it's first test run...I had a stock 5 & 10 round mag along with a Salem 6 ten round mag extension on a stock 5 round mag....I first tried the factory ten round and ended up having what appeared to be two shells wanting to extract at once. The salem 6 worked fine until it got to the last round as it wouldn't feed as I stretched the stock spring to work and it didn't....The factory 5-round mag functioned without a glitch....below is photos of my XN feed ramp plus the mags and ammo I was using...Any idea's? or thoughts on the matter? Edited February 25, 2013 by duggr Quote Link to post Share on other sites
ToysRUs 8 Posted February 25, 2013 Report Share Posted February 25, 2013 (edited) My thought would be to... Send it in for a replacement steel ramp. Looks like the bolt has already hit the ramp once or twice. It's just a matter of time, man. Edited February 25, 2013 by ToysRUs Quote Link to post Share on other sites
duggr 13 Posted February 25, 2013 Report Share Posted February 25, 2013 If i need a new feed ramp.... might as well just save up and get the new alloy receiver...I assume it comes already with a new feed ramp installed already! Am I correct?? Also with the Tac 12 lower im guessing you wouldnt need to be 922 parts in your gun being you now have an american made receiver on the MKA. Is this correct ? Quote Link to post Share on other sites
james lambert 3,059 Posted February 25, 2013 Author Report Share Posted February 25, 2013 The TAC-12 uses the same ARR ramp we put in poly lowers We spent quite a bit of time with ATF and they have ruled the upper receiver is and will remain the controlled serialized part in the MKA1919 That means 922 still applies and that the TAC 12 lower does not require a serial number. The TAC-12 upper will be available soon, and that will be considered an all USA made gun. Jim JimTook my new XN out today for it's first test run...I had a stock 5 & 10 round mag along with a Salem 6 ten round mag extension on a stock 5 round mag....I first tried the factory ten round and ended up having what appeared to be two shells wanting to extract at once. The salem 6 worked fine until it got to the last round as it wouldn't feed as I stretched the stock spring to work and it didn't....The factory 5-round mag functioned without a glitch....below is photos of my XN feed ramp plus the mags and ammo I was using...Any idea's? or thoughts on the matter? The follower in the salem mag is not rising to the top of the mag, that will cause malfunctions. I dont know if its the spring causing issues or the mag may be too narrow to allow the follower full travel. jim Quote Link to post Share on other sites
Flatland Shooter 22 Posted February 25, 2013 Report Share Posted February 25, 2013 With the "official" Serial Number on the upper, Anubis will not need to change to Anubis-1 on his gun and the rest of us do not need to mess with an FFL to receive the new lower. It will also make it easier on those sending in their current lowers to Firebird for work. Good news. Bill Quote Link to post Share on other sites
duggr 13 Posted February 26, 2013 Report Share Posted February 26, 2013 The follower in the salem mag is not rising to the top of the mag, that will cause malfunctions.I dont know if its the spring causing issues or the mag may be too narrow to allow the follower full travel Jim I used the newer five round mag spring on the salem 6...This mag actually functioned Great until the the last couple of rounds that failed to feed because of the weak spring! Quote Link to post Share on other sites
Ignition 9 Posted February 26, 2013 Report Share Posted February 26, 2013 The TAC-12 uses the same ARR ramp we put in poly lowersWe spent quite a bit of time with ATF and they have ruled the upper receiver is and will remain the controlled serialized part in the MKA1919 That means 922 still applies and that the TAC 12 lower does not require a serial number. The TAC-12 upper will be available soon, and that will be considered an all USA made gun. Jim That is awesome news, interesting to know that the ATF consider the upper on this the firearm, but the lower on the AR15 the firearm.... cant keep their story straight i guess Quote Link to post Share on other sites
duggr 13 Posted February 27, 2013 Report Share Posted February 27, 2013 (edited) After breaking down the 1919 for cleaning and inspecting the feed ramp (which looked fine to me anyway)... I thought I would check out to see why the Factory five round mag worked as it should but the Factory ten round hung up! The first photo below shows a 3" shell brass at the end of the magazines feed lips on the 5-rnd mag. In this position (right before the brass leaves the feed lips) the front of the 3inch shell not only has around 3/16" clearance between the shell and feed ramp but is at a higher position for better feeding of the shell into the chamber. This photo below shows the position of the "same" 3" shell with the the brass ready to leave the factory 10 rnd mag...One thing I noticed is that the front on the 3" shell was at a lower position and was also right up against the feed ramp. Taking a measurement with my caliper from the top of the shell to the bottom of the notch in the feed ramps shows that there is a difference in the height between the five and ten round mags... I think the salem 6 five round mags extension with the standard mag wood prove to be more reliable when used with a proper spring when shooting 3" shells rather than the Factory ten round......This is just my personal opinion though!! Edited February 27, 2013 by duggr Quote Link to post Share on other sites
BellaCorse 4 Posted February 27, 2013 Report Share Posted February 27, 2013 The followers in my two original mags (2-3/4 & 3") have a straight ramp whereas the followers in the three spare 5-round mags I got from Saiga Stock have a 45° downward slope at the leading edge. The springs in the two original mags worked well with the Salem 6 mag extensions, however the springs from the 3 spare mags were too weak. /M Quote Link to post Share on other sites
duggr 13 Posted February 27, 2013 Report Share Posted February 27, 2013 Oops I should have mentioned that all my mags have the new followeres In them Quote Link to post Share on other sites
voonman 133 Posted February 28, 2013 Report Share Posted February 28, 2013 yes i believe salem 6 is working on selling there new batch of 10round ext with an upgraded spring..All of the older model mka 1919 5round mags came with a much longer spring vs the new 2nd gen 5round mags..So far the salem 6 ext have been working flawlessly in my mka 1919..they are priced very well and made of good durable polymer material Quote Link to post Share on other sites
duggr 13 Posted February 28, 2013 Report Share Posted February 28, 2013 voonmanI was a little skeptical at first when I purchased my one and only Salem 6 mag ext.... I can say now after that I wish I would have purchased 4 or five more...I'm going to purchase a few firebird 10-15 round mag springs while waiting for more of the Salem 6's...I'm going to put a firebird spring in my Akdal factory 10-round mag to see if it performs better....If not, I will dump the factory tens for the Salem 6.... Quote Link to post Share on other sites
siggarue 0 Posted February 28, 2013 Report Share Posted February 28, 2013 The TAC-12 uses the same ARR ramp we put in poly lowersWe spent quite a bit of time with ATF and they have ruled the upper receiver is and will remain the controlled serialized part in the MKA1919 That means 922 still applies and that the TAC 12 lower does not require a serial number. The TAC-12 upper will be available soon, and that will be considered an all USA made gun. Jim Since you're making a new upper and lower are you going to come up with a pin design for holding it together? Seems to me a tongue & groove fit at the rear and a tab & slot with pin in front of the magwell would work. Not too different from the way it's held together now: minus the bolt through the stock; plus a pin in front. I guess I didn't use the quote feature correctly. My post makes it look like duggr is asking the question. Quote Link to post Share on other sites
Embermage 1 Posted March 1, 2013 Report Share Posted March 1, 2013 Got my money for the new lower just sitting by waiting for the word they are ready to go. Quote Link to post Share on other sites
timmmyy 9 Posted March 3, 2013 Report Share Posted March 3, 2013 duggr were are you buying the FB spring from , need web site thanks Quote Link to post Share on other sites
duggr 13 Posted March 3, 2013 Report Share Posted March 3, 2013 Timmmyy Call firebird precision....There website doesnt show all they have in stock! Quote Link to post Share on other sites
Hunter308 6 Posted March 3, 2013 Report Share Posted March 3, 2013 Is there a link to these "TAC-12" lowers? Are they a direct swap for our MKA 1919 shotguns? Quote Link to post Share on other sites
duggr 13 Posted March 3, 2013 Report Share Posted March 3, 2013 (edited) I called F.B. and had my name put on the list for the first batch of lowers...They are a direct swap for the 1919 accept you will need a butt stock as well.....I have a Railed Handguard system with the non reciprocating ambidextrous side charging system...just waiting for the parts i need to fit it to my XN Edited March 3, 2013 by duggr Quote Link to post Share on other sites
james lambert 3,059 Posted March 4, 2013 Author Report Share Posted March 4, 2013 The Tac-12 lower is a direct replacement part The Tac-12 upper is also a direct replacement The Tac-12a1 is a stand alone reciever set and uses a more conventional method of joining the receivers. It also has many other changes Jim Quote Link to post Share on other sites
Haycock 9 Posted March 4, 2013 Report Share Posted March 4, 2013 The Tac-12a1 is a stand alone receiver set and uses a more conventional method of joining the receivers.Jim wait, what? am i reading this correct as in you are going to be making a lower and upper set that will have take down pins!? Is this the first talk of this? please elaborate... Quote Link to post Share on other sites
duggr 13 Posted March 4, 2013 Report Share Posted March 4, 2013 (edited) The Tac-12a1 is a stand alone receiver set and uses a more conventional method of joining the receivers.Jim OOOOHH BOY! Here we go again, another Firebird Product I will have to save for....LOL I take it Jim that the New T 12-A1 will work with your Firebird short and long handgard rail system? Edited March 4, 2013 by duggr Quote Link to post Share on other sites
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