yekcoh Posted March 30 Share Posted March 30 (edited) I got a new gun built recently. 2011 with 5" KKM with TI comp and 4 holes into the barrel chambered in 9. barrel is pvd black. The usual load that I am used to with my existing open guns is 9.4gr of AA7. This gun for some reason seems to be leaving a lot of unburnt powder in the gun. Sometimes it gets so bad that the chamber gets build ups of unburnt powder causing the next round to jam. Builder said it's his first time hearing such a thing. Funny thing is when I first got the gun, it ran flawlessly for the first 500ish rounds then I started experiencing this problem. So I checked my ammo: 1.172" federal spp mag (cci srp seems to burn better). Ammo appears to be sized and crimped correctly. Any tips or suggestions are appreciated. Edited March 30 by yekcoh Link to comment Share on other sites More sharing options...
OpenshooterMclass4lyfe Posted March 30 Share Posted March 30 What does it chrono at compared to your other guns with the same load? Link to comment Share on other sites More sharing options...
yekcoh Posted March 30 Author Share Posted March 30 (edited) 1 hour ago, OpenshooterMclass4lyfe said: What does it chrono at compared to your other guns with the same load? It chronos slightly higher. barrel hole position is almost the same but this one is kkm which is known for higher muzzle velocity Edited March 30 by yekcoh Link to comment Share on other sites More sharing options...
OpenshooterMclass4lyfe Posted March 30 Share Posted March 30 10 minutes ago, yekcoh said: It chronos slightly higher. barrel hole position is almost the same but this one is kkm which is known for higher muzzle velocity I’d play around with the amount of powder some and see if that doesn’t reduce the excess powder being unburnt. Link to comment Share on other sites More sharing options...
jwhittin Posted March 30 Share Posted March 30 (edited) I run 9.6 gn of AA7 under a 124gn 9mm bullet. OAL is 1.170 and I use the same primers, no barrel holes. I have some unburnt powder too but it hasn’t caused a failure. I run 500 to 1000 rounds between light cleaning. could work up a load with magnum rifle primers. I’ve used cci450s without any problems. Didn’t look at the amount of unburnt pwdr and compare. Edited March 30 by jwhittin Link to comment Share on other sites More sharing options...
perttime Posted March 30 Share Posted March 30 What load did the seller use? What about round count on the barrel? Not worn out yet? Link to comment Share on other sites More sharing options...
yekcoh Posted March 30 Author Share Posted March 30 10 hours ago, jwhittin said: I run 9.6 gn of AA7 under a 124gn 9mm bullet. OAL is 1.170 and I use the same primers, no barrel holes. I have some unburnt powder too but it hasn’t caused a failure. I run 500 to 1000 rounds between light cleaning. could work up a load with magnum rifle primers. I’ve used cci450s without any problems. Didn’t look at the amount of unburnt pwdr and compare. If it's a primer issue, it would be an easy fix but even cci srp caused problems albeit less.. Link to comment Share on other sites More sharing options...
Wanna_Go_Fast Posted March 31 Share Posted March 31 I would suggest knocking the charge down a few grains and see if you get similar velocities. Unburnt powder usually means you have more powder than you can burn in the barrel. Link to comment Share on other sites More sharing options...
perttime Posted March 31 Share Posted March 31 ... or that you have too low pressure to burn efficiently. Link to comment Share on other sites More sharing options...
yekcoh Posted March 31 Author Share Posted March 31 48 minutes ago, Wanna_Go_Fast said: I would suggest knocking the charge down a few grains and see if you get similar velocities. Unburnt powder usually means you have more powder than you can burn in the barrel. My load recipe clocks in at 167pf at 9.4gr. Ive been practicing with it because Its feels great despite the jams. Dot tracks great. Its loaded for ipsc nats but Im afraid I wont be able to trust it. Link to comment Share on other sites More sharing options...
yekcoh Posted March 31 Author Share Posted March 31 (edited) 6 minutes ago, perttime said: ... or that you have too low pressure to burn efficiently. The gun is a middy length (5” with thread) with 4 barrel holes. If we measure barrel length to the first hole, itd be almost 4” Does that make this gun a shorty then? Low pressure and too short of barrel length to burn the powder but the gun tracks wonderful. And it makes either ipsc or uspsa power factor easily. Id do Anything to make this gun work! Edited March 31 by yekcoh Link to comment Share on other sites More sharing options...
jwhittin Posted March 31 Share Posted March 31 (edited) What PF does IPSC use? Is it 165? If so, and unless you know your standard deviation is low single digits, you are at risk of failing a PF check. If they use 160 PF then you are ok. Edited March 31 by jwhittin Link to comment Share on other sites More sharing options...
yekcoh Posted March 31 Author Share Posted March 31 34 minutes ago, jwhittin said: What PF does IPSC use? Is it 165? If so, and unless you know your standard deviation is low single digits, you are at risk of failing a PF check. If they use 160 PF then you are ok. Thats not the topic of discussion. Im not asking about making pf. Im asking about a potential solution to the malfunction I am experiencing with the particular powder I am using Link to comment Share on other sites More sharing options...
625 Posted March 31 Share Posted March 31 Any chance it is your bullet crimp? Link to comment Share on other sites More sharing options...
yekcoh Posted April 1 Author Share Posted April 1 3 hours ago, 625 said: Any chance it is your bullet crimp? So I did the push test and the bullets are guaged with a hundo it measures 3.780 at the edge(neck) so I dont know what else I could do to test for proper crimp. Any idea? Link to comment Share on other sites More sharing options...
shred Posted April 1 Share Posted April 1 Get a 10x loupe or magnifier or phone or whatever and look at the gap between case and bullet with magnification. If there's an obvious gap (bigger than maybe 1/4 of the brass thickness), you need more crimp. That said, it's very unlikely to be the source of your unburned powder. Btw, is it actual powder flakes or yellow cornmeal stuff or what? Link to comment Share on other sites More sharing options...
BoyGlock Posted April 1 Share Posted April 1 Get some of the “unburnt powder” throw it in an open flame and should ignite. Otherwise, its not “unburnt” Link to comment Share on other sites More sharing options...
yekcoh Posted April 1 Author Share Posted April 1 12 hours ago, shred said: Get a 10x loupe or magnifier or phone or whatever and look at the gap between case and bullet with magnification. If there's an obvious gap (bigger than maybe 1/4 of the brass thickness), you need more crimp. That said, it's very unlikely to be the source of your unburned powder. Btw, is it actual powder flakes or yellow cornmeal stuff or what? I should have uploaded pictures from the get go. https://imgur.com/a/Rp1Bnet I am using the same load that I used for MPA which works flawlessly. You can see with this gun, the chamber area gets whatever you call (cornmeal or unburnt powder) resulting the next round to not fully chamber. So Id have to “assist” the slide to close Link to comment Share on other sites More sharing options...
shred Posted April 1 Share Posted April 1 I think the yellow "cornmeal" is not unburned powder, it's some sort of combustion residue. I saw that a long time ago in an Open gun. Scrape some into a little pile and see if you can ignite it. Link to comment Share on other sites More sharing options...
APL-G35 Posted April 1 Share Posted April 1 Those pictures look just like what i get with my gun as well. I'm loading 9.9 of AA7 at 1.165 it looks like that after 300 or so rounds Link to comment Share on other sites More sharing options...
sandflea316 Posted April 2 Share Posted April 2 I use AA7 and get that yellow stuff in my gun. Not so much it causes jams. 9.8 gr of AA7 in 2 CZ Czechmates and an open 2011. PF is around 173 Link to comment Share on other sites More sharing options...
Intel6 Posted April 2 Share Posted April 2 Most "cornmeal" described by people is actually unburned powder. The powder is made and then usually coated with graphite in order to help it from clumping and to make it flow better. in poor combustion situations the graphite is burned off powder granules but there is no ignition so what is left is the unburned powder granule. Some powders do not have the graphite coating and the true color shows through. Why do you think Vit N320 is green. Link to comment Share on other sites More sharing options...
yekcoh Posted April 2 Author Share Posted April 2 Interim solution for now is switching to 3n38 which seems to be working so far; 200 no issue. Will test several hundred to confirm... Link to comment Share on other sites More sharing options...
lefty o Posted April 2 Share Posted April 2 for sure hotter primer, or a different powder is needed. that combo is lacking in space/time/heat to burn everything. Link to comment Share on other sites More sharing options...
Maximis228 Posted April 2 Share Posted April 2 (edited) AA7 is known to be a VERY dirty load due to burned/unburned gun powder getting everywhere. Ive seen charge weight as low as 9.0 for a 124 and as high as 11 for a 115 using AA7. IMO its not a great powder for 9 major. But I also think WAC is perfect for 9 major. Many people call me crazy. Edited April 2 by Maximis228 Link to comment Share on other sites More sharing options...
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