luketmv Posted February 20, 2015 Share Posted February 20, 2015 Here is the problem, I am using N320 with 124 gr FMJ. The gun is an M&p Pro. c.o.l = 29.05 mm N320 = 3.8 gr The bullets are crimped well enough however the gun is not cycling, most of the cases end up stove piping or remaining attached to the ejector and being put back into battery again. Basic problem is there is not enough force to cycle the gun properly, please help me solve this, i do not think more powder is the solution. Someone suggested shortening the rounds however i do not know by how much. is 1mm too much? Too little? is this even the solution? Please help Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted February 20, 2015 Share Posted February 20, 2015 I'd guess that your OAL (1.144") is probably okay - doesn't sound like it should be shorter - but wouldn't hurt to do The Plunk Test. What's the velocity? Link to comment Share on other sites More sharing options...
luketmv Posted February 20, 2015 Author Share Posted February 20, 2015 (edited) cant say..... this is a new load for me and dont have the chance to chrono. Edited February 20, 2015 by luketmv Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted February 20, 2015 Share Posted February 20, 2015 Stove piping might mean too little powder ??? Link to comment Share on other sites More sharing options...
luketmv Posted February 20, 2015 Author Share Posted February 20, 2015 Stove piping might mean too little powder ??? n320 vihtavuori say maximum load should be 4.0 gr. Link to comment Share on other sites More sharing options...
Sarge Posted February 20, 2015 Share Posted February 20, 2015 You are half a grain too light on charge. 4.2 - 4.3 is about right for 124 with 320 Link to comment Share on other sites More sharing options...
Durtarg Posted February 20, 2015 Share Posted February 20, 2015 I used 1.135" OAL in my m&p Pro You could also change your recoil spring weight. If you're using the stock spring, try a 13lb. It was the best weight spring I found for mine. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
al503 Posted February 20, 2015 Share Posted February 20, 2015 Is the pistol properly lubed? Are you using grease or a light oil? Grease will slow down the slide and could lead to or contribute to whats going on. The easiest solution would probably be to up the charge. You could always get an aftermarket guide rod and a weaker recoil spring, also. Link to comment Share on other sites More sharing options...
Youngeyes Posted February 20, 2015 Share Posted February 20, 2015 Increase the charge .3 gr and retry. Make sure that slide is lubed. Too dry it galls up. It won't cycle properly if dry. Link to comment Share on other sites More sharing options...
Steve RA Posted February 20, 2015 Share Posted February 20, 2015 You could try some factory rounds in it and make sure the gun is functioning properly. Link to comment Share on other sites More sharing options...
sk330lc Posted February 21, 2015 Share Posted February 21, 2015 You are half a grain too light on charge. 4.2 - 4.3 is about right for 124 with 320 I agree with Sarge. I just checked my test data for my 5" Pro. 4.0gr Up to 4.3gr of VVN320 is what I've used with several different 124gr bullets . if I were you I would get a chrono and start again increasing your powder charge .1 of a grain at a time. Link to comment Share on other sites More sharing options...
Pat Miles Posted February 21, 2015 Share Posted February 21, 2015 (edited) . if I were you I would get a chrono... +1 Edited February 21, 2015 by Pat Miles Link to comment Share on other sites More sharing options...
MGMorden Posted February 21, 2015 Share Posted February 21, 2015 (edited) Sounds like an echo, but get a chrono. N320 is a fast powder. It takes close to (or over) the published max to make minor PF and I know my M&P really doesn't cycle well until you get right at or above minor. Get a chrono (I recommend a ProChono Digital - last I checked you could find them for $100 or less at some places), and then load several rounds in 0.1gr increments. Shoot them going from lower to higher until you get a load that averages at around 130pf. That's your load. As to shortening the rounds - it will increase pressure (and increase velocity too) which may be enough "oomph" to work the action. Overall though you still want to get a chrono. Without one you're kinda reloading without really knowing what the ammo is doing. If you're picking medium burn rate powders that you just want to work then that's ok, but if you're using fast powders trying to make target loads I don't advise it. Edited February 21, 2015 by MGMorden Link to comment Share on other sites More sharing options...
Sarge Posted February 21, 2015 Share Posted February 21, 2015 As to shortening the rounds - it will increase pressure (and increase velocity too) With increased pressure does not always come increased velocity. Most powders will plateau with velocity output while the pressure continues to rise. Link to comment Share on other sites More sharing options...
CZ85Combat Posted February 21, 2015 Share Posted February 21, 2015 My last lot of N320 ran slower, had to go to 4.45gn to get the same results Link to comment Share on other sites More sharing options...
Red Ryder Posted February 21, 2015 Share Posted February 21, 2015 What they all said. Get a chrono. Your powder charge is too light. I use 4.2 gr N320 with a 124 FMJ OAL 1.135. Get a chrono. and, get a chrono. Link to comment Share on other sites More sharing options...
luketmv Posted March 2, 2015 Author Share Posted March 2, 2015 What they all said. Get a chrono. Your powder charge is too light. I use 4.2 gr N320 with a 124 FMJ OAL 1.135. Get a chrono. and, get a chrono. I was away and that is why the chrono wasnt an option, i will now try to chrono some slightly different loads however yesterday i had the chance to try out come rounds which i shortened to 28.4mm and they were working much better but still had a few stoppages, do you think at that length it is a safe load 4.0gr to test? Link to comment Share on other sites More sharing options...
Sarge Posted March 2, 2015 Share Posted March 2, 2015 Yes. Your loads are just too light. Load some at 4.2 as well and try them too Link to comment Share on other sites More sharing options...
Red Ryder Posted March 4, 2015 Share Posted March 4, 2015 Load 25 rounds at 4.3 grains also. Link to comment Share on other sites More sharing options...
dauntedfuture Posted March 4, 2015 Share Posted March 4, 2015 Everything said is good advice. I also suggest that you try some factory ammo. If it will not run then call S&W. If you call them with problems with reloads they will tell you its your ammo. There might be an issue with your extractor, but, like everyone else said, you most likely need to tip the powder can a little more. A chronograph is a very wise investment. It helps prevent pistol-bombs. Link to comment Share on other sites More sharing options...
racerba Posted March 4, 2015 Share Posted March 4, 2015 dry gun? Link to comment Share on other sites More sharing options...
luketmv Posted March 4, 2015 Author Share Posted March 4, 2015 vihtavuori states a maximum of of 4.0gr Link to comment Share on other sites More sharing options...
luketmv Posted March 4, 2015 Author Share Posted March 4, 2015 Everything said is good advice. I also suggest that you try some factory ammo. If it will not run then call S&W. If you call them with problems with reloads they will tell you its your ammo. There might be an issue with your extractor, but, like everyone else said, you most likely need to tip the powder can a little more. A chronograph is a very wise investment. It helps prevent pistol-bombs. def not the issue any other ammo flies through the gun, its definitely the load just cant understand since im almost at the maximum of the vihtavuori guides. im already increasing the pressure. Link to comment Share on other sites More sharing options...
al503 Posted March 4, 2015 Share Posted March 4, 2015 Everything said is good advice. I also suggest that you try some factory ammo. If it will not run then call S&W. If you call them with problems with reloads they will tell you its your ammo. There might be an issue with your extractor, but, like everyone else said, you most likely need to tip the powder can a little more. A chronograph is a very wise investment. It helps prevent pistol-bombs. def not the issue any other ammo flies through the gun, its definitely the load just cant understand since im almost at the maximum of the vihtavuori guides. im already increasing the pressure.If factory ammo is GTG, up the charge. You may have gotten a slow lot or your scale is slightly off, etc., or it might be a combination of those and other factors. The only way to confirm is with a chrono. Link to comment Share on other sites More sharing options...
Sarge Posted March 4, 2015 Share Posted March 4, 2015 Published loads are pretty conservative and only serve as a rough starting point for what we do Link to comment Share on other sites More sharing options...
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