Caffeinated Posted September 6, 2014 Share Posted September 6, 2014 Hitting considerably lower velocities than expected through 3 separate chronographs. 4.1 grains VV N320 1.14 OAL 124gr X-treme plated making around 121 power factor through a CZ Sp01. Also ran these through some friends guns and still failed to make 125 PF (don't remember exact numbers). Thought that perhaps my RCBS 505 balance beam scale was off so I borrowed a Lock N Load Bench scale. Both scales are showing consistent numbers. The press (Lock N Load) is throwing consistently for single and groups of 10 charges. With shooting the other guns and friends rounds through my gun, I feel the problem is definitely in my rounds. Is is possible I have a slow batch of powder? Any other suggestions? Link to comment Share on other sites More sharing options...
Torogi Posted September 6, 2014 Share Posted September 6, 2014 I looked in my old notes and I was at 4.4gr N320, 1.120" OAL. 128PF. CZ Aussie shadow. Link to comment Share on other sites More sharing options...
ChuckS Posted September 6, 2014 Share Posted September 6, 2014 I got just a hair over 125 with 4.1 gr under a Frontier 124 plated bullet loaded out 1.156 shot though an SP-01. I think 4.2 took it to around 130 (can't find chrono records, it was in 2008). Angus mentioned that he shot 4.2 under a 124 JHP. Later, Chuck Link to comment Share on other sites More sharing options...
Trunkmnky Posted September 7, 2014 Share Posted September 7, 2014 A friend of mine use's 3.4 on a xtreme 147 with a AOL 1.155 - pf of 129-130 Link to comment Share on other sites More sharing options...
CZinSC Posted September 7, 2014 Share Posted September 7, 2014 i was using 4.3gn of N320 to get to 130-133 in my SP01, 1.150 OAL. Montana Gold 124 FMJ. Link to comment Share on other sites More sharing options...
bowenbuilt Posted September 7, 2014 Share Posted September 7, 2014 Just bump it up a tenth or 2 until it does. I have found some lots to be just a feather slower burning than others and had to add a tenth or maybe two 2 tenths to keep me at a 130PF. Your barrel might be just a touch slow also but adding a tiny bit to get to minor or slightly above should not cause you a problem. Just pay attention to the pressure signs but you should be fine. Link to comment Share on other sites More sharing options...
DougCarden Posted September 7, 2014 Share Posted September 7, 2014 320 is notorious for variations on lots. A lot of people I know have gotten burnt not chronoing and just running their normal load. Bump it up.... DougC Link to comment Share on other sites More sharing options...
CZinSC Posted September 7, 2014 Share Posted September 7, 2014 And contrary to what a lot of people will tell you ( most with no data to support their opinions ) N320 is slightly temp sensitive. You will lose 10-20 fps when the temp gets down in the 40 degree range. If you're well within the PF, it shouldn't effect you, but if you like to play things close, you're looking for trouble. Link to comment Share on other sites More sharing options...
huskerlrrp Posted September 7, 2014 Share Posted September 7, 2014 For what it is worth, I use 4.3gr of VV320 and a 124gr Montana Gold Hollow Point at 1.1 and I'm 137-138 PF in my two SP01 Shadow Customs. With 4.2gr I'm at 133. These have been done around 80-85F in a chrono within a box. What is the bullet OD? Maybe they are sized a little small? Link to comment Share on other sites More sharing options...
DRichardson Posted September 7, 2014 Share Posted September 7, 2014 Is it a relatively new lot of powder. I got a few jugs of n320 recently and I am over .4 grains more than what some others have told me would make major in 40. The recent one out May be a slow lot. Link to comment Share on other sites More sharing options...
hops Posted September 7, 2014 Share Posted September 7, 2014 I use 4.0 gr of N320 with a 125gr Ibejihead out of a cz and I get 131pf. But then again a coated bullet shoots much faster than a jacketed bullet, at least in my tests. Link to comment Share on other sites More sharing options...
Caffeinated Posted September 7, 2014 Author Share Posted September 7, 2014 This was new 4lb jug that I opened but it had the same manufacturing date as the last 4lb jug - August 2013. This is the first I've chrono'ed the X-Treme plated bullets and was afraid of taking the powder charge over the listed specs. In my limited research of N320 I haven't seen too many folks having problems hitting PF. Been using Bayou 124 prior and had no issue making power factor. 4.0 grains took me around 129 PF at Area 6. Bumped it up to 4.1 for a little more insurance. The Bayou Bullets have a diameter of .356 and the X-Treme measure .354. Perhaps that is a part of the problem? Thanks for all the input! Link to comment Share on other sites More sharing options...
mike4045 Posted September 7, 2014 Share Posted September 7, 2014 3.2grs with Precision black bullets and I am getting 134 pf out of a 5" STI. Was at 3.4 for a while for 141 pf. Link to comment Share on other sites More sharing options...
CZinSC Posted September 7, 2014 Share Posted September 7, 2014 Been using Bayou 124 prior and had no issue making power factor. 4.0 grains took me around 129 PF at Area 6. Bumped it up to 4.1 for a little more insurance. The Bayou Bullets have a diameter of .356 and the X-Treme measure .354. Perhaps that is a part of the problem? Thanks for all the input! There's your answer. If you were using 4.1 for the Bayous, you'll need to go up further than that for Xtremes. Coated will require less powder than Plated, which require less than jacketed. Bump up the charge .2 and should be GTG. Link to comment Share on other sites More sharing options...
BF1080 Posted September 7, 2014 Share Posted September 7, 2014 I just opened a new jug of N320 manufactured on 05/15/14. Here is what I am getting with MG 124 round nose. Crimp .375-.377..CZ Accu-Shadow 9mm. 4.3 g 1.130 ovl 122 PF 4.3 g 1.120 ovl 125 PF I just started using N320, but these results seem a little low compared to other posts I have seen. I want to be at least around 130 PF. Back to the drawing board. Link to comment Share on other sites More sharing options...
CZinSC Posted September 7, 2014 Share Posted September 7, 2014 I just opened a new jug of N320 manufactured on 05/15/14. Here is what I am getting with MG 124 round nose. Crimp .375-.377..CZ Accu-Shadow 9mm. 4.3 g 1.130 ovl 122 PF 4.3 g 1.120 ovl 125 PF I just started using N320, but these results seem a little low compared to other posts I have seen. I want to be at least around 130 PF. Back to the drawing board. Wow! I was using 4.3gn at 1.150 with MG 124FMJ and was getting 130 comfortably out of my SP01. They've definitely changed the formula. Link to comment Share on other sites More sharing options...
Magsz Posted September 8, 2014 Share Posted September 8, 2014 I too was using 4.3 or 4.2 depending on bullet type. With my extreme 124 grain HP's i was using 4.3 and getting a consistent 130k power factor. Any chance you're over crimping and under sizing the bullets? Link to comment Share on other sites More sharing options...
Red Ryder Posted September 9, 2014 Share Posted September 9, 2014 Wow. I have used 8 or 9 jugs of N320 so far and never seen any lot to lot variation, or temp sensativity. All were different lot numbers. My go to load has chronoed the same for 4 years now at all the major matches. But I guess I will keep chroning each new jug. Got 6 four pounders. Link to comment Share on other sites More sharing options...
BF1080 Posted September 10, 2014 Share Posted September 10, 2014 (edited) Magsz, you may have hit the nail on the head. There is a slight bow inward in the middle case. Is this an example of over crimping? Edited September 10, 2014 by BF1080 Link to comment Share on other sites More sharing options...
Magsz Posted September 10, 2014 Share Posted September 10, 2014 No sir. The bottle neck appearance is a prime example of proper neck tension. It is NOT a bad thing. If your rounds look like a coke bottle all is well in the world. Pull some rounds and see if there are any indents in the copper plating. IF there are, you are under sizing the bullets which can result in lower velocity numbers. Link to comment Share on other sites More sharing options...
BF1080 Posted September 10, 2014 Share Posted September 10, 2014 Pulled a few rounds...no indentions. Link to comment Share on other sites More sharing options...
BeerBaron Posted September 10, 2014 Share Posted September 10, 2014 This was new 4lb jug that I opened but it had the same manufacturing date as the last 4lb jug - August 2013. This is the first I've chrono'ed the X-Treme plated bullets and was afraid of taking the powder charge over the listed specs. In my limited research of N320 I haven't seen too many folks having problems hitting PF. Been using Bayou 124 prior and had no issue making power factor. 4.0 grains took me around 129 PF at Area 6. Bumped it up to 4.1 for a little more insurance. The Bayou Bullets have a diameter of .356 and the X-Treme measure .354. Perhaps that is a part of the problem? Thanks for all the input! it's the bullets. I know a few guys here with shadows who recently tried them and found also they are sized too small for a CZ barrel. slug your barrel but in my experience the CZ shadow barrels like a pill sized .356 or .3565. the xtreme's at .354 are too small. a few guys also had trouble getting any decent sized group out of the xtremes. they seem to run great in a glock though. Link to comment Share on other sites More sharing options...
huskerlrrp Posted September 10, 2014 Share Posted September 10, 2014 I can mail you some blue bullets and Montana Gold to try out as well. Link to comment Share on other sites More sharing options...
RePete Posted September 11, 2014 Share Posted September 11, 2014 I too have found that the published data for N320 is low. I loaded 9mm with 147gr Frontiers and the data said that I should get a PF of 138, it came in at 132. I've the same results with 38 Special and 158gr Frontiers. Link to comment Share on other sites More sharing options...
leadhammer Posted September 12, 2014 Share Posted September 12, 2014 N320 4.1 131PF With zeros loaded at 1.080" 3.8" gave me 125PF Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now