Carpasteis Posted January 5, 2015 Share Posted January 5, 2015 My loads 9mm major loads are starting to leave casings with flattened primers. I'm barely making major with the loads so I was wondering if any one had any suggestions for keeping major and not blowing up a gun and keeping pressure down. I'm loading 7.2g of autocomp under a 124g bullet and at an OAL of 1.165 that makes a PF of 168. Magtech small pistol primers. Link to comment Share on other sites More sharing options...
shooter.860 Posted January 5, 2015 Share Posted January 5, 2015 Interesting I'm using a 124 bullet with 7.1 grains of autocomp at 1.14 OAL and make a 171 No signs of pressure, same load for open Glock and STI Are you sure of your charge weight ? Link to comment Share on other sites More sharing options...
cnote Posted January 5, 2015 Share Posted January 5, 2015 That must be a really slow barrel Link to comment Share on other sites More sharing options...
Whitefish Posted January 5, 2015 Share Posted January 5, 2015 I am using 7.2 grains of Autocomp with a 124 grain MG JHP at an OAL of 1.170 with Winchester small pistol magnum primers - no pressure signs on either cases or primers. The gun is a Dawson stroker with a 4.75 inch barrel, 2 small popple holes and a Dawson comp with 4 big chambers and 2 side ports. You could try extending the oal slightly to 1.170 which might make a pressure difference without significantly impacting velocity or you could try another brand of primers like Winchester small pistol to see if that makes a difference in the pressure signs. Link to comment Share on other sites More sharing options...
kneelingatlas Posted January 5, 2015 Share Posted January 5, 2015 What kind of gun? How long is the barrel? Holes? Link to comment Share on other sites More sharing options...
al503 Posted January 5, 2015 Share Posted January 5, 2015 If you're using magazines without a spacer and your chamber has enough freebore, go for a longer OAL. Depending on the 124/125 grain bullet I use for 9 major, I can load out to 1.22" before I see any set back when chambering a round. I back it down to 1.2" and call it good. The longer you go, the lower the initial pressure spike will be especially with a powder on the faster side like AC. Link to comment Share on other sites More sharing options...
Sarge Posted January 5, 2015 Share Posted January 5, 2015 I had a slow barrel initially (Briley). Took a lot more powder to get up to speed. Throw MG bullets on top which are also slow and you can dump quite a bit of powder in there. Still, I never have any pressure signs with WAC. I was running 7.4 WAC at 1.168 with MG 121's. I currently run 7.8 grains with a 115. But I use small rifle primers. No flattening. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted January 5, 2015 Share Posted January 5, 2015 My 9mm major loads have flattened primers with 7.2g of WAC, a 124g bullet at 1.165 & 168 PF. Can you shoot us some photos of the primers? My guess is that either : 1. primers are acceptable, or 2. you don't have an accurate measure of either the powder charge, bullet weight or PF. Also possible that you're getting some bullet set back - can you push the bullets into the case if you press them against a wooden block as hard as you can? Easy to make one of these five mistakes, if you're new to MAJOR 9mm. Link to comment Share on other sites More sharing options...
Steve RA Posted January 5, 2015 Share Posted January 5, 2015 Use small rifle primers ! Link to comment Share on other sites More sharing options...
Shmella Posted January 5, 2015 Share Posted January 5, 2015 why would using small rifle primers solve anything? wouldnt the pressure still be there but no sign because of the harder primer? Will a soft primer break and that is the concern with flattening out of primers? Link to comment Share on other sites More sharing options...
Sarge Posted January 5, 2015 Share Posted January 5, 2015 why would using small rifle primers solve anything? wouldnt the pressure still be there but no sign because of the harder primer? Will a soft primer break and that is the concern with flattening out of primers? Correct. Softer pistol primers will pierce, flow, etc under extreme pressures. Link to comment Share on other sites More sharing options...
Shmella Posted January 5, 2015 Share Posted January 5, 2015 why would using small rifle primers solve anything? wouldnt the pressure still be there but no sign because of the harder primer? Will a soft primer break and that is the concern with flattening out of primers? Correct. Softer pistol primers will pierce, flow, etc under extreme pressures. Good to know. I picked up a bunch of federal primers to have for my revolver and am down to only those right now. I'll be looking for winchester again and refrain from using these for any major loads. Link to comment Share on other sites More sharing options...
Steve RA Posted January 5, 2015 Share Posted January 5, 2015 Try Tula KVB-223 primers. Link to comment Share on other sites More sharing options...
OHIOAFC Posted January 5, 2015 Share Posted January 5, 2015 124g Berry's PHB 9mm bullet 7.0 gr Autocomp 1.148 OAL range Winchester SR Primer 124g Berry's PHB 9mm bullet 8.3 gr Alliant Power Pistol 1.148 OAL range Winchester SR Primer 124g Montana Gold .355 JHP 6.8 gr Autocomp 1.148 OAL Winchester SR Primer 124g Montana Gold .355 JHP 7.6 gr Alliant Power Pistol 1.148 OAL Winchester SR Primer Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
BoyGlock Posted January 6, 2015 Share Posted January 6, 2015 (edited) why would using small rifle primers solve anything? wouldnt the pressure still be there but no sign because of the harder primer? Will a soft primer break and that is the concern with flattening out of primers?Correct. Softer pistol primers will pierce, flow, etc under extreme pressures. Good to know. I picked up a bunch of federal primers to have for my revolver and am down to only those right now. I'll be looking for winchester again and refrain from using these for any major loads. Agree, hard primers just hide the high pressure and donot solve the problem. Edited January 6, 2015 by BoyGlock Link to comment Share on other sites More sharing options...
Sarge Posted January 6, 2015 Share Posted January 6, 2015 Hard primers will keep the possibility of primer debris locking up your firing pin etc. There is no solving high pressure in 9MAJOR. You can only try to control it. Link to comment Share on other sites More sharing options...
Shmella Posted January 6, 2015 Share Posted January 6, 2015 Hard primers will keep the possibility of primer debris locking up your firing pin etc. There is no solving high pressure in 9MAJOR. You can only try to control it. The primer mystery is finally making sense to me after wondering what the deal was with looking for pressure signs when it seems all 9major is high pressure. thanks for all the information. Link to comment Share on other sites More sharing options...
SilverBolt Posted January 6, 2015 Share Posted January 6, 2015 Am I missing something? The general consensus is to us a harder primer if you are showing signs of over pressure suck as primer flattening. Is that not just masking/concealing the issue? The pressure remains the same but the primer no longer exhibits the warning signs. Thought #2, does a softer primer (Federal) actually create a better seal under high pressure applications? I am new to 9-Major and experimenting with several powders and charges. I have seen some flat primers signs using Federal Match primers. Link to comment Share on other sites More sharing options...
Steve RA Posted January 6, 2015 Share Posted January 6, 2015 Federal primers are the softest out there ! There is no problem with high pressure if you are going to make Major power factor, you have to have it. Any problem would be with more pressure than needed to make Major. This is why you work up loads from below with a chronograph. Link to comment Share on other sites More sharing options...
SilverBolt Posted January 6, 2015 Share Posted January 6, 2015 Steve, That is exactly what I am doing. I start with confirmed load data but back it off a full grain as my start point. I load 15 rounds at .2-grain increments. I color code each load with a different color so the spent brass can easily be identified. All rounds go through the chrono. My chrono is set at 10ft and a USPSA target set at 15 yards. The target gives me an initial indication on accuracy as well as tracking how much the dot is moving. It seems to be a very fine line between enough gas to work the comp and over pressure. I realize that the Federal primers are the softest but in my mind that is safer when developing a new load. I would rather see signs early because it was a soft primer than too late with a hard/rifle primer. After about 2k rounds of various powders and charges I have not had any primer blow outs or piercing with the firing pin. I have seen some very flat primers. Link to comment Share on other sites More sharing options...
Steve RA Posted January 6, 2015 Share Posted January 6, 2015 Since you realize that the Fed primers are very soft, relatively speaking, the fact that they flatten isn't that big a problem. Of all the loads, did you find some that: A - make Major with a reasonable safety factor toward not sliding into Minor ?? B - provide the desired amount of accuracy you desire ?? Link to comment Share on other sites More sharing options...
BeerBaron Posted January 7, 2015 Share Posted January 7, 2015 I get some flattening of federal SPP in my 9mm MINOR loads for my CZ shadow. that's 3.6gn of AP50N (similar to N320) behind a 135gn RN CMJ shooting about 132PF. so i'm not surprised they are flattening out in 9mm major loads. as others mentioned what you want to avoid is bad primer flow and beyond that pierced primers. small rifle primers can help with this as they do have thicker cups. I use fed small rifle in my major loads (38 super though). Link to comment Share on other sites More sharing options...
kneelingatlas Posted January 7, 2015 Share Posted January 7, 2015 Richard, fast powders under heavy bullets at minor PF are just as susceptible to over pressure as slow powders at major PF. Some of the flattest primers I've seen are on super soft 40 loads. I use SPP with my major loads (as high as 181 with 9mm) with no pierced primers or flow. Link to comment Share on other sites More sharing options...
Sarge Posted January 7, 2015 Share Posted January 7, 2015 Some of the flattest primers I've seen are on super soft 40 loads. Amen! Only the ones I found were 9mm. Since I MD and get to know most everybody who shoots locally I know nobody shoots an Open glock yet I have found glock fired brass with primers so flat the base was perfectly flat all the way across. This tells me there are folks reloading who really need to read a manual or these forums! Link to comment Share on other sites More sharing options...
BeerBaron Posted January 9, 2015 Share Posted January 9, 2015 Richard, fast powders under heavy bullets at minor PF are just as susceptible to over pressure as slow powders at major PF. Some of the flattest primers I've seen are on super soft 40 loads. I use SPP with my major loads (as high as 181 with 9mm) with no pierced primers or flow. For sure. Understand that , but these are 'only' 135gn and ap50 is not as fast as say a clays or n310 etc. my point was only that federals are a fair bit softer than others and will flatten earlier that other brands. I've used the fed spp and srp in my super major loads and they are all fine at over 170pf. Link to comment Share on other sites More sharing options...
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