Help with my 45 load please

chris in va · January 23, 2015, 02:23 PM

As most of us know pistol powder selection is on the thin side, and all I could find last year was a dusty 8# jug of 7625. It works fine for my 9mm but my LRN 45 is having a little trouble.

CZ 97b
5.5gr 7625 230gr LRN 750fps

I was experiencing some 'bolt over base' stoppages which I may have fixed with a different recoil spring. However, my loads are still acting weird.

Most fire and eject fine. On occasion I get one that feels lighter in recoil and the slide makes this two stage 'ker-chunk' return to battery like it didn't come back as far as the others. Some sort of debris comes out as well, doesn't appear to be unburned powder.

Also I keep getting flame coming out of the breech as if the powder is still burning upon extraction. Fired cases are fairly dirty.

Bottom line, is this powder too slow for heavier 45's, and should/can I up the charge a bit to help?

454PB · January 23, 2015, 02:31 PM

I have no experience with that powder, but all the symptoms you describe would make me stop using that recipe. Offhand, it's sounds like it's bordering on squib loads.

Maybe someone else has some load data to direct you towards with this powder.

243winxb · January 23, 2015, 03:07 PM

Hodgdon list 6.0gr with lead as maximum. The highest i see is 6.3 grs. I would go up 3/10 gr or more. On the burn charts, its not to slow, just a singe base powder with no nitroglycerin.

Wreck-n-Crew · January 23, 2015, 03:59 PM

Ive seen the same thing with WSF When my loads were too light. looked like little bits of paper from time to time. Not that the powders too slow but slower powders tend to burn better on the mid to upper loads. Got those black powders streaks going down the side of the brass?

berettaprofessor · January 24, 2015, 10:44 AM

I've loaded 7625 to 5.5 grains behind a 230 grain cast bullet. Average velocity out of a Taurus 1911 is 695.9fps (SD 29.3), a little light, so you can go up a smidge if it will help. I didn't have the issues you had with 5.5 grains, but its a different gun.

chris in va · January 24, 2015, 07:44 PM

Quote:

Got those black powders streaks going down the side of the brass?

Definitely, looks like it was fired by a blowback.

noylj · January 24, 2015, 09:04 PM

The ONLY data I have for SR7625 and 230gn lead bullets in .45 Auto is 6.2gn. 5.5gn would be a starting load. Personally, that powder is a bit slow for a low pressure round.
Soot on the outside of the case is a VERY good indication that, for the lot numbers of components used and the COL used, pressures are too low. Having the slide not go all the way back under recoil is another very good indication. Having the cases drop at your feet would be another.
IF this is some load you really want to use, you may need to load longer so the bullet ogive touches the lede/rifling. This will eliminate head space and probably increase accuracy. Otherwise, load some heavier loads and see how they work.

Gregory Gauvin · January 24, 2015, 09:23 PM

My book shows a minimum load of 5.8 grains of 7625 @ 778 ft/sec and a max of 7.5 @ 860 ft/sec at 1.270".

You're seeing flame out the ejection port because the brass is not sealing the chamber. You are below minimum charge level.

Last poster is correct about seating depth - despite it being rumored that OAL does not effect accuracy in pistol rounds, it does. A little bit. Seating depth plays with pressure - and so does powder charge, and charge weight surely plays with accuracy. So set your OAL to minimize inaccuracy by not having the bullet jump into the lands and load up a batch from min to max, if less than listed min. OAL approach max load cautiously and find what charge your gun likes best. LRN typically, depending on shoulder, will have to be loaded at 1.240" to 1.250". My gun won't plunk test at 1.250", so I slowly decreased OAL a thousandth or two until I got "plunk", and settled at 1.245". I know my bullet is right there at the rifling and doesn't have to jump. If you are a bit further out and the round chambers fine, but you don't hear "plunk" during the plunk test, you may get 1 or 2 out of 100 that don't go into battery.

.45 ACP is low pressure and is somewhat forgiving. A listed max load won't exceed 21,000 PSI, and then there's the extra 10% for +p category. And this is even if lead can get that high. I would imagine, a firearm made of steel, other than a Liberator pistol, would not blow apart at any less than 40,000 PSI. You would certainly rattle yourself and peen the frame before making a hand grenade - providing you stay within listed load and OAL. Bump that charge up.

Wreck-n-Crew · January 24, 2015, 09:29 PM

Quote:

Definitely, looks like it was fired by a blowback.

Yup, not enough pressure to get a good seal. Bump it up. The light feel is when you were getting more blow by and the heavier was when it sealed a little better. Like I say those slower burning powders like to be ran middle to max charges. Got to get them a little warmer for better burn. Really not that slow but along the lines of 231 or Unique.

9mmSkeeter · January 25, 2015, 04:34 PM

Wow. Shelve the .45 for awhile until you find some decent powder.

chris in va · January 25, 2015, 04:50 PM

Thanks a bunch guys, I'll try 5.8-5.9 and see if that 'fixes the glitch'.

As for my OAL, CZ's have notoriously short leades and coupled with the goofy Lee ogive profile I have to seat it at 1.20 before it passes the plunk test.

Gregory Gauvin · January 25, 2015, 06:04 PM

By reducing the OAL by .070", from my experience, you may approach max around 6.8 grains.

You'll probably find great performance at 6.2 grains.

January 23, 2015, 02:23 PM	#1
chris in va Senior Member Join Date: December 26, 2004 Location: Louisville KY Posts: 13,806	Help with my 45 load please As most of us know pistol powder selection is on the thin side, and all I could find last year was a dusty 8# jug of 7625. It works fine for my 9mm but my LRN 45 is having a little trouble. CZ 97b 5.5gr 7625 230gr LRN 750fps I was experiencing some 'bolt over base' stoppages which I may have fixed with a different recoil spring. However, my loads are still acting weird. Most fire and eject fine. On occasion I get one that feels lighter in recoil and the slide makes this two stage 'ker-chunk' return to battery like it didn't come back as far as the others. Some sort of debris comes out as well, doesn't appear to be unburned powder. Also I keep getting flame coming out of the breech as if the powder is still burning upon extraction. Fired cases are fairly dirty. Bottom line, is this powder too slow for heavier 45's, and should/can I up the charge a bit to help?

January 23, 2015, 03:07 PM	#3
243winxb Senior Member Join Date: July 26, 2011 Location: USA Posts: 1,730	45 acp 230 lead bullet IMR 7625 Hodgdon list 6.0gr with lead as maximum. The highest i see is 6.3 grs. I would go up 3/10 gr or more. On the burn charts, its not to slow, just a singe base powder with no nitroglycerin.

January 23, 2015, 03:59 PM	#4
Wreck-n-Crew Senior Member Join Date: March 8, 2013 Location: Ohio Posts: 1,820	Ive seen the same thing with WSF When my loads were too light. looked like little bits of paper from time to time. Not that the powders too slow but slower powders tend to burn better on the mid to upper loads. Got those black powders streaks going down the side of the brass? __________________ If you ever have to use a firearm, *you don't get to pick the scenario!*

January 24, 2015, 09:23 PM	#8
Gregory Gauvin Senior Member Join Date: March 6, 2009 Posts: 368	My book shows a minimum load of 5.8 grains of 7625 @ 778 ft/sec and a max of 7.5 @ 860 ft/sec at 1.270". You're seeing flame out the ejection port because the brass is not sealing the chamber. You are below minimum charge level. Last poster is correct about seating depth - despite it being rumored that OAL does not effect accuracy in pistol rounds, it does. A little bit. Seating depth plays with pressure - and so does powder charge, and charge weight surely plays with accuracy. So set your OAL to minimize inaccuracy by not having the bullet jump into the lands and load up a batch from min to max, if less than listed min. OAL approach max load cautiously and find what charge your gun likes best. LRN typically, depending on shoulder, will have to be loaded at 1.240" to 1.250". My gun won't plunk test at 1.250", so I slowly decreased OAL a thousandth or two until I got "plunk", and settled at 1.245". I know my bullet is right there at the rifling and doesn't have to jump. If you are a bit further out and the round chambers fine, but you don't hear "plunk" during the plunk test, you may get 1 or 2 out of 100 that don't go into battery. .45 ACP is low pressure and is somewhat forgiving. A listed max load won't exceed 21,000 PSI, and then there's the extra 10% for +p category. And this is even if lead can get that high. I would imagine, a firearm made of steel, other than a Liberator pistol, would not blow apart at any less than 40,000 PSI. You would certainly rattle yourself and peen the frame before making a hand grenade - providing you stay within listed load and OAL. Bump that charge up. Last edited by Gregory Gauvin; January 24, 2015 at 09:33 PM.

January 25, 2015, 04:34 PM	#10
9mmSkeeter Senior Member Join Date: December 28, 2014 Location: South Dakota Posts: 205	Wow. Shelve the .45 for awhile until you find some decent powder. __________________ I kind of like weaponry.

January 23, 2015, 02:31 PM	#2
454PB Senior Member Join Date: February 23, 2005 Location: Helena, Mt. Posts: 122	I have no experience with that powder, but all the symptoms you describe would make me stop using that recipe. Offhand, it's sounds like it's bordering on squib loads. Maybe someone else has some load data to direct you towards with this powder.

January 24, 2015, 10:44 AM	#5
berettaprofessor Senior Member Join Date: November 23, 2008 Posts: 1,091	I've loaded 7625 to 5.5 grains behind a 230 grain cast bullet. Average velocity out of a Taurus 1911 is 695.9fps (SD 29.3), a little light, so you can go up a smidge if it will help. I didn't have the issues you had with 5.5 grains, but its a different gun.

January 24, 2015, 09:04 PM	#7
noylj Senior Member Join Date: October 21, 2007 Location: Between CA and NM Posts: 858	The ONLY data I have for SR7625 and 230gn lead bullets in .45 Auto is 6.2gn. 5.5gn would be a starting load. Personally, that powder is a bit slow for a low pressure round. Soot on the outside of the case is a VERY good indication that, for the lot numbers of components used and the COL used, pressures are too low. Having the slide not go all the way back under recoil is another very good indication. Having the cases drop at your feet would be another. IF this is some load you really want to use, you may need to load longer so the bullet ogive touches the lede/rifling. This will eliminate head space and probably increase accuracy. Otherwise, load some heavier loads and see how they work.

January 25, 2015, 04:50 PM	#11
chris in va Senior Member Join Date: December 26, 2004 Location: Louisville KY Posts: 13,806	Thanks a bunch guys, I'll try 5.8-5.9 and see if that 'fixes the glitch'. As for my OAL, CZ's have notoriously short leades and coupled with the goofy Lee ogive profile I have to seat it at 1.20 before it passes the plunk test.

January 25, 2015, 06:04 PM	#12
Gregory Gauvin Senior Member Join Date: March 6, 2009 Posts: 368	By reducing the OAL by .070", from my experience, you may approach max around 6.8 grains. You'll probably find great performance at 6.2 grains.