Can I bump OAL and charge up at the same time?

[cjsoccer3]

My starting load of 9mm was

.754-.744 case length
1.075-1.09 oal
115 gr hp xtp
5.9 of power pistol

I shot about 175 rounds of my first handload batch ever with 2 failures to extract in my g43. These failures seemed like shortstrokes - as the case fully extracted, but didn't fully clear itself out of the gun before the slide came back down.

Both ended up with a case free floating pinched on its ends holding the action open. Both had nearly cleared the gun.

I want to bump the charge to 6.1 grains and have a length in the 1.085-1.10 range. Bringing the pressure up slightly but also the length. I'm just curious if the increase in length would negate the slight increase in power charge and anyone here has experienced this 'balancing act' ?

Of course everything will still have to clear the 'plunk" test. I'm just looking to get the length off the minimums while getting some more reliable cycling in the 2nd batch.

Thank you

 

[ShootistPRS]

My data shows a maximum load of 6.5 grains of power pistol with a 115 gr Hornady xtp/HP with an overall length of 1.09" at near maximum pressures.
I am quoting the Lyman 49th edition manual.
I would approach that load incrementally but your listed load is the listed starting load in the Lyman manual so you may have properly diagnosed your failure to eject problem.

 

[Slamfire]

You are getting close to a maximum load but if you are stove piping, I would bump up the load no more than one half grain. Overall length seems to be important with that bullet, I have not twiddled with the OAL to get it to feed in my Bulleye 9mm.

Increasing the OAL will decrease pressure, but by how much, I don't have a means to estimate. I would say the little increase in OAL you want won't make much of a pressure difference. Just bump up the charge until you get reliable feed and extraction.

I don't know what pistol type you are using, but if you have a M1911, you can buy lighter recoil springs which allow the pistol to function with lighter loads. However, heavy loads will beat up a pistol with the lighter recoil springs.

[SIZE="3"]M92 FS Beretta Bar Sto Barrel		
					
115 Full Metal Case Master Factory Ammo 			
	20-Jun-09	T = 90 °F			
					
Ave Vel =	1180	 			
Std Dev =	10.19				
ES =	33.27				
High =1197				
Low =1167				
N =	8				
					
					
115 gr RMR Plated RN 6.0 grs Power Pistol lot 3-16 WSP OAL 1.150"  Mag Length
15-Sep-16	T = 94 °F		crimp 0.375"		
					
Ave Vel =	1175				
Std Dev =	22				
ES =	81				
Low =1130				
High =1211				
N =	20				
					
Very accurate					
					
					
115 gr XTP Hornady HP 0.355" 6.0 grs Power Pistol lot 3-16 WSP OAL 1.10"
15-Sep-16	T = 95 °F		crimp 0.375"		
					
Ave Vel =1161				 
Std Dev =54				 
ES =	197				 
Low =1111				 
High =1308				 
N =	11				 
					
Very accurate but rounds would not feed, jammed on barrel ramp. 	
One seated very deep produced 1247 fps, not included in data	
					
					
					
115 gr FMJ Hornady 0.355" 6.0 grs Power Pistol lot 3-16 WSP OAL 1.15"
15-Sep-16	T = 95 °F		crimp 0.375"		
					
Ave Vel =1187			 	 
Std Dev =16			 	 
ES =	58			 	 
Low =1157			 	 
High =1215			 	 
N =	9	 			
					
v accurate. 	[/SIZE]

 

[random guy]

I agree that your current load is on the mild side, likely contributing to your function problem.

No slight at all on any one data source but it is always good to consult multiple sources for comparison. My favorites are the powder manufacturers' sites and manuals.

Most manuals list a COAL of 1.12" to 1.125. I'd work my way there simply to make their data more applicable to my combination if nothing else. After verifying that your pistol will accept that length of course.

Even your next proposed charge level is pretty conservative so you would probably be fine increasing COAL at the same time. In the interest of caution though, you could load the first 5 or so rounds at the new COAL with your current charge and the rest of your batch at the increased charge. Most likely, the longer COAL will decrease pressure if anything as you project, which is safe and good.

No reason your entire batch has to be identical as long as you can keep changes organized and separate. I shot three different charges today out of one box of ammo. Can't say the day went perfectly (Chrono problems, I think) but I did learn more than I would have with only one load to try.

 

[jetinteriorguy]

Always one change at a time and then work up the load. Here is the approach I use, first take a sized, deprimed, empty case and seat the bullet you plan on using so it's way long. Then plunk, and keep seating deeper until it passes the plunk test in the gun you plan on shooting it in, or whichever of all your guns is the most sensitive to OAL of a loaded round. Then I screw in my seating stem 1/2 turn for a little extra leeway and apply a heavy crimp after screwing the seating stem out so as not to seat the bullet deeper while crimping. By doing this you've established the maximum available space to fill with powder before starting to compress the powder thereby avoiding an overfilled case creating a high pressure situation. Then just work up your load as normal from a recommended starting load while watching case fill as you approach the upper limit of a recommended load. It may just be you can't go to a max recommended load due to the limitations on OAL imposed by your guns chambers. One other thing that has helped me is to also use an undersize sizing die with 9mm since all I use is range brass and often times they are shot from guns with generous chamber dimensions and need a little extra sizing to make my loads more dependable, best thing I ever did for reliability in a gun with a tight chamber.