Bullseye powder confusion, 45acp

[chris in va]

I'm loading 228gr LRN and using Bullseye. My Lyman manual shows 5.0gr as a max charge, 815fps at 14,400 cup.

Other powders listed have the same bullet at 964fps and 17,300cup.

Any reason why 5.0 is a max charge with such a low pressure?

 

[243winxb]

Burning Rate of Powders

The faster burning rate of bullseye produces more pressure, quicker. The higher pressure would be +P loads & may work best with jacketed bullets.

 

[Unclenick]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

5.0 grains of Bullseye is an old standard hardball loading from about WWI, so it could be historical bias. They may have seen some other kind of pressure sign with that combination and just decided not to push it any higher. The old copper crusher system has poor absolute accuracy and can be off by 25%, and that could account for it or at least their fear of it.

I note that Hornady's book takes a swaged 230 grain RN bullet up to 5.7 grains of Bullseye and hits 900 fps. Speer stops their swaged LRN at 5.0 grains, though, same as Lyman.

So chances are that you can work up from 4.5 to 5.0 grains and then creep up from there towards Hornady's number. Just do it a tenth of a grain at a time and keep an eye peeled for pressure signs. If you see one, back down 5% and stop. Some powders can give you pressure spikes with some bullets. If you feel you really need more velocity, try a slower powder like Power Pistol.

 

[chris in va]

Thanks, I hardly ever load my LRN warm but was a little confused by the numbers. I didn't realize Bullseye was such a fast powder...probably not the best choice for lead.

 

[m&p45acp10+1]

Bull's Eye is all that I use in .45 ACP with cast lead. It does all that I need, and gives me the ability to load ammo that is way more accuratet than I will ever be able to milk it for.

 

[chris in va]

What load have you found to be the most accurate in your M&P? I have a CZ 97b, so probably need to start at 4.5gr.

 

[m&p45acp10+1]

I shoot a 200 grain home cast lead semi wad cutter. I use 4.2 to 4.4 grains of BE with any primer I can get. They shoot better than I will ever be able to milk them for.

 

[Shootest]

I load cast 228g RN (Lee mould) with 4.5g Bullseye. It is the best load I have found in my stainless Goldcup.

 

[Slamfire]

I look at the load data in manuals and I go out and test over a chronograph. As you can see, I started at 3.5 grains Bullseye with a 230 L bullet and worked my way up, actually above the data you see, till my bullets were clocking around 800 fps. This is the velocity specified in the original 1910 era specifications for the then new, 45 ACP round. The specifications called for 5.0 grains of Bullseye with a 230 FMJ.

For me, with a 230 LRN, 4.5 grains is where I want to be at. With a 230 FMJ 5.0 grains is exactly the load to use. I think it is totally amazing that 113 years ago that this cartridge was using the same powder and charge and was giving the same results.

Look at how fast the velocity jumps with half grain increments. It does not take much powder to be at too high of pressures.

If you can get same velocity with less pressure, that is a good thing.

[SIZE="3"]Kimber Custom Classic M1911

230 LFN Bull-X [B]3.5 grs Bullseye[/B] Mixed Brass WLP OAL 1.20"taper crimp .469"

8-Jan-06	T = 61 °F

Ave Vel=643.6				
Std Dev =14.07			
ES =	63.63			
High = 679.9		 		
Low =	616.3				
N =	32				 

shot a little high Pistol cycled each shot



230 LFN Bull-X 4[B].0 grs Bullseye [/B]Mixed Brass WLP OAL 1.20" taper crimp .469"

8-Jan-06	T = 61 °F

Ave Vel=715.9				
Std Dev =11.45			
ES =	48.32		 		
High = 742.9		 		
Low =	694.8				
N =	32				 
shot a little low

					
230 gr LRN [B]4.0 grs Bullseye [/B]Mixed Brass WLP OAL 1.250"	 taper crimp .469"

29-Jan-06 T = 68  °F
	
Ave Vel=698.8				
Std Dev =10.19		
ES =	36.33		 		
High = 713.5				
Low =	677.1				
N =	28
				 
Little High =  put close point of aim V. Accurate
		
230 gr LRN  [B]4.5 grs Bullseye [/B]Mixed Brass WLP OAL 1.250" taper crimp .469"
	
21-Jun-06 T = 97  °F
	
	
Ave Vel=805.2		
Std Dev =11.4		
ES=54.08		
High=836.9		 
Low=782.8		 
N =32

230 gr FMJ (R-P) [B]5.0 grs Bullseye [/B]99' & 2005 mixed lot Mixed Brass WLP (brass)  OAL 1.265" taper crimp .469"

12-Dec-11	 T= 53  °F
					
Ave Vel=793.5				
Std Dev =18.92				
ES =	61.99				
High = 	817.4				
Low =	755.4				
N =	16				

[IMG]http://img.photobucket.com/albums/v479/SlamFire/Pistols%20various/KimberRightSideDSCN0753.jpg[/IMG][/SIZE]

 

[Unclenick]

To Slamfire's point on rate of increase in velocity per unit charge weight as the load gets warmer, the fact some powder measures don't handle flake powders as precisely as some others, with errors of a third grain being common and half a grain not unheard of, it may be that one reason for the 5.0 grain limit by one load manual while another goes higher has to do with leaving some headroom for charge dispensing errors.