What happens if I switch primers?

[bachekermooni]

For my Kimber in .308 Win, I am using FC brass, Win primers, AA 2230 powder and Hornady 150 gr IB pills. Run out of Win primers and want to switch to CCI. Should I expect a large shift in POI? Large enough to matter for deer sized game? It is already zeroed in at 200 yards and I really do not have time to go back to the range. Plus, it is going to be a cold rainy weekend.
Thanks.

 

[556by45guy]

If you change a component the safe practice is to work up your load again. But they are your body parts to do with as you wish.

 

[Sam1911]

Most probably you'll be able to detect no change in practical accuracy.

A benchrest shooter measuring groups with a micrometer probably would.

Hunting conditions and distances? No.

Of course it isn't a very good idea to take a gun out for an important task with a load you haven't tried. But you aren't likely to be able to tell the difference.

Switching from Win primers to CCI standard rifle primers isn't going to blow your gun up.

 

[FROGO207]

I go back and forth with types and brands of primers as availability presents itself. Practically I see very little difference between them BUT I am not near or at the top end of the data either. Magnum primers are a bit more reactive (hotter) in my reloads in cold weather if I choose to use them however.

 

[buck460XVR]

If you change a component the safe practice is to work up your load again. But they are your body parts to do with as you wish.

Years ago when I first started reloading I did that. All those workups taught me one thing. Difference between brands of the SAME SIZE PRIMER made very little if any change in velocities. No more than the difference from one reloading session to another. Now I don't push the envelope nor do I even load max loads for most applications. If I did, I may be more concerned.

 

[556by45guy]

Years ago when I first started reloading I did that. All those workups taught me one thing. Difference between brands of the SAME SIZE PRIMER made very little if any change in velocities. No more than the difference from one reloading session to another. Now I don't push the envelope nor do I even load max loads for most applications. If I did, I may be more concerned.

I said it is the safe practice to do, I didn't say it was the only way to do it.

Likely he'll be fine, especially if he isn't close to max, but I value my eyeballs and all of my body parts more than guessing at a combination of components I haven't tried. I just read a thread here where a guy got complacent and found a small case inside a larger case that he had reloaded and shot. Fortunately nothing bad happened......this time. All it takes is one time and eyeballs don't grow back like a lizards tail, LOL. I am never in a rush to reload nor will I get complacent while reloading. That's the way I do it but it doesn't mean everyone has to do it that way. They are your body parts to do with as you wish.

 

[kerreckt]

I go back and forth between Winchester primers and CCI primers and have never noticed anything of significance. I believe all your body parts will be just fine.

 

[dagger dog]

The opposing fifth digit rule:

Drop back 10% and work up every time you change a loading component, especially with near maximum loads!

Does every one do it ? NO !

Would I do it ?

Probably not with just a primer change in the same magnitude (standard to standard VS standard to magnum).

But would I suggest someone else do it ? DEFINITLY NOT !

 

[Walkalong]

Some primers will give different velocities and sometimes different accuracy, but, as posted, it generally isn't a big different and for middle of the road loads for hunting or plinking or casual target ammo many people switch between primers as needed.

A serious target load? Yea, recheck everything.

 

[Capt. Ct.]

I have used CCI, Remington and Winchester with noticing any difference.

 

[ArchAngelCD]

Years ago I used only CCI primers but since 2008 I have been using both Win and CCI mostly. I switch back and forth between CCI and Win primers all the time and see no change in accuracy in handgun ammo and no change in POI with rifle ammo.

Like said above, if you are only changing the name brand of the primer and they are the same in all other ways the dead Deer will not know the difference... I can only give you first hand information on CCI and Win primers though since those are the ones I use most. I have used 600 Remington 7 1/2 primers in .223 ammo loaded for a semi-auto and didn't see any accuracy changes from the CCI #41 primers I was using before that.

 

[bachekermooni]

Just as an FYI, AA lists 45.2 gr max for Hornady SST and 45.3 gr max for Hornady BT-FMJ (both 150 gr pills). I used 44.5 gr with Hornady 150 gr IB.

I still have 5 shells left. So, if I shoot straight, I will have four when I get back home. I just want to take another 15 shells along - just in case.

 

[rfwobbly]

What happens if I switch primers?

When they disobey, switch them on the back of the calves. Then send them to bed with no supper.

They'll cry for awhile, but be 'back with the program' in the morning.

 

[Slamfire]

Changing primers brands won’t make much of a difference for low to mid range loads. However, if you are shooting maximum loads, not only will a change of primer brand make a difference, so will primer lot. And, the same is true for changing cases and powder lot. I have ruined LC 308 cases using maximum loads developed in light Federal cases. The LC cases average about 20 grains heavier and I changed from Federal primers to CCI #34’s, I had the primer pockets expand so much, on one firing, that the cases were unusable.

However, for loads that probably don’t exceed 45,000 pounds, which is the old match load for Garands, I did find velocity differences between primer brands, but since the pressures were so low, I did not have pressure problems.

I ran a test to compare velocity differences between primer brands (and accuracy) with my standard 30-06 match load of 168 SMK 47.0 grs IMR 4895. I am of the opinion that higher pressures move bullets faster. Therefore faster loads, where the only difference is the primer, are higher pressure due to the primer. However, these results could all be scrambled if I used different lots of the same primers. And that is because primer cake is a mixture of ingredients, all + - by weight, the purity of the ingredients vary, and the cake is mixed by hand. So each lot will be different.

I have lots of 174 FMJBT's, five gallon buckets of LC match brass, I used those and all the primers I have rolling around the reloading room. Any load I have developed with 174’s is perfectly safe with 168 match bullets.

I do not recommend the use of Federals in Garands, Federals are the most slamfiring primers around, so I am not publishing any federal primer data in my Garand, because someone may think it might be an endorsement of use.

I used the great old WLR nickel plated primers. These were made prior to 1999. Winchester changed their primers in 1999 to make them "more" sensitive and changed the primer color to brass. These brass Winchester primers have thinner cups than the older version I do not recommend their use in Garands/M1a's. I also do not recommend the use of brass WSR as primer piercing in my AR's ate up a handfull of firing pins at loads that never bothered the great old nickel plated WSR.

Tula 7.62 primers were advertized by Graf as equivalent to CCI #34 primers. CCI #34 primers are advertized as being “mil spec” primers by CCI. Mil Spec primers are the only appropriate primers to use in Garands and M1a’s as they are less sensitive than commercial primers and greatly reduce the risk of an out of battery slamfire.

Tula 7.62 and Wolf primers shot very well and I used Tula 7.62 a couple of weeks later in a match.


30-06 Primer Test

[SIZE="3"][B]Colombian Mauser Match 26" Wilson Match barrel[/B] 

174 FMJBT White Box 1968 NM M72, Headstamp LC67 match, box velocity 2640 fps 
							
14 Nov 2011 T =  68 °F					
							
Ave Vel =	2698						
Std Dev =	51						
ES =	117	 					
High =	2771						
Low =	2654	 					
N =	5						
							
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM CCI #34 OAL 3.30  	
							
14 Nov 2011 T =  74 °F					
							
Ave Vel =	2645						
Std Dev =	12						
ES =	42	 					
High =	2671						
Low =	2629	 					
N =	10						
Very good group							
							
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM Tula 7.62 lot 1-10 primers OAL 3.30  
							
14 Nov 2011 T =  74 °F					
							
Ave Vel =	2665						
Std Dev =	9						
ES =	28	 					
High =	2677						
Low =	2649	 					
N =	10						
Excellent Group					
							
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM Wolf NCLR lot 18-09 OAL 3.30  
							
14 Nov 2011 T =  74 °F					
							
Ave Vel =	2656						
Std Dev =	15						
ES =	36	 					
High =	2677						
Low =	2641	 					
N =	9						
							
							
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM Fed 210S OAL 3.30  	
							
14 Nov 2011 T =  74 °F					
							
Ave Vel =	2656						
Std Dev =	13						
ES =	34	 					
High =	2674						
Low =	2640	 					
N =	10						
							
							
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM WLR (Nickle)  OAL 3.30  
							
14 Nov 2011 T =  74 °F					
							
Ave Vel =	2665						
Std Dev =	18						
ES =	60	 					
High =	2696						
Low =	2636	 					
N =	10						
Excellent group							
							
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM CCI200  OAL 3.30  	
							
14 Nov 2011 T =  74 °F					
							
Ave Vel =	2680						
Std Dev =	14						
ES =	56	 					
High =	2712						
Low =	2656	 					
N =	10						
V. Good group

[ATTACH=full]680692[/ATTACH][/SIZE]

[SIZE="3"]
[B]M1 Garand  BMR Receiver Douglas Barrel 1:10 twist[/B] 			
								
150 gr FMJBT 1966 Ball 						
		 						
14 Nov 2011 T= 74 ° F						
								
Ave Vel =	2545				 			
Std Dev =	20							
ES =	68							
Low =	2513							
High =	2581				 			
N= 	8							
	
	
174 FMJBT White Box 1968 NM M72, Headstamp LC67 match, box velocity 2640 fps 	
								
14 Nov 2011 T =  74 °F						
								
Ave Vel =	2592							
Std Dev =	28							
ES =	103	 						
High =	2647							
Low =	2544	 						
N =	10							
								
								
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM CCI #34 OAL 3.30  		
								
14 Nov 2011 T =  74 °F						
								
Ave Vel =	2632							
Std Dev =	20							
ES =	60	 						
High =	2671							
Low =	2611	 						
N =	10							
								
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM Tula 7.62 lot 1-10 primers OAL 3.30  
								
14 Nov 2011 T =  74 °F						
								
Ave Vel =	2582							
Std Dev =	15							
ES =	49	 						
High =	2602							
Low =	2553	 						
N =	10							
	excellent group						
								
								
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM Wolf NCLR lot 18-09 OAL 3.30  	
								
14 Nov 2011 T =  74 °F						
								
Ave Vel =	2607							
Std Dev =	17							
ES =	57	 						
High =	2642							
Low =	2585	 						
N =	10							
								
								
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM WLR (Nickle)  OAL 3.30  	
								
14 Nov 2011 T =  74 °F						
								
Ave Vel =	2650							
Std Dev =	19							
ES =	68	 						
High =	2688							
Low =	2620	 						
N =	10							
Very good group							
								
								
174 FMJBT 47.0 IMR 4895  Lot L7889 thrown LC62NM CCI200  OAL 3.30  		
								
14 Nov 2011 T =  74 °F						
								
Ave Vel =	2599							
Std Dev =	22							
ES =	75	 						
High =	2637							
Low =	2562	 						
N =	10							
Very good group							


[ATTACH=full]680693[/ATTACH]

[ATTACH=full]680694[/ATTACH]

[ATTACH=full]680695[/ATTACH][/SIZE]

 

[ranger335v]

Changing primers will move your center of impact 1 1/8" towards 11:00 o'clock and make your groups 3/16" smaller. Otherwise, if I'm wrong you'll just have to find time to test it yourself. ??

 

[dagger dog]

M2C

It depends on the cartridge case capacity along with other alien influences , example a Hornet case loaded to max can exhibit over pressure signs with primer changes.

So it ain't a subject to take lightly !