Any experience with primer change affecting accuracy?

[Land_Owner]

Just read that one reloader, exhausted after hundreds of bullet/powder/length to land combinations, tried differing the primer and dropped his groups by 1/2 their previous best width.

Anybody else have this kind of luck or experience?

[SHOOTALL]

Yep , when i worked up a load for my 2506 years ago after using the listed primer i tried CCI-BR-2 and it was impressive .

[huntducks]

I reload for a bunch of rifles and between then have a mixture of primers Fed. Rem. and WW. in no instance does one Co. primer fit all, I keep trying till i'm happy.

[Lloyd Smale]

in my experince primers will do almost as much to change accuracy as switching  brands of bullets or powder. Ive seen group size cut in half just by changing primers.

[moorepower]

Yes, they like what they like, but reloading manuals are a good start to find out what they should like.

[victorcharlie]

What's a primer?

Do they still make them?

[Graybeard]

Yes but really just as much experience when it did not. Ya just never know until ya check.

[roper]

Here is something I did used 270WSM 58gr/IMR-4350, 150gr Sierra, Win cases,25" long Lawton barrel, 35P Oehler chrongraph

Primer  WLRM            3043fps                  
          WLR              3050fps
          Rem 9.5M       3045fps
          Rem 9.5         3047fps
          Fed 215         3038fps
          Fed 215m       3040fps
          Fed 210         3044fps
          CCI 200         3036fps

Took me afew days




Last thing I worry about is changing primers.  

[moorepower]

I was reading an old Handloader magazine the other day and they were testing primers in a 7mm mag and there was a 10000 psi spread from the lowest psi LR primer to the highest psi magnum primer.

[Graybeard]

Here is something I did used 270WSM 58gr/IMR-4350, 150gr Sierra, Win cases,25" long Lawton barrel, 35P Oehler chrongraph

Primer  WLRM            3043fps                  
          WLR              3050fps
          Rem 9.5M       3045fps
          Rem 9.5         3047fps
          Fed 215         3038fps
          Fed 215m       3040fps
          Fed 210         3044fps
          CCI 200         3036fps

Took me afew days




Last thing I worry about is changing primers.  

There is more to accuracy than velocity. Try your test again but this time actually shoot them for accuracy. I promise you some will be a lot different and some will not. There is no rhyme or reason to it either. As a for instance you have a 3043, 3044 and 3045. Try just those three and I promise you they will not hit to same POI regardless of basically same velocity and likely you'll notice a significant accuracy difference with at least one of the three.

I've had loads that gave Sd of 50-75 fps give sub inch loads and loads with Sd of 10-15 fps give over 3" accuracy. You just don't know until you shoot them.

[roper]

Here is something I did used 270WSM 58gr/IMR-4350, 150gr Sierra, Win cases,25" long Lawton barrel, 35P Oehler chrongraph

Primer  WLRM            3043fps                  
          WLR              3050fps
          Rem 9.5M       3045fps
          Rem 9.5         3047fps
          Fed 215         3038fps
          Fed 215m       3040fps
          Fed 210         3044fps
          CCI 200         3036fps

Took me afew days




Last thing I worry about is changing primers.  

There is more to accuracy than velocity. Try your test again but this time actually shoot them for accuracy. I promise you some will be a lot different and some will not. There is no rhyme or reason to it either. As a for instance you have a 3043, 3044 and 3045. Try just those three and I promise you they will not hit to same POI regardless of basically same velocity and likely you'll notice a significant accuracy difference with at least one of the three.

I've had loads that gave Sd of 50-75 fps give sub inch loads and loads with Sd of 10-15 fps give over 3" accuracy. You just don't know until you shoot them.

 

Did I say they were accurate loads and I wouldn't waste the ammo chronographing before accuracy

Here is afew post from another site on my reloading equipment

http://noslerreloading.com/phpBB2/viewtopic.php?t=11613
http://noslerreloading.com/phpBB2/viewtopic.php?t=11623
http://noslerreloading.com/phpBB2/viewtopic.php?t=11620
http://noslerreloading.com/phpBB2/viewtopic.php?t=11614
http://noslerreloading.com/phpBB2/viewtopic.php?t=11615
http://noslerreloading.com/phpBB2/viewtopic.php?t=11616
http://noslerreloading.com/phpBB2/viewtopic.php?t=11617
http://noslerreloading.com/phpBB2/viewtopic.php?t=11618
http://noslerreloading.com/phpBB2/viewtopic.php?t=11619
http://noslerreloading.com/phpBB2/viewtopic.php?t=11621
http://noslerreloading.com/phpBB2/viewtopic.php?t=11624
http://noslerreloading.com/phpBB2/viewtopic.php?t=11625

I need to find some of my targets that I posted.

We all load different to get the best accuracy and I've taken maybe to a level that would be hard for some to understand.  I'm a group shooter and what I expect is alot different than most but I pay to have what it takes (reloading equipment plus good gunsmiths)to get those groups.  My 270WSM will shoot groups in the .2's to low .3's and that is not needed in a hunting rifle but I load for me.  I've got targets shooting same powder,primer,case but different brand of bullets but same weight groups in the .3's/.4's. 

You get to reading all these gun rags about the doe's and don't and that for the general shooting public and most time  good information.  I have very few factory chamber rifles out of the 40 some that I own.   

[LaOtto222]

The only testing I did with primers was with CCI BR4 and Remington 7 1/2 primers in a 223 a couple of years ago (when primers were not hard to get). I shot 3 - 5 shot groups with each. They were not run over a chronograph - they were shot for accuracy. I got a low of .22" to a high of .4" at 80 yards with all groups. I could not find any significant difference between them. If any thing the Remington primers were a hair better than the CCI - but I would have to shoot a lot more to really know for sure. Since the Remington primers were significantly cheaper than the CCI primers, I got the Remington in some quantity. I can not get either of them now, so I bought Wolf 223 primers. I have yet to try any yet. I have to wait until the weather breaks before I can wring them out. On the other hand I developed a load for a 22 Hornet with CCI small pistol primers. For grins I loaded up a few with Winchester Magnum small pistol primers. Big difference. The magnums shot much hotter - causing stuck cases. Bottom line - Don't really know for sure, but I have a feeling that when you have a significant difference in primer strength and the smaller the case capacity the bigger the difference the primer makes. When you get into larger capacity cases and stay with the same type of primers (regular vs magnums) there is not as much variance between them. Like I said I have not done a lot of testing - I usually develop a load using the same primer and stick to it. In these times of hard to get primers - it makes it very difficult to compare one against another. I just get what I can and develop the best load I can for it. I have 2 new guns that I need to develop loads for - a 22 BR and a 7-08. I think I am going to start with Wolf primers in both. This is because that is what I have the most of and it looks like I can get them in the future.

[Bullseye]

I loaded 41 Mag and 44 Mag with IMR 4227 and CCI Magnum primers for years per the old Speer manual.  Out of my Contenders both would shoot under an inch at 50 yards any time I had them out.

Switched to CCI regular primers because the newer Speer book made that change.  My groups went to 3-4 inches at 50 yards.  Switched back to CCI magnums and my groups came back to under an inch.

So yes, primers can make a difference in accuracy.

[jhalcott]

 In OLDER  guns it made a bigger difference than the newer guns .Also their has been a steady improvemet in component production methods. The new bullets, primers and powders combined with smoother bores  have less difference unit to unit. This translates to easier swapping of components with less change in poi. You MUST start low and work up to the best load though! If you are running on the edge of pressure limits and swap a component, you CAN get an over pressure load as in the above 10000 (ten thousand) psi change. I have tried swapping components in a 6mm target rifle. Often the POI was changed while the group size was not. A 1/2" group that lands 2 inches from the previous 1/2" group is STILL an accurate load, all it needs is a slight SIGHT ajustment. MIXING these 2 loads may give a larger group than wanted!

[Steve P]

I shoot 7TCU out of an XP-100 in IHMSA and NRA Silhouette.  After I dialed in my brass, bullet, and powder, I tried 4 different primers at 100 yards and at 200 yards.  Some primers doubled my group size.  One cut it in half.  I didn't shoot just one group of each either. 

My buddy and I have DW Revolvers that are consecutive serial numbers.  Made on same machinery and completed on same day mid week.  (Custom order).  Shooting same bullet, brass, and powder, my load is 1.5 grains lighter with a Remington 7 1/2 primer vs his use of the WSR primer.  This is to get same velocity and accuracy.

Yes, primers make a difference....a lot of the time.  They can take a mild load and make it a WILD load.  Do your homework.

Steve

[Lloyd Smale]

large rifle cases seem to show less change with primers but in some cases its still substantial. Where you willl really notice it is in handguns and small rifle cases like the hornet, 762x39, 223 ect.

[Dezynco]

I changed from CCI large rifle to CCI Large pistol in my 7.62x39 Contender pistol.  Groups were cut in half!  I have also had point of impact change dramatically from one brand of primer to another.