Wrong primers

[uncle-buck]

Am developing a load for a .243 hunting rifle using Sierra 85 gr. bullets, Lapua cases, and IMR-4350 powder.

Have been using Winchester large rifle primers, but inadvertently loaded some rounds with CCI 200s that are usually used with a different caliber and rifle.

What changes in accuracy are likely to be seen with the different primers?

Thanks

 

[Ron Blain]

I doubt for a hunting rifle you will not see much if any change and any change would be negligible. Both primers are standard large rifle primers. Assuming start or mid range loads or loads below 43 grains of IMR 4350. I have experimented with primers in .223 Remington and while groups changed slightly there wasn't much to see and that included small rifle and small rifle magnum primers. I have about 50 .308 Winchester cases using 10 EA or five different primers but have yet to complete that little science experiment. Anyway, using mid range loads, .243 Winchester in a hunting rifle I doubt you will see much change. I would not be concerned about anything bad happening.

Ron

 

[uncle-buck]

Thanks, Ron.

The powder charges are between 41.0 and 42.2 grains of IMR-4350, so I'm not too concerned about pressure. I simply want to end up with a load that will consistently shoot 1 MOA or better.

Was getting there with the WLR primers so it will be interesting to see how the CCIs shoot.

 

[Steve Ladino]

Am developing a load for a .243 hunting rifle using Sierra 85 gr. bullets, Lapua cases, and IMR-4350 powder.

Have been using Winchester large rifle primers, but inadvertently loaded some rounds with CCI 200s that are usually used with a different caliber and rifle.

What changes in accuracy are likely to be seen with the different primers?

Thanks

If your groups are half MOA then primer changes might increase that , increase pressure or decrease pressure....keep an eye on fired primer appearance and start with low powder charges.

 

[KMart]

If you have problems finding the accuracy you want with IMR 4350, I have had very good luck using IMR 4064 in the 243 and 85 gr Sierra. In the 4th edition Sierra manual, their accuracy load is 37.3 gr 4064. That load and adjust the seating for your rifle, should produce small groups. It has worked in several 243's for me.

 

[DRNewcomb]

I agree with @Ron Blain The WLRs are a bit "hotter" than CCI 200s but it should not matter too much with stick powder. If you were loading a slow ball powder, I might not give the same advice. If you were loading for match shooting, I'd suggest you break them all down and start over.

 

[ireload2]

You might want to review your process and material control methods.
If you make mistakes handloading they can turn into something serious.

 

[Larryh128]

Thanks, Ron.

The powder charges are between 41.0 and 42.2 grains of IMR-4350, so I'm not too concerned about pressure. I simply want to end up with a load that will consistently shoot 1 MOA or better.

Was getting there with the WLR primers so it will be interesting to see how the CCIs shoot.

You are very likely to see a gain in accuracy.

 

[Shaggy357]

Agree with several others above. WLR primers are a little hotter than the CCI200s. At 100 yards, your group may move a little and change in size some, but more likely than not, not a whole bunch of either. At 200 yards, and beyond, you may notice more of a difference. If hunting beyond 200, you should double check point of impact and group size. This is for your own confidence in shooting the load. Most targets will not notice the difference in loads.

 

[Ron Blain]

For the curious at heart I always found this link of primer flash interesting. Compliments of our friends at 6mm BR. Not to be confused with primer brisance but amusing photos none the less. Also not to say primer flash is identical lot to lot within any given manufacturer.

Ron