CCI450 v. Remington 7 1/2

[shoot4fun]

Okay, I do have enough 450's to last a while but just got to thinking about all the 7 1/2s I have. I have used them for stuff like 17 Ackley Hornet but never tried in any Benchrest or even 223 match loads. Have you? If so, how did they compare? Imagining the cups on 7 1/2 not quite as hard but could be.
Let's hear your real world experiences with these two primers substituting one for the other is the same cartridge.

 

[LA50SHOOTER]

Okay, I do have enough 450's to last a while but just got to thinking about all the 7 1/2s I have. I have used them for stuff like 17 Ackley Hornet but never tried in any Benchrest or even 223 match loads. Have you? If so, how did they compare? Imagining the cups on 7 1/2 not quite as hard but could be.
Let's hear your real world experiences with these two primers substituting one for the other is the same cartridge.

IMO the cup on the 7 1/2 REM is everybit as hard as the CCI-450. - I use both in a straight 6mm BR (17 Lb LG) with Varget and H4895. - They are not "exactly" interchangable (from a powder charge standpoint to achieve the most accurate load) and I believe the CCI-450 is a bit hotter of a primer than the 7 1/2 REM.
As with any change of component some tuning will be required. - I've had no problems using 7 1/2's in AR platforms either. I believe that the 7 1/2 is quite versatile and decent loads can be achieved with some logical tuning if your planning on replacing the 450.

- Ron -

 

[watercam]

I have used both in .308 & .223 Palma loads with excellent numbers and performance. I used to only shoot the primer with the smallest flash (see German Salazar's experiments) but it seems a larger but reliably consistent flash works as well.

 

[jepp2]

Have you? If so, how did they compare? Imagining the cups on 7 1/2 not quite as hard but could be.

The Rem 7 1/2 was my most used SRP for no good reasons. I had more on hand, and the dual identity of a "bench rest" or "magnum" primer held me back.
I just always assumed the CCI BR4 was a better accuracy primer. But then I ran some tests using CCI BR4, Rem 7 1/2, and Fed GM205M primers. In all the tests the Rem 7 1/2's gave better ES & SD and slightly better accuracy.
When I have used the CCI 450 or CCI 41, I normally see a velocity increase of approximately 30 fps over the BR 4, 7 1/2. BUT I have seen the increase be as much as 100 fps in a few instances.
All except the Federal have 0.025" thick cups and you just have see what works best for you.

 

[243winxb]

My CCI 450 have been sitting for a while.

My CCI 400 lot has had 2 misfires so far. They flow into the firing pin hole in 223 bolt action when nearing maximum data.

No issues with the Rem 7 1/2. Wish they were available.

 

[BoydAllen]

One common mistake when comparing the accuracy of different primers is not tuning the load for each. Not doing that can provide useful information, but if you are just talking about accuracy, you need to tune for each.

 

[Lone Hunter]

I get more FPS with the CCI 450’s than with the R 7 1/2’s. 20-30 FPS more but accuracy is about the same. Using 7 1/2’s in the 6XC right now and they are doing pretty good. Wouldn’t hesitate to use either one.

 

[shoot4fun]

One common mistake when comparing the accuracy of different primers is not tuning the load for each. Not doing that can provide useful information, but if you are just talking about accuracy, you need to tune for each.

Maybe I've done things backward. I was working on a load for 223 with Varget and 80 VLD. It was shooting well but I felt the SD was a little higher than it should be for 1,000 yards so I did a primer test. I pitted the Federal Gold Medal I was using against the CCI400, 450 and the standard Federal SRP. The CCI 400 won that battle hands down. The ES dropped to under 5 and the accuracy at longer distances really came to life.
I've had these 7 1/2's a while and it's good to know I could use them in a pinch. Maybe I'll work up a good load with them for club matches next season .

 

[JFrank]

The most effective primer testing method I’ve seen is an abbreviated incremental charge test covering ground on each side of the original node as the pressure curve seems to move a bit it’ll probably need to be re established.

 

[dolek]

To me I look at it as two different primers ,two different tunes . I have had equal success with both primers. I have never pitted them against each other, instead I adapt the load to adjust for the differences in ignition . Sometimes the 450s are more accurate and sometimes the 7 1/2s win out.

 

[biggun2869]

I like the 7 1/2, you would probably see an accuracy increase with 6 1/2 in the hornet stuff. I used mag CCI pistol before I found the 6 1/2s

 

[Robert Weidler]

Here is a link to a very well done primer test done by one of our British cousins. Worth reading.
http://www.targetshooter.co.uk/?cat=58

 

[BoydAllen]

I like the 7 1/2, you would probably see an accuracy increase with 6 1/2 in the hornet stuff. I used mag CCI pistol before I found the 6 1/2s

I believe that the CCI mag. small pistol primer is the same primer as their 400 with a different label. Some time ago, I was talking with a successful shooter about a rifle load, and he told me that he was using 550s and I asked him if he meant 450s and he told me that no, he meant 550s. After that,I did a little research, actually quite a bit, and found out about their being the same as the 400s.

 

[243winxb]

https://www.accurateshooter.com/technical-articles/primers-and-pressure-analysis/

 

[Ggmac]

I like the 7 1/2, you would probably see an accuracy increase with 6 1/2 in the hornet stuff. I used mag CCI pistol before I found the 6 1/2s

61/2 remintons are meant for the lower pressure small rifle cases . 71/2 are great and have had no problems with them .

 

[Steve Donlon]

When you guys that shoot much more than I do say that you need to adjust your load when changing primers, would you please explain how much you would need to change a powder weight that you have done. An example would be changing Lapua 6.5 Creedmoor SRP brass from using CC1 450 primers to Remington 71/2 primers. Say with 41.5 grs. of IMR 4350 and 147 eld bullets. 27" Pac-Nor barrel. It seems the variables are so many . Of course the velocity will change but the accuracy unless dramatic from day to day could change either way depending on conditions. I just would like to know how much of a difference in powder weights you have encountered to adjust going from 450's to 71/2 primers. Maybe sometimes no change is needed. I ask because some of you can shoot much better than I can and I respect your option. Thanks.

 

[doctorh]

2 tenth of a gr.

 

[Laurie]

Here is a link to a very well done primer test done by one of our British cousins. Worth reading.
http://www.targetshooter.co.uk/?cat=58

Robert, I think you meant this piece.

https://www.targetshooter.co.uk/?p=2662

One common mistake when comparing the accuracy of different primers is not tuning the load for each. Not doing that can provide useful information, but if you are just talking about accuracy, you need to tune for each.

Just so! My experience is also that small cartridges are (unsurprisingly) more affected by a primer change than large ones. 223 Rem performance for instance (MV average as well as ES/SD) can change significantly between primers.

 

[varget204]

Have CCI 450's CCI BR, Fed 205M,& Rem 71/2, Rem 7 1/2's have been the best in 204 Ruger,6 Creedmoor, & 6 BRA

 

[Steve Donlon]

I went out this morning same time as yesterday shot a 5 shot group with the exact same load but with the Remington 71/2 primer instead of the 450. My group was exactly the same. The first shot from a cold clean barrel was about 1/4" low and the other four were in one hole. The exact same with both primers. But with the 450 primers I had a very very slight mark from the extractor. With the 71/2 primer no mark . That was the purpose of me wanting to try the 71/2 primer. To see if they would drop the pressure enough to not leave any mark.. I don't think they were that hot but I could barley see a shinny spot on some of the brass with the 450's. My bolt face is covered in a black nitrate coating and the brass is new unfired Lapua so I don't know if that is a factor. But I do think that with the 30-06 and 6.5 Creedmoor the node is wide enough to not notice a difference in accuracy from going from a CCI 450 to a Remington 71/2 primer. The 71/2 might end up being a little more accurate in some conditions.