Fed 215m vs CCI 250

[easternoregonballistics]

I have a brand new tikka t3x lite in 7 PRC. I like bonded bullets for elk hunting so I tried the 175 ABLR. Using H1000, hornady brass and CCI 250s I found a load that was super accurate at 100 yards but velocity extreme spread was mid 90s (2700s to 2800). I switched out the 250s for the Federal gold medal match 215ms. It brought my 5 shot ES down to 12 fps. More testing coming tomorrow. I thought I would share my findingss

 

[338edge]

With my 7mmstw the 215 match increased my velocity by about 30 fps and my ES by about 10 fps over the CCI 250

 

[Lou (Louis)]

Welcome!

 

[easternoregonballistics]

Welcome!

Thanks!

 

[338edge]

I have a brand new tikka t3x lite in 7 PRC. I like bonded bullets for elk hunting so I tried the 175 ABLR. Using H1000, hornady brass and CCI 250s I found a load that was super accurate at 100 yards but velocity extreme spread was mid 90s (2700s to 2800). I switched out the 250s for the Federal gold medal match 215ms. It brought my 5 shot ES down to 12 fps. More testing coming tomorrow. I thought I would share my findingss

Did it also change the group size

 

[Blackdog317]

Interesting. How many shots in the CCI 250 group? New brass?

 

[swavescatter]

Hard to trust any sample sizes that small (5 rounds). At a minimum I'd want 10-shot groups, but 30 rounds is kind of the conventional floor for statistical significance.

If you're not shooting F-class, then maybe just go with the one that gives you the best 10-round groups size at your max distance?

 

[SloppyJ]

Ive seen small changes but never anything like that. Im willing to bet something else was going on.

New brass to once fired?

 

[338edge]

Ive seen small changes but never anything like that. Im willing to bet something else was going on.

New brass to once fired?

Mine was new brass

 

[EdP]

New brass to once fired?

From your description of events it sounds like you loaded new brass using the 250's, shot them and reloaded using 215s. So new brass with the first firing and once fired (fire formed to your chamber) on the second firing. If that's what happened you should expect some difference between firings. In fact, it may take 2 times to fully fire form. More testing will tell. The second firing with the 215's, having given much better stats, should also have given smaller groups, but depending on what "super accurate" is, you may not see much difference in group size at 100 yds.

 

[SloppyJ]

From your description of events it sounds like you loaded new brass using the 250's, shot them and reloaded using 215s. So new brass with the first firing and once fired (fire formed to your chamber) on the second firing. If that's what happened you should expect some difference between firings. In fact, it may take 2 times to fully fire form. More testing will tell. The second firing with the 215's, having given much better stats, should also have given smaller groups, but depending on what "super accurate" is, you may not see much difference in group size at 100 yds.

Not to mention if you use the same load, the velocity will go up on the once fired brass compared to the new brass. Been there and starred in that show many times.

 

[338edge]

Not to mention if you use the same load, the velocity will go up on the once fired brass compared to the new brass. Been there and starred in that show many times.

Also will velocity ir accuracy change after the brass has been fully fire formed?

 

[easternoregonballistics]

It was all 3-4 firings

 

[easternoregonballistics]

Im dropping the h1000 and trying it with staball HD instead. Maybe jt will give me better case fill too

 

[EdP]

It was all 3-4 firings

What does that mean? Please be more descriptive, more specific. Otherwise, no good advice can be given.

 

[easternoregonballistics]

What does that mean? Please be more descriptive, more specific. Otherwise, no good advice can be given.

The brass was on its 3 and then 4th firing. Even at 66 grains ("max" load according to the load data) i had a ton of extra space in the case. Im wondering if the issue isn't that. Im going to try staball HD and see if I can bring my SD down.

 

[SloppyJ]

What does that mean? Please be more descriptive, more specific. Otherwise, no good advice can be given.

I think he's saying it happened over 3 or 4 firings. If that's the case, I'm wondering if the brass is from different lots and the volume is different or something along those lines? That's a huge swing for any sort of modern reloading techniques so either the brass is all over the place or the powder charge is.

Good luck with the Staball HD, I couldn't get that to shoot in multiple rifles that consistently shoot well. Let me rephrase that, the velocity increase did not outweigh the dispersion increase both on paper and in ES/SD. You will want the magnum primers for that powder. Interested to hear what your results are.

If you're getting stable ES/SD with the 215s and H1000, why change? I have a load with H1000 and N570 in my 300prc. The N570 groups are insane by any metric but the ES/SD are just a little higher around 10/15. Works just fine for first round impacts out to 800yds so no complaints from me. I'm not one to scrap a load if the ES/SD is a little high but 90fps isn't acceptable.

N570 will increase your case fill. Not sure that the Staball will because it's a ball powder so it will fill all of the voids left by stick powder.

 

[Elkman17]

Welcome!

 

[EdP]

The brass was on its 3 and then 4th firing.

Got it, makes sense now. Not a fire forming issue.