Load Testing for the CZ600 .308

[swampratt]

On that scope you are using I assume it is probably cranked up to highest power setting.
Now Parallax can get wonky at high power 9+ and long distances.

First thing I do when shooting is move my head back and forth and up and down while looking into the scope without moving the rifle at all.

Make absolutely sure the cross hairs stay still on my target and I adjust Parallax to make it happen.

I never assume 300 yard mark on the scope is going to make the cross hairs stay still when I move my head.
I have a Nikon 4-12 power scope and it is not adjustable and you better be darn sure you have the same hold and same cheek weld and eye position or the groups suffer.

My centerpoint 4-16 shoots tighter groups at long distances but only because I can adjust Parallax.
And the scope is a bit high on a particular rifle which makes it harder than a low mounted scope.

Fun stuff.
Next trip I take to Gene sears I will ask about Varget.
We got to keep you shooting.

 

[thaHooligan]

I never assume 300 yard mark on the scope is going to make the cross hairs stay still when I move my head.
I have a Nikon 4-12 power scope and it is not adjustable and you better be darn sure you have the same hold and same cheek weld and eye position or the groups suffer.

Fun stuff.
Next trip I take to Gene sears I will ask about Varget.
We got to keep you shooting.

Funny you mention that, because this was in the evening with the sun starting to be in my face/scope and I could tell I was moving my head around a lot trying to get a good picture.

That would be great if they have some Varget, just let me know. I've never been there, but have planned on going several times and just haven't made it. I think mostly because I believe he is closed on the weekends. I also had a few people recommend IMR4064, so if he has either of those I would make the trip for it. I have also wondered about Alliant RL15 and IMR4895, any thoughts on either of those? It looks like they have good speeds from what it shows in the book.

 

[swampratt]

I tested Varget IMR4064 and RL15 all back to back in different temps in my .308.
I was looking for my group size to stay the same and only tested to 200 yards.
All powders stayed close enough to point of aim in all temps that a scope adjustment was not necessary.

BUT only IMR4064 would keep those groups tight.
RL15 was the worst and I got rid of it.
I tested RL15 in my 30-06 also and found I could load same velocity as 4064 but the recoil was much less with the RL15.

H4350 for the king of velocity as far as my 30-06 testing went.
I have not ever used IMR4895 but have tried H4895 and like my 4064 much more.
H4895 in my .223 and 5.56 is awesome for tight groups but velocity is eeehhh and N133 with my 55gr bullets will move much quicker.

I do not need the high velocity to do the killing with the 55 v-max though so my go to is H4895.

I would be lost without my IMR4064.

 

[diggler1833]

Funny you mention that, because this was in the evening with the sun starting to be in my face/scope and I could tell I was moving my head around a lot trying to get a good picture.

That would be great if they have some Varget, just let me know. I've never been there, but have planned on going several times and just haven't made it. I think mostly because I believe he is closed on the weekends. I also had a few people recommend IMR4064, so if he has either of those I would make the trip for it. I have also wondered about Alliant RL15 and IMR4895, any thoughts on either of those? It looks like they have good speeds from what it shows in the book.

Reloader 15 and 4895 (both IMR and Hodgdon) are excellent .308 powders. Heck, I have a Savage 6.5 Creedmoor that shoots under 1/2" @ 100, and 1.5" @ 300 with IMR-4895 and the 120gr Nosler BT. If need be I'll produce target photos.

Re-15 is one of my go-tos for a. 223 trainer rifle that is a little laser with the 69gr SMK. Again, I can provide target photos if so desired.

The downside to Reloader 15 is that it is very temp sensitive again...so you'll really want to do load development and gather drop data in the same temp range that you'll be routinely using it in. IMR-4895 is a bit temp sensitive too, but not as bad. H4895 (if you can find it) is one of Hodgdon's extreme powders, which are all very temperature stable.

Basically, if your .308 won't shoot Varget, Reloader 15, H4895, IMR-4895, or IMR-4064...its time for a new barrel.

I managed to find one pound of Varget and 2lbs of H1000 today at the McAlester Walmart! Score me!

 

[thaHooligan]

I managed to find one pound of Varget and 2lbs of H1000 today at the McAlester Walmart! Score me!

Oh wow, thanks for rubbing that in my face!
None of the walmarts around here ever get any powder!

 

[Jcann]

@thaHooligan

I don’t know if you knew about this but take it for what it’s worth

https://cz600recall.com/

 

[thaHooligan]

@thaHooligan

I don’t know if you knew about this but take it for what it’s worth

https://cz600recall.com/

Yes sir, I knew about the recall before I bought the rifle. The way it's made is there are 3 bolts on the receiver that clamp on to the barrel. They made them to be changed easily for different calibers, but I assume after they did that they realized what the consequences could be if someone didn't fully insert the barrel and wanted to avoid any legal ramifications that could come of it. I called and spoke to them and was told that if I send it in, they will permanently locktite the bolts in place. I thought maybe they would actually tac weld the bolts or tac weld the barrel to the receiver, but I guess not. I'm not to worried about the barrel ever being changed. I never planned to change the caliber and I've never needed a new barrel for any other rifle I have. The guy I spoke with made it sound like one of the bolts would have to be completely left out for it to move at all and create space between them. It's free to send it in and get it "fixed", so I may do that later on. For now I've marked the barrel with pencil and will keep an eye on the bolts to make sure nothing comes loose or moves.

 

[thaHooligan]

I might be on to something here. Tried out the Interlock bullets thinking they wouldn't do as good as the sst's, but apparently I was wrong. I'm not sure if the flyer was due to the cold bore shot or if I just pulled the first one, but the next 4 grouped really well. Average speed was 2914 fps.

 

[diggler1833]

I might be on to something here. Tried out the Interlock bullets thinking they wouldn't do as good as the sst's, but apparently I was wrong. I'm not sure if the flyer was due to the cold bore shot or if I just pulled the first one, but the next 4 grouped really well. Average speed was 2914 fps.

View attachment 297246

Shoot a group of six next time and find out! Regardless, I think you're onto something too.

Even a 1/2 MOA shift from a cold bore to subsequent shots is pretty good.

Keep it up man.

Oh, and the 150gr Interlocks are a hammer. I quickly became a huge fan of those on hogs.

 

[thaHooligan]

Oh, and the 150gr Interlocks are a hammer. I quickly became a huge fan of those on hogs.

Yea I watched the video and it looks like they hit pretty hard! I'm pretty impressed that they are this accurate and as cheap as they are, currently on sale on Midway for $28.50 per 100. That's a lot better than the $46 per 50 I just spent on the Barnes ttsx.