7x57 info

[303carbine]

Originally Posted by 7mm08

From what I have been told, modern rifles loaded with handloads perform almost identical to the 7mm-08 Remington. 130-140 gr bullets over a medium burning powder like varget should be your best bang for the buck. As long as your rifle can handle the modern loads.
Good luck

I have had a few 7mm-08's, none of them could match the velocities I get with the 7x57.
Bigger case, more powder, more velocity.

[303carbine]

Originally Posted by Cowtown guy

BRNO 600 ZKK is what I have. It is a beautiful little rifle. Can't wait to shoot it.

I had a ZKK 600 in 270 and one in 7x57, you will really like that rifle, you can load it up and not worry about the action strength.
I had good luck with 160 grain bullets in my ZKK 600 in 7x57, it seems the Europeans (Brno) use a different twist rate than I have in my Remington 700 7x57.
I got my ZKK 600 7x57 with a 4x Leupold , 1.5 boxes of loaded factory Nosler Partitions for $400 because the guy didn't think it was powerful enough for moose.
I took it moose hunting that fall season and got a moose with it, I brought him a steak and the bottom half of a 140 Nosler Partition that I picked out of the offside of the critter.
With proper shot placement, that 7x57 will do anything you need it to do. It's not a magnum, but it kills like one.

[303carbine]

Originally Posted by Cowtown guy

So the preliminary results are less than pleasing to say the least.

I ordered a Timney for it. It doesn't fit. So I polished and ground the existing trigger's sear as best I can. It still has some creep but it is significantly better than it was.

I have taken her out to the range twice now. The first time out I got a best group of about 7 inches with Hornady Superformance 139 grainers. I got the ingenious idea that I would just load those 20 brass my way and make something work. Nope. The case heads expanded too much and I can't even get them in the shell holder.

I bought a box of 140 Corelokts and thought I'd give those a try instead. I fired a few and mic'd them. Everything stayed the same with those measurements as the factory ammo, so I was at least happy with that. I was a little concerned that there was a headspace issue after those Hornady rounds swelled so bad. All seems well on that front.

The bad news there is that I was only able to get her down to about 4 inches. I had a buddy that was with me shoot it and he said he really concentrated on holding the gun super tight and was able to get one decent group. I fired off 5 shots after him and it didn't group all that well for me. Maybe 2 1/2 inches.

Next up will be a scope change and some 120 TTSX handloads, pushed with IMR 4064, that I whipped up with the Remington brass. I just got my hands on some 139 interbonds last night so I will try those if the 120's don't work.

I am a little frustrated right now. Here's to hoping.

My ZKK 600 7x57 shot 160 and 175 grain bullets the best, as I stated before, I believe Brno use different twist rate than American made rifles, try heavy bullets before you do a lot of work to it.
The twist for a lot of 7mm over here is 1 in 9.5, yours may be 1 in 8 like mine was, I suppose that's why the heavy bullets shot better.

Originally Posted by Cowtown guy

Last owner said no issues with it being a shooter. Scope is good. Check for rings later tonight. Is that carbon I'd be looking for? Didn't notice any diameter changes

No not carbon. Obstruction, with subsequent increase in diameter. Accuracy with this condition......lucky to hit a 8.5x11 paper at 100 yards. Damaged scope with loose eye piece can have similar results.

[tony d]

Before yesterday I would totally be blaming the scope rifle etc I tried a box of superformance gmail in my kids husky wow never ever have I seen such inconsistent poor results I normally hand load 120 ballistic tips and it groups nice but a thief decided they needed our ammo more than us pulled out a box of remington and this were much better

[bigjohncdn]

Did you check the headspace? If you case head was expanded to the point of not fitting in the shell holder there may be an issue.

[honz]

Originally Posted by 303carbine

My ZKK 600 7x57 shot 160 and 175 grain bullets the best, as I stated before, I believe Brno use different twist rate than American made rifles, try heavy bullets before you do a lot of work to it.
The twist for a lot of 7mm over here is 1 in 9.5, yours may be 1 in 8 like mine was, I suppose that's why the heavy bullets shot better.

This thread is coming up at just the right time. I just picked up a ZKK600 and am getting into.free time to start playing with loads for it.

As far as my research has gone, the 1:9 twist prefers nice and heavy bullets. I'm going to be working with 160~175 the most, but I also have some 120 and 139 grain bullets for it.

The common denominator of powders for it are 4320, 4350, w760, varget and RL19. If there is interest, I can scan and send my reloading booklet that goes through a dozen different combinations. PM me an email address if you're interested it.

Also note that as the years have gone by the publiahes recommended loads has decreased. My 2ed Hornady reloading manual has values about 12% higher than the current edition. This and the fact the 7x57's originates from old Spanish rifles, commercial loss will be quite conservative to the point of almost being too weak to spin properly on a modern manufacture.

Overall, I haven't had hours of experience with the rifle yet, I'm hoping to really get it out this weekend to feed it a variety of ammo.

Did your ZKK come with a two stage trigger?

[Cowtown guy]

Originally Posted by honz

This thread is coming up at just the right time. I just picked up a ZKK600 and am getting into.free time to start playing with loads for it.

As far as my research has gone, the 1:9 twist prefers nice and heavy bullets. I'm going to be working with 160~175 the most, but I also have some 120 and 139 grain bullets for it.

The common denominator of powders for it are 4320, 4350, w760, varget and RL19. If there is interest, I can scan and send my reloading booklet that goes through a dozen different combinations. PM me an email address if you're interested it.

Also note that as the years have gone by the publiahes recommended loads has decreased. My 2ed Hornady reloading manual has values about 12% higher than the current edition. This and the fact the 7x57's originates from old Spanish rifles, commercial loss will be quite conservative to the point of almost being too weak to spin properly on a modern manufacture.

Overall, I haven't had hours of experience with the rifle yet, I'm hoping to really get it out this weekend to feed it a variety of ammo.

Did your ZKK come with a two stage trigger?

I just have the regular trigger with it. It is not too good at all. It has easily 1/8" of creep. It had more before I polished it up. It also felt scratchy before the polishing. At least now it is just creep.

I had it out to the range today shooting 120 TTSX bullets with IMR 4064. It showed some promise with these lighter bullets. I have 2 groups that are in the 1" range. One may be smaller. I haven't properly measured the groups yet. Twice I had a bullet in almost the same hole and the last shot went bad, moving the group size up. The shots felt good so I don't think it was operator error on those 2.

[Cowtown guy]

Originally Posted by bigjohncdn

Did you check the headspace? If you case head was expanded to the point of not fitting in the shell holder there may be an issue.

Was only an issue with the Hornady rounds. The Remington ammo and the reloads are good.

[Cowtown guy]

Originally Posted by Precisionshooter

No not carbon. Obstruction, with subsequent increase in diameter. Accuracy with this condition......lucky to hit a 8.5x11 paper at 100 yards. Damaged scope with loose eye piece can have similar results.

All looks good on this front. Bore is shiny all the way thru that I can see. Barrel feels and looks fine.

[Cowtown guy]

Well it appears that the rifle seems to like lighter bullets.

I now have 2 different groups that go sub MOA. This is with 120 grain TTSX bullets and IMR 4064. One is at .777" and the other is .908".

I will now play with some seating depths and see what else I can get it to do.

Thanks for the help in this thread so far folks.