I’m still pretty green on reloading, so any help would be appreciated. Im shooting a CZ 600 Range 6mm Creedmoor with a 24” 1in7 barrel. I started out using starline brass with H4350 and a Berger 105g hybrid target bullet. After doing a little load development I found that 43g of powder was shooting great (consistent 3/8” 5 shot groups at 100). Now that being said, Ive been told by a few people that my group sizes are too small and I agree to an extent. BUT if my POI is the same every group, and every group is consistent at shooting under 3/8” I feel that its proving to be a consistent load to start with before i start shooting 30 round groups. The problem Im having is that Im 150fps over max velocity with that charge (still not showing signs of pressure on cases, but I dont want to exceed max velocity regardless). So I did a ladder test dropping my charge by .2 grains at a time all the way down to 40.6 grains. EVERY load shot absolutely terrible. Anywhere from 1.25-2” groups. After fighting this for a few weeks I decided to play with seating depth. I shot .015, .030, .045 and .060 from the lands as berger recommended. No change in group size. At this point i change powder hoping for a change. I try H1000, H4831SC, Superformance and Hybrid 100v. Now when ai do this I change to Lapua brass just incase Starline isnt as consistent as I had hoped. Plus I wanted to change to lapua anyways since I had it. I got pretty decent groups with the 4831 and superformance. (3 shots per charge, 2 charges per powder). I load some more of the exact same loads, go out the next morning and my groups have opened back up. All in the process of this im also rushing to find a load so I can go stock up on powder before the election in case components go dry again. So my question is what am I doing wrong? I couldnt find another node with the 4350 that was even close to as good as 43g. I changed up powders and tightened my groups a little the first time but the second go round they opened up again. Everything on my gun is tight, im by no means a competition shooter but I can also shoot pretty well. Shooting sub 1/2 moa is not an issue with the right equipment. My gun has proven time and time again with the 4350 charge that it is in fact capable of shooting a consistent group. At this point all I can think to do is change bullets (at which time ill go to 115g vld hunting bullets).
Only seem to be hitting a single node
- Thread starter Tyler98
- Start date
Tyler -
Howdy !
Q - What do you mean " I'm 150fps over " Max velocity " ?
" Max pressure " I understand. But...." Max Velocity, without linking it to max pressure ? In other words...it's common practice to relate the velocity a load had reached, when excess pressure signs showed up.
Another Q -
You have been told that your " group sizes are too small " ?!?
How small is too small ?!? IF that's your situation, you should shoot benchrest !! HAaaaa haaa HAaaaa.....
" Ricky...you got some 'splaining to do " ! HAaaaa...haaa....
With regards,
357Mag
Coyotefurharvester
Silver $$ Contributor
What does your bolt tell you at velocity 150 over book. Does it open after firing as easy as it closes/opens without firing? Marks/swipes on case head?
jelenko
Gold $$ Contributor
That's a good way to identify people to stop listening too.
If there is no signs of pressure pay the book MAX velocity no mind. All barrels are different.
How can your group sizes be to small? As long as you are seeing no pressure problems, shoot it and be happy! Then go find some new friends as the one's you have are jealous of your success. Move on to some intelligent friends.
Paul
Paul
You beat me to this one .
Ive read forums relating to “max velocity” and from that I gathered that “velocity isnt free” and with velocity comes pressure. I also have a buddy that has been reloading for 20+ years that I often go to for advice. When I came to him about the issue, I explained that the only pressure signs I had (which i forgot to mention in my original post) was slight ejector marks. He said I should be fine just not to push any further on my charge. Then he asked what my velocity was in relation to published data. (Im .7 grains above max published data). When I told him how high my velocity was he immediately said to back off and that he had the same scenario pop up with a rifle in the past and that his rifle had blown up on him. I also posted a thread somewhere about cases showing signs of pressure and got several responses by people stating that studies have shown that brass doesn’t show any pressure signs until 80,000psi. With all of that I have gone with the thought that I could very possibly be over pressure at my load.
Ive read forums relating to “max velocity” and from that I gathered that “velocity isnt free” and with velocity comes pressure. I also have a buddy that has been reloading for 20+ years that I often go to for advice. When I came to him about the issue, I explained that the only pressure signs I had (which i forgot to mention in my original post) was slight ejector marks. He said I should be fine just not to push any further on my charge. Then he asked what my velocity was in relation to published data. (Im .7 grains above max published data). When I told him how high my velocity was he immediately said to back off and that he had the same scenario pop up with a rifle in the past and that his rifle had blown up on him. I also posted a thread somewhere about cases showing signs of pressure and got several responses by people stating that studies have shown that brass doesn’t show any pressure signs until 80,000psi. With all of that I have gone with the thought that I could very possibly be over pressure at my load.
Bronsin
Silver $$ Contributor
That's only .001. If you have a bushing die, get one that gives .003 or .004, and don't use the mandrel after it.
@Tyler98
You seem to be changing a lot of stuff, the old line of thought is one thing at a time nevertheless Brosin is correct IME light neck tension can cause havoc with erratic groups. Some combos end up liking it but not a great place to start.
I would go with Lapua , 105 Hybrid, and run a couple side by side ladders of H4350 & H4831sc ,nodes tend to repeat themselves about 3% apart so I would load enough to see a couple nodes and stop at pressure.
J
You seem to be changing a lot of stuff, the old line of thought is one thing at a time nevertheless Brosin is correct IME light neck tension can cause havoc with erratic groups. Some combos end up liking it but not a great place to start.
I would go with Lapua , 105 Hybrid, and run a couple side by side ladders of H4350 & H4831sc ,nodes tend to repeat themselves about 3% apart so I would load enough to see a couple nodes and stop at pressure.
J
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Yea, now with the pressure signs added that sheds a different light on the subject. Originally you stated no pressure signs. Back off a grain and see how that works.
^^^^^^^^excellent advice.
I backed off with the 4350 down to 40.6 grains in .2 grain increments and never could seem to find a node. Thats what confused me because I have always understood that if you have one node youll have another. I will run another ladder test starting one grain from where i was though and see if i continue to get the same results. Ill also try a different neck tension as suggested. I appreciate the help guys! Like I said before, im still pretty green to reloading and trying to progress, just dont want to blow a gun up in the process lol.
Although some rifle/loads may be harder to find a lower node most will show one lower down from too hot. It may require changing powder/charge/primer/seat depth/neck tension combos but there should be one hanging around.
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