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CZ Varmint and the 35 gr Berger

Posted: Sat Sep 08, 2007 6:31 pm
by montana hunter
I wanted to know if any other CZ varmint owners have chronographed there loads with this bullet. I am finding my chronograph results considerably slower than what I expected. My tube is 25.6". I was expecting maybe an extra 25-50 fps? One such reading I got consistent 3800fps velocity from a max load of H335 which hodgedon listed above 3900? Maybe just par for the course inflated fps published? I am just wondering where I stand compared to others with same model. I would not mind hearing any chrono'd velocities with same bullet and your barrel length/load etc. Thanks Greg

Re: CZ Varmint and the 35 gr Berger

Posted: Sat Sep 08, 2007 7:48 pm
by skipper
montana hunter

Here are some chronograph results using RE-10X and 35 gr. Bergers. These were shot out of a 26 in. barrel. (not a CZ though) All are Average Velocities of 5 shot groups. As you can see, you should be able to get them flying well above 4000 fps. As always work up slow and watch for signs of pressure.

23.6 - 3694
23.8 - 3769
24.0 - 3784
24.2 - 3882
24.4 - 3855
24.6 - 3905*
24.8 - 3963
25.0 - 4068
25.2 - 4041
25.4 - 4053
25.6 - 4074
25.8 - 4118

* most accurate

Re: CZ Varmint and the 35 gr Berger

Posted: Sat Sep 08, 2007 9:40 pm
by montana hunter
Thanks skipper, I appreciate the feedback, I want to try some 10X powder. I will head back to the range this week and get do some more testing etc. It seems you have done some extensive testing. The only source other than your here I found for the 10x with this bullet comes from Berger and he listed max load at 23.8gr 10X at 3821-Walt noted "Load data was generated using Quick Load and a 26 inch barrel and a COAL of 2.220 inches and your COAL and velocity could be a little different."
I have never strayed much over published max load, kinda makes me nervous. But it seems your loads are about 2 grains over what he was showing. Any advise for working up a load over published limits? I always where safety glasses and look for pressure signs but anything else your looking for or want to be aware of? Thanks Greg

Re: CZ Varmint and the 35 gr Berger

Posted: Sat Sep 08, 2007 9:45 pm
by Silverfox
montana hunter--I don't have a CZ, but I do shoot a Savage 12VLP with a 26" barrel. My favorite powder for the 35 gr. Berger FB HP is H4895. I use an EXTREMELY STIFF LOAD of that powder, well above the max listed by Hodgdon and my MV is 4,225 fps. It does a good job on coyotes both in knock-down power and saving fur.

The only drawback I see with the 35 gr. Berger is that it is highly subject to wind deflection and drops off rather rapidly once you get out past 200 yards or so. However, if you call them in like I do, there is seldom need to take a shot much over 100 to 150 yards.

Re: CZ Varmint and the 35 gr Berger

Posted: Sat Sep 08, 2007 10:05 pm
by montana hunter
Thanks Silverfox, I guess it is a quest for the hottest and most accurate load for me like many. I don't have any experience with working loads over max loads listed. I am familiar with signs of pressure-flattened primers/stiff bolt opening/ pierced primers/cracked cases...some of these I have seen in my .17 Remington and in other calibers. I see from reloading manuals that these max limits changed even as the new manual comes out. How do you know when to stop? Or may I ask your method when working above these listed max limits? Silverfox any advise for using drop tube for compressed loads? I know at 28.0 gr of H4895 I was about to run out of room in my new win cases. I have never used one. Sorry for all the questions, as always I appreciate everyones time and input. Thanks Greg

Re: CZ Varmint and the 35 gr Berger

Posted: Sun Sep 09, 2007 4:36 am
by skipper
If you have a chronograph you can watch for signs that adding more powder isn't making the bullets go faster. If you notice my Chrony data showed a couple of times that the velocity was less than the previous group. I didn't stop there, in both cases, because of a wild Extreme Spread. If you have a large Extreme Spread there are probably other factors that caused it such as inconsistent neck tension, etc. I have learned to reduce my Extreme Spread with more neck tension. I am currently using a .223 bushing in my die that reduces the Spread to the teens.

When you can tell that adding more powder isn't actually causing the velocity to increase, that's a definite sign of trouble. If every other time you added .2 gr. of powder produced a 30 fps increase and this time it only produced a 10 fps increase you are at max. When you reach that point, you need to back off a little. If you start getting other pressure signs before that, stop. Use all the indications.

You need to use a little common sense also. If Hornady can get their little 32s going at 4225 fps safely then I would expect that a heavier bullet (35 Berger) at the same velocity would be producing more pressure. Probably too much pressure to be safe. You have to ask yourself how much velocity you're striving for and do a little common sense feasibility test. How much velocity do you need? For what application; what will you be hunting and at what distance? How much energy do you need at that distance to do the job? A good ballistics program can help out there.

Now if you're chasing an accuracy node, you have to ask yourself if it's worth it. Why not use a node lower in charge weight as long as there's reasonable velocity. I often find a node down low in my ladder tests. With Benchmark, I've noticed that I seem to get good groups every .8 gr. increase. Currently, I'm shooting very good groups at 26.5 gr. at 3830 fps. Adding another .8 gr. would probably put me very close to 4000 fps but I choose to stop here because my goal is shooting groups at 100 yards. Benchmark is easy to clean out of my rifle and this load is easy on my barrel. That's good enough for me.

Re: CZ Varmint and the 35 gr Berger

Posted: Sun Sep 09, 2007 5:07 pm
by montana hunter
Thanks Skipper I appreciate your advise. :D Greg

Re: CZ Varmint and the 35 gr Berger

Posted: Sun Sep 09, 2007 8:20 pm
by Silverfox
montana hunter--I definitely DO NOT encourage anyone to go above the recommended maximum loads listed by the powder and bullet companies. Like skipper mentioned, there are certain pressure limits these modern rifles are safe to shoot at and if you go above those pressure limits you are flirting with DANGER!!!

Skipper also has a good suggestion about using a chronograph and watching for plateaus in velocity. This is a procedure that I follow in my reloading process. I also pay close attention to the shoulder shape on the primers, whether primer pockets are getting loose with certain loads, and the old bolt lift problems high pressure loads sometimes produce. While it has been hinted by skipper that the load I use produces too much pressure to be safe
If Hornady can get their little 32s going at 4225 fps safely then I would expect that a heavier bullet (35 Berger) at the same velocity would be producing more pressure. Probably too much pressure to be safe.
Who says that Hornady is pushing the pressure of their 32 gr. loads to the maximum recommended pressure limits????? I would be extremely surprised if they were. There are too many law suit happy folks out there for any powder/bullet/gun manufacturer to suggest load data or sell ammo that is at or over the maximum pressure limits for a given caliber. But, while I have NEVER had problem one with this load, that does not mean other shooters won't have pressure problems so I'd suggest you stay within the manufacturer's listed load maximums.

For me, the 35 gr. FB HP Berger moving at the velocity I am getting is working GREAT for me. This load is extremely accurate in my Savage 12VLP--more accurate than any other load I have tried, including loads at velocities from the 3,800 fps range on up. I have put in my time at the range and done plenty of testing to the point I am very satisfied with my load for the 35 gr. FB HP bullet. The higher velocity helps this low BC bullet buck the wind and gravity much better than if I were to shoot it at 3,800 fps or 3,900 fps. We do have LOTS of wind up here in North DaColder. Also, this bullet has not worked nearly as good on coyotes at the lower velocities, so I will stick with the faster loads.

Here are a couple 100-yard targets with my load for the 35 gr. FB HP Bergers

Image

Image

The other load I had fairly decent accuracy with for these 35 gr. bullets was 28.0 gr. of H4895. My velocity with that load was 3,875 fps, but it did not give me as tight a group as my HOT LOAD did. I do know several .204 Ruger shooters who are using 28.0 gr. of H4895 with the 35 gr. FB HP Berger and are getting pretty good results with them on coyotes.

I experimented with the 39 gr. Sierra BlitzKings on a couple of coyote depradation outings this past spring and liked the results I got on coyotes. Small entrance wounds and no exits. However, I only shot two coyotes with those bullets. One at 40 yards broadside and the other was about 100 yards away and broadside. The 39 gr. Sierra BK has a superior BC when compared to the BC of the 35 gr. Berger. If it keeps making itty bitty entrance wounds and doesn't blow baseball sized holes out the other side of a coyote, I may just put my 35 gr. Bergers on the shelf.

As for a drop tube setup, here is a setup I have used once in awhile to get a little more powder in the casing. I have found, though, that dropping the powder from the pan and making it hit the sides of the funnel and swirl down into the casing while holding the pan about 3 to 4 inches above the funnel works about as good as this drop tube combination I have in the photo below.

Image

Re: CZ Varmint and the 35 gr Berger

Posted: Sun Sep 09, 2007 9:00 pm
by montana hunter
Thanks Silverfox, I appreciate the additional information. I will do some more testing at the range and see what I can come up with. I started with these 35gr pills because so many have good terminal performance on coyotes with them. I wish it had a higher BC but it is what it is. I might try some different pills down the road, as always I appreciate the input of others and THANKS for everyones help. :D Greg