I loaded several rounds at the lower end of the velocity range to get "acclimated" to my first big bore.

270gr Hornady SP's over 58-60grs IMR4895
300gr Hornady RN's over 58-60grs IMR4895
220gr Hornady FP's over 76-78grs RL15

Not really intending to do load development, I just wanted to pull the trigger and get used to the recoil and the feel of this rifle. Using only the open sights as set from the factory I first set up at 100yds. This was waaaay too ambitious on my part as my eyes sure ain't what they used to be.

The 270gr rds were hitting ~12+" low and 12+" right. I assumed this was a combination of using open sights and the sights not adjusted for this load. Similar results with the 300gr rds. Overall, at these velocities, the recoil was a non-factor.

I then moved in to 50yds. Better target visibility but still not great (indoor range). The 270 and 300gr rds were low and right by about 6". The 220gr rds were pretty much dead-on and I was able to get a ~2", 5-shot group.

In total, I fired 25 rds: 10 x 270gr, 5 x 300gr, and 10 x 220gr. The 220’s actually kicked the hardest of the three.

So, the “Good”:
- The rifle fit me well and it was not nearly as intimidating as I was expecting.
- There were no issues with feed and extraction. The action was a little rough especially when feeding the short 220gr rds from the left side, but this seems like a normal phenomenon with a brand new CZ.
- I was certainly the center of attention on the range with this thing which was interesting.
- I’m definitely ready to load up to full velocities.

The "Bad":
- How does a 220gr bullet hit dead on at 50yds but 270 or 300gr bullets land 12MOA low and right? I would think the factory regulated sights would have been closer than that with all loads at 50yds.
- Easily adjustable sights sure would be nice from the factory rather than having to grind the rear or replace front posts.
- Copper fouling was pretty bad. All lands had a nice coating over almost the entire barrel. I foamed it 4 times back at the house and was able to get it out.

Overall, I like this rifle. I don't really know what I have yet as far as accuracy potential and recoil. I have convinced myself it’s time for a scope and some full-power loads before I can draw any real conclusions.

quote:

- How does a 220gr bullet hit dead on at 50yds but 270 or 300gr bullets land 12MOA low and right? I would think the factory regulated sights would have been closer than that with all loads at 50yds.

Factories regulate with factory ammunition or a laser (I don't know which CZ uses, or even if they regulate the sights at all), and neither is likely to match your handloads' POI.

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- Easily adjustable sights sure would be nice from the factory rather than having to grind the rear or replace front posts.

You expect too much for a few hundred dollars. Replace the sights with NECG sights; problem solved.

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- Copper fouling was pretty bad. All lands had a nice coating over almost the entire barrel. I foamed it 4 times back at the house and was able to get it out.

That's typical, and nothing to worry about. I certainly wouldn't go crazy trying to clean the bore down to bare metal as some fouling will be deposited with the very next shot, and you're not going to shoot enough rounds to have fouling become an issue with regards to accuracy.

Welcome to the Big Bore Club.

George

Aye, the 58 to 60-grain charge of IMR-4895 with 270 to 300-grain bullets is a very low-ball load.
Your bullets are just plodding.
No wonder they are so low for POI.
Not enough recoil to raise the muzzle, and too much time for gravity to act on them before they get to target.

Step up the powder charge and watch the POI and POA get closer together.
You might find they shoot really close to your reasonable 220-grain load, with little work on the sights required.
The windage difference can be related to barrel dynamics, and/or you may need some drift on the rear sight.

Start with 65 grains of RL-15 and the 300-grainer and work up to 72 grains.
A couple more grains than that may be required for the 270-grainer.

You really have to get close to the standard factory ballistics. That is 72 grains of RL-15 with 300-grainer in most of the .375 H&H rifles I have loaded for.

A beautiful thing about the 375 H&H, when you load’m up, seems like no matter what weight of bullet I shoot, the POI is very close to being the same, I can't remember the last time I made an major adjustment to my scope (1.5x5 Leupold) even though I tinker with different weight bullets, I like target shooting with 235 Speer and hunt with 270 or 300 Barnes & Swift, even 300 solids hit the target at same place out to 100 yards

My experience too is that they seem to do better with a little higher power factor. My 2800fps 225gr Hornady shoots to exactly the same POA at 100 yrds as does my 2700fps TSX load.

I HOPE YOU LIKE YOUR CZ AS MUCH AS I LIKE MINE.
MINE WILL FEEDEVERYTHING THAT HAS BEEEN PUT IN THE MAGAZINE.
IT WILL SMOOTH UP QUICKLY.

One thing that's kind of counter intuitive is the effect recoil has on point of impactin the larger calibers. My friend has a 454 Casull revolver and the slower rounds shoot "higher" because the muzzle lifts more before the bullet leaves the barrel. +1 on the NECG sights by the way.

Regards,
Chuck

Made my second range session on Saturday. This time, based on input I received above, I took along some hotter rounds along (270gr Hornady over 71 and 72 grs of RL15).

Recoil was still completely manageable and they were hitting POA at 50yds, just like the 220gr rounds from the previous session.

I get the feeling the groups would improve substantially with the addition of a scope or with a lot more practice over these open sights. I would have 2 shots touching, then the next 2 would be touching about and inch below, and the fifth would be off by itself an inch above the first 2. In each case I felt like the variation was my fault due to the unfamiliarity with the sights and lack of a consistent cheek weld (and vision not being what it used to be).

So overall, I think this is going to be a keeper. My fear of having to learn to handle this level of recoil seems like it won't be a problem. Unless something completely falls apart, I am a happy camper. Thank you all for your input!

A CZ doesnt fall apart particularly often, so I think you can consider yourself a happy camper!

Try 76.0 gr of ww760 and a 300gr Nosler sp. Every .375 H&H I've ever shot would put that bullet into a inch at 100yrds with a scope. Even with open sights and offhand you should be able to keep all your shots in 2".-Rob

OPEN SIGHTS AND OFFHAND=2" groups at 100 yds??? Sign up for the Army Marksmanship Unit immediately---they need you!!

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OPEN SIGHTS AND OFFHAND=2" groups at 100 yds??? Sign up for the Army Marksmanship Unit immediately---they need you!!

That would be some shooting with those express sights. I think his post said 50 yards. My best open sight group was 100 yards with a Swiss 1911 with a Furter rear sight(adjustable leaf) at 2 1/1 inches off a bench and I doubt if I could repeat it. Nowdays with my CZ 375 at 50 yards shooting fairly quick offhand I can get about 3-3.5" on a good day. If I were to hunt dangerous game I would mostr certainly practice like this much more.

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Originally posted by xs headspace:
OPEN SIGHTS AND OFFHAND=2" groups at 100 yds??? Sign up for the Army Marksmanship Unit immediately---they need you!!

While it was the US Army that taught me to shoot several years ago, I have to admit it was 2" at 50yds.

But when my eyes were younger, it sure was fun to drop those man-sized silhouettes at 300M with open sights on an M16A2. Not sure I could pick them out from the background now.

I load the 300 Hornady RN Interlocks with 76.3 IMR 4350, the max load in the Hornady manual. I get excellent accuracy with that load. That's my practice load.

As you have noticed, Hornady bullets cause substantial copper fouling. I usually run a copper cleaner through my rifle after 20/25 rounds and get most of it out. It will affect accuracy after 25 rounds or so in my rifle.

BTW, I'm shooting a 24" bbl. Model 70 Safari Express.

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Originally posted by Robgunbuilder:

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Originally posted by Robgunbuilder:
Mr julian 1970- I was attempting to help you with a load of known and verified accuracy that took me years to verify. It seems your more interested in questioning my accuracy claims than finding a load that actually works! Sorry I provided it in fact! While I was intending to mean 2"at 50 yrds offhand, Do you REALLY think 2" at 100 yrds offhand is phenomenal shooting with open sights? If so, then lets get together and shoot for money! Heck I'll use a old Win .375 H&H with open sights and lets shoot 100m, 200m , 300m and 600m. You bring lots of Money. I'm in Vegas and I'm an old fart my eyes just are not what they used to be. -Rob

Rob.. no offense intended on my part. I thought "xs headspace" was commenting on my post about my groups during the second trip and was responding to him. Re-reading the string of posts I can see how I might have confused the story.

I definitely appreciate the load info.

No offense taken. Try the load, start at 72 grs and work up just to be safe. BTW I consider 1"-1.5" at 100m offhand as just good competitive level shooting. Their are guys who can do that with Encore pistols.Nearly anyone can shoot 2" at 50 yrds with a accurate rifle if they practice. I've personally shot .3" groups off the bench with a scoped gun with that load and so can you! Just trying to speed up your learning curve. You can do amazing things with a .375 H&H. It is a cartridge that often will shoot various bullrt weights to the same point of aim. I would also suggest that you JB the bore every 10 shots ( 20 strokes with a tight fitting patch coated with JB, then clean )till the copper fouling goes away. copper fouling is usually a result of "stepped" button rifling" and hurts accuracy as it builds up. Its never a good sign, but can be minimized and sometimes eliminated by carefull barrel breakin.Seriously, shoot your .375H&H at a paper plate offhand at 50 yrds till you can shoot a large one hole group. You will enjoy it most that way!-Rob

I would just stick with the 300 grain bullet weights and not play around with the 220 and 270 grain bullets.

Thats the best bullet weight for the 375H&H. If you want less recoil and flatter shooting, there are other calibers.

375 H&H is the KING.