I have yet to find a load for the 235 SP that groups better than about 1.5 inches for 3 shot group at 100 yards. I have been concentrating on RL-15.

What kind of accuracy are others getting with this rifle? Maybe this is as good as it gets.

thanks rch

I never got my CZ550 375 to ever shoot really good groups. RL15 was one of the best powders for velocity. I do remember the 235 was particularly bad. 300gr then 270's were better. The throat and freebore section is VERY long. 300gr Horn. RN was totally out of the case before it engaged the rifling. I sold the gun and the test targets went with it so don't remember actual group sizes but you are doing better than I did. The strengths of the gun are 100% function, 5 down, steel and wood mo plastic and fed like a champ. Great execution of a M98. I loved the gun but just had to get something bigger. Maybe someone else is getting better results.

I could not count the number of 375s I have owned and also many other where I have had direct involvement.

Rifles have been main M70s and Also the early Sako and Mark V Wbys.

78 grains of Win 760, full length sized brass and Fed 210 primer with 300 grain Hornady round nose was always my " go to load" for testing a 375. I can't recall an accurate 375 failing to shoot tops with that load....to the point I that load did not shoot then there were problems with rifle, scope or mounts etc. or all of them together.

Same load was tops with 300 grain Sierra but I have not used that bullet in nearly as many rifles.

In general I found the 375 to be load fussy with lighter bullets and especially spitzers. However some of that problem dissolved when Reload 15 became available.

I found 270 grain Hornady spitzers good with R15 but otherwise very fussy but not so the 270 grain round nose. I don't know the reason as the Hornady round noses (at least years ago) are below bullet diameter in front of the cannelure so not a freebore situation when compared to spitzers.

However, R15 is the powder that gives the best velocity and best accuracy over the widest range of bullets.

As Dan 416 said the 375 has a long jump. Of course with the original bullets and also Winchester 270 grain Power Point and 300 grain Silvertip this was not the case due to the bullet shape.

Actually the H&H has almost the same distance to the rifling as a 375 Wby, however, the Wby free bore is a parallel section that is specified as .0005 over bullet diameter.

While I don't have a CZ 550 in 375 H&H, I do have a left handed Zastava Model 70 in that caliber. 64 grains of RL 15 gives 2350 with a 270 grain Barnes, and it will stay in .650 to .700 at 100 yards if I do my part. Try a heavier bullet at a moderate velocity, and I think your groups will improve.

RCHOUSER,

I think you'll find a number of folks will come on telling you that their CZ 550 is quite accurate. As for the 235 SP (I'm assuming Speer) has never shot well for me in several 375's but I'm sure other's mileage has been better.

Mark

quote:

Originally posted by MARK H. YOUNG:
RCHOUSER,

I think you'll find a number of folks will come on telling you that their CZ 550 is quite accurate. As for the 235 SP (I'm assuming Speer) has never shot well for me in several 375's but I'm sure other's mileage has been better.

Mark

I agree with Mark and would try a heavier bullet. In my CZ 550 375 H&H before it grew up, Swift A-Frame 250g shot sub-inch for me as do the 300g A-Frames. I had it rebarreled to a 500 Jeffery by Harlan at Triple River and the 1 in 10" McGowen barrel shoots lights out.

I got a box of free Hornady 235s. The only thing they are good for in my gun is to fire form new brass to my gun - they shoot 3 MOA where heavier bullets, from Barnes 250 TTSX to 300 grain Hornady round nose will shoot MOA or better.

Your gun doesn't like those light bullets. (Neither do a lot of other .375's.)

I just ordered in some Sierra 270's. I held back on the 300's because the one I wanted to try was out of stock.

I will try the 270's and see if things "tighten up".

thanks rch

Try different bullets. My 375 (Mauser M03) will only shoot Barnes (300 TSX and 250 TTSX) and Norma 203B well. Everything else is horrible.

My experience with two factory CZ Lotts was not good accuracy wise.Both had terrible oversized barrels with very shallow rifling.The only bullets they would shoot somewhat accurately but not for long were the soft pointed Woodleighs.Everything else was spray city.

Mine shot well with 300 Hornadys RN, and 270 and 300 TSXs. I seem to remember 270 Rem factory loads that I was shooting up for brass being quite good. Anything that had much slope to the nose was crap. The long magazine helped a lot, the Barnes eventually had a couple grooves hanging out before it died altogether. 2400 rounds if anyone cares.

W760, H414 and a surplus version of the same were the powders of choice.

I have custom CZ550 Magnum in .375 H&H. I can shoot into 10 mm diameter steel rod at 100 m easy with 300gr A-Frame and RL-17. It will print one nibbled hole if fired from the rest. It will not print more than inch at 200m, if reasonable wind.

Jiri

If you want a light bullet load; you may want to give the 235 grain CEB a try. Accuracy and a non sensitivity to jump seem to be characteristics of design
design of these lathe turned bullets. Load developement has seldom amounted to
More than finding maximum.

Jiri, may I assume that you are no longer shooting a stock CZ barrel?

Dogleg, I have a bunch of 760. I love it in my 260rem and 243ai. I will give 760 a try as well.

It may just be that I need to get up to the 270 and higher bullets.

thanks to all rch

I've had a CZ .375 H&H for about eight months now and I will say it's taken a fair bit of patience to find an accurate load for it. I tried four different bullets and three different powders including Re15, but none with good results.

Then just recently I tried IMR4350. You don't normally see that recommended for the .375, but it's working for me. With 79.0 grains and 270 grn TXS's I'm finally getting less than moa. I've only shot a couple of groups with that load so far, but haven't been able to do that with anything else I've tried.

quote:

Originally posted by RCHOUSER:
Jiri, may I assume that you are no longer shooting a stock CZ barrel?

It is stock barrel, but chamber polished and other works made. Not sure if barrel was removed and assembled again or not. It has custom stock etc. Maybe factory bedding is not the best too.