Author Topic: 375 H&H load ? (Read 2204 times)

Old Moss · « **on:** July 09, 2010, 03:58:33 PM »

Good evening Gents

Quick question, Took my CZ 550 375 H&H out and tried a new load, 300gr Sierra Sptz BT, Win Case, Rem Lg Mag Primer, 76gr of Win 760 powder. With a 24.5 inch Bbl I was getting average 2600 fps 15ft from muzzle, 89 deg weather.

Cases extracted fine, primers flat but did not fill all the pocket and still had rounded edges and no cratering. measured just in front of belt was 0.513 compared too - once fired and sized case which measured 0.511 inchs

Should I back off a grain or two?

The hard part is I shot an honest 4 rounds into 1/2 inch at 100yds. This will become my everything load except for big buff.

The manuals say that max load for Win 760 and a 300gr Sierra should be 2540fps at 77.5 to 78 grs of powder in a 24" Bbl.

Would like to pass the rifle on to my grand kids some day, don't want to blow it up or batter it to death.. Any recommendations are appreciated Thanks Old Moss

FN in MT · « **Reply #1 on:** July 15, 2010, 10:17:10 AM »

  Each barrel is different...but sounds a little hot to me...2600 fps! If it was me I'd back it off a grain or two and see how that chrono's and shoots. I'd be happy with 2500 fps and the 300 gr slug.

  I use RL-19 and the 300 Sierra. They are very accurate bullets. My loads go 2550 or so and can go an inch or less on average. Have a 760 load as well...but the RL-19 shoots a bit better in my gun.

  For elk I shot the 300 Sierras for several years...until the Nosler partitions came back again. The Sierras will spit the lead core out most of the time on big stuff ...but mushrom nicely.
  I know retained weight is the big deal now...I could care less that the Sierras come apart. I always found the core and jacket seperate....but in a VERY dead bull.

300 gr .375" slug at a screaming 2500 fps...worked fine on this guy. And... My best "Bwana" pose as well! 1998 RSA.

FN in MT

searlock · « **Reply #2 on:** July 15, 2010, 01:19:32 PM »

From what you report it looks like a great load. That is a real good four shot group. I do not know how tough the cz is for I have not owned one. As far as beating up the weapon goes if it is like my a bolt it will batter you long before you batter it. Happy shooting. Searlock

foxx1 · « **Reply #3 on:** July 17, 2010, 07:39:40 AM »

I had a few problems with my 416 rigby.same as u did, I switch to a diff. batch of brass and it never did it.. may try a diff brass to see if it does that.

drdougrx · « **Reply #4 on:** July 17, 2010, 09:10:25 AM »

Nice load but MAYBE a bit hot. I use 72gr RL-15 with 300gr nosler partitions and they group 1" at 100yrds. I get 2460fps on average and need to go to 74gr to beat 2500 and 76 to get 2550. I was kinda worried that the load was accurate but underpowered...till I shot a bull bison at maybe 80-90 yards and bang-flop, 1-shot. Soooo.....maybe another 100fps isn't needed?

FN in MT · « **Reply #5 on:** July 17, 2010, 04:51:02 PM »

Doug,

I doubt there is an animal out there that can tell the difference of 100 FPS.

Knew a guy who hunted a lot with both the .270 and the .280 Rem...two hotly contested "Which one is better" rounds. He used 140 gr in the .270 and 150 in the .280 Rem. NP's for all his hunting. He shot antelope, spring bear, deer and elk each year. He also shot the .30-06 for several years before he started on the two others.

He stated; "Other than making sure I had the right rds for the gun...I could NEVER tell the difference between either round on game". Interesting statement.

FN in MT

drdougrx · « **Reply #6 on:** July 18, 2010, 03:36:32 AM »

Thanks FN...I believe that you are correct! In the Africa thread, JJ Hack was discussing the velocities that he gets with his 375HH and 300gr bullets. I was curious about mine, have a chrono and had at it. I was surprised that my loads were not anywhere near the velocities that I thought they would be.

No matter...the killing power was way more than I expected and I'm very pleased! Same thing happened with my 45/70. I use a 350gr speer sp over 46gr of IMR4895 and a velocity of 1700fps. Had them up to 1970fps in my #1 but man...worse recoil than my Ithaca 37 slug gun. Flattens big (over 300lb) hogs like all get out.

FN in MT · « **Reply #7 on:** July 18, 2010, 05:38:30 AM »

The .45-70 has always been one of my favorites. Reminds me a bit of the .45 Colt..despite being 100+ yrs old...both can still show the current upstarts a thing or two...especially on game.

Had a Ruger #3 30 years back. Loaded some hot 350 and 405 loads and also found out all about the Laws of Physics.....opposite and equal reactions, etc. Dang those little #3's CAN kill on BOTH ends with hot loads. A 350 gr at even 1400 or 1500 fps is still a heck of a rd for deer or elk.

I like the shot of you and the big hog! I envy you southern guys having the opportunity to hunt them as well as the usual deer. Spices things up...plus I really like bacon! Then again I suppose there are southhern guys who would kill to shoot an elk or antelope too.

FN in MT

Grumulkin · « **Reply #8 on:** July 18, 2010, 08:17:45 AM »

Quote from: Old Moss on July 09, 2010, 03:58:33 PM

Good evening Gents

Quick question, Took my CZ 550 375 H&H out and tried a new load, 300gr Sierra Sptz BT, Win Case, Rem Lg Mag Primer, 76gr of Win 760 powder. With a 24.5 inch Bbl I was getting average 2600 fps 15ft from muzzle, 89 deg weather.

Cases extracted fine, primers flat but did not fill all the pocket and still had rounded edges and no cratering. measured just in front of belt was 0.513 compared too - once fired and sized case which measured 0.511 inchs

Should I back off a grain or two?

The hard part is I shot an honest 4 rounds into 1/2 inch at 100yds. This will become my everything load except for big buff.

The manuals say that max load for Win 760 and a 300gr Sierra should be 2540fps at 77.5 to 78 grs of powder in a 24" Bbl.

Would like to pass the rifle on to my grand kids some day, don't want to blow it up or batter it to death.. Any recommendations are appreciated Thanks Old Moss

If you're getting consistent 1/2 inch 3 shot groups at 100 yards, you're doing well. If you're getting no signs of high pressure, don't worry about the chronograph; just be happy.

By the way, some may be surprised to hear this, but a chronograph does NOT measure pressure. I never even use one in load workup because ONLY accuracy with no excessive pressure is important.

Old Moss · « **Reply #9 on:** July 18, 2010, 11:01:50 AM »

Hello Gents,

I really appreciate all the great advice! I believe I will throttle back a bit and see if I can maintain the accuracy or at least get close to MOA. Always better safe than sorry.

Quote

By the way, some may be surprised to hear this, but a chronograph does NOT measure pressure. I never even use one in load workup because ONLY accuracy with no excessive pressure is important.

Grumulkin, I have been reloading for some years and have learned that most "so called" pressure signs such as - sticky ejection or cratered primers; are not as reliable as we would like. In all reality velocity when matched with reloading manual max velocities is actually a more reliable and safer method to check pressures. I am afraid I do not have your skill in judging pressure signs (a honest complement) so I think I will stick with watching velocities.

I probably already new the answer to my question. But, with that accuracy I thought I would query the experts on the 375 H&H - which I have not loaded for much. I will back off a couple of grains and see if I can get around 2500 fps or bit less and good accuracy.

So I have heard of good and bad concerning the Sierra 300gr, Elmer Keith sure liked it, So what is the over all consensus? a lot of great bullets out there but I have some OCD = (obsessive compulsive disorder) when it comes to accuracy

This post finally got some momentum, no need to stop now what are your favorite 375 H&H Loads?

Old Moss

mauser98us · « **Reply #10 on:** July 18, 2010, 12:20:24 PM »

I use IMR 4350 in mine. Works really well in both my Whitworth and CZ.

drdougrx · « **Reply #11 on:** July 18, 2010, 03:51:24 PM »

Hey FN....if I'm a southern guy, you must be from Maine!!!

I'm from Massachusetts!!!

FN in MT · « **Reply #12 on:** July 18, 2010, 05:28:35 PM »

Quote from: drdougrx on July 18, 2010, 03:51:24 PM

Hey FN....if I'm a southern guy, you must be from Maine!!!

I'm from Massachusetts!!!

The hog filled picture threw me. Have relatives in Mass; Deerfield and Greenfield area. Also did a short stint 40 yrs back at Otis AFB on the Cape.

FN in MONTANA

Old Moss;

WHAT are you going to hunt? And where...what expected ranges?

Austin1 · « **Reply #13 on:** July 19, 2010, 10:58:57 AM »

I use N204 in my .375H&H BRNO 602 Older gun made in the late 80s and have no Trouble hitting 2600fps with 204 or IMR4350 204 works better for me and I have a stock pile of it as it was on sale for $10.00 for 500grams yep more than a pound for $10.00

But I have a fast rifle the old yellow old box of win Silvertip 300gr bullets came out at 2550fps the only factory ammo I ever tried.
One load I want to try and I still have not got around to it after more than 20 years is IMR4320 with the 270gr hornady Spire point I shot 50 rds of it at targets and gophers when I first had the gun but have never tried that load on big game.
Should be a good one a bit over 2700fps and a pointy bullet.

Doesniper · « **Reply #14 on:** October 11, 2010, 04:17:39 PM »

Your issue sounds like you may have a fat chamber.

jro45 · « **Reply #15 on:** October 15, 2010, 03:45:10 AM »

I use IMR4350 for my 375 H&H.