375 Win Ammo/Loads

[Ranch Dog]

I hated hijacking the topic concerning the 375 Win BB so I started a new topic related specifically related to ammo and loads for this caliber. Never sure why Winchester only offered a 200-grain bullet. Also wonder why Hornady never offered factory ammo, they have a bullet and brass?

So here you go guys, give us your loads data! How about titling each reply with your bullet and Powder so they are easy to search!

[Ranch Dog]

Shot from my Marlin 375

Average Velocity: 1928 FPS
AD: 24 FPS
ES: 67 FPS
Accuracy: 1.30 MOA

Range Conditions
Altitude: 300'
Temp: 78°
Pressure: 29.67"

I've been using this ammo a "proof" ammo for my pressure testing but have never hunted with it.

[Ranch Dog]

All my load work with the 375 has been with cast bullets. Specifically, a 235-grain bullet of my design. The bullet was based on the dimensions taken from chamber casts of my three rifles with a software program dictating what the bullets final dimensions/weight would be. It does this by constantly adjusting bullet fit to balance center of gravity and center of lift. I won't get into the bullet any deeper as I'm not retailing the molds any more but you might use my load data as a reference for your work with other bullets.

My web page for this bullet is can be referenced here: TLC379-235-RF. The drawings on this page are very helpful for understand the huge chamber cuts on this cartridge.

[Hobie]

Winchester also offered a 250 gr. bullet. They dropped the load due to lack of demand. I guess it kicked too much as it went as fast as the .30-30 170 gr. and the rifles weigh about the same and have the same configuration. Some folks think the Winchester stock design accentuates recoil a bit especially when compared to more modern designs.

In a proper gun, with proper bullets, one can duplicate the .375 Win load in the .38-55 Win. One thing you shouldn't try is to load the Hornady 220 gr. for the .375 in the .38-55. The nose is just too long. However, the 220 is THE bullet for the local .375 Win shooters.

[Ranch Dog]

I've worked with 7 different loads H4895 from 35.0 to 39.0-grains.

Velocities averaged from 1760 to 1937 FPS and accuracy 3.36 to 5.56 MOA (5-shot). If you are not use to working with MOA, this would be 1.76" to 2.91" 5-shot groups at 50-yards. This is measured electronically.

Sorted by average MOA from group center, 37.5 delivered 1.354 at 1848 FPS.

[BenT]

I'm going to throw in this 38-55 load into the mix because it shoots so well. The gun is a model 94 with a 28 in Numrich octagon barrel with .375 bore. The bullet is 235GR RD sized at .377. I've tried slow to hot loads but this gun shoots this load great. 200 yard milk jugs don't stand a chance from the bench with Iron sights.

H4895 34gr
Av .Vel 1863 fps.
E.S. 21 fps.
Shoots 3/4 in at 50 yards
I'm using this load for deer hunting.

This one also shot well , but I've gone the cast bullet route.

200gr FP sierra
H4198 35gr
Av. Vel. 2205 fps
E.S. 49fps
This also shoots 3/4 in at 50 yards.

But remember I have 8 inches more barrel than most for higher velocity.

[TedH]

I shoot the Hornady 220 with 36.0 gr. of Re7. That load runs 2150 fps, and it's the most accurate load in my Winchester. I have also tried some AA1680 with the Hornday. It'll get you a little more speed but the accuracy has never matched the Re7 load. The data I've found list 38.0 gr. of RE7 as max, but I've never been able to get that much in a case and still be able to crimp to the cannelure of the Hornady bullet.

I've also developed cast bullet loads with both the RCBS and Lyman gas check designs. They both shoot well when sized .377" and ran about 1800 fps with ACWW. Work good on deer too.

[Ranch Dog]

Hobie,

I think one consideration in dropping the 250-grain bullet was pressure. If you look at the 375 Win chamber, it is cut to relieve pressure quickly. The cartridge needs high pressure to develop performance but it needs to relief that pressure rapidly. That is the basis for the differences in this cartridge and the 38-55 Win. The step/throat/leade are different. Hence the warning for the 38-55 Win using 375 Win data. It really has nothing to do with the "brass" and everything to do with the step/throat/leade and the pressure curve that it forms. I digress...

A 250-grain jacketed bullet is going to fill the chamber (step/throat/leade) compared to the 200-grain bullet they offer and the pressure effects the chamber experiences would be greater as there is less space to relief the pressure. The pressure curve would also be different, how it builds and dissipates, and I expect this had more to do with them dropping the bullet than demand. The demand for heavy 375 bullets has always been here, but there is a very fine line in putting the pressure to them for performance.

I believe the effects of pressure, not demand, had everything to do with Marlin dropping the chambering. I've owned three and examined a number of rifles. I've seen wear on the locking bolts and erosion in the throats. Making that Hornady 220-grain FP jump across that great expanse has a price.

[Ranch Dog]

I've worked with 6 diffferent loads from 28.8 to 34-grains.

Velocities averaged from 1670 to 2082 FPS and accuracy 2.89 to 5.58 MOA (5-shot). Sorted by average MOA from group center, 28.8-grain delivered 1.024 MOA at 1776 FPS.

Max pressure generated with H4198 was 67.5K PSI!. 31.4-grains delivered 58.7K PSI which is acceptable for this cartridge.

[txpete]

I shoot the Hornady 220 with 36.0 gr. of Re7. That load runs 2150 fps, and it's the most accurate load in my Winchester. I have also tried some AA1680 with the Hornday. It'll get you a little more speed but the accuracy has never matched the Re7 load. The data I've found list 38.0 gr. of RE7 as max, but I've never been able to get that much in a case and still be able to crimp to the cannelure of the Hornady bullet.

I've also developed cast bullet loads with both the RCBS and Lyman gas check designs. They both shoot well when sized .377" and ran about 1800 fps with ACWW. Work good on deer too.

+1 on the hdy 220 gr and RL-7.

the lyman 375449 sized .377 and 20 grs 2400 is very accurate also.

[Ranch Dog]

I've worked with 4 different loads of Benchmark from 32.1 to 37.0-grains.

Velocities averaged from 1632 to 1851 FPS and accuracy 2.53 to 4.62 MOA (5-shot). Sorted by average MOA from group center, 35.7-grain delivered .909 MOA at 1730 FPS.

Max pressure generated with Benchmark was 50.4K PSI.

[Ranch Dog]

I shot two loads of H4227, 26.6 and 28.0. Not good! Scared the hell out of me!

26.6-grains indicated 63.6K PSI and 28.0-grains 73.9K PSI! It kicked like it too! The velocities were 1949 and 2022 FPS respectfully.

[Hobie]

I shot two loads, 26.6 and 28.0. Not good! Scared the hell out of me!

26.6-grains indicated 63.6K PSI and 28.0-grains 73.9K PSI! It kicked like it too! The velocities were 1949 and 2022 FPS respectfully.

Can you clarify which powder you used?

In my .38-55 I use 32 gr. RL-7 (RE-7) for 1999 fps with the factory, Barnes or Stone Fence 255 gr. jacketed bullets. It seems to give pressure no greater than .30-30 factory loads. This old load has produced anywhere from 1760-2000 fps in different guns with groove diameters of .375 to .381. The larger bores producing the lower velocities and lower pressures even though they are using correctly fit bullets.

[Ranch Dog]

I've worked with 9 different loads of H322 from 28.1 to 37.0-grains.

Velocities averaged from 1808 to 2009 FPS and accuracy 1.09 to 7.79 MOA (5-shot). Sorted by average MOA from group center, 36.0-grain delivered .457 MOA at 1945 FPS. This is the load I now shoot in my Marlin 375. I figure it exceeds the velocity of the factory ammo while delivering the thump of 35 more grains of projectile weight. It is very accurate. This is what I expect at 50-yards...



Max pressure generated with H322 was 57.4K PSI.

Here is my ballistic table for my rifle with the 36.0-grain load.



Edit: added pressure data and ballistic chart.

[Ranch Dog]

Can you clarify which powder you used?

Sure I can, it was H4227. This was a primary load generated by the Load From A Disk software. The result are what I've come to expect from that program and have stopped using it. I've listed the power in the title bar of each reply but I will go back and edit the individual post.

It seems to give pressure no greater than .30-30 factory loads.

Hobie, I respect your experience but the pressure trace equipment has "learned" me that you cannot tell with most levergun cartridges especially those that are straight walled such as the 375 and 38-55 Win. The pressures generated by H4227 were not reflected in the case, only the recoil and the pressure curve display.

[Hobie]

Can you clarify which powder you used?

Sure I can, it was H4227. This was a primary load generated by the Load From A Disk software. The result are what I've come to expect from that program and have stopped using it. I've listed the power in the title bar of each reply but I will go back and edit the individual post.

Sorry I missed that. After the first post I almost never read the subsequent title bars.

I don't think H or IMR 4227 is appropriate for higher level loads in the .38-55 but is great for duplicating BP velocities with 18 gr. of either doing the job.

It seems to give pressure no greater than .30-30 factory loads.

Hobie, I respect your experience but the pressure trace equipment has "learned" me that you cannot tell with most levergun cartridges especially those that are straight walled such as the 375 and 38-55 Win. The pressures generated by H4227 were not reflected in the case, only the recoil and the pressure curve display.

Note that I said "seems". I'm fully aware of the inability to measure pressures through the laying on of hands.

[Ranch Dog]

Factory 375 Win ammo can be hard to find but Wisconsin Cartridge Company has it and they use the Hornady 220-grain bullet. I've just finished up my supply of Winchester factory ammo that I use for verification with the pressure trace gear and have will be using the WCC offering in the future. I do not have any statistics from it yet.

[Lefty Dude]

The .375 really comes alive when shot from a Ruger #3 single shot with a a Speer 235 gr. Semi-Spitzer. In the early 1980's I shot a three point bull Elk with this load & bullet. It was a quartering shot, blew out the Heart & lungs end up in the front chest between the hide and Briscuit. I cut my finger on the Jacket when skining the critter. The bullet did a perfect mushroon and shed 100 gr. of weight. I still have this slug.

At the time I also owned a Winchester BB in .375, being a Hunter at the time and not shooting cast bullets. I lost interest in the piece and sold it off.

Wished I'd kept the Big Bore .375, Would be only shooting lead in the piece now.

[thornblom]

As I remember, it was 1979, I bought the first Winchester 94 Big Bore .375 wcf to come to Marble Falls, Texas. It was at Burnham Brothers shop in down town Marble Falls. I also bought a box of 250 grain factory loads and a box of 200 grain factory loads. After a range session that weekend, I found that the 250 grain loads shot a lot better groups at 50 and 100 yards than the 200 grain loads did. I went back to Burnham Brothers and bought all of the 250 grain factory loads he had in stock, six boxes. Over the next few years I killed white tail deer (Texas and Arizona), mule deer (Arizona and New Mexico), elk (Arizona and New Mexico), black bear (Arizona) and Javelina (Texas, New Mexico and Arizona). I never recovered a single bullet from any of those animals. The bullet passed compleatly through every animal shot. And, with very little destruction of edible meat.

When I finally ran out of 250 grain factory loads, I went to the 220 Hornady and 37 grains of RL-7. It worked but the bullet came apart too easily and ruined a lot of meat. About that time Barnes came out with a 250 or 255 grain bullet for the .375 Big Bore. I worked up a load with that bullet and life was good again. Sadly, I let my 94 Big Bore get away. But just recently I replaced it with a Ruger #3 single shot that was a .375 wcf, but I sent it to JD Jones and he re-chambered it to his .375 JDJ. It has a 1.5 x 5 Leupold in Warne rings and wears Ruger #1 butt stock and forend. I load the 225 grain Hornady spire point to about 2400 ft/sec with H-4895. I have only killed Texas white tail and feral hogs with this rig so far but it does the trick, and looks good doing it. Recoil is exhillerating, to say the least.

Dave (Bubba) Thornblom

[Ranch Dog]

Here are my bad boys! Just in from checking the zero on my Marlin and everything is perfect out to 200-yards. I'm using 36.0-grains of H322 for 1945 FPS. The .379" bullet provides an overall length of 2.555" which perfectly fills the huge step/throat/leade of this cartridge. The different lube grooves accommodate the various configurations of 375 and 38-55 Win brass plus the cartridges themselves. Had I made this mold specifically for the 375 Win, that nose would have been all lead. Still I'm wondering why this is a cloverleaf shooter, might just leave well enough alone with future replacements.

[new pig hunter]

using the accepted forum slang, I am, "+2 on the hdy 220 gr and RL-7."

Great accuracy in my Marlin 375, both on paper and bowling pins at 50 and 100 yards.

Cheers,

Carl

[Old Time Hunter]

Factory 375 Win ammo can be hard to find but Wisconsin Cartridge Company has it and they use the Hornady 220-grain bullet. I've just finished up my supply of Winchester factory ammo that I use for verification with the pressure trace gear and have will be using the WCC offering in the future. I do not have any statistics from it yet.

Mike, I have used WWC's to very good effect in the past. They consistantly shot at 1980+/- one or two FPS with the chrono set at 15'. I have also found that 31 grains of H4198 and the 220gr Hornady gives a very accurate load, but also pushes the pressure issue. AA1680 can give you excellent velocity, but have not found a recipe to equal the accuracy of either the WCC's or the H4198 loads(30.5 of H4198 seems to be the sweet spot between accuracy and velocity). I believe this one below is the AA1680 loads I sent to you back a couple of years. Never paid much attention as this is at a 100 yards standing next to the bench, not resting on it.