Reloading big bore techinque vs others

[CIG]

Just bought my first big bore, .375 H&H and was wondering if people work up loads differently than with standard cartridges.  I usually start at the bottom by the manual and load one round increase per grain up to the top - ladder loading.  I pattern and find the spots that group.  I load in the middle of that group and check for accuracy.  Now those have all been match guns and usually the first group load shoots great.  This seems like a lot of rounds through a gun that will not be shot anywhere near as much as a match gun.  I was thinking run the thing at about 2,700 FPS and I get drop about like my .270 with 130 grain bullets.  If that is what I want, should I just load rounds near there for accuracy?  Just wondering if I'm missing some technique for these big bores.  Thanks.

[GrassLakeRon]

I have been loading the 375 for about 5 years now.  I looked and reading several internet sources and sent emails to a few folks who owned them.  I finally settled on a load that was not max but close enough.  It gave me good results on accuracy.  I have found that IMR-4064 works well on the accuracy and is my "go to" powder for the 375 using 270 and 300 grain bullets.  A 270 grain Hornady SPBT and 72 grains of IMR-4064 gave me .92" groups at a 100 yards in a remington 700.  Not a max load, but a good one.

Ron

[Catfish]

I would start at the bottom and fire at least 1 round each powder level to check for presure signs. If all is good try a load and if the accuracy is suitable to you that`s all you need for a hunting gun. A 4 in. group at 100 yrds. is good enough if all of your shots will 50 yrds. or less at big game and off handed. If your going to be shooting 400 yrds. I would like 1 in. groups or better at 100 yrds.

[Steve P]

I usually read up on the cartridge before reloading.  See what several reloaders manuals say.  What is their best accuracy load?  What do the gun writers say?  Any articles on the internet about your gun? etc etc.  After getting read up, I choose a load somewhere in the mix of my new knowledge.  If a gun writer says he got good accuracy with factory ammo at 2700 and a little better accuracy with hand loads at 2800, I would choose a load in this area and start there.   I load up 5 cartridges in 1.0 grain increments.  I shoot three shot groups as I work my way up.  If any load or even several loads show some respectable grouping at the end of the session, I shoot two more shots into the group.  Hence my 5 of each load.  If I find that best accuracy is between 50.0 and 53.0 grains, I will load up some loads in .5 grain increments.  If I get groups getting smaller and smaller to 49.0 and then at 50.0 and above they start getting bigger, I may load up some ammo at 49.2, 49.5, 49.7, 50.0 etc to find that sweet spot.  

A lot depends on how much time you have and the size of your wallet.  If you want to dial in a Barnes bullet, it is going to cost you some bucks.  If shooting a Rem Corlokt bulk bullet gets you in the ball park, so much the better.  I have several guns where the sweet spot didn't come.  After 100+ round of different loads, its on the back burner until I get some different powders or different bullets to try.

Doing the homework ahead of time does help narrow the possibilities to some extent.

Steve

[huntswithdogs]

I tried starting low on one Mag cartridge and haven't done it since! I now start in the middle of the charts with any new cartridge I'm playing with.

HWD

[mcwoodduck]

While you do not want huge groups this is a heavy meduim bore and you are not going to be shooting ground hogs with it at 300 yards,
This is not where Varmint accuracy is needed.
You will be shooting at Deer and larger game out to meduim ranges.  say 30 to 250 yards.
Not sure what you are planning on using it for.  But I am guessing Elk, Bear, Moose, Africa or what have you.
That big 270 -300+ grain slug is going to do something and at 2600 to 2700 FPS it will produce well over two tons of foot pounds of energy. 
I sighted mine in at 100 yards as was happy with my group.  I then resighted in the gun to 200 yards and while my group did open up from the 100 yard group I am still confidant if an (insert big animal) is 250 yards or under I will be able to make a lung shot off hand.  If you are thinking bear, even a 4" group will still be a head hit on something running at you.

[CIG]

I just shot this .375 H&H for a break in of 10 rounds at the lowest level of powder.  I think off the top of my head for 275 grain Hornady bullet under 65 grains of Varget - maybe it was 60 grains - whatever the Hornady manual said to start at.  I was able to get a four inch group at 100 yards with my last 5 shots.  I was reading Hunting Africa a Practical guide and that guy says reload at the lowest level because it might be at the max level from the start.  He says you need a chronograph, well I don't have one. 

I was planning on just going up one grain at time until I hit pressure signs - flat primers or sticky bolts.  Now that is something I have never actually had happen following a loading manual.  Are these big guns more temperamental than the 30-06, .270 or 7-08 that I currently load for or all the pistols I load for?   

[Dand]

This is why I became a fan of Ken Waters and his Pet Loads. I have had great luck with the top performing combinations he recommended for 30-06 and 300 win mag, 223 rem. Saved me some $, time, and get me off to a good start. I'd start a little lower than his one of his "pets" and work up. But reading his articles and checking other books along the way so I knew where I fit on the pressure & performance scale. He tends to be conservative, not pushing limits as much as Bob Hagel and others did.

CIG - regarding that book you are reading: could be since its talking about Africa, he may be warning that a mild load developed at 30-50 degrees in the US may be close or over max on a very hot day in Africa with ammo baking in the sun. Depends on powders and such but I have read numerous references / warnings to consider the heat likely to be encountered in the field. Now these more modern "extreme" powders and such are less heat sensitive - buy its something to keep in mind.

I usually don't start at the very bottom load in a book unless I have reason to believe that my gun might be sensitive. I might start a grain above the minimum, load 3 and see how they do. Go up a grain or 1.5 and try again, depending.

One thing, that 375 H&H is a big case and I'd doubt you'll see it react dramatically to charge variations of less than a grain unless you are really pushing the max - compared to a 22 hornet or 204 Hornady.

Given its a big whomper round you might not want to pound yourself grain by grain for too long.