375 BR loads anyone???

[crustyrusty]

I have just built my 375 BR and I am using 175gr Lehigh match bullets.....can anyone suggest a good load to start with?? I have quickload but it doesn't have this round in its library,so it also doesn't have this bullet in its library as well......I took the 7mm BR and swapped out the 7mm bullet and traded in the 375 bullet that closely matched was 185gr aroe bullet....it said to use 4227 powder. velocity was quite extraordinary something in the 2500fps range. so this is as close as I have gotten for now so I am thinking ……. but I want your input please!!!!! ps the 375 BR and 375 Whisper are just about identical.

 

[MClark]

Try looking at data for 375 Reaper.

M

 

[polebilly]

I,m hoping someone chimes in. I'm trying to build the entire line of BR's. So far .22, several 6's, 25BRA, 6.5, 7, and 30. Want to do 338, 35 and 375.

 

[crustyrusty]

I,m hoping someone chimes in. I'm trying to build the entire line of BR's. So far .22, several 6's, 25BRA, 6.5, 7, and 30. Want to do 338, 35 and 375.

I am really impressed with the BR lineup..... they all perform way all out of proportion to their case size... I mean who could think that a case 1.5 inches long yielding data reserved for much larger cases.....I mean my 375 BR/Whisper will take deer and bear easily with the 185gr Lehigh pill...... and with a 235gr speer an elk is on the rollcall...All of this is in quick load and muzzle energy is 2660flbs well within what needs to be for Elk....as I have stated before I call 'em the Case That Could!!!! as for the most versatile BR case my vote goes to the 7mm and/or the 30 BR.... I have a hard time picking between the two.... 7mm will push 110gr speers 3000fps and push130gr speer spbt at 2850fps and the 30BR will push a 125gr HP to 2925fps and a 150gr FMJ to 2650fps... and a 165gr spbt speer to 2545fps.. so these two cases in my mind are the two most useful of the BR family but I have no regretts in my 375 BR,, well just one actually its expensive to shoot at a buck a round.... Ohhh and yeas I have a chronograph to confirm my loads

 

[JayHHI6818]

I have a 14 inch Thompson Center Contender barrel chambered in 338 Whisper base on the 7 BR case. There is 338 Whisper #2 by SSK) is based on the .221 Remington Fireball case. I attached the load data from SSK and Sonic Velocities are impressive for a 12 inch barrel.

 

[357Mag]

Crusty -

Howdy !

How long is your rifle's barrel length ? If something like 20 - 22", you'd want to use a pretty fast burning powder.

FWIW:
I shot a .357 AutoMag-chambered rifle, set-up for true .358" calibre; to allow use of .35 calibre rifle bullets.
My rifle had a 22' custom stainless 5-groove 1-16 barrel. I got great accuracy results all the way out to 350yd ( longest distance I tried the gun ) shooting WW 296 under .358" 180gr bullets; and best groups shooting ( surprisingly ) surplus Remington .358" cal 150 PSPs ! That " .358 AutoMag " had case capacity just a tad less than what a notional " .35BR " would have. I formed my cases from 6BR and 7BR basic, and did use SR primers.

More recently, I am migrating my powder choices ( all rifle calibres ) over to powders w/ proven low sensitivity to temperature changes. I continued my .358" cal accuracy tests using a Marlin M-336 XLR .35 Rem.
A lot of people don't realize that the .35Rem has case capacity that puts ipotential powder choices square in the " benchrest" powder burn rate range. My XLR ( for whatever reason) made it out of the CT factory w/ a 1.5oz ( yes ounce ) trigger. I was OK w/ that , since I only intended to use the rifle for accuracy shooting onto paper targets.

My point:
While I obtained great results shooting the 150PSPs over a reduced charge of SR4759....... when I ran out of the 150s I switched over to shooting H4198 under Cutting Edge 150 Extended Range " Raptors ".
H4198 is the fastest burning rifle powder that ( to knowledge ) is proven to have low sensitivity to temp changes and has shown capable of providing superb accuracy in cases like .222 and .30BR. I have shot a one ragged hole 5-shot group @ 50yd, shooting the turned brass 150s over 20.4gr H4198. That is however...just 50yd; and I fer she want a valid 100yd load; so I'll be going up on charge wt when I continue my .35 Rem testing in my CVA Hunter.

Another thought:
When I first got into shooting " reduced loads " in .358" calibre, I had some concerns about the potential for experiencing " secondary explosive effects " ( S.E.E. ) . This is perhaps been shown to occur more in larger calibres ( .40" + ) when reduced charges of fast burning powder are being tried. I came across an article authored by a ballistics technician, that had performed S.E.E. testing to the point of even barrel destruction.
His data seemed to indicate H4198 was more friendly to reduced loads, than H4895. He also stated that no reduce load of any charge wt of 2400 produced any barrel failures. 2400 would be a potential fast burning powder choice for your application, however.... is not said to be temp insensitive. I have also not read that 4227 is temp insensitive. IMHO - for me, this all points towards H4198.

DK if any of that helps ?!


With regards,
357Mag

 

[crustyrusty]

Crusty -

Howdy !

How long is your rifle's barrel length ? If something like 20 - 22", you'd want to use a pretty fast burning powder.

FWIW:
I shot a .357 AutoMag-chambered rifle, set-up for true .358" calibre; to allow use of .35 calibre rifle bullets.
My rifle had a 22' custom stainless 5-groove 1-16 barrel. I got great accuracy results all the way out to 350yd ( longest distance I tried the gun ) shooting WW 296 under .358" 180gr bullets; and best groups shooting ( surprisingly ) surplus Remington .358" cal 150 PSPs ! That " .358 AutoMag " had case capacity just a tad less than what a notional " .35BR " would have. I formed my cases from 6BR and 7BR basic, and did use SR primers.

More recently, I am migrating my powder choices ( all rifle calibres ) over to powders w/ proven low sensitivity to temperature changes. I continued my .358" cal accuracy tests using a Marlin M-336 XLR .35 Rem.
A lot of people don't realize that the .35Rem has case capacity that puts ipotential powder choices square in the " benchrest" powder burn rate range. My XLR ( for whatever reason) made it out of the CT factory w/ a 1.5oz ( yes ounce ) trigger. I was OK w/ that , since I only intended to use the rifle for accuracy shooting onto paper targets.

My point:
While I obtained great results shooting the 150PSPs over a reduced charge of SR4759....... when I ran out of the 150s I switched over to shooting H4198 under Cutting Edge 150 Extended Range " Raptors ".
H4198 is the fastest burning rifle powder that ( to knowledge ) is proven to have low sensitivity to temp changes and has shown capable of providing superb accuracy in cases like .222 and .30BR. I have shot a one ragged hole 5-shot group @ 50yd, shooting the turned brass 150s over 20.4gr H4198. That is however...just 50yd; and I fer she want a valid 100yd load; so I'll be going up on charge wt when I continue my .35 Rem testing in my CVA Hunter.

Another thought:
When I first got into shooting " reduced loads " in .358" calibre, I had some concerns about the potential for experiencing " secondary explosive effects " ( S.E.E. ) . This is perhaps been shown to occur more in larger calibres ( .40" + ) when reduced charges of fast burning powder are being tried. I came across an article authored by a ballistics technician, that had performed S.E.E. testing to the point of even barrel destruction.
His data seemed to indicate H4198 was more friendly to reduced loads, than H4895. He also stated that no reduce load of any charge wt of 2400 produced any barrel failures. 2400 would be a potential fast burning powder choice for your application, however.... is not said to be temp insensitive. I have also not read that 4227 is temp insensitive. IMHO - for me, this all points towards H4198.

DK if any of that helps ?!


With regards,
357Mag

Thank you for that info,,, I really like H4198 it performs well I havent ran it yet but I have ran it in my 7mm Bench Rest with excellent results... so far of all the powders out there I have ran only Hodgdon family of powders and IMR powders and reloader 19 Barrel length is 24'' long

 

[rickiesrevenge]

You can measure the bullet and put it in the library. You can also chance the cross sectional bore area to that of a .375 and then change the groove diameter when you select a 6mm BR case. Then you'll be able to run numbers for the .375BR

 

[crustyrusty]

update! ! after much load development i settled on a speer 270 gr spbt moving 2083fps. when it came time
to sight in i was was amazed at how accurate this load really is. And the recoil is very easy to handle i didn't flinch at all. its got enough juice to go after elk out to 250 yards(with 1500 ftlbs as a minimum) and obviously
is great medicine for whitetails!