375 RUM 350gr. Bullets?

[bruce moulds]

toby 458,
if that was one bullet you might wonder if it hit a stick or something, but 2 bullets is forming a pattern of behaviour.
I do not blame you for your questions.
I have reappraised my thinking on this subject after seeing the above.
keep impact velocities down with those bullets.
bruce.

 

[Forrest Halley]

Well I hope your theory testing goes well. If the RUM doesn't work out, you could always build your own .375 stopping rifle on a .505 Gibbs action and use the .375 Cheytac. I'm pretty sure you'd win any penetration contest at that point and you could tailor from 175-450 grains... I just wonder how much the Cheytac would recoil without a brake...

 

[TOBY458]

i know a PH who has used 200gr .375" GS Custom bullets in a 375 H&H on buffalo. he said it provided some of the most spectacular DRT kills.

-matt

Does he have any recovered bullets for us to gander at?

 

[colorado]

I would soooo stay away from that.

 

[JMJ888]

Going to stick with Barnes load data initially and get a good baseline over chrono with the 350TSX and H2O capacity with ADG brass. Testing AA2700, H4350, and IMR4350 from Barnes data.

Once I can establish the H2O on fired case I will dial Quickload in a bit and move forward with the VV N560. RL26 actually shows to be at the top of powder query but given that it is about as rare as unicorn farts I am going to avoid it.

Should be an interesting load development project.

 

[bruce moulds]

back to the op's question.
my friend shot some std 375 Woodleigh 270 gn pp into dead camels.
at close range, one stayed in the head when shot from behind.
when I reported this here, ben kk mentioned that 300 gn woodleighs might have been a bit soft for water buffalo at close range.
Woodleigh have a harder version for tougher conditions, which might well include the 375 rum.
not sure it a 350 gn is available.
if all else fails, bill hober recommends running his swift aframes as hard as you can and hitting bone where possible.
bruce.

 

[Wyatt Smith]

Woodleigh has a 350 heavy duty round nose as well as the standard soft nose and 350 protected point

 

[IvW]

a 350gr bullet will not perform as well as a 300gr bullet on game. the only reason to use a 350gr bullet over a 300gr bullet would be the higher BC for long range shots (400+ yards). a problem the 350gr and even the 300gr TSX will have is traveling in a strait line when inside an animal. expanded bullets of greater length are more likely to tumble inside an animal which will change the bullets course and could lead to missing the vitals on less then perfect shots.

for close range dangerous game id take a 235gr TSX pushed to 3000fps over a 350gr TSX at 2500fps any day! most people are too stuck in the past to use lighter mono-metal bullets so a happy medium would be to use the 270gr TSX pushed as fast as you can.

-matt

What!!!

You have no clue about hunting and STOPPING DG at close range with a 375 caliber rifle....

A 340, 350 or 380 gr Rhino bullet will outperform any 235 gr TSX all day any day under the most dire situations on DG every time...and they will keep going in a straight line much better than any 235 grainer! SD and momentum is what is needed for DG not BC!!!

You wanna shoot 235 gr or close to buy a 338....

 

[IvW]

And so will a good premium 300 grainer...which should be the minimum weight for the old 375 H&H.

 

[IdaRam]

a 350gr bullet will not perform as well as a 300gr bullet on game. the only reason to use a 350gr bullet over a 300gr bullet would be the higher BC for long range shots (400+ yards). a problem the 350gr and even the 300gr TSX will have is traveling in a strait line when inside an animal. expanded bullets of greater length are more likely to tumble inside an animal which will change the bullets course and could lead to missing the vitals on less then perfect shots.

for close range dangerous game id take a 235gr TSX pushed to 3000fps over a 350gr TSX at 2500fps any day! most people are too stuck in the past to use lighter mono-metal bullets so a happy medium would be to use the 270gr TSX pushed as fast as you can.

-matt

Matt, are you referring strictly to the 350 gr TSX here? "a 350gr bullet will not perform as well as a 300gr bullet on game" seems like a pretty broad net to cast.
Regardless, 235 gr TSX is no way, no how the best choice for DG. 275 gr CEB TSG Safari Raptor at 2600 fps, 300 gr A-Frame at 2400 fps, or 350 Rhino at 2250 fps win hands down every time in my opinion.
Of course, I'm not that big a fan of the TSX anyway, so...

 

[JMJ888]

Finished up the first phase of load development with the 350gr. Barnes TSX and IMR 4350 powder in the Ultra Mag. Used new unfired ADG brass with charges of IMR 4350 from 80-85gr in 1/2 gr increments lit off with Federal 215 GM primers. Outside air temperature ranged from 98-101 degrees. All velocity was recorded with a LabRadar chrono...3 shot groups fired at 100 yds. OAL at 3.595” putting the TSX 0.030” off the rifling and functioning out of magazine.

Velocity ranged from an average of 2425fps at 80.0g and peaked out at an average of 2586fps at 85.0g. I found a lower accuracy node at 80.5 and 81.0gr that were both sub 1”. The two that stood out were 83.5 and 84.0 loads by far.

83.5g - 2529, 2529, 2529 - ES 0, SD 0, 0.540” group
84.0g - 2557, 2541, 2559 - ES 18, SD 8, 0.760” group

Was going to try a few other powders but don’t see much reason to at this point. 1/2” accuracy capable big bore with a ton of SD, trajectory matching the H&H/300gr combo, and the energy approaching or matching a 416 Rigby.

Will load up some rounds to confirm loads and hunt a few pigs around here, and then likely try some wet newsprint penetration tests to see how the longer TSX performs.

 

[CoElkHunter]

Have just finished up my 375 RUM build the way the cartridge should have been originally introduced. As a lefty I am a bit limited but was able to find a LH M70 CRF in 300 Win and have my smith convert it. Ended up with a #6 Krieger barrel finished at 24” with Sunny Hill bottom metal and restocked in a nice piece of Turkish by Al Lind. Swaro 1.7-10 sitting in Talley QR adds a lot of versatility on optics and dummy rounds feed through it like it was designed for it. Gun is a bit heavier at 10.9lbs but extra weight offsets the recoil and makes it fairly comfortable.

Had the rifle throated with 350gr Barnes TSX’s at about 3.580” in mind or even the 350 PP Woodleighs, but 300gr TSXs will work fine if my load development doesn’t work as planned. The main goal for the rifle is to mimic the classic 375 H&H 300gr 2500-2600fps “all around” combo ballistically, but with 50gr. more bullet weight putting it on par with the 416 Rigby. Kind of a “one rifle for all” concept.

Has anybody done any development with the RUM/350gr. combo? Quickload is pointing to RL26/VVN560/MRP/7828 SSC for higher velocity (2550-2600) and H4350/H4831SC for lower end 2475-2500). I have N560 and H4350 on hand and will likely start there but wanted to see if anybody had notes to compare first.

Do all the RUMs have rebated rims? I know the .300 does. I’ve read where the rebated rims are not ideal for DG, but maybe it’s not a big deal? Thanks!

 

[JMJ888]

Do all the RUMs have rebated rims? I know the .300 does. I’ve read where the rebated rims are not ideal for DG, but maybe it’s not a big deal? Thanks!

Yes it’s rebated 0.016”. Less than half of the 0.039” rebate on the 500 Jeffery. No feeding or extraction issues on the rifle and would have zero issues taking it after DG

 

[CoElkHunter]

Yes it’s rebated 0.016”. Less than half of the 0.039” rebate on the 500 Jeffery. No feeding or extraction issues on the rifle and would have zero issues taking it after DG

Thanks! So why design the rebated rim into the various cartridges in the first place? What’s the purpose? Thanks!

 

[bruce moulds]

to fit a std boltface?
bruce.

 

[Hoss Delgado]

I have been so content with 300 grain Cutting Edge Monolithic meplat brass Solids , than l never bothered to go to 350 grain... BUT
Woodleigh does a 350 grain Soft nose and Full metal Jacket for the .375 bore

 

[CoElkHunter]

to fit a std boltface?
bruce.

Bruce,
I don’t know for sure, but I would think a CRF rifle wouldn’t work with a rebated rimmed cartridge?
CEH

 

[CoElkHunter]

Have just finished up my 375 RUM build the way the cartridge should have been originally introduced. As a lefty I am a bit limited but was able to find a LH M70 CRF in 300 Win and have my smith convert it. Ended up with a #6 Krieger barrel finished at 24” with Sunny Hill bottom metal and restocked in a nice piece of Turkish by Al Lind. Swaro 1.7-10 sitting in Talley QR adds a lot of versatility on optics and dummy rounds feed through it like it was designed for it. Gun is a bit heavier at 10.9lbs but extra weight offsets the recoil and makes it fairly comfortable.

Had the rifle throated with 350gr Barnes TSX’s at about 3.580” in mind or even the 350 PP Woodleighs, but 300gr TSXs will work fine if my load development doesn’t work as planned. The main goal for the rifle is to mimic the classic 375 H&H 300gr 2500-2600fps “all around” combo ballistically, but with 50gr. more bullet weight putting it on par with the 416 Rigby. Kind of a “one rifle for all” concept.

Has anybody done any development with the RUM/350gr. combo? Quickload is pointing to RL26/VVN560/MRP/7828 SSC for higher velocity (2550-2600) and H4350/H4831SC for lower end 2475-2500). I have N560 and H4350 on hand and will likely start there but wanted to see if anybody had notes to compare first.

I’m assuming your .375 RUM with a rebated rim is still a CRF action after the conversion? I have been wondering if a CRF would work with a rebated rim cartridge? Thanks!

 

[Wyatt Smith]

It should work fine as long the rim can slip under the extractor. Cz550 in 500 Jeff?

 

[CoElkHunter]

It should work fine as long the rim can slip under the extractor. Cz550 in 500 Jeff?

Thanks!