.375 Project Questions - Page 2

hhunter318 · December 2, 2012, 01:05 PM

Jimro,

Yes, I have a 7mm WSM on a blueprinted Rem 700 SA with a 30 1/2" PacNor Select Match Grade. Sits in a Choate Ultimate Sniper stock, but I'm thinking about getting a McMillan. Using a Millett LRS 6-25x56. Not the most high end scope there is but it has given me no problems whatsoever, besides being a pain in the A$$ to buy scope rings for being a 35mm tube. A buddy and I shoot out on his farm out to about 1,200 yards. I just have the urge to stretch the limit. This build is for pure fun. What direction would you take on a .375 build for long range then? 9.53 Saturn or .375 RUM? The .378 Ackley Mag sounds promising also. This build won't start til next year but I'm starting to get parts now. Your input is very very helpful.

Hayden

Jimro · December 2, 2012, 05:28 PM

Sounds like you have a good setup for pig.

A 175 gr bullet at max charge from a normal barrel 26" is 2850 with Win 780, if you used the 175gr Sierra Game King or Berger 180gr VLD Hunting with your longer barrel I'd say you should be able to get above 2900 fps without too much trouble. 2950 with the Berger gets you just shy of a mile before it drops subsonic.

If I had to choose between the 375 RUM and 9.53 Saturn I would choose the RUM. It can launch a 300gr bullet to 2,945 from a 26" barrel (alliant data). Adding five inches to the barrel should keep you above 2,900 fps with a 330 or 350gr bullet from brass that is cheaper and easier to procure (multiple vendors).

The RUM family is all based on the 404 Jeffrey case, so it isn't like it gives up much at all to the 416 Rigby based cases. The reloading data available at Hogdon is a tad anemic compared to the alliant data, but this is one of those cases where you are taking a Safari round and turning it into a long range round, so Quickload might be the best bet for figuring out the optimal powder (from looking at the data H1000 looks like a good bet with a 330 or 350 gr bullet).

Jimro

Jimro

hhunter318 · December 3, 2012, 05:01 PM

Jimro,

Not trying to make matters worse by complicating the subject at hand, but as I said earlier, I'm just brainstorming every possible option. What do you think about a .375 AX? Ballistics seem good and it utilized the stronger .338 Lapua case. Also, how much difference is there between the 9.53 Saturn and the .375 Allen Xpress? I can't find a good enough resource to get dimensions on the Saturn for a comparison.

Jimro · December 3, 2012, 11:41 PM

Using 338 Lap brass as the parent cartridge will give you thicker walls than using real 416 Rigby brass, so it is a plus in my book.

In reality, pick a cartridge and go with it. When you handload with a reasonable case, you can generally find a powder that will get you to the performance level you desire, especially if you have a long barrel. Take a look at what the Palma shooters do with the 308.

Between the RUM and the A.X. I'd be tempted to get the AX solely because of the availability of Lapua brass as the basis for the round. No one I know of ever got looser groups switching to Lapua.

However, at the ranges you are talking about shooting, the difference in a quarter MOA at one hundred yards is irrelevant once the wind picks up. But it never hurts to have a more accurate load.

Jimro

SHR970 · December 4, 2012, 12:16 AM

In my 375 RUM with a 300 gr. Hornady BTSP and 97 gr. of RL-22 I got 2850 - 2900 fps. in a 26" barrel Rem 700 AWR. I only got to fire three shots over the screens so I don't have enough data to give SD / ES, etc. That load in my gun is very accurate. Sierra says I can squeeze 2 more grains in with correct OAL to feed in my gun. BTW, at 97 gr. you are already into compressed loads.

Loaded to the cannelure; I have 3/4" of the bullet down in the brass. If I had a longer action, I would be able to load it out further and add more powder. Then if you add a long throat like a Weatherby you could get away with running it longer. Add another 6"-8" of barrel and even with a 330 gr. bullet you should be in the markers.

RUM brass is $1 a pop, 338 Lapua about $2 and 416 Rigby about $3. All three will be available for some time to come. Even if the 375 RUM was discontinued, you could form it from 300 RUM or 404 Jeff. and turn down the rim.

The RUM family uses standard Magnum bolt faces...the Weatherby, Rigby, Lapua use a less common size.

December 2, 2012, 05:28 PM	#27
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	Sounds like you have a good setup for pig. A 175 gr bullet at max charge from a normal barrel 26" is 2850 with Win 780, if you used the 175gr Sierra Game King or Berger 180gr VLD Hunting with your longer barrel I'd say you should be able to get above 2900 fps without too much trouble. 2950 with the Berger gets you just shy of a mile before it drops subsonic. If I had to choose between the 375 RUM and 9.53 Saturn I would choose the RUM. It can launch a 300gr bullet to 2,945 from a 26" barrel (alliant data). Adding five inches to the barrel should keep you above 2,900 fps with a 330 or 350gr bullet from brass that is cheaper and easier to procure (multiple vendors). The RUM family is all based on the 404 Jeffrey case, so it isn't like it gives up much at all to the 416 Rigby based cases. The reloading data available at Hogdon is a tad anemic compared to the alliant data, but this is one of those cases where you are taking a Safari round and turning it into a long range round, so Quickload might be the best bet for figuring out the optimal powder (from looking at the data H1000 looks like a good bet with a 330 or 350 gr bullet). Jimro Jimro __________________ Machine guns are awesome until you have to carry one.

December 3, 2012, 11:41 PM	#29
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	Using 338 Lap brass as the parent cartridge will give you thicker walls than using real 416 Rigby brass, so it is a plus in my book. In reality, pick a cartridge and go with it. When you handload with a reasonable case, you can generally find a powder that will get you to the performance level you desire, especially if you have a long barrel. Take a look at what the Palma shooters do with the 308. Between the RUM and the A.X. I'd be tempted to get the AX solely because of the availability of Lapua brass as the basis for the round. No one I know of ever got looser groups switching to Lapua. However, at the ranges you are talking about shooting, the difference in a quarter MOA at one hundred yards is irrelevant once the wind picks up. But it never hurts to have a more accurate load. Jimro __________________ Machine guns are awesome until you have to carry one.

December 2, 2012, 01:05 PM	#26
hhunter318 Senior Member Join Date: September 15, 2010 Posts: 163	Jimro, Yes, I have a 7mm WSM on a blueprinted Rem 700 SA with a 30 1/2" PacNor Select Match Grade. Sits in a Choate Ultimate Sniper stock, but I'm thinking about getting a McMillan. Using a Millett LRS 6-25x56. Not the most high end scope there is but it has given me no problems whatsoever, besides being a pain in the A$$ to buy scope rings for being a 35mm tube. A buddy and I shoot out on his farm out to about 1,200 yards. I just have the urge to stretch the limit. This build is for pure fun. What direction would you take on a .375 build for long range then? 9.53 Saturn or .375 RUM? The .378 Ackley Mag sounds promising also. This build won't start til next year but I'm starting to get parts now. Your input is very very helpful. Hayden

December 3, 2012, 05:01 PM	#28
hhunter318 Senior Member Join Date: September 15, 2010 Posts: 163	Jimro, Not trying to make matters worse by complicating the subject at hand, but as I said earlier, I'm just brainstorming every possible option. What do you think about a .375 AX? Ballistics seem good and it utilized the stronger .338 Lapua case. Also, how much difference is there between the 9.53 Saturn and the .375 Allen Xpress? I can't find a good enough resource to get dimensions on the Saturn for a comparison.

December 4, 2012, 12:16 AM	#30
SHR970 Senior Member Join Date: January 24, 2011 Posts: 1,427	In my 375 RUM with a 300 gr. Hornady BTSP and 97 gr. of RL-22 I got 2850 - 2900 fps. in a 26" barrel Rem 700 AWR. I only got to fire three shots over the screens so I don't have enough data to give SD / ES, etc. That load in my gun is very accurate. Sierra says I can squeeze 2 more grains in with correct OAL to feed in my gun. BTW, at 97 gr. you are already into compressed loads. Loaded to the cannelure; I have 3/4" of the bullet down in the brass. If I had a longer action, I would be able to load it out further and add more powder. Then if you add a long throat like a Weatherby you could get away with running it longer. Add another 6"-8" of barrel and even with a 330 gr. bullet you should be in the markers. RUM brass is $1 a pop, 338 Lapua about $2 and 416 Rigby about $3. All three will be available for some time to come. Even if the 375 RUM was discontinued, you could form it from 300 RUM or 404 Jeff. and turn down the rim. The RUM family uses standard Magnum bolt faces...the Weatherby, Rigby, Lapua use a less common size.