the claw
Member
Is anyone running the Rocky Mountain projectiles in either a 338 or 375 Chey Tac variant? Interested to hear results on these.
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375 cal barrel twist and projectiles?
- Thread starter the claw
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yeah mate i hear ya.... however i opted to go for the 375 as high BC bullets are starting to become more available day by day. wont be long and we shall have a few more decent options.
when i started research, truflite said they will be able to do 375cal barrels within a year or so.
Also, as to the weight issue, by choosing a shorter barrel, say 29inches, you eliminate an apparent fouling ring near the muzzle end according to some knowledgeable people, i cant wait to verify the truth in this for myself. Also a shorter barrel should be inherrently more accurate by being stiffer, and also less forward weight would make a better balanced rifle without having to add weight to the butt. I cant see velocity being a problem with such a large case.
yes, wild dog did the rifle for me.
when i started research, truflite said they will be able to do 375cal barrels within a year or so.
Also, as to the weight issue, by choosing a shorter barrel, say 29inches, you eliminate an apparent fouling ring near the muzzle end according to some knowledgeable people, i cant wait to verify the truth in this for myself. Also a shorter barrel should be inherrently more accurate by being stiffer, and also less forward weight would make a better balanced rifle without having to add weight to the butt. I cant see velocity being a problem with such a large case.
yes, wild dog did the rifle for me.
Great post guys.
At this stage of the game, I would go with a big 338. The caliber has already had all the bugs worked out of it as far as barrel twist, bullets, ect.
There is alot of developement going on in the 375 area, and I think it would be prudent to let it all shake out before jumping in.
However, someone has to do it, so good luck on your choice.
At this stage of the game, I would go with a big 338. The caliber has already had all the bugs worked out of it as far as barrel twist, bullets, ect.
There is alot of developement going on in the 375 area, and I think it would be prudent to let it all shake out before jumping in.
However, someone has to do it, so good luck on your choice.
Claw, My Snipe Tac will come in just under 16 pounds...However, Im modifying it so I can add another 5-7 pounds on the fly for target shooting. To get the 375 under 16 pounds (this includes the scope), I went with one of the lightest Manners stocks you can find that will still accomodate the big Bat action, also went with a 32 inch brux 1--10 barrel......
If you are worried about weight, the 375 over the 338 really isn't heavier if you build it light. Both Kirby Allan and Dave Viers pointed me towards the 375 over the 338 early on. I would do the same with you. The powder selection is good wtih the 375 and the bullet selection is really comming of age with the 375 and the barrel life is better. If you big game hunt, you will also have frontal mass working for you on the 375.
Just my .02 cents
zman
Claw here are the details of mine below. The Snipe Tac is loaded with 134 grains of retumbo and 215 primers. The twist is 1:12 but the 375 Am is 1:10.
Dave Viers builds a great rifle if you decide to go with the SnipeTac; the AM is very good for long range beyound 1000yds but is heavier with the longer barrel and magazine.
I have a S&B scope and it weighs about 16lbs on the SnipTac, the AM with NFS is about 19-20lbs
For accuracy and punch you can't go wrong with the 375 and 350SMK and it can only get better with the newer rounds.
Here is Dave Viers post on the Snipe Tac; if you d like the one on the AM I can find that also.
· 375 Snipe Tac...Barrel and Bullet tests
Hello to all fellow powder burners!
Recently i built myself a 375 Snipe Tac (375-408 imp) mostly just for fun shooting. As most of you know its an improved 408cheytac case necked down to .375cal and shoulder blown out to 35deg and pushed forward about .050
I ordered a McGowan barrel for this build, i talked with Jon there and he got the barrel out to me in about 3 weeks. It is a 32" light contour 12 twist, fluted, muzzle .925 I finished the barrel at 31.5" plus added a Lawton stainless muzzle brake.
The Action is a 1.550" dia x 10" long Viersco single shot chrome moly with Stainless steel bolt body. The bolt is double diamond fluted, and accented with black Cerakote, as is the entire action. Jewel trigger, extended bolt handle, sako extractor are a few of the little things. On top of the action i cut a steel 40 MOA scope base for the 5.5-22 nightforce scope.
The stock is a Lone Wolf 100% carbon/ hunting style. I completly gutted the inside of the receiver area and filled it in with fiberglass, carbon fiber and resin. I re-inletted the stock for my action and pillar bedded and layed several layers of carbon cloth to seal it all in.
The stock is camo finished with dura coat and a special light weight recoil pad i make myself. The weight of the rifle alone was 13# with the nightforce and rings it came out to 15 3/4 # Here are a few pics of the finished rifle...
375 Snipe Tac, Long range hunter
Viersco Mfg single shot magnum action with fluted bolt
Barrel break in
I finally got some time to get out and pull the trigger on this bad boy. I formed up some brass in my special forming rifle, saves on barrel life. I trimmed the cases and got them ready for the break in loads. I used 260 AB's for the first part of my tests. I ran the loads rather mild at 132gns of Retumbo, vel was averaging 3200fps. The groups from these loads
were running in the .6 range. I also tested a few of the first run of the Sierra 350grn SMK bullets, same powder charge, 132 retumbo. These were flying at 3000fps, groups were about 1". The barrel was breaking in real nice, after the first 8-10 shots cleaning was a breeze. So i decided it was time to ramp it up to the full loads and 3 shot strings.
Next day i loaded up some 260 AB's at 145gns of Retumbo. I moved the rest back to 275yds. I fired the three shots, speed was right at 3500fps, groups were terrible. Might be due to the longer throat and the bullet has too far to jump to the lands.
I wanted to test some 333grain Lehigh solids he sent me. I loaded up two test lots, 140grns and 142grns of Retumbo. I set the bullets .065 from the lands. He told me the calculated BC was .941 From a clean bore i fired three shots on target at 275yds, all three landed aprox 5" left of center bulseye. Group was just at 2" Vel was 3250 average.
The case extracted very easy so i pressed on to the 142gn load, same bullet. I only had three of each so i wanted to take a shot at my steel gong at 700yds and see what kind of results i could get. I fired up the exbal....shoot..batt dead. So i walked back to the house and input the numbers on the main computer, i figured 3250fps with 140grns , 142 should bring it up a bit more. I input the numbers for my area, 1400' elevation, 75deg, 60% hum, ect. BC .941, speed 3295 i put in, just a guess. It came up with 7.75moa at 700yards with a 275yd sight in. So i walk back to the range, a whole 200yds from my house, clicked up the nightforce, held dead center on the plate, BOOOOOOOM, WHAAAAAAAAAAAANG...i was amazed! I fired the remaining two loads and they both hit on target. That steel plate weighs close to 40# or more and it flipped it around like a toy. I got on my UTV and drove out too see what it all looked like, all three shots landed 1/2moa to the right of center with a spread of 4.5" I was happy with this for initial tests. The chrono ave for the three shots was 3297fps. I didn't think these Lehigh solids were going to stabilize to good in the 12 twist barrel, the bullets are right at 2" long, im very pleased. This weekend i will load up the new run of Sierra 350SMK bullets for testing, i might stretch the distance out to 1200yds.
Here is the steel plate target.
It looks like an upside down bell. If you look close you can see these were drops from cutting out man sized sillouettes for the tactical range. Its AR400 steel. Pretty pink!
355 gr solids for the 375 cheytac...a 1-10 twist will do fine with these...These GS bullets get even bigger....all the way out to 420 gr
And then, here are some more, these are from Dave at Black Diamond......
Here is a comparison of some 375cal bullets that we have been talking about.
From Left to Right...
1. Sierra 350gn SMK "Jacketed"
2. Rocky Mountain 361gn Alum tipped "Jacketed" VLD
3. Predator 347gn Brass solid
4. GS Custom 355gn Copper solid
5. ZA 6.5cal length Copper solid 400gn
6. ZA 7.0cal length Copper solid 420gn
375 Snipetac shell casing
Adios,
KZ
Dave Viers builds a great rifle if you decide to go with the SnipeTac; the AM is very good for long range beyound 1000yds but is heavier with the longer barrel and magazine.
I have a S&B scope and it weighs about 16lbs on the SnipTac, the AM with NFS is about 19-20lbs
For accuracy and punch you can't go wrong with the 375 and 350SMK and it can only get better with the newer rounds.
Here is Dave Viers post on the Snipe Tac; if you d like the one on the AM I can find that also.
· 375 Snipe Tac...Barrel and Bullet tests
Recently i built myself a 375 Snipe Tac (375-408 imp) mostly just for fun shooting. As most of you know its an improved 408cheytac case necked down to .375cal and shoulder blown out to 35deg and pushed forward about .050
I ordered a McGowan barrel for this build, i talked with Jon there and he got the barrel out to me in about 3 weeks. It is a 32" light contour 12 twist, fluted, muzzle .925 I finished the barrel at 31.5" plus added a Lawton stainless muzzle brake.
The Action is a 1.550" dia x 10" long Viersco single shot chrome moly with Stainless steel bolt body. The bolt is double diamond fluted, and accented with black Cerakote, as is the entire action. Jewel trigger, extended bolt handle, sako extractor are a few of the little things. On top of the action i cut a steel 40 MOA scope base for the 5.5-22 nightforce scope.
The stock is a Lone Wolf 100% carbon/ hunting style. I completly gutted the inside of the receiver area and filled it in with fiberglass, carbon fiber and resin. I re-inletted the stock for my action and pillar bedded and layed several layers of carbon cloth to seal it all in.
The stock is camo finished with dura coat and a special light weight recoil pad i make myself. The weight of the rifle alone was 13# with the nightforce and rings it came out to 15 3/4 # Here are a few pics of the finished rifle...
375 Snipe Tac, Long range hunter
Viersco Mfg single shot magnum action with fluted bolt
Barrel break in
I finally got some time to get out and pull the trigger on this bad boy. I formed up some brass in my special forming rifle, saves on barrel life. I trimmed the cases and got them ready for the break in loads. I used 260 AB's for the first part of my tests. I ran the loads rather mild at 132gns of Retumbo, vel was averaging 3200fps. The groups from these loads
were running in the .6 range. I also tested a few of the first run of the Sierra 350grn SMK bullets, same powder charge, 132 retumbo. These were flying at 3000fps, groups were about 1". The barrel was breaking in real nice, after the first 8-10 shots cleaning was a breeze. So i decided it was time to ramp it up to the full loads and 3 shot strings.
Next day i loaded up some 260 AB's at 145gns of Retumbo. I moved the rest back to 275yds. I fired the three shots, speed was right at 3500fps, groups were terrible. Might be due to the longer throat and the bullet has too far to jump to the lands.
I wanted to test some 333grain Lehigh solids he sent me. I loaded up two test lots, 140grns and 142grns of Retumbo. I set the bullets .065 from the lands. He told me the calculated BC was .941 From a clean bore i fired three shots on target at 275yds, all three landed aprox 5" left of center bulseye. Group was just at 2" Vel was 3250 average.
The case extracted very easy so i pressed on to the 142gn load, same bullet. I only had three of each so i wanted to take a shot at my steel gong at 700yds and see what kind of results i could get. I fired up the exbal....shoot..batt dead. So i walked back to the house and input the numbers on the main computer, i figured 3250fps with 140grns , 142 should bring it up a bit more. I input the numbers for my area, 1400' elevation, 75deg, 60% hum, ect. BC .941, speed 3295 i put in, just a guess. It came up with 7.75moa at 700yards with a 275yd sight in. So i walk back to the range, a whole 200yds from my house, clicked up the nightforce, held dead center on the plate, BOOOOOOOM, WHAAAAAAAAAAAANG...i was amazed! I fired the remaining two loads and they both hit on target. That steel plate weighs close to 40# or more and it flipped it around like a toy. I got on my UTV and drove out too see what it all looked like, all three shots landed 1/2moa to the right of center with a spread of 4.5" I was happy with this for initial tests. The chrono ave for the three shots was 3297fps. I didn't think these Lehigh solids were going to stabilize to good in the 12 twist barrel, the bullets are right at 2" long, im very pleased. This weekend i will load up the new run of Sierra 350SMK bullets for testing, i might stretch the distance out to 1200yds.
Here is the steel plate target.
It looks like an upside down bell. If you look close you can see these were drops from cutting out man sized sillouettes for the tactical range. Its AR400 steel. Pretty pink!
355 gr solids for the 375 cheytac...a 1-10 twist will do fine with these...These GS bullets get even bigger....all the way out to 420 gr
And then, here are some more, these are from Dave at Black Diamond......
Here is a comparison of some 375cal bullets that we have been talking about.
From Left to Right...
1. Sierra 350gn SMK "Jacketed"
2. Rocky Mountain 361gn Alum tipped "Jacketed" VLD
3. Predator 347gn Brass solid
4. GS Custom 355gn Copper solid
5. ZA 6.5cal length Copper solid 400gn
6. ZA 7.0cal length Copper solid 420gn
375 Snipetac shell casing
Adios,
KZ
Here s the orginal post link for David s post. The pics did not copy and paste
http://www.longrangehunting.com/forums/f19/375-snipe-tac-barrel-bullet-tests-32926/
http://www.longrangehunting.com/forums/f19/375-snipe-tac-barrel-bullet-tests-32926/
the claw
Member
Thank you guys for the replies so far. Seems as though this 375 cal thing is a bit of a moving target...
I am kind of leaning towards a 1 in 10 twist barrel at this stage... Reasons are:
1. It seems that the SMK's are quite forgiving with twist rate
2. It allows me to shoot solids if I wish (most likely the Predators)
3. Should allow me to shoot any new hunting orientated projectiles that come out (Although I am only guessing about this, but a faster twist should put me in a better position than a slower twist right?)
Still interested to get some feedback on the 370gr Rocky Mountains. I have heard that the jacket is quite soft, but that maybe this is being worked on?
What is the continuing availability of the 350gr SMK likely to be? I would hate to build based on this projectile alone to find that i is going out of production...
Lastly (in this post anyhow!), has anyone used the solids (such as predators) on game and what results have you experienced?
I am kind of leaning towards a 1 in 10 twist barrel at this stage... Reasons are:
1. It seems that the SMK's are quite forgiving with twist rate
2. It allows me to shoot solids if I wish (most likely the Predators)
3. Should allow me to shoot any new hunting orientated projectiles that come out (Although I am only guessing about this, but a faster twist should put me in a better position than a slower twist right?)
Still interested to get some feedback on the 370gr Rocky Mountains. I have heard that the jacket is quite soft, but that maybe this is being worked on?
What is the continuing availability of the 350gr SMK likely to be? I would hate to build based on this projectile alone to find that i is going out of production...
Lastly (in this post anyhow!), has anyone used the solids (such as predators) on game and what results have you experienced?
If the SMK`s can stand up to the RPM`s, i would suggest going for a 1:9.25ish twist. Basically, as fast a twist as possible without the SMK`s deforming or flying apart at 3200fps muzzle velocity. This way you can shoot the longer solids with more stability when they become available. Someone here i believe has tested this limit, but i cant remember who this was...??? i believe they shot them out of a 1:8 twist and they still held together, just....
As for the solids on game, they are a mixed story, people have reported them to tumble upon impact and do incredible damage. Other times they simply pencil straight thru with no expansion or tumble at all. So you get spectacular success sometimes, but also some spectacular failures and no doubt some lost game aswell.
Thing is, CNC solids can be machined with a small hollow point in them that only reduces the BC slightly, but the entire front of the bullet will now expand or fragment on impact whilst the rear half continues straight thru like a wadcutter. This is the ideal LR hunting bullet IMHO, and GScustom (and others) can already do them... just finding the best design is the hard part... and waiting 6 months for them after you order them
As for the solids on game, they are a mixed story, people have reported them to tumble upon impact and do incredible damage. Other times they simply pencil straight thru with no expansion or tumble at all. So you get spectacular success sometimes, but also some spectacular failures and no doubt some lost game aswell.
Thing is, CNC solids can be machined with a small hollow point in them that only reduces the BC slightly, but the entire front of the bullet will now expand or fragment on impact whilst the rear half continues straight thru like a wadcutter. This is the ideal LR hunting bullet IMHO, and GScustom (and others) can already do them... just finding the best design is the hard part... and waiting 6 months for them after you order them
Groper, you are right on the money...Those of us that hunt, can have our cake and eat it too. GS and others can take those solids and make them into hallow points. I have been waiting to cut my 375 ST barrel based on results of the new GS 414 solid. Dave Viers from Black Diamond is testing a second round for them shortly and hopefully, they will stabilize. Once this is done and pending good results, I will be cutting my barrel accordingly. Shortly after that, I will order the same solid from GS in a hallow point for both target shooting and hunting. This is my solution. We will lose a little BC, but at the same time we will gain speed. The 414 will probably go down to near 400 gr or so, but I will welcome the speed and the ability for the bullet to open up.
I really do believe the 375 bullets are comming of age, we are on the cusp of something really cool. This new bullet will max out my BC paramaters on my night force Xbal program, creating another new problem.
c ya
zman
I really do believe the 375 bullets are comming of age, we are on the cusp of something really cool. This new bullet will max out my BC paramaters on my night force Xbal program, creating another new problem.
c ya
zman
