Hello everyone, I hope someone out there can be of help. I have a 30-378 Accumark which I bought new 20 years ago. It has a total of 400 - 600 rounds through it. I have shot Weatherby factory Ammunition 200gr, 180gr Accubond and TTSX, 165gr TTSX, 165 Gr Nosler Ballistic Tip, Nosler Trophy Grade 210gr Accubond, HSM 185 Gr VLD Hunter. I have a NIghtforce NSX 8-32X56 MOAR Reticle with .250 MOA Adjustment sitting on a One Piece 20 MOA HD Base held by Nightforce HD rings. I have struggled with repeatability in groups with this rifle from the beginning, hence all the different ammo I have purchased. It is always the same thing I can shoot sub moa .713 at 100yds for 3 rounds 5 rounds it always opens up a bit to .850 - 1.00. At 200 yds it is a whole different story. I can not get a repeatable group with any ammunition I have tried listed above. I sent the rifle out to have it accurized and a Timney trigger installed. I couldn't wait to get it back. When finished they gave me the target they shot after the work was completed and they shot a 3-Shot group under .500. BY the way this is the same shop that holds the long range world record at 4200 meters set recently. I think I should be fairly confident they know what they are doing. I took the rifle to the range and I to was shooting at just under or at .500 3 and 5 shot groups. At 200yds nothing under 5.75" groups. I started thinking it was me, so I shot my Ruger Predator in 6.5 Creedmoor, .257 Weatherby Vanguard, 300 Weatherby Mark V, Weatherby Mark V Lasermark chambered in Winchester .243 and finally my Savage BA 110 in .338 Lapua. All shot sub MOA at 200yds. The Ruger Predator in 6.5 Creedmoor, 338 Lapua shot 5" groups at 750yds. I had to go through this exercise to be sure it wasn't me being a bad shooter. I routinely go through a couple dry fire exercises to check my process and be sure i am not pulling off target when squeezing off rounds. I love this rifles ballistics and what I want to or in hopes to use it for long range shooting and hunting. I have exhausted everything I can think to try or do, I am openly asking for help I am very tired of buying 165.00 boxes of ammunition and spending thousands on accurization. It is either going back in the safe to sit out its life or traded to the gun library for something that shoots. Please ask questions and provide serious and experienced suggestions. Thank you
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Accuracy/Grouping Problems
- Thread starter TimSues
- Start date
If you are confident in your ability and the rifle was shooting well after being accurized I would pull the scope check all of the base screws and try a different scope on it to rule that out.
Even though it's a NF that caliber combined with the lighter weight of the Accumark rifle I'm sure is more than capable of pulling the pants down on even a well built scope.
Even though it's a NF that caliber combined with the lighter weight of the Accumark rifle I'm sure is more than capable of pulling the pants down on even a well built scope.
I don't know anything about the Accumark but what I've googled.
It looks like it has a fairly long-thin fluted sporter or hunting profile. Like most hunting rifles, I imagine three rounds is about the best you're going to get as the barrel heats and expands.
My random guess -- if you want optimal performance, changing nothing else you'll need a thicker or heavier taper barrel. The rest of your rig sounds first-rate.
"SAAMI recommends a 6 groove barrel with a 10-inch twist."
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"The .30-378 Weatherby Magnum is a .30 caliber, belted, bottle-necked rifle cartridge. The cartridge was developed in response to a US Army military contract in 1959. While still unreleased to the public, the cartridge went on to set world records for accuracy including the first ten-shot 10X in 1,000 yards (910 m) benchrest shooting. This record stood for over 30 years.
"The .30-378 was originally designed by Roy Weatherby as an anti-personnel/anti-materiel military cartridge for a government contract. The cartridge was created by necking down the .378 Weatherby Magnum to accept a .308 in (7.8 mm) diameter bullet. The United States Army’s Redstone Arsenal requested a rifle cartridge that could develop 6,000 ft/s (1,800 m/s) for the effects of light bullets against armor.
"Given factory ammunition, Weatherby guarantees 1.5 MOA accuracy from their Weatherby Mark V action rifles ."
It looks like it has a fairly long-thin fluted sporter or hunting profile. Like most hunting rifles, I imagine three rounds is about the best you're going to get as the barrel heats and expands.
My random guess -- if you want optimal performance, changing nothing else you'll need a thicker or heavier taper barrel. The rest of your rig sounds first-rate.
"SAAMI recommends a 6 groove barrel with a 10-inch twist."
============
"The .30-378 Weatherby Magnum is a .30 caliber, belted, bottle-necked rifle cartridge. The cartridge was developed in response to a US Army military contract in 1959. While still unreleased to the public, the cartridge went on to set world records for accuracy including the first ten-shot 10X in 1,000 yards (910 m) benchrest shooting. This record stood for over 30 years.
"The .30-378 was originally designed by Roy Weatherby as an anti-personnel/anti-materiel military cartridge for a government contract. The cartridge was created by necking down the .378 Weatherby Magnum to accept a .308 in (7.8 mm) diameter bullet. The United States Army’s Redstone Arsenal requested a rifle cartridge that could develop 6,000 ft/s (1,800 m/s) for the effects of light bullets against armor.
"Given factory ammunition, Weatherby guarantees 1.5 MOA accuracy from their Weatherby Mark V action rifles ."
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I agree with this answer.
Thin long barrels whip more than heavy profiles and shorter.
To get the best out of it reloading is probably the only way.
A charge and seating length to catch the barrel at a pause in its movement.
Your odds of getting factory ammo that hits that tiny node are not good in my experience with thin barrels.
Ammo loaded with each charge trickled to 0.1 and loaded on a single stage press may fix your problem.
I have probably bought my last thin barrel and hand load everything I can to minimize groups I'm capable of,
best I can.
300RUM Sendero and factory at the time wouldn’t group even after accurization to include cryo. Was so mad at factory ammo that wouldn’t group after the smith ‘Fixed it’ that I drove straight from the desert where I was shooting to the nearest Sportsman’s Warehouse and spent $1,200.00 on reloading equipment. Problem solved after first round of load development by simply following Sierra’s direction for a 200g bullet in Nosler brass and Fed 215 match primer. Minute of basketball to 1/2” +/- MOA was my experience and my reloading equipment hasn’t owed me anything in a long damn time?
Edit:
Sendero barrel is not a thin hunting barrel and I lucked out with a damn straight one when Remington was still making a good rifle.
Edit:
Sendero barrel is not a thin hunting barrel and I lucked out with a damn straight one when Remington was still making a good rifle.
With research and help from SH, u tube videos , a standard press and die set, electronic scale, vibro tumbler.
You can beat factory ammo easily because you match it to your guns performance.
I was surprised how easy it was to beat factory groups.
It can be done with full length sizing and no chronograph.
The game can be upgraded by a lot from there one step at a time but the bare basics can beat the shelf stuff.
It's very satisfying.
You can beat factory ammo easily because you match it to your guns performance.
I was surprised how easy it was to beat factory groups.
It can be done with full length sizing and no chronograph.
The game can be upgraded by a lot from there one step at a time but the bare basics can beat the shelf stuff.
It's very satisfying.
My father has a Mark V .30-.378 and its lucky to print a 5 shot group under MOA. Braked or unbraked it's just not that impressive.
He is setting up a reloading room in his basement, and then we will work up some loads for all of our rifles.
Hope you can find a load that will work for your rifle.
He is setting up a reloading room in his basement, and then we will work up some loads for all of our rifles.
Hope you can find a load that will work for your rifle.
Over the years, I've had a couple of Accumarks (as part of trade deals), but never tried to run extended bench testing with them. They were OK, but like production rifles, they were not consistent enough IMO, even with careful handloading. Unknown what your "smith" did to "accurize" the rifle, so whatever it was did not accomplish what you wanted.
Depending on when your rifle was made, it might have an SD barrel (before the change to Criterion). The fluted Criterion is button-rifled, so it seems possible that some shift could happen (stress from fluting, etc.) as that barrel heats up. One of those rounds definitely burns a bunch of powder and creates heat.
The advice about checking your scope mounting seems good.
Also you could check your action screws and try torquing to 40 in/lbs and see if that helps.............something I saw once on the Weatherby forum about a 30-378 like yours with similar problems.
Otherwise, you could have the barrel cryo'd to see if that relieves the stress, or have a new barrel put on it
If you rebarrel you need to decide if you want the Weatherby freebore so that you could shoot factory ammo with it.
If you cut a conventional throat without the excess freebore you might have some pressure "issues" when shooting factory ammunition.
Will add that due to the freebored Weatherby chamber, adjustments to bullet seating depth might not help much (IMO). Maybe get some cerrosafe and make a chamber cast to see what you have to work with before getting too far with load seating variations?
While a barrel may not last long with this cartridge, I'd hope to get 1000 rounds or so before needing to rebarrel.
The cartridge has been around for awhile. This was mentioned by by PO Ackley in his handbook, 3rd Ed. in Vol II, on page 198, pushing a 150gr at (-redacted-), and 180gr at (-redacted-)
Depending on when your rifle was made, it might have an SD barrel (before the change to Criterion). The fluted Criterion is button-rifled, so it seems possible that some shift could happen (stress from fluting, etc.) as that barrel heats up. One of those rounds definitely burns a bunch of powder and creates heat.
The advice about checking your scope mounting seems good.
Also you could check your action screws and try torquing to 40 in/lbs and see if that helps.............something I saw once on the Weatherby forum about a 30-378 like yours with similar problems.
Otherwise, you could have the barrel cryo'd to see if that relieves the stress, or have a new barrel put on it
If you rebarrel you need to decide if you want the Weatherby freebore so that you could shoot factory ammo with it.
If you cut a conventional throat without the excess freebore you might have some pressure "issues" when shooting factory ammunition.
Will add that due to the freebored Weatherby chamber, adjustments to bullet seating depth might not help much (IMO). Maybe get some cerrosafe and make a chamber cast to see what you have to work with before getting too far with load seating variations?
While a barrel may not last long with this cartridge, I'd hope to get 1000 rounds or so before needing to rebarrel.
The cartridge has been around for awhile. This was mentioned by by PO Ackley in his handbook, 3rd Ed. in Vol II, on page 198, pushing a 150gr at (-redacted-), and 180gr at (-redacted-)
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Thank you, everyone for your input. I am going to conduct a test as follows, after check the scope mounts and action screws.
Thank you I am familiar with the term "Cold Barrel" and will conduct a test using this method.
My thoughts of the test and how I will proceed is below. Please provide input and let me know if it sounds like It will produce results that are consistent, so I can come back with good data.
I will use 3 shot groups, waiting for the barrel to return to cold between every shot. I will begin at 100yds and increase by 25 yds after 3 rounds at each distance. I will use a lead sled to take as much human error out of it as possible and to expedite the process by not having to wait for another Cold Bore shot, if I happen to pull one shot off a little.(I have never used a lead sled with this rifle). I will post all targets after the test here to be reviewed. I am thinking I will use HSM VLD Hunter in 180Gr.
Diablo, I am sorry to say I have a lot to learn, most of the reloading and technical information you shared I will need to research because I do not know any of that.
I have talked to a couple different companies about installing a new barrell.
This opens up a whole other topic Carbon wrapped vs Steel. Anyone have any thoughts if I have to replace the barrel.
Steel:
Benchmark
Hart
Krieger
Carbon:
Proof Research
Hart
BSF
Christensen Arms
Thank you I am familiar with the term "Cold Barrel" and will conduct a test using this method.
My thoughts of the test and how I will proceed is below. Please provide input and let me know if it sounds like It will produce results that are consistent, so I can come back with good data.
I will use 3 shot groups, waiting for the barrel to return to cold between every shot. I will begin at 100yds and increase by 25 yds after 3 rounds at each distance. I will use a lead sled to take as much human error out of it as possible and to expedite the process by not having to wait for another Cold Bore shot, if I happen to pull one shot off a little.(I have never used a lead sled with this rifle). I will post all targets after the test here to be reviewed. I am thinking I will use HSM VLD Hunter in 180Gr.
Diablo, I am sorry to say I have a lot to learn, most of the reloading and technical information you shared I will need to research because I do not know any of that.
I have talked to a couple different companies about installing a new barrell.
This opens up a whole other topic Carbon wrapped vs Steel. Anyone have any thoughts if I have to replace the barrel.
Steel:
Benchmark
Hart
Krieger
Carbon:
Proof Research
Hart
BSF
Christensen Arms
Any of your listed mfg will do, price personal preferences etc.
Get a single stage press, I have a Lee with the quick change dies.
The lee may not be "premium" but can be used to get sub moa results.
A look into forster might be a choice since you have a lot of calibers.
I also have a dillon but use it for pistol mostly, progressives will not get you
the accuracy you want IMHO.
A digital powder scale.
Watch several utube videos on set up and use to help decide.
It gets addictive, I spent the weekend building another 13 ft of reloading bench. Lol
5 ft will do nice for a single stage or turret press setup.
Get a single stage press, I have a Lee with the quick change dies.
The lee may not be "premium" but can be used to get sub moa results.
A look into forster might be a choice since you have a lot of calibers.
I also have a dillon but use it for pistol mostly, progressives will not get you
the accuracy you want IMHO.
A digital powder scale.
Watch several utube videos on set up and use to help decide.
It gets addictive, I spent the weekend building another 13 ft of reloading bench. Lol
5 ft will do nice for a single stage or turret press setup.
have you had others shoot it at 200 or more? maybe your eyes, parallax, focus or you're doing something a little different at 200? or maybe the recoil gets to you again after shooting at 100? can't see it being scope or ammo issues with 1/2" 100yd groups. maybe just not letting the barrel cool after you do your 100yd shots? i'd just start off cold at 200 and let someone else do the same.
Yes when we shot last week I happened to have my daughters mental management coach for archery with us. He and his brother are World Cup Shooters back in the day and their father is an Olympic Gold Medalist in rifle.
He was having the same difficulty I was. We both adjusted the Parallax individually. I went throug hthe process of reseting my diopter with no change in results.
Thank you
Tim
Looks like you picked out some good barrel makers, and cant go wrong with any of them. Maybe see what the turnaround is for each? I went with Benchmark. Still waiting for the barrel to be finished as they have my action as well. I was told 8-12 weeks.
