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Old 01-17-2014, 02:17 AM   #11
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Originally Posted by JonM
Are you shooting groups faster than 1 shot every 4-5 minutes??

Thin hunting barrels are designed to fire one shot well. Not shot after shot. When a barrel heats up especially with these big magnum rounds thin barrels lose accuracy stupid fast.

Train like you hunt. You dont shot dozens of shots when you see your target animal then shoot the beastie... Shoot wait 5 minutes shoot again and so on. I'm sure you will be happy with the results.
Thank you JonM for the advice in both posts. Unfortunately there isn't enough room on a single post to tell the whole story. When I developed my loads I would wait five minutes between shots to try and cool the barrel down. I like your advice to train like I hunt. Sage advice.
You also gave kind of an informal equation in your second post: lighter bullet + slower velocity = generally poor accuracy. I will take that council.
A good friend told me when I was discussing getting rid of this rifle, "Never let a firearm go." So, heeding his advice I will work harder at figuring this rifle out.
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Old 01-17-2014, 02:31 AM   #12
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Originally Posted by SSGN_Doc
A thin barrel can still shoot accurately if it is made properly and stress releived so that it does not warp as it heats. Keeping barrel vibrations the same from shot to shot is the imoprtant thing. carefully tailored loads should help, so that shot to shot consistency is at it's best. Also make sure the action is propperly torqued into the stock. If it is bedded make sure the bedding is good and solid. make sure the barrel channel is not toucing the barrel unevenly, or having uneven pressure on the barrel. As a barrel heats the pressure inconsistencies become more magnified. Free floating the barrel like this may help, but it isn't always the answer. Some guns with sporter weight barrels benefit from some consistent pressure at the tip of the forend in the form of a pressure pad in the barrel channel. Some gasket cork material from an auto parts store can work to help you add thin layers until your consistency is at it's best. I've done this barrel channel clean-up and corking with Ruger 10/22s and Mosin Nagant rifles and seen significant results in groups size reduction.
Thank you SSGN_Doc. The most successful bullet weight I have shot so far is the 175 gr Berger VLD Hunting bullet. This is the bullet I did one of my load developments on. As I researched methods for load development I ran across one concept that made great sense and it is why load development works. It has to do with barrel vibrations as you mentioned and why a specific bullet with a specific powder charge shoots the most accurate for that rifle. It goes something like, when the primer ignites the powder and the pressure builds up enough to shoot the bullet, a pressure wave is released up the barrel. This pressure wave resonates up and down the barrel until it dampens to zero frequency. If the bullet exits the barrel at the same moment the back pressure wave hits the chamber then the rifle whip will be at its neutral point and will not harm the bullet's trajectory. Anyone else heard of this?
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Old 01-17-2014, 02:35 AM   #13
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Originally Posted by Axxe55

i would even suggest trying other brands of bullets for your loads. even a different brand in the same weight may act totally different. also try different powders. seating depth can play a role in accuracy as well.
Agreed. In addition, I have tried a 180 gr Nosler AccuBond, a 165 gr Hornady Interlock, a 230 gr Berger Hybrid target and a 180 gr Sierra Spitzer. All with various degrees of frustration. But as I look back at my reloading records I really have only developed loads for the 175 gr Berger VLD. So room to try more. There are innumerable combinations so I will keep at it. Thank you.
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Old 01-17-2014, 02:38 AM   #14
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Originally Posted by jpattersonnh
I think JD has a valid point. I shoot an inexpensive 7mm Rem Mag. It is good for 2 quick rounds, that is all. I'm good with 300 yards. Could I make a shot at 400, 500? Yes, but it is not realistic. Just to many variables. I load Barnes XFB 140 and 160. Out to 400 yards, there is no advantage from one to another. My barrel is pencil thin and made for humping over terrain. It does work well. My .308 HB is more accurate at range, but that is what the tool was designed for. I'm not humping an 13+lb rifle in the mountains.
I couldn't agree more sir. Carrying a heavy rifle all day makes for very tired forearm muscles. The last thing you need is to have your forearms all knotted up in charlie horses when that trophy buck shows up. That is the nice thing about the Mossberg 4x4, it is very light and won't wear you down.
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Old 01-17-2014, 02:53 AM   #15
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Originally Posted by MTPlinker View Post
Thank you SSGN_Doc. The most successful bullet weight I have shot so far is the 175 gr Berger VLD Hunting bullet. This is the bullet I did one of my load developments on. As I researched methods for load development I ran across one concept that made great sense and it is why load development works. It has to do with barrel vibrations as you mentioned and why a specific bullet with a specific powder charge shoots the most accurate for that rifle. It goes something like, when the primer ignites the powder and the pressure builds up enough to shoot the bullet, a pressure wave is released up the barrel. This pressure wave resonates up and down the barrel until it dampens to zero frequency. If the bullet exits the barrel at the same moment the back pressure wave hits the chamber then the rifle whip will be at its neutral point and will not harm the bullet's trajectory. Anyone else heard of this?
Yes, the Browning BOSS system is designed control barrel harmonics. You are supposed to be able to adjust the BOSS system until the gun shoots right with the load you are shooting. One of the things shimming your barrel with gasket material does is control barrel harmonics. Every 91/30 you see that shoots great groups like a modern rifle has been shimmed or has a sporter stock on it, with good modern ammo loaded in it.

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Old 01-17-2014, 03:33 AM   #16
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So, a year ago I purchased a Mossberg 4x4 300 Win Mag rifle. I know, I know, cheap rifle. I have fired it a lot and done a few load developments with various powders and bullets. It does okay at 200 yards (within 1 MOA) but beyond that I get pretty wild results. Wild enough that I don't feel confident using it for hunting. I would say at best the barrel is a #1 contour and for a magnum rifle that's crap, I know. My reasoning for the wildness beyond 200 yd though is barrel whip.
Here is my theory and for which I would like some feedback. The heavier grain bullets I have been shooting (nothing less than 175 gr) and the high pressures needed to push these rounds down range at velocities of 3,000 fps or better are contributing to barrel whip and thus the erratic rounds at 300 yd or further. My theory is to drop the bullet weight to 150 gr or below to minimize the barrel whip. I plan on doing a load development on a 150 gr bullet and see what happens. Any thoughts on my theory?
try 168grainers...
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Old 01-17-2014, 02:59 PM   #17
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Originally Posted by JonM View Post
One other thing.

The 300mag is designed to run heavy bullets fast. They have the correct twist rates for this.

Going to a lighter bullet at a slower speed is likely to have a poor effect on accuracy
So why do they manufacture so many factory 150 gr. loads ?.............
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Old 01-17-2014, 10:21 PM   #18
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So why do they manufacture so many factory 150 gr. loads ?.............
Because not all 300 WM rifle barrels have a 1-10 twist. All of my .308 caliber rifles are a 1-10 twist,but the lightest bullet I've ever loaded for my 300 WM is a 165 grain. The higher velocities that the 300 WM makes with the lighter bullets can do weird things for accuracy down range.
I shoot the lighter bullets out of my 308 and 30/06,but their velocities are much less than the 300 WM with the same barrel twist. The harmonics of the barrels have a lot to do with the accuracy of the weapon,and velocities/pressures have an effect on the harmonics of the barrel.
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Old 01-18-2014, 02:51 AM   #19
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Originally Posted by MTPlinker View Post
So, a year ago I purchased a Mossberg 4x4 300 Win Mag rifle. I know, I know, cheap rifle. I have fired it a lot and done a few load developments with various powders and bullets. It does okay at 200 yards (within 1 MOA) but beyond that I get pretty wild results. Wild enough that I don't feel confident using it for hunting. I would say at best the barrel is a #1 contour and for a magnum rifle that's crap, I know. My reasoning for the wildness beyond 200 yd though is barrel whip.
Here is my theory and for which I would like some feedback. The heavier grain bullets I have been shooting (nothing less than 175 gr) and the high pressures needed to push these rounds down range at velocities of 3,000 fps or better are contributing to barrel whip and thus the erratic rounds at 300 yd or further. My theory is to drop the bullet weight to 150 gr or below to minimize the barrel whip. I plan on doing a load development on a 150 gr bullet and see what happens. Any thoughts on my theory?
Barrel whip would not contribute to things going wild past 200 yard. It would be wild at 200 or 20 yards if that were the case. If you are not heating up the barrel and this is happening, the bullet may not have it's act together yet and may have a case of the yaw's. But, if you are shooting moa at 200, you should be moa at 300 as those Bergers usually get in the groove and settle down after about 150-200 yards.

I figured that out when I first tried Berger's and was stumped as to why I would get 1-1/4" groups at 100 yards, 1-1/2 groups at 200 then 1-1/4" groups at 300 yards. Truly head scratching until an old benchrest gent informed me as to what he thought it was.

I don't know. My 30-06 doesn't care for the 175's but loves 185's and 168's. My friends M700 300WM hates Bergers all together.
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