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308 win and the berger 215

 
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  #36  
Old 10-19-2013, 02:34 PM
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Re: 308 win and the berger 215

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Originally Posted by Canadian Bushman View Post
I think i will mainly shoot targets with this rifle, but could you elaborate on why you feel that way?
Sure, in the past I have talked to people that have had wrecks with 3 grove jacketed bullets. They were indeed smaller caliber than the .308 but it was our general consensus that some 3 grove barrels leave a deeper inscription in the jacket than 5 or 6 grove rifling. The result could be a jacket that is ready to let go before impact. I doubt the .308 and 10 twist would ever cause the bullet to come apart before impact, but some higher Velocity chambering could. The rifle you are building, I feel would be a great hunting rifle for long range within the limits of the chambering. The 215 works very well on game at lower velocities. I will admit also to not being a 3 or 4 grove fan so maybe that is some of my problem too. My opinions stem from a 4 grove I threw in the trash after much grief, and the fact that the best shooting custom barrels I have ever owned were all either 5R, 5C or 6 grove barrels. This is just my personal opinions and findings.

Jeff
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  #37  
Old 10-19-2013, 03:15 PM
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Re: 308 win and the berger 215

Honestly i never had any understanding of the difference and was always under the impression it made very little difference. I asked the man at lilja what he would recommend, and he suggested 3 groove. Ill definitely keep your words in mind as i look into this more.
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  #38  
Old 11-16-2013, 06:05 PM
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Re: 308 win and the berger 215

Broz,
Ive been doing some research on what you stated about three groove barrels and ive found exactly what youve said to be true. I do see the majority of people having trouble with bullets coming apart were using small calibers, (.223, .25, .243 ) and were pushing them extremely fast. There were a few accounts of 30 cal bullets having trouble but they were in chamberings much larger that the 308.
Ive decided to proceed with the three groove, mainly because i like the idea of the non opposing grooves, hopefully i don't regret it.



Ive just finished doing some preliminary load development to help me finalize chambering dimensions for the new barrel. I thought i would share.

The gun is a factory remington 700 sps varmint, with a 26" 1:12 barrel.
It was sporting a nightforce nxs 5.5 - 22.
All shots were fired at 100yds with the chronograph placed 12-15' in front of the barrel.
I was using an alpha chrony which typically reads a little fast.
My current load shoots 2570-2590 (inferred through drops) and chrono typ reads 2585-2605.

I also weighed each case to account for early pressure signs

Results were as follows.

75 deg 29,94in/hg 91%hum 61ft elev.
.308 winchester, winchester brass 3x firings -NS only.
Reloader 17
215 berger hybrid
CCI #200 Primer
C.O.A.L 3.140 - .005" off the lands

Case weight Charge weight Velocity
157.7 gn 44 gn 2401
160.1 gn 45 gn 2440
163.3 gn 46 gn 2519 slightly flattened primer
165.3 gn 46.5 gn 2548
165.4 gn 47 gn 2575
152.5 gn 47 gn 2573
155.0 gn 47 gn 2575 slightly flattened primer
157.8 gn 47 gn 2572 flattened primer
157.8 gn 47.5 gn 2577 slightly flattened primer
160.0 gn 47.5 gn 2590
160.0 gn 47.5 gn 2591
158.7 gn 48 gn 1035 err slightly flattened primer
158.8 gn 48 gn dead primer
158.5 gn 48 gn 2611 flattened primer
158.6 gn 48.5 gn 2675 flattened primer
158.1 gn 48.5 gn 2646 flattened primer
158.2 gn 48.5 gn 2634 slightly flattened w/ ejec mark
158.0 gn 49 gn 2675 slightly flattened primer
158.0 gn 49 gn 2656 slightly flattened primer

Notes
47 gn produced good E.S. with bad accuracy. aprx 2" groups

47.5 gn produced slightly erratic E.S. with decent accuracy. aprx 1" groups

48 - 48.5 was slightly compressed load that maintained 1" accuracy but seemed to produce slightly more erratic velocity's. 48 gn - A charge weight that deems inconclusive because of bad primer and chrono error. Load may be worth revisiting.

Case with flattened primer and ejector mark was marked having a loose primer before firing, ejector marks could of gone unnoticed and been from previous firings.

48.5 - 49 may of yielded slightly heavier bolt lift, but minimal at best and hardly noticeable. No other signs of excessive pressure.
49gn was a compressed load.

Shots were carried out in strings of 6 shots and barrel heat was quite pleasant and not considered excessive.

I think accuracy would be better with a barrel with the correct twist as these bullets are quite long.

Recoil was increased from my 185gn loads but still very manageable with my 16lb gun.

I wanna extend a very gracious thank you to Montana Marine for sharing his data with me and helping me understand what i need to look for while carrying out this small test. From what i remember our results were pretty similar. Im really looking forward to getting this new barrel and going a bit more in depth.
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  #39  
Old 11-16-2013, 07:20 PM
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Re: 308 win and the berger 215

I shoot the 215's in my F-T/R rig. COAL at 3.170" and that's 15 thou off. I shoot a light load running 2550 FPS with Varget in a 28.5 inch barrel. I will warn you that these bullets are difficult to shoot accurately in these long barrels, as the are slow and spend a lot of time in the barrel.
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  #40  
Old 11-16-2013, 07:21 PM
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Re: 308 win and the berger 215

I worried about the 3 groove as well. I went ahead with it and don't regret it. It's nothing magical but being a typical lilja, shoots lights out. Flat out. This is on a 6.5x284. I have had zero problems. Then again I haven't ran any bullets past 3100'sec either. The story might change if pushed to magnum velocities.

A few notes on the 308 with the heavies. VV N550 also works well but gets to higher pressures quicker so don't use the same charge weights as R17. The nice thing about 550 is that it settles in the case better and allows me to seat the 208s to 2.990 which lets me feed them in and out of a Wyatt box. Accuracy with 550 has been superb. Magnum primers have worked the best for me with 550. All that said, I've had higher velocities with R17. I've belched them out in excess of 2700'sec with R17 but 2650ish is a better place to be IMHO in 26" tubes. I get 2600 with N550. 12 twist bbls will stabilize the 208 but very marginally. I see bullets key-holing at 700 yards in freezing temps. 11.25 twist or faster barrels solves this problem. If you're getting a 10x then you're good to go.
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  #41  
Old 11-16-2013, 08:17 PM
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Re: 308 win and the berger 215

Quote:
Originally Posted by mitch260 View Post
I shoot the 215's in my F-T/R rig. COAL at 3.170" and that's 15 thou off. I shoot a light load running 2550 FPS with Varget in a 28.5 inch barrel. I will warn you that these bullets are difficult to shoot accurately in these long barrels, as the are slow and spend a lot of time in the barrel.
This is something i have considered and am concerned about. I figured if i could not make it work i would just shoot the 185 juggernaut. What kind of accuracy are you getting out of your rifle?
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  #42  
Old 11-16-2013, 08:24 PM
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Re: 308 win and the berger 215

Quote:
Originally Posted by Michael Eichele View Post
I worried about the 3 groove as well. I went ahead with it and don't regret it. It's nothing magical but being a typical lilja, shoots lights out. Flat out. This is on a 6.5x284. I have had zero problems. Then again I haven't ran any bullets past 3100'sec either. The story might change if pushed to magnum velocities.

A few notes on the 308 with the heavies. VV N550 also works well but gets to higher pressures quicker so don't use the same charge weights as R17. The nice thing about 550 is that it settles in the case better and allows me to seat the 208s to 2.990 which lets me feed them in and out of a Wyatt box. Accuracy with 550 has been superb. Magnum primers have worked the best for me with 550. All that said, I've had higher velocities with R17. I've belched them out in excess of 2700'sec with R17 but 2650ish is a better place to be IMHO in 26" tubes. I get 2600 with N550. 12 twist bbls will stabilize the 208 but very marginally. I see bullets key-holing at 700 yards in freezing temps. 11.25 twist or faster barrels solves this problem. If you're getting a 10x then you're good to go.
I have not considered vv n550 but im willing to try anything at this point. Im planning on ending with a 28-29" tube when the smith is done and after the little test i did im expecting to find a consistant load in the 2650 area. If it landed closer to 2700 that would be great but im more concerned with maintaining a low E.S. and consistant .5 moa performance.
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