308 win and the berger 215

[MontanaMarine]

3.10" is probably a fairly sensible max, but having said that, I've heard some of the F/TR shooters going out to 3.25", still leaving about .15" of bearing surface in the neck.

Speaking of F/TR, if you look around on some of their forums I'll bet you can find a wealth of additional info and considerations on long-loading the heavies in 308 Win. I've read 32" barrels launching 208s, 210s, 215s up to 2700 fps is fairly routine in those circles.

 

[Canadian Bushman]

.15 of a bearing surface doesnt sound like much. I suppose its enough though.

Ive been lurking on some other forums but i havent found any better info than ive found here.

Is it a pain to moly bullets?

 

[MontanaMarine]

I like to have one caliber of bearing surface in the neck myself. But for example, the 300 WinMag case only has a .264" neck, and the 300 Savage only has a .221" neck. So I can't be all that important.

Molying bullets is very easy. I simply dump 200 bullets into a vibratory tumbler, add 1/4 teasponn of moly powder, and let it tumble for an hour or two. That's it.

If you go down that road You will want a dedicated tumbler bowl because it will get 'seasoned' with moly too. Or, you can put (fewer) bullets and moly powder in a vitamin bottle, tape it closed, and toss that in the tumbler. Works well, and your tumbler bowl stays clean.

Also, regarding moly, if you are real anal about a clean-to-the-metal bore, moly is not your gig. If you go with moly, the idea is to leave it in the bore. Some folks go hundreds of rounds without cleaning the bore. i usually clean mine now and then, but just a few passes with bronze brush and Montana Extreme solvent, then patch it out. Mainly I'm just removing any excess carbon from the bore.

If you are shooting a good quality hand-lapped barrel, there may not be much point in moly. I use it in my Rem factory bbl's, and a Douglas barrel. For me it eliminates copper fouling, and grants the ability to shoot as many rounds as I want without accuracy going away. In fact mine seem to shoot better good and dirty. You will also be able to eek out a little more speed with moly, but an extra 30 fps at the muzzle doesn't really amount to much at 1000 yards, in drop, drift, or energy.

Shane

 

[Canadian Bushman]

Moly should of been something i tried with my factory rem barrel, that thing is rough and takes forever to clean. I may just leave that experiment for another time. I don't
wanna crowd myself with too many new things all at once.

 

[Canadian Bushman]

Ok so ive figured a few things out and thought i would report my findings in case shane and i are not the only two interested in this topic.

I got my hands on 4 lbs of re17 and 250 berger 215 hybrids, and started taking measurements on my rifle.

SAAMI spec for throat length for .308 win is 2.302 ( correct me if im wrong )
My rem 700 has a throat length of 2.325. ( erosion? )
This allowed a 3.145 C.O.A.L with the berger 215 to touch the lands.
That yielded a length of engagement of .215 between bullet and case.
My rifle can not normally eject a cartridge any longer than aprx 3.050.

I ordered a 30" lilja in a #7 contour w/ a 1:10 3 groove twist that should show up between jan-feb.

Now i will do some quick load development and find a charge that yields a velocity of aprx 2550 fps and see what COAL is required to compress that charge and add .02-.03 to finalize a throat dimension for the new barrel.

I also need to decide whether i want to cut the barrel to 26" and shoot it suppressed or leave it as long as possible and utilize every inch of barrel i paid for.

My suppressor gave me an additional 60 fps in my current load but im still uncertain about accuracy with it.
Im uncertain about what velocities i could achieve with a 29.5" barrel but fairly certain accuracy would be more consistent and wont miss the additional length and weight of the can.

Needless to say the next few months ill be burning up my current stock of ammo and finalizing dimensions of the new barrels chamber and length. Hopefully it shows up a little early.

 

[Broz]

If it were me and I was intending to hunt with the 215's I would go with the 5r or a 6 grove barrel. I am not a fan of 3 groove cuts in a jacketed bullet.

Just a thought.

Jeff

 

[Canadian Bushman]

If it were me and I was intending to hunt with the 215's I would go with the 5r or a 6 grove barrel. I am not a fan of 3 groove cuts in a jacketed bullet.

I think i will mainly shoot targets with this rifle, but could you elaborate on why you feel that way?

 

[Broz]

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

 

[Canadian Bushman]

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.

 

[Canadian Bushman]

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.

 

[mitch260]

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.

 

[Michael Eichele]

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.

 

[Canadian Bushman]

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?

 

[Canadian Bushman]

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.