Improving the 308 Win performance

[nralifer]

Want to alert everyone who has a 308 Win. Check your throat length. Turns out that Savage was throating their 308Win long in the 1990s. Nothing wrong with that except that at the COAL short enough to fit in the magazine one will have a large jump of about 0.080-0.090". That jump will allow the shooter to use larger than normal powder charges and get higher velocities. I discovered this fact on a Savage barrel I had bought in the mid 1990s. It never shot lead core bullets very well at recommended COALs, so i put it aside for about 17 yrs. Got Douglas and Bartlein barrels instead. For this testing I decided to resurrect that barrel for this thread and to my surprise it was shooting the copper bullets much better and was yielding outstanding velocities which I have posted on. This morning I decided to see if I could replicate these results in my 24" Bartlein and to my surprise I could not get the same jump. Turns out the Barlein chambered barrel had a throat that was 0.100" shorter. A shorter throat will overpressure sooner, at a lower powder charge. From all this it appears that a longer throat is another way to substantially improve MVs in the 308 Win. Turns out that Dave Kiff makes a longer throated "bore rider" chamber for the 308 Win. Will see what the difference in performance is attributable to throat length. It may be surprisingly significant.

 

[Mike D Texas]

Want to alert everyone who has a 308 Win. Check your throat length. Turns out that Savage was throating their 308Win long in the 1990s. Nothing wrong with that except that at the COAL short enough to fit in the magazine one will have a large jump of about 0.080-0.090". That jump will allow the shooter to use larger than normal powder charges and get higher velocities. I discovered this fact on a Savage barrel I had bought in the mid 1990s. It never shot lead core bullets very well at recommended COALs, so i put it aside for about 17 yrs. Got Douglas and Bartlein barrels instead. For this testing I decided to resurrect that barrel for this thread and to my surprise it was shooting the copper bullets much better and was yielding outstanding velocities which I have posted on. This morning I decided to see if I could replicate these results in my 24" Bartlein and to my surprise I could not get the same jump. Turns out the Barlein chambered barrel had a throat that was 0.100" shorter. A shorter throat will overpressure sooner, at a lower powder charge. From all this it appears that a longer throat is another way to substantially improve MVs in the 308 Win. Turns out that Dave Kiff makes a longer throated "bore rider" chamber for the 308 Win. Will see what the difference in performance is attributable to throat length. It may be surprisingly significant.

Yep. My .308 has a loooonnnnggg throat. I currently seat 175VLDs at 2.950 (mag limited) and still have .055 to reach the lands.

 

[nralifer]

Yep. My .308 has a loooonnnnggg throat. I currently seat 175VLDs at 2.950 (mag limited and still have .055 to reach the lands.

I seat mine at 2.950 also and have 0.080 to the lands. Is yours a custom or factory rifle?

 

[bamban]

OP, if you have not read Montanamarine's work on his 308, this is worth the read.

Range Report - 308 Win, 208 AMax, RL17

I'm doing some testing with this combo. Here are some chrono results Win Brass, fireformed, neck-sized CCI 200 primer 20.5" bbl, 1/12 twist. (Rem chamber/throat) 208 AMax (moly'd) 3.00" OAL (kissing lands) RL-17 46 gr - 2380 fps (velocities 15 feet from muzzle) 47 gr - 2430 fps 48 gr - 2480...

www.snipershide.com

 

[KiwiIan]

The use of LVR has given the 308 a boost in velocity, and from what Ive read in an assortment of forums the accuracy is right up there as well!

 

[Mike D Texas]

I seat mine at 2.950 also and have 0.080 to the lands. Is yours a custom or factory rifle?

Factory Remington 700 5R Milspec.

 

[sierracharlie338]

The Savage 10FP I had was waaaaaay SHORT!! but man did it shoot 150gr interlocks like no ones business!! Deer killing machine

 

[bigngreen]

Don't even think about 900 yds on an elk with a 308. It won't have enough energy to ensure a clean kill. At that range, target only. I've been shooting 308 and 30.06 for over 40 years. There is no way with today's tech that you can make a 308 equal to or exceed the 30.06 performance at that range. Pushing at 600 or so yds is even difficult to make a clean ethical shot. There is simply not enough case capacity. IF tech improvements catch up, we'll see. Until then.....

Wow, 600 yards isn't really even a challenge honestly to make quality clean kills with a properly set up 308 with the intent to hunt at range. A 215 Berger pushed will do an elk dirty at nearly double the range you think if you and the conditions are up to it!!

 

[nralifer]

OP, if you have not read Montanamarine's work on his 308, this is worth the read.

Range Report - 308 Win, 208 AMax, RL17

I'm doing some testing with this combo. Here are some chrono results Win Brass, fireformed, neck-sized CCI 200 primer 20.5" bbl, 1/12 twist. (Rem chamber/throat) 208 AMax (moly'd) 3.00" OAL (kissing lands) RL-17 46 gr - 2380 fps (velocities 15 feet from muzzle) 47 gr - 2430 fps 48 gr - 2480...

www.snipershide.com

Yours is a really interesting load shooting that heavy a bullet from a 20" barrel. Correct me if I'm wrong, but if you are kissing the lands that means your throat is a bit on the long side with a COAL of 3". What other powders have you tried using that rifle, bullet and brass? My Savage chamber to hit the lands is 3.04" using the 175 BD2 bullet (1.535" long).

 

[nralifer]

So you say with the newest tech you can improve the 308, With that same tech you can also improve the 3006. I see this is a possibility with all cases. Just look At what some creed guys are claiming to get with 40 grains of powder, same or better than a 6.5-284.

I don't disagree with you. That is the point of this thread. Components that improve the 308Win also, to some degree, can be applied to other cartridges. It's just that the 308 Win is such a convenient platform to test things.

 

[CCAguns]

The 308 is a great and efficient round but there isn't a rational discussion to be had on performance. Within a given caliber, a large capacity case will deliver the same bullet faster or a heavier, higher BC bullet as fast as a smaller case. In no way will a handloaded 308 out perform a handloaded 30-06.

If I'm going to chase elk at 900yds I'm going to leave all the 30 calibers at home and take my 338 Edge.

With Hornady's Superperformance 150gr factory ammo my 22" 30-06 gets 3050fps. My handloads for the '06 easily exceed that of the .308 Winny when loaded to comparable pressure. The argument that the 308 outperforms the 06 only works when comparing 308 to lower pressured factory rounds in the 06. Credibility is lost when claims such as these are made.

I hunt elk with my 340 Weatherby and have not yet failed to find the animal I shot. As has been stated, any 30 cal with a properly placed bullet of good construction can kill elk at a reasonable distance for the cartridge in question. If I had to shoot elk at 900 yards, I'd want much more power than the OP suggests. As an ethical hunter, I'd definitely want to get closer.

 

[nralifer]

Maybe I'm confused, in the first post you said the 150 BD at 3050 was your 900y elk gun, but now you're saying it's the 175 bd at a velocity you "think" is achievable? And this is the basis for saying it's better than 30-06?

The .308 is a great round, probably my favorite hunting round...but I guess I'm not sure what you're trying to prove/say.

You are reading more into my post than is there. At 3050 fps, which I do all the time from the 308Win using a 24" barrel, at 900 yds at 5000 ft altitude ( where a lot of Elk are taken) the bullet has over 1000 ft-lbs of energy and will expand at 1700 fps impact velocity. Since then I used the same bullet from a 26" Savage barrel whose 308Win chamber had a longer throat allowing me to seat the bullet out a little further and use a couple of grains more powder The 150 BD2 had an average MV of 3170 fps which at 5000 ft adds another 200ft-lbs of energy to the bullet. The OAL of the load was 2.950", powder 52 gr LVR using Lapua Palma brass and a CCI 450 primer. Test temp was 38F. Impact velocity is 1891 fps and energy is 1191 ftlbs at 900 yds at 5000 ft. Knowing the penetration power of that bullet with a well placed broad side shot you are not likely to recover the bullet. Now, to be clear, I am not saying that one necessarily should take a shot like that but at a closer range there is more than adequate performance. It also illustrates the point that components available to be used do improve performance significantly.

 

[Kentuckywindage]

I want to see the 175 class bullets going 2900 out of a 308. Not saying it can't be done but it would be dam sure impressive if they did!

I run a hot load in my 308 Winchester. I haven't tried, (because of having an abundance of) any other 175gr but the SMK. I run this load in cold weather. Lapua brass, CCI large primer, Hodgdon CFE223 powder 46.0gr. (Do not try this load without working up from minimum load. This powder SPIKES QUICKLY.) at 2.800 C.O.A.L.. Chronographed at 2832 fps. average at 10ft. In the heat of summer I run 45.5gr CFE223. Both loads have light flattening of primer. With all that said, it would be interesting trying the 150gr And 175gr Badlands. A Berger 168gr Hybrid load with 46.6gr CFE223 chronographed 2850. C.O.A.L. 2.870 Lapua brass lit with Large CCI primers. I have brass loaded with the first 175gr Matchking with 12 loadings. Of course I worked and kept it clean etc. I'm no professional and read these threads to get all the knowledge I can. If someone needs help I try to give the best helpful, honest advice I can. I load for a 6.5 creedmoor also. 140gr ELDM at 2835 fps average with different components. This load has well rounded primers with no problems over a few years. I love my .308 but the little 6.5 creed, (mentioned earlier in this thread) has thoroughly impressed a guy who just bucked against it for a few years. Recoil is tough for me as I'm pretty busted up making the 6.5 great for my needs in my area.

 

[Argon Glen]

But I like how I have the 212 gr ELDX loaded in my 300 Win Mag. Can I just use that?

<stirring pot>