Improving the 308 Win performance

[JAYgs8163]

^^^ absolutely correct. Stay on track folks. I'm guilty of this also.

 

[jbcason]

This thread would be dedicated to ways to improve the performance of the 308 Win or the 7.62x51 mm cartridge without wildcatting the case. Experienced and innovative reloaders should find this interesting and are encouraged to participate. The 308Win is so versatile, inherently accurate and commonly used, and yet its performance in terms of MV, trajectory and speed is a bit mediocre. I am sure it can out perform the 3006. To start with I offer up my favorite hunting load I have used for the past 6/7 years in the 308Win. The 150 gr BD or BD2 with 49 gr of Leverevolution going 2920 fps from a 1:10, 20"Douglas barrel in a short action rifle. The same load from a 24" Bartlein 1:9 twist barrel goes 3050 fps. This load would be a pretty decent long range Elk load to 900 yds or so.

How did you come up with that load using that powder? I can't find any loading manuals that shows a load using that powder.

 

[Maol]

This is from Starline's web page for their new SRP brass:

*As with all types of cases this large with small primer pockets, it will require care in powder and primer selection in cooler temperatures to prevent hang fires. Single-based propellents are generally easier to ignite and a quality primer such as the Remington 7 1/2 BR are recommended.

Since many of us live and shoot in northern and extreme cold climates, specifically what can we expect to see using Lever & magnum SRPs in below zero weather?

 

[Kentuckywindage]

Recoil from the 280 Rem cannot be blamed on getting scope bit. The 280 Rem does have a bit of a recoil, but it is still moderate, that is unless it's being shot with some hopped up handload. Getting scope bit comes from either not having the eye relief set right on the rifle, which is probably not the case since your brother in law shoots it. The issue was that the rifle was not being shot from a good shooting position and not held tight enough letting the recoil push the entire rifle scope included back to bite the eye. A .308 also has a moderate recoil and if shot from a good position, held tight against the shoulder the body should recoil along with the rifle preventing any issue with the scope biting the eye. Cabelas has shirts available that have recoil pad inserts that take a lot of the recoil out of any rifle including the magnums. As far as hunting ammo for the .308 I use 40.5 gr of IMR 4895 with a 165 gr Nosler partition bullet. I also use the 168 gr Nosler HPBT match bullet for practice since it's much cheaper than the partition. These loads approximate the ballistics of military Lake City Match ammo,b oth of those loads chrono out at around 2600 fps out of a 24 inch barrel and are deadly on Whitetail Deer out to 300 yards. With my Winchester Model 70 .308 I can shoot either of those rounds interchangeably with absolutely no change in zero. When he is up for a little more recoil, and I do mean very little more than the 110 gr you are now shooting. Give it a try.

Without derailing this thread, Terri there are scopes out there with very little eye relief. Saw this very thing cause a 300 Win. Mag. Ruger stainless drop a fella's eye. He had been shooting his 30-06 wanting to try the 300 W.M. which had one of those short eye relief scopes on what is already a light rifle in the Ruger 77 stainless with that plastic stock on some of them.
I plan on trying the 308 Winchester and 130 gr Barnes along with some BD 2 150 when the weather warms up. I do very little testing in cold weather for a couple of reasons.

 

[nralifer]

How did you come up with that load using that powder? I can't find any loading manuals that shows a load using that powder.

I tried CFE 223 first and ran into problems with fouling of the throat because it was burning dirty. Since LVR was slower burning I tried at first equivalent CFE223 charges of LVR in my 308 and found that the throat fouling stopped. Gradually increased LVR charges and found that I could get 3006 equivalent speeds for our 150 gr BD bullet out of a 20"308Win barrel without pressure signs developing in LRP primed 308 Win brass. Have subsequently found that LVR is really good in the 308 Win and yields suprerb velocities in 24" and 26" barrels, and that longer throated 308Win chambers allowing longer jumps actually allow for larger LVR charge weights to be used in Lapua Palma (SRP) brass to generate safe high speed loads using magnum small rifle primers.

 

[Frank in the Laurels]

....someone's either baiting us or hitting the alcohol too much... the .308 is a fine whitetail cartridge and will handle anything most can hit BUT my 68 Z/28 Camaro with a cross ram and 4:10 rearend is an amazing vehicle til' I challenge a Hellcat !! Unless you have repeatedly practiced actually shooting 750 +++ your not going to be big game hunting beyond that and you'll soon be rudely awakened why you need a bigger casing and those extra 300-500 fps....so sober up or wake up...putting a hold in one at 900 is one thing, harvesting it is another..

 

[nralifer]

....someone's either baiting us or hitting the alcohol too much... the .308 is a fine whitetail cartridge and will handle anything most can hit BUT my 68 Z/28 Camaro with a cross ram and 4:10 rearend is an amazing vehicle til' I challenge a Hellcat !! Unless you have repeatedly practiced actually shooting 750 +++ your not going to be big game hunting beyond that and you'll soon be rudely awakened why you need a bigger casing and those extra 300-500 fps....so sober up or wake up...putting a hold in one at 900 is one thing, harvesting it is another..

....someone's either baiting us or hitting the alcohol too much... the .308 is a fine whitetail cartridge and will handle anything most can hit BUT my 68 Z/28 Camaro with a cross ram and 4:10 rearend is an amazing vehicle til' I challenge a Hellcat !! Unless you have repeatedly practiced actually shooting 750 +++ your not going to be big game hunting beyond that and you'll soon be rudely awakened why you need a bigger casing and those extra 300-500 fps....so sober up or wake up...putting a hold in one at 900 is one thing, harvesting it is another..

There are a few things you are not considering in your criticism. The first is the BC of the 150 gr BD2 bullet (G1=0.515). The second is the altitude at which most Elk are taken (5000 ft). The third is the fact that with the right components discussed in this thread already, have shown that that bullet is safely propelled from a 24" barrel at 3100 fps. I have done it multiple times at a COAL=2.960". A longer COAL can be used in an intermediate length magazine with a longer throated bore rider chamber to get over 3100 fps. I have done that in s 26" barrel and got a safe average speed of 3144fps with absolutely no pressure signs or primer flattening. At 3100 fps, 5000 ft, 50% humidity and 59F the 150 BD2 bullet is going 1840 fps with an energy of 1127 ft-lbs. A friend of mine has done a single shot DRT of a Bull Elk at 1225 yds using a 195gr BD2 where he calculated from his load development data that the bullet was traveling at 1770 fps at impact. I don't know whether you are familiar with these bullets but they are all copper, have the highest BCs for their weight, and will expand to about 1.5 caliber at 1700 fps impact velocity. Both bullets exceed that velocity under the conditions and distances specified. Although there is no replacement for displacement with the right components you get more out of the displacement you have. To use a real life automobile analogy, my brother has a '95 300ZX with a 190 CID engine that with the right turbos, clutch, flywheel weight, E85 fuel and carbon drive shaft along with an up to date engine management computer has dynoed 759.5 HP at the rear wheels. UTube video title is "My Perfect 300 ZXTT" showing the dyno chart in case you are skeptical.

 

[Maol]

NRAlifer. Have you done enough shooting in extreme cold with your projos and loads to address possible hang fires?

For instance is Lapua Palma with the smaller flash hole better or possibly uniforming it to the larger LRP diameter better?

BR better than Magnums?

ETA:
Extreme Spread (ES) and Standard Deviation (SD) is better with the smaller diameter flash hole with some combos. Is this one? But if a small diameter is an issue with extreme cold, is a larger one better?

To try these BDs I will need to buy SRP brass and would rather get what works best for the extreme cold.

 

[nralifer]

NRAlifer. Have you done enough shooting in extreme cold with your projos and loads to address possible hang fires?

For instance is Lapua Palma with the smaller flash hole better or possibly uniforming it to the larger LRP diameter better?

BR better than Magnums?

ETA:
Extreme Spread (ES) and Standard Deviation (SD) is better with the smaller diameter flash hole with some combos. Is this one? But if a small diameter is an issue with extreme cold, is a larger one better?

To try these BDs I will need to buy SRP brass and would rather get what works best for the extreme cold.

The coldest I have shot these SRP loads with CCI 450 primers is 30F with no hang fires using both SB6.5 and LVR powders moderately compressed. In SD we certainly can see below 0 temps, but my enthusiasm for spending much time in that kind of weather is getting smaller as time goes on. Typically those temps follow lots of snow so just getting to the shooting area that I have is problematic.

I will say that I routinely see 5-6 shot strings with high single digit SDs without any attempt to weight sort brass or uniform neck thickness.
I do lubricate the necks with graphite, so that helps. I like the Lapua brass because the necks are more uniform and straighter in their virgin brass than Peterson. Some of the factory "match" ammo has ESs of 30 fps by comparison. Have seen that in the 6.5PRC Norma ammo.

 

[nralifer]

The coldest I have shot these SRP loads with CCI 450 primers is 30F with no hang fires using both SB6.5 and LVR powders moderately compressed. In SD we certainly can see below 0 temps, but my enthusiasm for spending much time in that kind of weather is getting smaller as time goes on. Typically those temps follow lots of snow so just getting to the shooting area that I have is problematic.

I will say that I routinely see 5-6 shot strings with high single digit SDs without any attempt to weight sort brass or uniform neck thickness.
I do lubricate the necks with graphite, so that helps. I like the Lapua brass because the necks are more uniform and straighter in their virgin brass than Peterson. Some of the factory "match" ammo has ESs of 30 fps by comparison. Have seen that in the 6.5PRC Norma ammo.

Forgot to tell you that I don't modify the flash hole size in the Lapua Palma brass.

 

[BEEMAN]

I run CCI 450 in lapua brass for my 6.5x47's. I'm in southern Manitoba and have shot many times hunting or practice, from just below freezing to -35C. I've never had a problem. I know people talk about it, but no issues for me so far.

 

[xsn10s]

I run CCI 450 in lapua brass for my 6.5x47's. I'm in southern Manitoba and have shot many times hunting or practice, from just below freezing to -35C. I've never had a problem. I know people talk about it, but no issues for me so far.

I think some of the srp brass flash holes were enlarged to .80" to help with ignition. Here's an thread on this. https://forum.accurateshooter.com/threads/flash-hole-size-test.4041875/

 

[JAYgs8163]

I run CCI 450 in lapua brass for my 6.5x47's. I'm in southern Manitoba and have shot many times hunting or practice, from just below freezing to -35C. I've never had a problem. I know people talk about it, but no issues for me so far.

I do the same in my 6.5x47. Have hunted in Missouri freezing temps with never a issue.

 

[xsn10s]

I run CCI 450 in lapua brass for my 6.5x47's. I'm in southern Manitoba and have shot many times hunting or practice, from just below freezing to -35C. I've never had a problem. I know people talk about it, but no issues for me so far.

I forgot to say that I've read that CCI 450 fix the issue too. Good to see a confirmed report. I'd probably use those or some other magnum SRP.