.308 Heavy Bullet Loads

[Steve Blair]

The problem with either Hodgdon or IMR 4350 in .308 is case capacity. The case cannot hold enough to reach full operating pressure. My experience is that the slower or more progressive the powder, the more it needs to operate near or at full pressure. Reloder 17 barely reaches that point with 210s seated out a bit and it is denser than either 4350. H414 is dense enough but I have not found good loads with slow ball powders. I have almost 8 pounds of H414 and would like to use it but only my .22-250s like it. I hope N550 works for German but its burning rate and bulk density would not encourage me.

 

[ericskennard]

I am getting ready to try some also. Do you think that N140 is too fast?

ERIC

 

[memilanuk]

The Lapua/Vihtavouri load manual shows N135, N140, N540, N150, N550 for the various 185-190gr bullets... but just N140/N150 for the 200gr projectile. I would have thought N135 a bit fast (close to 4895 burn rate)...?

 

[Steve Blair]

It looks to me that either N140 or N540 are about ideal for 190 .308 loads; high density and full pressure. This comes from someone that does not use them, so take it for what it is worth. I don't take QuickLOAD for gospel but it is a good tool for choosing candidates. It shows N140 and N540 close to 60 ksi near 100% density.

 

[GermanS1]

Monte, I use an Oehler 43 system for pressure measurement. I haven't put this load on it yet, but hope to as soon as I find more N550.

That graph is odd, and I understood the little cross on the RSI graphs indicated the end of barrel time; if so, that second rise would be after bullet exit and not of concern but I haven't used the RSI system so am not at all sure.

 

[memilanuk]

German,

Good point; some of the prior discussion centered around what was causing the that second peak... whether it was a secondary pressure wave or something else, and how/if it was even possible once the bullet was out of the barrel.

The examples shown on this page would be more worrisome as the barrel exit time is clearly *after* the second peak...

Monte

 

[GermanS1]

I shot the N550/Berger 190 load at 500 yd. today. I scored 199-12X with it with a bit more elevation that I would like to see. I'll have to work on it a bit to see if it tightens up. For comparison, I shot the next string with my 4064/Sierra 190 load and scored 200-16X in virtually identical conditions.

It seems promising, but more work needs to be done and for that, I have to find more powder!

Borden action, Eliseo Tubegun, Krieger 1:11" twist .308, Warner rear sight, Riles front, CG X-treme trigger.

 

[Laurie]

Do either of you have access to someone with pressure testing gear like RSI Pressure Trace?

Monte,

'fraid not. It's suck and see dynamics normally. I hope to do some work with a ballistics lab on .223 Rem with heavy bullets over the winter, so we'll see what this throws up in a similar scenario.

However, returning to topic ........ as German correctly surmised a few posts back, the Match Rifle guys know all about .308W and heavy bullets at some quite ridiculous MVs too. Viht N150 and N550 have been amongst their powders of choice for some years now and they seem to get along with these propellants very nicely too.

It's not just in our dark, damp and chilly land too as they send teams out to rather hotter places, to wit Australia and use their 200gn + loads at similarly impressive MVs there too.

I wonder if you've seen this Long-Range Rifle Shooting Forum post with information about 210s in the New South Wales Coonabarrabran 1,500 yd MR competition last winter (local summer). It seems the MR lads and lasses run their 210s at around 2,600 fps from N150 and can achieve over 2,800 fps with some batches of N550 and a properly throated barrel.

http://www.usrifleteams.com/lrforum/index.php?showtopic=12577

You don't hear of too many MR shooters blowing their rifles up either!

 

[1000yardstare]

The first place finisher in the 10 day Grand Agg in the combined F(O), F/TR at the recently completed Canadian Fullbore Championships was an F(O).

BUT........the second place chap was an F/TR shooting 185 Bergers out of his 12 twist Krieger. He placed ahead of all the other F(O)s.

So behind the line all of a sudden I am hearing everyone talking about rebarreling to an 11 twist in a .308 for next year.

What goes around comes around.

 

[Laurie]

So behind the line all of a sudden I am hearing everyone talking about rebarreling to an 11 twist in a .308 for next year.

Bill,

you're about a year behind us in the UK, although several people here also want to play with the 210s. The only problem with the 185 Berger BT Long-Range is that they've been unobtainable here for some time now. With the F-Class European Championship matches coming up at Bisley in the first week of November, there is a mixture of praying to Mecca, or maybe that should be California, and more practically desperately searching for alternative bullets / loads amongst many of our F-TR shooters.

Great bullet though it is, your F-TR shooting chum did very well to come 2nd overall. We've had the F-TR - Open gap close up significantly often enough and top F-TR shooters such as World Champion Russell Simmonds would have taken overall podium places in individual matches on several occasions in our League rounds, but I can't remember an overall score that was anywhere near second place.

Laurie

 

[1000yardstare]

Laurie,

The 185 gr F/TR shooter in question comes from an unusual background. He is a young fluently bilingual Anglophone living in the Quebec eastern townships close to the U.S. border. So he speaks English, French and American. (Sorry, couldn`t resist that).

I don`t want to mention his name because some nutcase in Afghanistan could be assembling an improvised explosive device while reading this thread. I can`t believe what Western people put on their YouTube and FaceBook blogs but that is a whole other topic that has nothing to do with 6mmBR.

My most satisfying moment at the Canadian Nationals was on the very last target of regular competiton, a 600 yarder. I beat my 185 gr buddy by one point, 48 to 47. I was shooting 168 gr Scenars out of a 26 inch .308 Savage VLP, my backup emergency gun.

I won`t bore you with the sordid details of how it came to pass that I would be shooting a National Championship with what amounts to a coyote rifle. Suffice it to say that I have three new barrels in various calibers on order from my barrel maker here in Ontario. The first action ships out next week.

Bill

 

[Laurie]

Suffice it to say that I have three new barrels in various calibers on order from my barrel maker here in Ontario

Bill, just like us here in the UK! Fortunately, True-Flite in New Zealand has much shorter lead times than the US barrelmakers.

Laurie

 

[dreever]

I've been playing with the 185 grain Berger LR bullets for the past couple of months in my .308. N540 worked in the cooler temperatures for me, but as the temperature climbed so did my group size compared to Varget. I'm shooting a moderate load in my GA Precision Hospitaller with an 11 twist 24 inch Bartlein consisting of Lapua large primer brass, CCI 250 primers, Berger 185 LR's with 43.3 grains of Varget giving me an average 2610fps. Bullets are seated to AI mag length of 2.880. So they are off the lands by .045.
Accuracy trumps velocity in my book and this load delivers small groups with little or no vertical to speak of. Great bullet for the .308.

Danny

 

[45bpcr]

I used nearly that exact same load a couple of weeks back to win a lemon shoot at our club. The only differance was OAL @2.9 even and CCI BR primers. The rifle was a bone stock Savage F/TR with a 10X50 Sightron scope.

Craig

 

[boltgunluvr]

I recently had success using IMR4350 & H4350 using 168 SMKs. Was told not to waste my time and guess I lucked into something. Any others tried these powders for 308? I'm not out for velocity, just accuracy.

 

[XTR]

Zombie thread resurrection here.

German if you see this I'd be interested to know if you got to do any more experimenting with the 190 VLDs and N550. I've got a bit of both coming in. I'm planning to use them for practice shooting F-TR in the absence of other available bullets in this silly world we're in this yr.

 

[TonyR]

N550 worked very well with the 200 Hybrids in my 308. I used Winchester brass. I don't see why it shouldn't work with 190VLDs. As I recall, it worked a lot better in the Win than the LR Lapua but I think Laurie said somewhere on here the Brits have had better success with the SR Palma brass with N550 and the heavy bullets.

 

[Laurie]

Yes, N550 works very well with 185s and 190s in standard brass. The reference to the Lapua 'Palma' small primer brass and the powder was that we've decided we can push the MVs of 208-230gn bullets up a bit further in these cases over N550 and Re17 without suffering from excessive pressures. They're nearly indestructible too, so last a long time with these heavy loads.

PS congratulations Tony on being chosen for the US team for the FCWC. We should have started our GB League season last weekend at Diggle, but it was snowed off - 5ft drifts on the access road to the range. Also had an email cancelling the start of season range-maintenance session at Blair Atholl range due to heavy snow on the site and access roads.

 

[TonyR]

Thanks, Laurie. I hope to get back over there in 2014 to shoot either the Scottish Long Range or the Murray Cup. See you then if not at the Worlds.

 

[Steve Blair]

The reference to the Lapua 'Palma' small primer brass and the powder was that we've decided we can push the MVs of 208-230gn bullets up a bit further in these cases over N550 and Re17 without suffering from excessive pressures. They're nearly indestructible too, so last a long time with these heavy loads.

[br]
Exactly what I've found. With H4350/230 Hybrid loads around 2470-2500 fps, the cases appear to have no pressure effects at all. I suspect that velocities could be a bit higher but accuracy is excellent in that range.