.308 @ 1k F-TR
- Thread starter Lynum Up
- Start date
TonyR said:
Tony,
I ran a series but am not at home. When I get back, I will send you the series results.
WOW!!! I'd like to thank everybody that responded to my original question, especialy Laurie. I don't know if he has no job or lots of free time, but that is one well thought out and informative page of information. I think I can learn alot from it!Thanks again. I also like how it sparked other side issues and discussions. If anybody ever shows up in Lodi Wisconsin, I'll look you up. Good shooting to you all ;D Rick
Steve,
They are equivalent MVs to a 155 at 3,000 fps obtained on the basis of producing the same ME in ft/lbs. You can usually obtain similar MEs with different weight bullets in any given rifle at similar pressures, all other things being the same (other than powder grade which often has to change).
Other than the 190gn SMK which I've not used much in my rifle, I have actually achieved these MVs and often more with those bullets. My rifle is a Barnard Model P in an Eliseo tubegun stock with 30" heavy profile 1-10" Broughton. The chamber reamer is minimum SAAMI with a throat designed around the 155gn Lapua Scenar 'seated long', and is not too far from optimum for this 155, 168s and the Berger 175 and 185gn BTs, but is throated on the short side for 200s and 210s. My favourite long range match load in this rifle is the 185gn Berger at 2,785 fps, (Lapua brass, Fed 210M and Viht N550) and I've had them go faster, but with larger groups and velocity spreads.
Even with the overly short chambering, I've achieved and even bettered 2,581 fps with both Berger 210gn models with N550 and Re17 (preferred powder) and will give H414 a try which has given promising results with 175gn Bergers. For really warm loads with 210s, it's much better to use the new small primer Lapua 'Palma' brass that happily accepts loads that risk blowing primers in standard cases. I can't - so far anyway - get the groups I expect from this rifle with 210s however, half-MOA is as small as they want to go.
I've yet to try the 210gn Sierra and 208gn Hornady, and am looking forward to the upcoming Berger 200gn Hybrid which I suspect is going to be THE heavyweight bullet for the .308W in long-range F/TR in a year or so time.
memilanuk said:
No Monte - providing temperatures are reasonable. We got the brass here late last year and I deliberately ran some tests over the winter to see how the design worked out in cold (by our standards) weather. In 2-5 deg C (30s F) some combinations worked out fine, but others were disappointing. I also noticed that MVs would sometimes 'plateau' in these conditions - they just stayed the same after a certain charge weight was passed. I reran one - the near standard UK Target Rifle load of a 155gn Scenar over a hefty charge of Viht N140 - earlier today, to see if a temperature increase improved things. Despite it being a chilly morning for June somewhere in the low 50s, (can't be more precise, my Kestrel wind and environment meter needed a new battery I discovered on trying to fire it up) groups had halved in size and were usable again.
Some of our F/TR guys are really pushing 210s using this brass over massive charges of Viht N550 and are allegedly getting up to the 2,700 fps mark. They complain however that these loads don't produce as good 'elevation' at 1,000yd as 155s, so some are now taking two lots of ammo to matches and use whichever according to wind strength / variability. The argument goes that in rough enough conditions, the odd lost point due to an over high or low shot is more than compensated for by the reduction in lateral deflection. My view? I'm not sure yet about the 210s and reckon that if you take the trouble to get the 185gn Berger to shoot really well at somewhere in the 2,750-2,800 fps range it takes some beating at 1,000yd. There is something happening with the 210s - at first I thought it might be a rifle management problem on a bi-pod with the recoil and torque these bullets produce. I'm using my .308W in overweight form at the moment with a Nightforce BR stuck on top and shooting it off a front-rest in 'Open' and will see if these bullets perform in a more benign environment for the shooter that makes it easier to get the rifle to track well. There may be something else though, and I wonder if you need to have the barrel throated properly for these long bullets to get the group sizes down.
My research and that of some others I know suggests that Re17 is a better powder than N550 for small primer brass and 210gn bullets if you want small groups. I'd previously tried Re17 with standard Lapua brass and Fed210ms with the 185gn Berger BT L-R, and while it gave very high MVs, groups sizes and MV ES values were also high, so it only apparently becomes suited to .308W with the heaviest bullets.
Lynum Up said:
Lynum,
If you are going to be at Lodi in the next week or two. Keep your eyes out for Precision Rifle & tools. You could see some intresting things.
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