1:13 twist and 175g pills 1200yrds ?

LEE .308 · Post by **LEE .308** » Sun Jan 23, 2011 8:02 pm

I have a rifle I use for f standard which is a 1:13 twist, using 2209 is it possible to make a load using 175g pills to reach 1200yrds and be accurate or am I starting to get to ambitious for a 1;13.

M12LRPV · Post by **M12LRPV** » Sun Jan 23, 2011 8:19 pm

The rules say no but there are people out there successfully shooting projectiles that shouldn't work. Like me shooting 80gr 223 projectiles in a 1 in 9.

So try it and see

LEE .308 · Post by **LEE .308** » Sun Jan 23, 2011 8:41 pm

was shooting 1200 today with 208 AMAX using a 1;10 and was just wondering about using my 1:13 as a spare if I needed to in a match situation. Was thinking about the new 178g AMAX as I don't think a 1;13 will stabilise much more than that. Just looking at a balistic chart it looks like it
needs to be going at 3200fps.

HMMMMMMMMMM time for some careful experimentation. :twisted:

johnk · Post by **johnk** » Sun Jan 23, 2011 10:01 pm

Lee,

There are those who've shot 175s at 1200 yards in the past in Australia but I don't recall the twist, though it was likely 12.

Why don't you give your BJD HBCs a good kick up the butt? Get them as far over 3000 as you safely can. Ernie Mace has been shooting them in match rifle for a couple of years now with passable success.

John

mike H · Post by **mike H** » Mon Jan 24, 2011 9:52 am

Lee,
I am sure the 175`s would do it , in a 1-13 twist, however I think it would be easier to use 155 HBC`s as John suggested. I tried the 175SMK in a 1-14 twist, in a quick practice they looked OK at Match Rifle ranges, when I passed the rifle over to a fairly new shooter, the wheels promptly fell off. Retired that one, and gave him my Match rifle, shooting long range F/class for a lot better result.
Mike.

mike H · Post by **mike H** » Mon Jan 24, 2011 11:36 am

Lee,
I missed the question re 2209 powder, 2208 is suitable.
Mike.

LEE .308 · Post by **LEE .308** » Mon Jan 24, 2011 5:05 pm

Ahh ok wasn't to sure whether or not the 155gHBC's (and the rest up to 178g) would get blown around too much or not but if they are getting used then they would be a good one to play with. A lot cheaper too since I have plenty of them already as with the 2208. I'm guessing I will be having to use a drop tube. When thinking of using the 2209 I contemplated using magnum primers, would 2208 need these as well or are they not necessary with the faster burning powder. Also on the 2208 would there be enough room in the casing(using Winchesters and a 50 thou jump) or should the load be not that much bigger in volume as if I can get away with it (don't think I will some how)I'm trying not to compress the load so reducing the jump could always be an option I suppose just means re jiggering the tuner which I would have to do anyway I suspect. :-k

Woody_rod · Post by **Woody_rod** » Tue Jan 25, 2011 9:07 am

With a case size restriction as per match rifle, the only way to get the most case volume is to run a longer throat in the chamber. The volume is directly related to MV, as the lower the volume, the higher the pressure for the same powder weight. This is why I use 46 grains of 2208 in a lapua case, and 47 in a Winchester for essentially the same MV. Neither is compressed with a slightly longer throat than a std B150 for example.

In my TR chamber, it has a very long throat, so I then run only 0.150" engagement of the bullet bearing surface and the case neck (using HBC's). This provides more space in the case under the bullet. I can get 2 -3 more grains of powder in the case just doing this.

I am not sure there would be any benefit to using magnum primers, as the powder is not that slow burning. I use 48 grains of 2209 in my 260 INCH and have no problems with a CCI BR2. There is plenty of room to use 2206H powder, but you can get enough in a 308 to make for high pressures easily enough. 3100 fps should be attainable with some careful testing.

LEE .308 · Post by **LEE .308** » Tue Jan 25, 2011 8:34 pm

Thanks a lot for all the helpful advice guys I will be spending tomorrow at the loading bench to see what I can come up with. Hopefully will get a chance to test a few in the afternoon. Depends if the neighbours have visitors or not. If in the event they do then testing will have to wait until I'm at the range on Saturday. I think I will stick with the 2208 and HBC's to start with as I have them on hand,my local gun shop stocks CCI BR primers so that's easy. I will start at 46g working up in lots of .2g until I see signs of pressure then make a few rounds up at the maximum load to see what sort of velocity range I'm getting with that load. hopefully the spread will be under 15fps.
Will let yas know how I get on.
Thanks again.

BATattack · Post by **BATattack** » Wed Jan 26, 2011 9:28 pm

LEE .308 · Post by **LEE .308** » Thu Jan 27, 2011 5:23 pm

Hiya Bat,
Thanks, made up a heap of 155HBC's to try and if I don't get any joy from them then will be looking at them seriously. As well as the 168 Amax.
Cheers

LEE .308 · Post by **LEE .308** » Fri Jan 28, 2011 8:47 pm

Fired some rounds off today of 155g HBC's from 47g to 48g of 2208 going up in increments of .2 with no signs of pressure. The projectile was set into the case as suggested by Rod (0.150 of the bearing surface in contact). Although 48's were very close none of them were compressed and there was still room in the case for maybe 1g more if I need. It will be interesting to see what speeds the 48's are travelling when I get the chance to shoot the load over a crono in a couple of weeks time.
Cheers