I have found a load that my 260 Rem highpower silhouette rifle loves (at least at 100m) using the 139gr Lapua Scenar and 36.5gr of Varget. I'm worried that the velocity isn't high enough, though. I'm getting about 2575fps at 3ft from the muzzle, which gives me a velocity of 1840fps and 1.136lb*s momentum at 500 meters. I've heard that I need at least 1 lb*s of momentum at 500m to reliably take rams down, but 2575 seems like a low muzzle velocity and I don't know how accurate the manufacturer-supplied ballistic coefficient of 0.615 really is. I plan to keep looking for a faster load that's as accurate as this one, but an 8-shot (all I had left from the last match) group at 100m that measures .30" center-to-center isn't something that I have happen every day. It was 40 degrees (F) and 80% humidity today, so the load might be faster on a warmer/less humid day, although that Varget powder is usually pretty resistant to changes due to temperature. Of course, the rifle might not like the load nearly as much at a different temperature, too.

What do you guys think?

I use a half grain less than you do for my ram loads, with either a Sierra 142 or a Lapua 139, which either I have at the time, both of mine SR & HR are in a 6.5x47 case though. You are going to lose a few rams along the way no matter what. When I was using a .260 with the same bullet combo, I was using 37.0 gr of VV N-150, a pretty mild load, lost a few rams and sometimes they went down slow, but wouldn't hesitate to use that one again, also used that load in a 6.5x55, for my HR. Picked that load from an old post on Greybeard, but the original load was to warm in my gun so I had to cut it a couple of grains. As far as velocity and momentum goes, I find a load that is safe and will shoot in my gun and then if it will take rams, then I'll run with it. Just my 2 cents

With my 243;
Energy (ft lb) Mom (lb/ft)
100 gr 1131 32.2 About 50% success
107 gr 1167 33.9 Takes them down with a high front leg hit

Jason, depending on how tight your rifle's chamber is and what kind of brass you are using you may be able to bump your load one more grain. Agustin used that load for several years and did not have much trouble with rams, the first time he shot at Nationals in Ridgway 2003 he set a new National record with a 39X40.

I recommend you use 41.5 gr of H4350 and a heavy bullet 139, 140, 142, 144 if you are concerned about ringing rams. You may want to talk to some of the WA shooters about what their ram load is.

141gr Cauterucio's bullets are very popular with some WA shooters if you don't mind paying a little bit extra for those great bullets.

Agustin and I use 139 and 144 Lapua for rams and you can get the 144 gr from Powder Valley for about the same price of 142 Sierras. Some people say they are not as accurate but I have never had any accuracy issue with them and they are in my opinion one of the best commercially made ram bullets you can buy.

The load Tony mentions has worked well in a number of my rifles and those of other people as well. It is a good load, but all the usual cautions apply. It recoils a bit more than 36.5 grains of Varget, but gets more velocity in the process. If you are using Lapua bullets, they should stand up to the velocity you get with it, but Sierra 142 MKs may need the load backed down a little bit (somewhere around 2750 fps probably).

If the light load works at your range, it is a pleasant load to shoot. You can keep the other load for either days when you know the rams will be a problem or you are going to a range where you know the light load may have some trouble.

Cheers!

To answer your original question about momentum...I shoot a 7BR. My Ram load is 32.0 Varget pushing a 168 Mk. That gets me to 2300 fps or just a hair under if it's cold. I have only rang one ram in 3 years...on a cold day and the Rams had muddy feet from all the rain. My Sierra Infinity program tells me that this equates to 1491 fps/830 ft/lbs and 1.11 lb/sec momentum at 500 meters.

Skydiver, I'm using the velocities from my chrony and the manufacturer-supplied ballistic coefficient in Sierra Infinity to calculate my momentum, too. I'll see how my numbers come out after I try that 41.5gr of H4350 load that Tony posted. I only shoot highpower at one range and the rams are not kind. I might check into those 144gr Lapuas also. I really like these 139-grain moly-coated Scenars, though, and the rifle definitely loves them. Thanks again to everyone who has offered advice.

I also use the ram load Tony describes, but with Hornady A-max 140 grain bullets. It also works with Sierra 142s.
If you are using H4831, a load of around 44 grains also works really well in a .260 Remington.

in my 6.5x47 i use 39.5 of 2209 with a 139 lapua at 2746 fps and i ring some now and then

I have seen people ring rams with a 308. Nothing is a sure thing. A high hit in the ass with almost anything will take them down most of the time.

I shot a 6BR with Hornady A-Max 105's at about 2700 and didnt ring any..go figure....But I shot a 260 now and have had no issues...I shoot 142 sierras on the slow end of the speed scale and it seems to work better than when I was screaming them down range....But the big issue with ringing rams at least what I have run accross is the variation in feet and stands and how they are set upon them...if the feet are wide and they are set forward even the big guns can have trouble..it just happens sometimes.