6.5x55 SM Velocity!

[Jonathan Zimmerman]

I built a straight 6.5x55 SM LR Prone rifle this spring, and put the first rounds over a chronograph tonight. Before building the rifle I went back and forth on whether or not the 6.5x55 would have enough velocity for what I wanted with the 140gr Berger LRBT. Ultimately, I decided on the 55 over a 6.5x284 because of barrel life, brass selection and cost, etc. This rifle is built on a Barnard "P" action, Bartlein Barrel (29" Heavy Palma 8.5" twist), and CSS B1 stock. With Lapua cases, Fed 210, H4350, and 140 Berger LRBT I am getting some serious velocity. I started at 43 grains and a velocity of 2783 fps. I made my way up to 45.8 grains and stopped at 2991 fps. I had 4 rounds left that would have taken me well over 3000 fps, but started to notice extraction effort was increasing (heavy bolt lift). The cases and primers held up fine. I could not believe how fast they were running. I was concerned before load testing that I wouldn't be able to push 2850 fps without pressure issues. It seems as though that will not be a concern. I fired a total of 15 rounds during this ladder test at 300 yards and the last 9 were under 2" (6 under 1.25"). Just thought I would share what I found with the 6.5x55 in a modern action. It seems like a really good choice to me for Long Range competition. Lapua cases for $65 and plenty of velocity for anyone. Have a good one. Jonathan

 

[jlmurphy]

I have been shooting a 6.5x55 from a Winchester Model 70 for the last few years. I use H4831 to push 139gr. Scenars to 2850 fps from a 26" barrel. I use it for Long Range and Tactical matches, great cartridge. I love competing against .308s.

 

[Matt Pitchon]

The 6.5x55 can go plenty fast. I'm shooting 50gr of 4831 behind a 142SMK, and getting and easy 2900. Could go faster, but its so accurate, there is little need. I'm sure some of the newer double base powders could easily get it above 3,000.

 

[Exercion]

I'm using 48grs of RL22 in mine and pushing the 139 Scenars at 2900 and change from a 30" tube. No pressure signs in my rifle using the Wolf primers. I've been faster but don't see a reason to stay there when this speed node seems to work well.

Eric

 

[Jonathan Zimmerman]

It seems like all who have posted have shared the same experience with the 6.5x55. I still need to test groups of ammunition to decide what velocity to run in a match but will definitely be between 2850-2900. I just know that the faster I run it the quicker I will be changing out the barrel. Thanks for the feedback, hopefully others will see the 6.5x55 as a viable option. Seems too good to pass up.

 

[acloco]

JZ - Check your pm about brass.

 

[2506]

I am shooting 140 Sierra and Hornady SP game bullets out of my sporter 96 Mauser Swede with the 29" barrel and with a max load to stay under 46,000 CUP of 45 grs Accurate 4350 I average 2800 fps with glint edge accuracy. With 46 grs AA 4350 and 120 Nosler BT I get 3000 fps. Either one will hammer deer waaaaaaay out there. Long barrels with the 6.5X55 really pay off with great velocity with lower pressure.

 

[Jonathan Zimmerman]

I have a quick update. Made it to the range yesterday to do some more testing. I shot 5 over the chronograph while adjusting my front sight windage. The same load that gave me 2900 fps two nights ago was between 2850-2860 yesterday afternoon. I wonder if all of my velocity readings from the previous range trip were off due to lighting...? Maybe the chronograph is not good. Either way it is in the safe zone with pressure, but that adds a little confusion when trying to dial in a load for 1000 yards. The group sizes were promising though, so I guess I will have to just go with it. It bothers me though that the variation is so great with the chronograph. That makes me doubt my ES, SD numbers etc. Oh well, we'll have to see what happens. Jonathan

 

[acloco]

What was the difference in temperature, humidity, and barometric pressure of the two days that you shot over your chronograph?

 

[Jonathan Zimmerman]

I did a little research on the weather station. It was in the mid 80's both times I shot over it. The barometric pressure was the same both days (29.9-30.0), and humidity went from an average of 67 the first night then down to 57 the second time out. I can't believe that would have been enough for a 50 fps difference but obviously I don't know. Maybe that is all it would take. Maybe it was the $100 pricetag. Thanks again. Jonathan

 

[flatlander]

I've had a Krieger 30" med Palma 6.5x55 bbl. for a Nesika K since 2002, and have never had problems running 139-142gr. bullets at 2910-2940fps with 4831, N160, and even N165. It's a pleasant cartridge to shoot prone, as well as being consistently very accurate. Only thing I didn't like about it was the need to trim cases every other loading or so, most likely due to a lot of body taper.

I finally gave in to temptation and bought a 6.5x55 AI reamer. While I haven't seen a whole lot more velocity out of the AI, I betcha I never have to trim those 6.5 cases again.

 

[jrkappy]

I just built a 6.5x55 on a PacNor using a Mauser 98 action, it cost $50, Hornady brass and Sierra 142 BT match. Used H3450 and need all the MODERN load data that I can find, which isn't much. So far it seems promising but, all the load data I can find is for any Mauser below a 98 action. No load data takes into consideration rifles built on modern actions. I would appreciate any help

 

[jrkappy]

Two things: action cost 50. and powder is H4350. Need to reload my typing.

 

[mj2evans]

What Mauser 98 action is it? Inter war years, CZ, or 1944 German three letter code? There is a lot of variety in quality and I wouldn't load a Mauser to custom action pressure. Don't get me wrong, I shoot military Mausers and I am working on turning a Turk into a 7-08 hunting rifle. Honestly the commercial loading info appears conservative to me but around 45 grains of H4831SC and 140g AMax .010" off the lands has done well for me (start lower, work up ofcourse).

 

[jrkappy]

Good question. Action had been reworked when I got it. I know it!s military and Obendorf. I don't need top loads, but something above Swedish 96 data.

 

[tsiero]

I have 4 of these rifles configured for different applications. Varmint hunting, F-Class, General hunting and another practice target rifle. Don't question the velocity and just pursue the accuracy capabilities of this rifle. My rifles like H4831 with about 46gr and a 142gr Sierra, Fed 210 seem to yield consistently boring accuracy.

 

[benchracer]

I have a commercial 98 mauser with a 26" Shilen barrel in 6.5x55. Using 140gr Bergers and H4831, it shows distinct accuracy nodes at 42.2g and 48.2g powder charges. I have not chronoed either load, so I have no idea what kind of velocity I am getting. I would be surprised to see anything above 2800fps or so.

For some reason (and contrary to conventional wisdom), my rifle shoots these bullets best with considerable jump to the rifling. My max COAL at my preferred seating depth is just 3.020". At that COAL, 48.2g of H4831 comes pretty close to maxing out case capacity. I don't have sufficient volume to chase the next higher accuracy node and don't feel brave enough to push pressure limits to the ragged edge.

I am very happy with my 6.5x55 and have another one in the process of being built.

 

[jonbearman]

Has anyone evr built a 6mmx66 sm or is it so overbore and hot that it isnt worth it. Just curious as I also love the swede in its parent form.