270 loads?

[zr600]

ok I have been trying to get my Ruger m77 markii shooting 150g bergers. Today I chronographed them they are shooting only like 2550-2600 FPS. Using 54gs of h4831sc federal brass and federal 210m primers. Does this seem right? My factory ammo with 130 was shooting 3050 FPS.

 

[cohunt]

Seems pretty slow, does the chrony need new batteries?

All my 130 and 140 loads are 3025-3100, I do jave a 150 ablr load that hits 3020, but those bullets are soft and you can push them faster than most 150's

I'm not sure asbout your powder, but I use RE22 and have great accuracy results

What barrel length? 22"? I just looked up the m77, and I see several models...my barrel is 24"' rem700

 

[zr600]

Just put a new one in. Was reading another guns load at expected velocity. In the last I had a 140g accubond load with h4831 55.5 grains and it was slow to like 2700 or less.

 

[zr600]

My 6.5 Creedmoor with 142 accubonds and 46g rl26 was reading 2770 on the same trip.

 

[cohunt]

By the data, 54 grains with a 150 should be around 2800, give or take...sounds like something is off.

 

[zr600]

Yea I was really disappointed when I chronoed them. Same with the 140s. Hell my creedmoor would have less drop and windage and have more energy then that load would. That's why I'm wondering maybe do I just have a slow barrel? It's a 22" barrel factory Ruger barrel.

 

[Dosh]

600, perhaps re-check the chrono, maybe a friend has one you old use.

 

[Shortmagman]

Whose data are you using? Hodgdon lists 55.7 grains as a max.. I have loaded a number 0f 270 Wins in my day and I have used 56-57 grains of H4831 many times and you will get the velocity over 2800 ft/sec

 

[wboregon]

Maybe your batch of h4831 is a little slow?

Are you finding pressure at your current node? might try working up to pressure and see if there is another accuracy node up higher.

My favorite load in 270win is 150ablr over 60.5 grains of IMR 7977, its doing ~3050fps out of a 24 inch barrel with only slight stickyness on bolt lift in hot weather.

 

[cohunt]

I'd try another chron y or new batteries just to rule that part out...seems really slow

 

[zr600]

Was using bergers data. Don't think it's the chrono because the factory ammo I shoot shot right on with what it always shoots. Plus the factory ammo was hitting way high and I was sighted in for the slow load.

 

[Shortmagman]

The Berger manual that I have shows 55.7 grains of H4831SC as a max load for a 150 grain bullet. This is the same max load that Hodgon lists. In a 26 inch barrel it gets 2897 ft/sec. You are going to have to increase the powder charge to get close to 2800 ft/sec out of a 22 inch barrel.

 

[cape cove]

I have a Browning BBR with a 22" tube in 270 Win. With most 130gr bullets I can get appx 2990 ft/sec and with the 150 gr bullets I would get about 2790 ft/sec. The only exception was when I used RL-26 with the 150 gr Hornady and got 2875 ft/sec. I found I got better accuracy and velocity with IMR 4831, or RL-22 than with H 4831.

 

[zr600]

Well I think for deer I'm going to give up on the heavies and go to the 110g Barnes ttsx they are supposed to hammer deer hard. And be fast and flat.