270 wsm bergers

[lightflight]

bellow is some data I found online
65wsm - I had R19 which is why I started with that Powder. I also have IMR4350 but that looks to be faster burning. Powder is hard to come by right now.

the start velocities below were with a 24" barrel.

I was hoping to get a 150gr bullet up around 3150fps accurately.





270 WSM Start Load Approximate Start Velocity Max Load

Fill
Bullet-----Powder---------Start load-Velocity--Max Load--Ratio

150 Grain--H4831 SC-------57.5-------2728------64.0------96.7%

150 Grain--NORMA 204------56.0-------2856------59.0------90.1%

150 Grain--RE-19----------56.0-------2827------60.0------94.6%

150 Grain--AA 3100--------57.0-------2726------62.2------97.0%

150 Grain--H1000----------61.0-------2757------66.5------100.8%

150 Grain--IMR 7828 SSC---56.5-------2756------62.9------95.5%

150 Grain--Ramshot Magnum-61.0-------2722------67.9------98.9%

150 Grain--VIHT N160------54.5-------2658------60.8------95.0%

150 Grain--WW WXR---------57.5-------2796------62.4------94.8%

150 Grain--AA MAGPRO------59.5-------2752------66.0------97.2%

150 Grain--IMR 4350-------51.5-------2780------57.5------90.7%

150 Grain--RETUMBO--------63.0-------2707------70.0------104.4%

 

[mildot1960]

Well that settles it then as soon as I get back home I'm going shopping,

I like the idea of not needing a packed lunch while I dial the scope in because it does shoot very flat and I have always wanted a .270 and these newer chamber SWM's seem to be the way to go,

Thanks again for you're help here thats very decent of you,

John

 

[mildot1960]

Thankyou LightFlight for all that info, Thats so hours you've put in there

Also what was the best FPS that was the most stable and what grouped the best,

Thanks again, John

 

[lightflight]

Thankyou LightFlight for all that info, Thats so hours you've put in there

Also what was the best FPS that was the most stable and what grouped the best,

Thanks again, John

This was load data from berger I found online. Velocities are at start loads.

 

[mildot1960]

Well im sure glad you knew where to look and took the time

many thanks John

 

[65WSM]

The 140 Berger is the most bullet that my barrel will stabilize. I have shot 150 Ballistic tips that have the same BC as the 140 Accubond. I have not found a way to make them go fast. I have several 200 yard groups inside an inch with MagPro and the components listed and one 300 yard 4 shot group under an inch and that will do for long range hunting. I stopped shooting the group after 4 shots at 300 because the rangemaster, who was spotting for me, said he could only see two holes. It turned out there were two doubles.

Why is velocity bad? I like Roy Weatherby. He built a good .270 cartridge and I have experience handloading that one as well.

 

[mildot1960]

Thats A strange one to me because I would of thought that the 150s would buckk the wind a little better,

Winchester claim with a 130gr @ 3275fps and 3,096 ft lbs of muzzle Energy so maybe the 140s are the best alrounder because the 130s are a bit too Hot on their exit speed, and what you have done is found the most stable of the bunch,

Here's the link for their chart on the WSM Serie's Rifle's

WSM Ballistics - Winchester Repeating Arms Article

Thanks again, john

 

[lightflight]

Why is velocity bad?

I don't remember saying it was so you lost me there.

 

[65WSM]

I guess you may not be familiar with ballistic coefficients. The 140s have more aerodynamic shape to stabilize in a 10 twist barrel. The bullets are length limited. The 150 gr bullet is chunkier so it will stabilize in the same barrel. The 140s shed velocity slower than the 130s and at the same rate as the 150s which start slower. If you do not reload and are limited to factory ammo, the 140 Nosler Accubond will outperform many cartridge - bullet combinations up and down the cartridge scale. There are some better handloads possible and with custom barrels of tighter twist we can get greater downrange performance in many cartridges but the Nosler .270 WSM 140 gr Accubond may be the best factory ammunition below .30 caliber ever created.