270-300 Win Mag now feasible

[CogburnR]

Thanks for the data Big Jake Duke! Looks like our rifles are fairly similar but being they are from the same barrel maker and cut with the same reamer... not too surprising. My chrony is noted for reading a tad slow.

I started with RL26 because I just got done doing some loads for a 7WSM with it and it is known for producing small speed variations. I may possibly revisit it to look for that. I do not have much RL25, I may check it out also.

I have pressure series of H1000, RL33 and 7977 loaded. I am developing my baseline data and that should be pretty well complete by the time I get 50 rounds down the tube.

I am pretty happy that the rifle is starting to produce groups while doing pressure testing.

I might have to load up a few more with Retumbo and go ring some gongs.

 

[270DT]

Hello all I am new here and searching for 270-300 Win Mag load data has led me here. I just got my rebarreled action back a couple weeks ago. Pac-Nor did the work and I rebarreled a Tikka M695 with a 26" stainless tube 1:10 twist. Just finished up getting brass ready and finally going to range this weekend to fireform and see how everything is meshing together. I am going to use this for a hunting rifle so I am interested in loads for the following 130 Swift Scirocco, 130 Barnes TTSX, 140 Accubond and 150 Woodleigh PPSP.

I am using Speer 130 gr with 72 grains of IMR 7828 as a test load. I will be happy to share my loads and data with you guys if you will do the same.

Thank you and good shooting.

 

[270DT]

I just spent the last hour reading this entire thread, a lot of good info especially with the heavier bullets but I am wanting to stay in the 130-140 range that is why I went with the 10 twist.

 

[Longtooth32]

Thanks for the data Big Jake Duke! Looks like our rifles are fairly similar but being they are from the same barrel maker and cut with the same reamer... not too surprising. My chrony is noted for reading a tad slow.

I started with RL26 because I just got done doing some loads for a 7WSM with it and it is known for producing small speed variations. I may possibly revisit it to look for that. I do not have much RL25, I may check it out also.

I have pressure series of H1000, RL33 and 7977 loaded. I am developing my baseline data and that should be pretty well complete by the time I get 50 rounds down the tube.

I am pretty happy that the rifle is starting to produce groups while doing pressure testing.

I might have to load up a few more with Retumbo and go ring some gongs.

Was there any reason that you stopped load development with RL26? I just ordered a jug of RL26 at Powder Valley as I was getting primers...

 

[CogburnR]

"Was there any reason that you stopped load development with RL26? I just ordered a jug of RL26 at Powder Valley as I was getting primers... "

I started to get pressure signs at 72g. Guessing it would be around 3170fps. RL26 is supposed to be pretty consistent and temperature stable. If I can get a load that has a low ES and acceptable velocity It may be pretty good at longer ranges.

 

[Big Jake Duke]

I just spent the last hour reading this entire thread, a lot of good info especially with the heavier bullets but I am wanting to stay in the 130-140 range that is why I went with the 10 twist.

Welcome- and nice choice

The only 140s i have shot from this caliber have been the Cutting Edge MTH and they suggest a faster twist.

I have had excellent results with the Nosler 150 LRAB. they stabilize quite well in my 270ai, and that is a 1-10 twist, also the Matrix 165s will stabilize in a 1-10 at 3000 fps in my 270AI.

This caliber will push the 150s to near 3400fps., with the .625 high bc that should get you anything you want. I moved off the 140s soley for long range shooting, even though they were my bread and butter bullet for over 30 years.

 

[270DT]

BJD do you think 869 is the go to starting powder or too slow for the 130-140s. Not much data out there and how I found you guys. About all I could find is start with 270 weatherby data and go from there.

 

[Big Jake Duke]

BJD do you think 869 is the go to starting powder or too slow for the 130-140s. Not much data out there and how I found you guys. About all I could find is start with 270 weatherby data and go from there.

869 is uber slow. When i hit the 140s i could use a medium slow powder like imr4350

They also shot well with Retumbo.

I would only try the 869 on the heavier rounds.

I have not tried 130s. A hunting bullet may have unforseen issues traveling over 3500 fps. You'll be in new territory that's for sure.

 

[Big Jake Duke]

The retumbo load was about 8 grs more powder than the imr4350 for the Cutting Edge 140s.

 

[Longtooth32]

BJD do you think 869 is the go to starting powder or too slow for the 130-140s. Not much data out there and how I found you guys. About all I could find is start with 270 weatherby data and go from there.

130s to 140s will be smoking…Now you have me curious to push the lighter bullets faster...

I have a 270Wby, Benchmark, 1-9 twist, 28" barrel. It "seems" like I am having similar results with the same powder and bullets as you 270/300 Win guys. My cartridge holds about 5-6 grs of water less than you guys…So you "may" be safe using the 270 Wby data.

It looks like the only "modern" data on the 270Wby is from Nosler and Alliant…some reloading data still has the 270 Weatherby running 1-12 twists in a 24" barrel...

Do you have a chronograph?

What powders do you have on the shelf?

In your application…the slowest that I would go is H1000 and the fastest I would go, is as the OP stated…4350…You have a bunch of powders to pick from in that range…

Have fun, be safe, and let us know what you find...

 

[270DT]

I have a multitude of powders on hand and I have a shooting chrony but am about to order a Magnetospeed. I will definitely let you guys know what my results are. Sounds like I will really be able to push the velocity envelope but my goal is to find an accurate combo around 3400 for each weight from 130 - 150. I haven't had an opportunity to even fire any test and fire forming rounds yet. I got custom dies from Redding and I ended up having to turn my case necks as was too tight for my comfort level upon chambering. Not sure if it is my dies or the brass I have but I have 20 loaded and ready to go now as soon as I can get to the range.

 

[270DT]

I have

IMR 4350, 7828 and 7977

Hodgdon H1000, Retumbo, US869

Alliant 23, 25, 26

Once I get some brass fireformed I will begin working on a load ladder probably starting with 7828 and the 130 scirocco.

 

[Big Jake Duke]

I have

IMR 4350, 7828 and 7977

Hodgdon H1000, Retumbo, US869

Alliant 23, 25, 26

Once I get some brass fireformed I will begin working on a load ladder probably starting with 7828 and the 130 scirocco.

Rl22, imr7828, h4831 all hit high pressures before the desired velocity for me.

 

[Big Jake Duke]

130s to 140s will be smoking…Now you have me curious to push the lighter bullets faster...

Try the Cutting Edge 140grs. They have a .590 bc and your 1-9 will send them just fine. They are a monolith hunting bullet so they wont detonate like theNosler LRAB.