twist rate for rebarreling .270

[sedancowboy]

Freddie
The 170s shoot really well in a 1-8. The 150s are more stable and have a better BC with a 1-8. I shoot H1000 and Retumbo but RL -26 has been the shinning knight is the 270WSM.

 

[FEENIX]

I am rebarreling my .270 winchester this fall with a lilja 1 in 8 twist barrel to stabilize the berger 170 grain bullets. I am wondering if I want to shoot say a 130 or 140 grain bullet with the 1 in 8 twist what velocities am I going to be looking at ?

I have a Lilja SS 30" 3G 1:8" #6 on my .270 AI propelling the 175 Matrix at 2993 FPS (have gotten close to 3100 FPS but group opened up and pressure sign) with H4831SC. It was build primarily for the 165/175 Matrix VLDs and was going to go with the 170 when I ran out but I acquired more of the 175s for the life of the barrel. As other noted, I do not think you'll have any problem with the lighther bullets you mentioned. You'll love that barrel, mine stays very clean, hardly fouls, and very easy to clean.

 

[amork]

I have a Lilja SS 30" 3G 1:8" #6 on my .270 AI propelling the 175 Matrix at 2993 FPS (have gotten close to 3100 FPS but group opened up and pressure sign) with H4831SC. It was build primarily for the 165/175 Matrix VLDs and was going to go with the 170 when I ran out but I acquired more of the 175s for the life of the barrel. As other noted, I do not think you'll have any problem with the lighther bullets you mentioned. You'll love that barrel, mine stays very clean, hardly fouls, and very easy to clean.

I really hope I do love it, I notice you did a 270 ackley along with A stainless barrel. Do you ever have pressure issues ? I talked with a couple people, they may not know what their talking about, but said going with both the ackley improved and a faster twist was going to cause me more headache and pressure problems than it was worth.

 

[FEENIX]

I really hope I do love it, I notice you did a 270 ackley along with A stainless barrel. Do you ever have pressure issues ? I talked with a couple people, they may not know what their talking about, but said going with both the ackley improved and a faster twist was going to cause me more headache and pressure problems than it was worth.

I only loaded for the 175 Matrix and I am not sure what you've heard but the only pressure I have is at max end as expected, i.e., my current accuracy is 58g 4831SC, WW brass, BR2, .020" off lands (NOTE: This load is safe for my rifle only, proceed with caution). Anything over 58g shows pressure signs and group opening up so no need for me to push the envelope. I experienced the same thing, people are telling me it is not worth the effort, but it is for me. I do not fireform, I have an accuracy load for .270 Win (2919 FPS). Velocity is not the only advantage AI offers. Others are experiencing higher velocity with RL-26 but have not tried it yet.

 

[codyadams]

I have heard a lot of people say that the ackley design is not worth it. I feel that is 100% personal preference. For some it may not be. I run a .260 AI, and the only pressure signs (as stated) I get are at max pressure. I am running the 156 at 2920 fps, I could run it up to 3000 fps but best consistency is where it is at. Essentially (with a 29" barrel) it gets 6.5x284 performance out of a .260 case.

The people that said twist and improving a cartridge will cause you immense pressure issues likely haven't done it and don't know what they are talking about, because in the several improved chambers with tight twists I run or have loaded for that simply isn't true. Only pressure signs come at max load. Don't expect to gain 300+ fps, but you usually gain 100-150 fps or better depending on the improved design, and you also get brass that doesn't need to be trimmed near as much. In 12 fireing I trimmed my lapua .260 brass once, maybe twice. Few enough times I don't remember doing it. With my Peterson SRP brass, I'm on 5 fireings, haven't needed to trim ot yet.

It does require special does and fireforming, but when I think of fireforming, that just means I get to shoot more.....why would I complain about that??? Ha ha

 

[amork]

I have heard a lot of people say that the ackley design is not worth it. I feel that is 100% personal preference. For some it may not be. I run a .260 AI, and the only pressure signs (as stated) I get are at max pressure. I am running the 156 at 2920 fps, I could run it up to 3000 fps but best consistency is where it is at. Essentially (with a 29" barrel) it gets 6.5x284 performance out of a .260 case.

The people that said twist and improving a cartridge will cause you immense pressure issues likely haven't done it and don't know what they are talking about, because in the several improved chambers with tight twists I run or have loaded for that simply isn't true. Only pressure signs come at max load. Don't expect to gain 300+ fps, but you usually gain 100-150 fps or better depending on the improved design, and you also get brass that doesn't need to be trimmed near as much. In 12 fireing I trimmed my lapua .260 brass once, maybe twice. Few enough times I don't remember doing it. With my Peterson SRP brass, I'm on 5 fireings, haven't needed to trim ot yet.

It does require special does and fireforming, but when I think of fireforming, that just means I get to shoot more.....why would I complain about that??? Ha ha

I like your thoughts there. I mean who here would honestly complain about having another excuse to go shooting. I think I am going to talk to my smith and see what his thoughts are as well once I get closer to pulling the trigger. I can hardly wait to be working up the load for it.