PDA

View Full Version : 260 REM Twist Rate?



posimag
04-06-2003, 01:05 PM
Was on the Remington web site looking @ the 260 Rem. Twist was 1 & 9" on all the Remingtons, is this fast enough for the elk loads? Was wondering if 1 & 8" would be the better choice for the 140 grains or would the 9" get the job done?

Another ? what would be the twist rate for say the 120gr Barnes-X?
Need starting load data, if someone has a pet load they would like to share?
Thanks in advance
posimag

Roger Beach
09-02-2003, 05:44 PM
Real Guns has a ballistics calculator and it includes rate of twist. You need to measure the bullet for diameter, length, and give the velocity.

I have a 6.5-06 but on a 270 case which is the longest of the 06 family so I can use what ever brass is available, 25-06, 270, 280, 30-06, etc.

The barrel has a 10" twist and shoots everything from 85 grains to 140 grains beautifully. For the 160 Hornady round nose and the Norma 156 gr, it takes maximum loads for highest possible velocity to get the group size to a huntable level of accuracy, but the loads are useable. Groups are just under 2" and with those heavy bullets you are probably shooting elk or moose or bear over bait so they are just fine for that work.

If you are particular I think you may want a 7.5 or 8 in twist for the 140's but I'd bet a 9 will do just fine with 140's. Remington isn't going to sell a rifle it knows is inaccurate for reason of twist.

If you go to a 7.5" or 8" twist you will not get good accuracy with 85, 100, 120, grain bullets, but purhaps you aren't interested in the lighter bullets. The 6.5/270 "6.5/06 Long Neck" (as I call it) is now a factory cartridge in Europe known as the 6.5X64 Brenneke.

I built mine for antelope and mule deer on the prairies of the west. The 125 or 129 grain bullets shoot great for that application. The 6.5/06 is better than either the 25-06 or 270 as it has a great bullet selection and is far more versatile than either. You have 85, 100, 120, 125, 129, 139, 140, 56, and 160 grain bullets. If I had it to do over again I'd go with 9"

As you have surmised I am a big fan of the cartridge, but 260 Rem promises to be a good one as well. Layne Simpson did an Ackley improved on the 6.5/308 (260 Remington) and called it the 6.5X52. It does what the 6.5X55 Swede does and on a case that is easier to find.

Roger Beach
Forest Lake, MN

Roger Beach
09-02-2003, 05:44 PM
Real Guns has a ballistics calculator and it includes rate of twist. You need to measure the bullet for diameter, length, and give the velocity.

I have a 6.5-06 but on a 270 case which is the longest of the 06 family so I can use what ever brass is available, 25-06, 270, 280, 30-06, etc.

The barrel has a 10" twist and shoots everything from 85 grains to 140 grains beautifully. For the 160 Hornady round nose and the Norma 156 gr, it takes maximum loads for highest possible velocity to get the group size to a huntable level of accuracy, but the loads are useable. Groups are just under 2" and with those heavy bullets you are probably shooting elk or moose or bear over bait so they are just fine for that work.

If you are particular I think you may want a 7.5 or 8 in twist for the 140's but I'd bet a 9 will do just fine with 140's. Remington isn't going to sell a rifle it knows is inaccurate for reason of twist.

If you go to a 7.5" or 8" twist you will not get good accuracy with 85, 100, 120, grain bullets, but purhaps you aren't interested in the lighter bullets. The 6.5/270 "6.5/06 Long Neck" (as I call it) is now a factory cartridge in Europe known as the 6.5X64 Brenneke.

I built mine for antelope and mule deer on the prairies of the west. The 125 or 129 grain bullets shoot great for that application. The 6.5/06 is better than either the 25-06 or 270 as it has a great bullet selection and is far more versatile than either. You have 85, 100, 120, 125, 129, 139, 140, 56, and 160 grain bullets. If I had it to do over again I'd go with 9"

As you have surmised I am a big fan of the cartridge, but 260 Rem promises to be a good one as well. Layne Simpson did an Ackley improved on the 6.5/308 (260 Remington) and called it the 6.5X52. It does what the 6.5X55 Swede does and on a case that is easier to find.

Roger Beach
Forest Lake, MN

Roger Beach
09-02-2003, 05:44 PM
Real Guns has a ballistics calculator and it includes rate of twist. You need to measure the bullet for diameter, length, and give the velocity.

I have a 6.5-06 but on a 270 case which is the longest of the 06 family so I can use what ever brass is available, 25-06, 270, 280, 30-06, etc.

The barrel has a 10" twist and shoots everything from 85 grains to 140 grains beautifully. For the 160 Hornady round nose and the Norma 156 gr, it takes maximum loads for highest possible velocity to get the group size to a huntable level of accuracy, but the loads are useable. Groups are just under 2" and with those heavy bullets you are probably shooting elk or moose or bear over bait so they are just fine for that work.

If you are particular I think you may want a 7.5 or 8 in twist for the 140's but I'd bet a 9 will do just fine with 140's. Remington isn't going to sell a rifle it knows is inaccurate for reason of twist.

If you go to a 7.5" or 8" twist you will not get good accuracy with 85, 100, 120, grain bullets, but purhaps you aren't interested in the lighter bullets. The 6.5/270 "6.5/06 Long Neck" (as I call it) is now a factory cartridge in Europe known as the 6.5X64 Brenneke.

I built mine for antelope and mule deer on the prairies of the west. The 125 or 129 grain bullets shoot great for that application. The 6.5/06 is better than either the 25-06 or 270 as it has a great bullet selection and is far more versatile than either. You have 85, 100, 120, 125, 129, 139, 140, 56, and 160 grain bullets. If I had it to do over again I'd go with 9"

As you have surmised I am a big fan of the cartridge, but 260 Rem promises to be a good one as well. Layne Simpson did an Ackley improved on the 6.5/308 (260 Remington) and called it the 6.5X52. It does what the 6.5X55 Swede does and on a case that is easier to find.

Roger Beach
Forest Lake, MN

JF
09-03-2003, 07:56 AM
Roger:........You can say that again..... /images/%%GRAEMLIN_URL%%/laugh.gif

Posimag: I'm working on a very light rifle that will end up as a 6.5/284. I am using an 8" twist bbl. due to expediency (basically instant availabilty). However, I have corosponded with several target shooters who have used fast twisters with no problems.

The issue with fast twists seems not to be accuracy. Within reason, it's hard to "overstabilize" a bullet, but very easy to understabilize one. There is however a question about bullet integrity with thinner jacket bullets. For a light weight varmint bullet such as the 85's for example, I plan to slow them down maybe 200 fps below the maximum available velocity.

Despite Shilen's recommendation of an 8 twist for anything over 130 gr. I doubt that 140's would be problem with a 9" or even a 10" twist. From my recent research on this subject, I'd guess that the 9" that's on those remmys is probably the best all around. I'd like to be able to carry a magazine full of 156 Oryx or 160 Hornies if I were Bou hunting in a "bad neighborhood" so the 8" is my call.

(Mr Grizz lives on the same street as Mr 'Bou.)

JimF

Patrick
09-03-2003, 08:50 AM
Hey all--

The 9" twist on my .260 spits out old 165gr. Barnes bullets just fine. The sectional density of that projectile is somewhere in the stratosphere! 6.5 caliber is a favorite.

Jim S
09-03-2003, 09:42 AM
Patrick, I was wondering what speed you are getting from the 140 grain load. I am working with both the 140 Nosler part and a 100 Nosler BT. I have the 100 grain shooting under 1" at 2900 FPS. Loading one grain below the setup you gave me I am getting 2520 FPS but getting over a 2" group. This load is giving me the most consistant speed and the best group. I was thinking I might be getting close to the max due to the speed. My manuals show a top speed of 2700 from a 24" barrel and the rambler is 18". I am going to work on seating depth and see if it makes a differance. What do you think?

Patrick
09-03-2003, 05:21 PM
Jim S--

Well, I show 2700fps from 43gr. IMR 4350. This with 140 Partitions. Hmmm. There are fast barrels and slow barrels. Also, there are fast and slow lots of powder lots. As for seating depth, the old rule is this: for horizontal groups seat deeper and/or lower powder charge. Reverse for vertical groups. BTW, how many shots is your group? Three is fine. In fact, the first two are all that really count--know what I mean? Finally, your .260 barrel just may not like Partitions! Try Hornady/Speer/Sierra. Thing is, the speed of a 260 doesn't need a "premium" bullet. And the sectional density of the 140 in this caliber is quite high; any good bullet will do fine.

posimag
09-05-2003, 08:41 PM
I did the 260 AI 8" and am waiting for the barrel to get here. I just had to go with the heavy, long bullets.

If I have to play with lighter bullets the idea of having a switch barrel works this way for me. Go with the 22/250 or the 243 that I already have. Next thing was to get another bolt in the 223 class and fit the switch barrel to a 17 cal (maybe a 17 rem. if I can use it with the bolt face?). But that is going to have to wait for the 358 win. barrel to get back from LaBounty ( I have heard all good about his work), have to save money where I can.

Changing from the 308 parent cartage is making things more complicated, the lazier bore sight will have to be updated 17 and the 22/250. Patrick thanks for the bore sight Idea, changing from barrel to barrel is very easy for the scope adjustments, if it is put in the in the chamber the same way every time. I did this buy putting a mark on the lazier bore sight so it will go in the chamber the same way every time, a small witness mark on the barrel. Line all up and leave lazier in the barrel as screwed to the action. Lock the bolt down and put on the target paper that was pre-marked from the sight-in. This should work from load to load also but will have to be tested for finality.

Posimag

pointer
09-06-2003, 07:02 AM
Posimag- Is this with a rambler or another type of switch barrel rifle? BTW, the 223 and 17Rem have the same bolt face. But being so much thinner than the '08 based rounds, will they feed?

posimag
09-08-2003, 07:44 PM
Pointer, I wish the 600 Remingtons were a Rambler.

Patrick did not offer the gun at the time I started this project (with Patricks help), or I would have a Rambler. As it turns out I have a ULA 300 Win Mag I do not take west with me any more, it is the home-made switch barrel that will go this year also.

This home made project just keeps growing in my spare time (and money). Now I have the spare parts (three 600's) to make the 223 base case to feed, as it grows it gets more complex and there is no end in sight. So far the 308 is the most impressive the way it kills big game, the 243 is the most accurate and most fun to play with.

Posimag

pointer
09-09-2003, 07:46 AM
So, are just swapping barrels with a barrel vice and action wrench? I'd be interested in the system you are using to swap barrels, as I am completely enamored with switch barrel rifles.

posimag
09-11-2003, 01:41 PM
Pointer,
Barrel vice and action wrench is just used for the first take-off. Than I just set the head space with a Go and No-go Gauge (from Brownells). The first ones I made were all done a drill press. I tried files on the shoulder of the barrel as it was spinning in the drill press, the best was a hack saw blade laid where the teeth cutting on the shoulder only, threads will end up on the side of the blade. If you try this go slow as the saw blade will take the shoulder of Quickly!

I have invested in a lathe and have checked the shoulders on all of the barrels I have done in the past all are very strait to my disbelieve. The lathe takes a lot of time out of the process but is not needed. As for the crowns on the muzzle end of the barrel the lathe does a lot better job.

The barrel is screwed on hand tight with a set screw on the side of action. . I than go back to the drill press and start drilling holes in the wood stock and bolt, hate to carry unnecessary weight. Now down to five pounds and dreaming of a Kifaru Rambler.

pointer
09-12-2003, 06:09 AM
So, head space is kept constant via the set screw into the side of the barrel like the Rambler? John Barsness had an interesting article in Rifle where he would mark witness marks on the action and barrel and then would just line them up with the barrel vice and action wrench.

posimag
09-12-2003, 03:51 PM
Pointer

Yes, somewhat like the Rambler. Have not seen the set-up on Patrick's, I just made it up as I went along.

There are witness marks on mine just to make sure there is not some small piece of dirt that would alter the head space. When all looks good then the set screw is tightened. Been playing with the idea of making a shallow hole on the barrel. The Swiss knife that I use on the set screw has a hook for opening bottles. Put the hook in the shallow hole twist barrel for more leverage?

John Barsness's barrel vice and action wrench was close to doing it that away. Even had plans to make a receiver hitch action wrench to fit trailer hitch but would have to be at the truck to make changes. If had the trailer on, that would be another hassle.

pointer
09-17-2003, 06:49 PM
THanks for the info. I'm enamored with switch barrel rifles, as it just seems it could be cost efficient in the long run and FUN! I'm just interested now in one that I can switch at home, so as to play with different chamberings on one action.