A new Long Range Build.

[Jerry D]

Hey everyone, I'm building a new rifle and I am looking for some opinions.

I'm going to start by saying - I don't like the recoil of .30 calibers so no mentioning of .308's or .300 Win mag or the .338 Laupa etc etc... Also because this is a true long range rig - many of the 6.5's and 6mm's outperform the 30 calibers in every aspect except for "perhaps" downrange energy. I'm shooting paper/targets/varmints so all will have the required energy. What I am looking for is advice on something that has relatively good barrel life and good long range performance which is why I am leaning towards a 6.5 - a compromise between the .243 for barrel burning and the .308 for recoil.

#1 Which 6.5? I honestly do not know so advice on an efficient 6.5 would be very much appreciated.

#2 I am basing my rifle off a Savage action and I have been told use a long action so I can magazine feed .260 rem rounds with long high BC bullets. Do I need to do this as if I go a .260 rem will the rounds load into the standard .30-06 magazine and feed into the barrel? Would a .308 magazine be long enough? or would I have to hand feed them individually?

#3 Is an 8 twist barrel the best for the 140 grainers? I will be shooting them

#4 What velocities can I expect with 140 grainers from a 26" barrel.

#5 Do I need to do anything special to the barrel (Change where the bullet meets the rifling) as I don't want the long bullets to seat to far into the brass as it takes up powder space I will be reloading and can change the seating depth.

#6 Please add anything about anything that I might need to know.

Thanks Very Much - your help is appreciated.

 

[taliv]

go to 6mmbr forum and read up

Things to think about
A larger cal in a semi auto (ar10 or maybe fnar) maybe in 6.8 SPF or Grendel

6mmXC
6.5 creedmore
6.5x47 lapua or neck down 6x47
6 dasher

 

[Dr. Tad Hussein Winslow]

Well, take this with a grain of salt, because I ainno expert. But from what I've read, if you ain't going .308 win (and I don't blame you there on the recoil), a 6mm cartridge of some type is where its at, in the 200 yard up to 600 yard arena. There are many specialized/oddball 6mm calibers optimized for precision shooting, in terms of good brass and such available (6mm BR, 6 XC, etc., or even "normal" calibers like 6mm Rem or .243 Win). But out at longer ranges (800 up to 1000 or more) the super high BCs of the 6.5 cartridges are where it's at, and trump the 6mm rounds - at these extreme ranges, the BC of the 6.5 trumps the higher vel of the 6mms. But, most people consider the super high vel rounds like the .264 win mag (a 6.5mm round) to be overbore barrel-burners, and thus not a good choice. A good compromise between getting high vels without excessive barrel burn, are the 6.5-.284 Norma (fka 6.5-.284 Win), the 6.5x55 Swedish, and the 6.5mm-'06. Particularly the 6.5-.284 is popular due to the excellent brass available. But a lot of the practical shooter guys will use slightly lower powder volume rounds such as the .260 rem, the 6x47mm, and 6.5mm Creedmoor. These rounds can allow for a very long barrel life and still very impressive long-range ballistics, but a little more drift and drop than say, the 6.5-284, due to lower vels. That's caliber. There are many other facets though, so I'd definitely suggest reading up at www.6mmbr.com as a starting point. As for me, when I buy/build my ultimate long-range rig (to supplement my .243 win current long rang rig), it's gonna definitely be chambered in 6.5-284 Norma. This round is of course based on the Winchester round of .284 Winchester, a very good 7mm round in its own right (necked down to 6.5mm), which was somewhat popular but never knocked it out of the park in popularity for some reason (what with 7x57, .280 / 7mm Rem Express, and then 7mm Rem Mag as competitors).

On twist, my understanding is that a 1 in 8 or 1 in 7.5 bbl is only needed for superlong 160/162 gr rounds, whereas a 1 in 10 is just fine for *ordinary* 140s. But if you are gonna shoot "long-for-weight", lower density bullets, such as the Barnes MRX all-copper bullets, or other crazy-long sloping bullets, then even the 139s/140s are long enough to call for a 1 in 8 twist. IINM.

 

[browningguy]

Like they said, go to 6mmbr, I would up going with a standard .243, and there have been some winners built in .260. I just liked the idea of using factory ammo if I needed to. Mine is a Savage 12FV with 28" barrel, a 6.5-20 Weaver Grand Slam and Sharpshooter Supply LVT stock. The scopes were on sale so I wound up building this one for around $950, which seems a pretty good deal. It shoots 100 gr. factory loads sub-moa even with the cheap Remingtons, my handloads run in the low-mid .3's on a regular basis and it maintains sub -moa out to 600 yards which is the farthest I have shot it.



THis is a reasonably good example of what it shoots most of the time with the factory accutrigger and barrel. And as you can see my twitching pulled one of the shots high and left.

 

[USSR]

#1 Which 6.5? I honestly do not know so advice on an efficient 6.5 would be very much appreciated.

#2 I am basing my rifle off a Savage action and I have been told use a long action so I can magazine feed .260 rem rounds with long high BC bullets. Do I need to do this as if I go a .260 rem will the rounds load into the standard .30-06 magazine and feed into the barrel? Would a .308 magazine be long enough? or would I have to hand feed them individually?

#3 Is an 8 twist barrel the best for the 140 grainers? I will be shooting them

#4 What velocities can I expect with 140 grainers from a 26" barrel.

#5 Do I need to do anything special to the barrel (Change where the bullet meets the rifling) as I don't want the long bullets to seat to far into the brass as it takes up powder space I will be reloading and can change the seating depth.

#6 Please add anything about anything that I might need to know.

Jerry D,

I highly recommend the 6.5x55. Reason? Quality brass (Lapua) is readily available, and you get high velocity with reasonable barrel life. My 6.5x55 F Class rifle gets 2950fps with 139-142gr match bullets. No matter whether you go with a .260, 6.5x55 or a 6.5-.284, make sure you use a long action, as 6.5mm bullets are long and you don't want to seat them deeply and take up valuable powder space.

Don

 

[gvnwst]

Porbably the best compromise of barrel life in 6.5s is the 6.5x47 lapua. It can fit 140gr class SMKs in the mag, and fires slightly faster than the .260, IIRC. Then there is the 6.5 Creedmoor, very similar, but without Lapua brass to back it, so i would stay away from that. The .260 is a good choice, but again, not great brass available. Usually, you must buy horribly expensive brass, or make it from norma 7-08 or lapua .243win brass.



Premium, i am glad you gave me premissin to correct you , with the new 115gr DTAC 6mm bullets, fired out of cartridges such as the 6XC and .243 win, it beats the 6.5/284 norma (BTW, this cartridge doens' have the best barrel life, about 1-1.5k rounds, the 6.5x47 is 3k+, IIRC) for wind, drop, and a bit in accuracy. Wiithout moly coating too. That isn't even going to the .243 AI or the .243 WSSM, which sends the bullet faster! 6mm and 6.5mm cartridges are known for being easy to tune.


The only calibe that gives you the better than .243 AI/115gr DTAC combo is a 7mm cartridge, something like the 7mmWSM, or a faster one. With berger bullets, the 30s have to go about 70gr heavire, and then barely win. The 7mms have really good ballistics, while retaining good energy. If all you want to do is punch paper, it is probably not nessicary, it offers little paper punching benifit over the 6mm caliber.

 

[Coyote_Hunter_]

Jerry D –

Several weeks ago I purchased a new Interarms Mark X Mauser action and have been in the “which cartridge” mode ever since. At first I thought I would build a .338-375 Ruger, which would give me .340 Weatherby ballistics, and then some. For a number of reasons, however, I decided to build a sub-.30.

The goal was still to have a rifle capable of 700-800 yard shots on deer and antelope if needed but more importantly be capable of 500-600 yard shots at the range. Specifically, I was looking for the best balance of trajectory, retained energy, recoil and powder efficiency. The ballistics for a number of cartridges were investigated with a variety of bullet weights and types in each cartridge. The cartridges studied included the .257 Roberts, .25-06, .257 Weatherby Magnum, 6.5mm-06, 6.5mm-06AI .264 Winchester Magnum, .270 Winchester, .280 Remington, .280 Remington AI, 7mm Remington Magnum, .300 Win Magnum and the previously intended .338-.375 Ruger (using .340 Weatherby data). Since I already have a .257 Roberts, 7mm Remington Magnum and .30 Winchester Magnum they were used for comparison purposes only but were not candidates for the new rifle.

What I found was the 6.5mm-06 and 6.5mm-06AI with 120 Ballistic Tip and 130g Scirocco bullets did very well. They shot nearly as flat as the .257 Weatherby 110 AccuBond and flatter than the .257 Weatherby with 120g Partitions but offered more downrange energy, burned less powder and generated less recoil. The 130g Scirocco was just behind the 7mm Remington Magnum in terms of trajectory and energy, but again burned less powder and generated less recoil. Estimates for the 6.5mm-06 Ackley Improved, using up to 10% more powder and generating 3% more velocity, are even more impressive in terms of trajectory and energy and still provide better powder economy and generate less less recoil than the other loads. (The 6.5mm-06 AI/130g Scirocco actually beats the 7mm Rem Mag 140g AB load at 800 yards in terms of both trajectory and energy – at least on paper.)

For a couple of reasons, I am leaning toward the 6.5mm-06 Ackley rather than the standard version. The primary reason for this is that I could use inexpensive .25-06 brass without fear that someone might chamber a loaded cartridge in a .25-06 rifle. The additional velocity provided by the AI version is tempting but I might find myself loading to standard 6.5mm-06 velocities and reaping the benefits of lower pressure and longer barrel life.

Below are some of the comparisons I ran using “Point Blank” ballistic calculator (available free at www.huntingnut.com).
A few notes on the data:
1. Most velocity data is from Nosler 6th Edition. Some are estimates or are from other sources.
2. In some cases bullets have been changed from that in the data books – notably for the Scirocco, but also for the TTSX.
3. Manufacturer Ballistic coefficients have been used when available. In some cases they are estimated.
4. Recoil data is calculated for a 8.3 pound rifle and scope combo.
5. MPBR (Maximum Point Blank Range) is calculated for a maximum rise or drop of 3” from Line Of Sight (6” diameter target).

=============================================================

Name: .257 Roberts, 100g TTSX
Ballistic Coeff: 0.418 (estimated)
Bullet Weight: 100
Velocity: 3250
Target Distance: 270
Powder charge: 48g
MPBR: 317
Recoil: 12.2fpe @ 9.7fps

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3250 fps  2345 fpe    0.00 in
300 yds   -1.81 in  2591 fps  1491 fpe    5.91 in
400 yds  -11.26 in  2392 fps  1270 fpe   10.80 in
500 yds  -26.94 in  2201 fps  1076 fpe   17.64 in
600 yds  -49.70 in  2019 fps   906 fpe   26.40 in
700 yds  -80.85 in  1846 fps   757 fpe   37.35 in
800 yds -123.07 in  1685 fps   631 fpe   51.30 in


=============================================================

Name: .257 WBY 110g AB 
Ballistic Coeff: 0.418
Bullet Weight: 110
Velocity: 3480
Target Distance: 289
Powder charge: 71.0g
MPBR: 338
Recoil: 19.6fpe @ 12.3fps

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3480 fps  2958 fpe    0.00 in
300 yds   -0.58 in  2787 fps  1898 fpe    5.38 in
400 yds   -8.46 in  2579 fps  1625 fpe    9.93 in
500 yds  -21.46 in  2380 fps  1384 fpe   15.99 in
600 yds  -40.79 in  2191 fps  1172 fpe   24.03 in
700 yds  -67.23 in  2009 fps   986 fpe   33.97 in
800 yds -102.25 in  1837 fps   824 fpe   46.15 in


=============================================================

Name: .257 Weatherby 120g Partition
Ballistic Coeff: 0.391
Bullet Weight: 120
Velocity: 3427
Target Distance: 250
Powder charge: 70.0 (estimated)
MPBR: 330
Recoil: 20.9 @ 12.7fps

Scope Height: 1.500
Temperature: 70
Altitude: 500

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3427 fps  3129 fpe   -0.00 in
300 yds  -2.70 in  2699 fps  1941 fpe    5.94 in
400 yds  -11.73 in  2481 fps  1640 fpe   10.94 in
500 yds  -26.40 in  2273 fps  1377 fpe   17.73 in
600 yds  -47.92 in  2076 fps  1148 fpe   26.69 in
700 yds  -77.22 in  1888 fps   950 fpe   37.76 in
800 yds -117.09 in  1713 fps   782 fpe   51.91 in



=============================================================

Name: 6.5mm-06 120g BT
Ballistic Coeff: 0.458
Bullet Weight: 120
Velocity: 3294
Target Distance: 276
Powder charge: 55.5g
MPBR: 324
Recoil: 16.4fpe @ 11.3fps

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3294 fps  2891 fpe    0.00 in
300 yds   -1.38 in  2683 fps  1918 fpe    5.26 in
400 yds  -10.21 in  2497 fps  1661 fpe    9.65 in
500 yds  -24.52 in  2318 fps  1432 fpe   15.48 in
600 yds  -45.51 in  2147 fps  1229 fpe   23.22 in
700 yds  -73.96 in  1984 fps  1048 fpe   32.76 in
800 yds -110.98 in  1827 fps   889 fpe   44.27 in



=============================================================

Name: 6.5mm-06 130g Scirocco
Ballistic Coeff: 0.571
Bullet Weight: 130
Velocity: 3151
Target Distance: 270
Powder Charge: 55.3g
MPBR: 318
Recoil: 16.6fpe @ 11.3fps


Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy   10mph Wind Deflect
  0 yds   -1.50 in  3151 fps  2866 fpe   0.00 in
300 yds   -1.79 in  2670 fps  2057 fpe   4.37 in
400 yds  -10.94 in  2520 fps  1833 fpe   7.94 in
500 yds  -25.51 in  2376 fps  1629 fpe  12.69 in
600 yds  -46.41 in  2236 fps  1443 fpe  18.92 in
700 yds  -74.29 in  2101 fps  1274 fpe  26.59 in
800 yds -109.83 in  1971 fps  1121 fpe  35.70 in



=============================================================

Name: 6.5mm-06 Ackley Improved 130g Scirocco
Ballistic Coeff: 0.571
Bullet Weight: 130
Velocity: 3245
Target Distance: 278
Powder Charge: 60.8g
MPBR: 327
Recoil: 19.2

Scope Height: 1.500
Temperature: 70
Altitude: 500

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy   10mph Wind Deflect
  0 yds   -1.50 in  3245 fps  3039 fpe   0.00 in
300 yds   -1.24 in  2754 fps  2189 fpe   4.20 in
400 yds   -9.73 in  2601 fps  1953 fpe   7.69 in
500 yds  -23.27 in  2454 fps  1739 fpe  12.25 in
600 yds  -42.59 in  2312 fps  1543 fpe  18.12 in
700 yds  -68.62 in  2174 fps  1365 fpe  25.51 in
800 yds -101.83 in  2041 fps  1203 fpe  34.27 in


=============================================================

Name: 7mm RM 140g AB
Ballistic Coeff: 0.485
Bullet Weight: 140
Velocity: 3340
Target Distance: 282
Powder charge: 67.5g
MPBR: 331
Recoil: 23.5fpw @ 13.5fps

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3340 fps  3468 fpe    0.00 in
300 yds   -0.99 in  2755 fps  2359 fpe    4.84 in
400 yds   -9.29 in  2576 fps  2063 fpe    8.88 in
500 yds  -22.72 in  2404 fps  1797 fpe   14.20 in
600 yds  -42.31 in  2239 fps  1559 fpe   21.21 in
700 yds  -68.88 in  2081 fps  1346 fpe   29.91 in
800 yds -103.11 in  1928 fps  1156 fpe   40.27 in


=============================================================

Name: .300WM 165g AB
Ballistic Coeff: 0.475
Bullet Weight: 165
Velocity: 3290
Target Distance: 277
Powder charge: 79.0g
MPBR: 325
Recoil: 31.9fpe @ 15.7fps

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3290 fps  3965 fpe    0.00 in
300 yds   -1.31 in  2700 fps  2671 fpe    5.06 in
400 yds  -10.01 in  2520 fps  2326 fpe    9.23 in
500 yds  -24.13 in  2347 fps  2017 fpe   14.84 in
600 yds  -44.75 in  2181 fps  1742 fpe   22.24 in
700 yds  -72.53 in  2021 fps  1496 fpe   31.29 in
800 yds -108.63 in  1868 fps  1278 fpe   42.24 in


=============================================================

Name: 300WM 180g AB
Ballistic Coeff: 0.507
Bullet Weight: 180
Velocity: 3160
Target Distance: 268
Powder charge: 73.0g
MPBR: 315
Recoil: 31.8fpe @ 15.7fps

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3160 fps  3991 fpe    0.00 in
300 yds   -1.94 in  2620 fps  2744 fpe    4.96 in
400 yds  -11.39 in  2454 fps  2407 fpe    9.01 in
500 yds  -26.63 in  2294 fps  2104 fpe   14.54 in
600 yds  -48.64 in  2140 fps  1831 fpe   21.76 in
700 yds  -78.20 in  1993 fps  1587 fpe   30.66 in
800 yds -115.98 in  1850 fps  1368 fpe   41.16 in


=============================================================

Name: .338-375 210g TTSX
Ballistic Coeff: 0.482
Bullet Weight: 210
Velocity: 3223
Target Distance: 272
Powder charge: 83.5g
MPBR: 319
Recoil: 43.6fpe @ 18.4fps

Ballistic Data
~~~~~~~~~~~~~~~
  Range  Elevation  Velocity   Energy  10mph Wind Deflect
  0 yds   -1.50 in  3223 fps  4843 fpe    0.00 in
300 yds   -1.66 in  2649 fps  3273 fpe    5.11 in
400 yds  -10.80 in  2474 fps  2853 fpe    9.33 in
500 yds  -25.60 in  2305 fps  2477 fpe   15.01 in
600 yds  -47.13 in  2143 fps  2141 fpe   22.49 in
700 yds  -76.15 in  1987 fps  1841 fpe   31.71 in
800 yds -113.60 in  1838 fps  1575 fpe   42.72 in
=============================================================

 

[NCsmitty]

I'm with PremiumSauces in choosing the 6.5-284. The 6.5 class of bullets provides the best BC under 338 caliber as a rule.
The newer powders available only enhance its long range capabilities and barrel longevity. It's at least the equal of the 6.5-06, with factory brass available.
You do need to have a long action to be able to seat those long bullets out properly.

NCsmitty

 

[Jim Watson]

What do you consider "long range"? The NRA says 800+ yards. If you are not that far out, one of the smaller cases will give up a little trajectory and wind but will gain in barrel life. I don't have a 6.5 but would sure look hard at the Lapua. Or I might look at a 6x47 Lapua or other 6mm. A more experienced friend has a very fine 6mm Remington that is flat and accurate.

Why do you consider a magazine of any importance in a bolt action target and varmint rifle? I don't want to be running my carefully loaded ammo around the corners from magazine to chamber. I've got the ejector spring out anyway so it doesn't throw my prepped brass in the weeds.

Are you going to be doing the gunsmithing yourself? If not, show the 'smith a dummy round and let him throat the chamber. I have heard of people throating a little short so they can load longer as it wears. Also have a long enough straight section in the barrel profile so you can have it set back as it wears.

I think an 8 twist is best for 140 gr 6.5s, but don't have one myself. Ask around and look it up.

Why a mere 26 inch barrel? Longer will get you some free velocity and move the noise farther away from your head. Also allows more for set back to get a clean throat after a while. Only reason I have a 28" instead of 30" is because they started charging extra per inch over 28.