6.5X55 Ackley Improved. [Report]

Eagleye

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I recently had Dennis Sorensen [Guntech] put together a new long range rig for me. It is built on a 721 Remington action I had. 26" Lothar Walther SS barrel, 1-8" twist, bedded into a 700 BDL Pepper laminate stock, and equipped with a Jewell trigger. Dennis trued up everything and made sure the threads were straight in the receiver, etc. Started breaking in the barrel. [and fireforming some Lapua Brass I had] Just threw together a few rounds with WLR primers, 120 Ballistic Tips and 4350 powder. Seated these about .010" off the lands. I did not cull any rounds from the groups, and did not take into consideration cold, clean barrel shots. Just shot a group on one target and moved on to the next, cleaning at increasing intervals as I went along. Shot a total of 8 groups. Smallest was around .3" and largest was .55" I am very pleased, to say the least. No load development, no match bullets, no bullet depth adjustment, and fireforming brass!! This rifle, previously a 30-06, had a hard time getting under 2½" at 100. Now to try some of those 139 Lapuas, 140 A-maxes and 142 Sierras! Regards, Eagleye.
 
or, the ever popular:
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Pics will be coming as soon as I get the film developed. As for Velocity, I have no idea yet, since I'm not interested in the velocity of the break-in ammo, and I will have to develop loads that shoot the best, then I will measure velocity. Potential is 2950+ with 140 grain bullets. Very close to the 6.5-284, but with less powder for longer throat life. Regards, Eagleye.
 
It should be neck-and-neck with a 260AI, as capacity is similar. Then again, 260AI load data isn't really any easier to come by than 6.5x55AI is
 
It has about 4-5 grains more capacity than the 260 AI, so one could probably use the 260AI loads as a starting criteria, and work up carefully from there. EE
 
sounds wicked, keep us updated on how it shoots the VLD match bullets :D
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due to the taper of a regular 6.5x55, it really benefits from Ackley, much more so than a 260 would :)
 
not to mention that, in this rifle, you could load it a LOT hotter than the typical swedish mauser. The remingtion action's good for at least 65000psi, where the swede's are usually kept to 45000 (IIRC). So between the extra capacity and the stronger action, I have no doubt that you could get this to near-6.5/284 levels
 
Physically, here's what happens. Body taper goes fron .040" down to .010", shoulder angle changes from 25º to 40º. Capacity of the case increases by about 8 grains. Velocity gains are in the area of 150 ft/secs over stock in the original M38/96 action. In a strong modern action, greater gains are possible. Regards, Eagleye.
 
In your view, is the 150-200fps gains worth all the extra trouble?

Also how do 6.5swede, 6.5swede ai, 260rem and 6.5-.284 compare?
 
If loaded to the same pressures with the same powder and fired from the same length barrel acomparison would look something like;
6.5x55 140 grain bullet, 26" barrel, 4831 powder---- Max velocity about 2800
6.5x55AI same components------------------------max velocity about 2860
260 Rem likewise-----------------------------------------------------2780
65/284--------------------------------------------------------------2920
Now, I have gotten in excess of 2900 with 142's with the standard 6.5x55. I also known some to exceed 3000 with the 6.5/284. With a longer barrel or different powder. This is pretty close to what one can expect though as a comparison.
Ultimately, in a comparison like this, the rifle is more important than the specific chambering. In his case, Eagle Eye has had a rifle assembled by a skilled gunsmith using quality components so it's potential is right up there. Regards, Bill.
 
I can get the 142 gr Sierra MK to 2775 fps out of my 23" 260 Remington (non Ackley), no overpressure signs. 3" group at 300 yards for three shots :)
 
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