? 260 vs 260AI vs 6.5-.284 w/27.5" barrel; velocity gains?

[chris matthews]

The 3.06" is the outside measurement of the Wyatt's mag box. The inside is indeed 2.9" for a OAL. With that barrel length you should be able to run the 140 MK at near 6.5-284 velocities. Approx 2800-2900 fps.
PS- Stick with the MK - it will kill everything you mentioned.

[ 06-15-2004: Message edited by: chris matthews ]

 

[WindTrax]

I currently am having a rifle built up. Here are the current specs:
1) Rem. 700 short action, fully accurized (face squared, lugs machined, raceway lapped, shroud reworked (was not enough clearance under recoil), etc. and trigger reworked.
2) Lilja 6.5 bore, 3-land, 8" twist barrel on order spec'd at 27.5" long, #4 countour, fluted for a 24" barrel in case I want to shorten it at a later date once the barrel wears out for use as a brush gun for whitetail.
3) Borden/Rimrock custom ADL rifle stock (http://www.bordenrifles.com/stocks.shtml) pillar bedded and barrel floated.
4) Wyatt extended box magazine, allowing a 3.06 overall cartridge length; Gun smith is machining the bolt stop/receiver to allow for as much length as possible but suspects we won't get that much length out of it, probably closer to something just over 2.9".
5) Gun use will be for target up to 600 m. plus regular use on whitetail and black bear up to ? yards with occasional use on coyotes, bobcat and cougar.

My question is this. I hope to find an accurate load for 140 grain Nosler Partitions for hunting plus some make of target bullet around 140 gr. for target use. How much of a difference, loaded for a 2.9" overall cartridge length, the 8" twist and the 27.5" barrel will I likely see between the .260 Rem, 260 Ackley Improved and 6.5-.284?

Any helpful info would be EXTREMELY appreciated. This is my first 6.5 gun as well as my first gun built for even part-time target use.

[ 06-15-2004: Message edited by: Beartrack ]

[ 07-20-2004: Message edited by: Beartrack ]

 

[Mysticplayer]

estimated muzzle vel all being the same.

260 2700fps
260AI 2800fps
6.5-284 2900fps

I am shooting the 140gr SST in my hunting 6.5 and find it to be superbly accurate and should work just fine on all big game.

As a bonus, it should have a BC higher then the MK. Just going by length of bullet. The SST is longer.

Jerry

 

[milanuk]

Hmmm... what's this Wyatt extended box you mention? What's the cost to have one installed thru Jim (He's done most of the work on my 6.5-08 XTC match rifle)? On second thought, it wouldn't do me much good. 700SA is my limitation -> 2.750" for rapid fire strings to ensure getting them into the gun in the first place.

As far as velocities... dunno about the others, but I've heard .260/6.5-08 speeds all over the place for 140 class bullets, from 2600+ to high 2800, some almost 2900fps. Depends some on barrel length, powder choice, brass (internal volume), etc. Most people are pretty happy w/ 2700-2750 out of a 6.5-08, sometimes abit more, mostly using 26-28" barrels and thick heavy brass like Lapua. At least one fellow I know that shoots down at RattleSnake swears by a 142gr SMK over 50.5gr H-1000 in a Winchester case (has to work at it to get it to fit in there!) producing (he claims) 2854fps. Seeing as how he set a range record w/ it at Rattlesnake... I'd say maybe he's got something.

No experience w/ the others. I kind of stuck w/ the 6.5-08 for the same reason most people in HP do... does most everything pretty well w/o being too much (barrel life). For hunting, I don't know if I'd change my choice much.

Good luck, and let us know what you end up going with!

Monte

 

[chris matthews]

Look at Chris and me went huntin in the general discussion. That pretty much sums up my bear experience with MK. I have killed everything from prairie dogs, fox, coyote, feral dogs & cats, Russian hogs, axis deer, tons of whitetails, two bears, cattle and numerous other critters that I am forgetting. All are in animal heaven because of a MK.
I worked at Sierra for a sort stint before I started building rifles. I made MK by the millions and they ain't much different than the GK.
Bullet construction don't have a lot to do with killing stuff- it's all about SHOT PLACEMENT. The key to accurate shot placement is accurate ammo- usually match ammo.

 

[milanuk]

Scott,

Jim's done most of the work on my 6.5-08. Trust me, I've sent waaayy too many $$$ over the hill his direction

At any rate, the concern isn't the box magazine or feed rails/ramp, it's the distance btwn the receiver bridges. For the game I play, I have to be able to shoot 5, reload, shoot 5 more, in 60-70 seconds, so I have to use stripper clips as most options for detachable magazines for bolt guns are extremely spendy and/or suck. As such, even w/ the rear bridge clip-slotted, and a little divot taken out of the front bridge for the bullet tip, I could *maybe* get away w/ 2.775", but 2.750" is a safer bet. Gun still shoots plenty accurate like that. For longer range where I am single loading, I seat to the lands.

As far as target use, why limit yourself to 600m? Rattlesnake (Tri-Cities) has F-class along w/ the Palma shooters (if I'm not mistaken) out to 1000yds. I've been meaning to get down there one of these days when they have the 300-600-800-900-1000yd shoots (for those of us w/ shaky zero's for longer range due to not getting to shoot that distance very often)

Monte

 

[WindTrax]

Chris Matthews: Thanks for the info on the Wyatt box internal dimensions, when I called Brownells and was told 3.06 it seemed too good to be true! On using the MatchKing bullets - I've read about a few others doing the same thing - is it really safe? We do have some fairly large bears up here on occasion - I took a 6'8", 550 lb. one some time back (pics on my home page.) I know that Sierra doesn't recommend it but then several folks here have said they've had no problems. Can you tell me a bit about your experiences with that bullet?

Jerry Teo: thanks for the info! Can you tell me the source, i.e. your experiences with the rounds and those you've seen or was this from a computer program or just off the cuff estimates? Also, what are the differences between the SST and the Nosler Ballistic Tips? Thanks for any additional info!

Milanuk: The gun smith (edited after gun was ready) charged $66 including the cost of the box itself. He didn't seem to have any concerns about getting the longer rounds to feed properly from the magazine if that's what you are referring to for rapid fire; I believe he reworks the ramp and of course the bolt stop accordingly. Thanks too for the load info and great observations on the 6.5-.308 that you and others are shooting.

This is great guys! Being new to the board I really, really appreciate this help.

[ 07-20-2004: Message edited by: Beartrack ]