.223 bolt action 600 yd

[Hand Skills]

What's your max mag length? I'm not familiar with Tikka actions, but you should be able to seat the bullets out pretty far. My Remington with 70gr RDF's ends up being around 2.335 to get close to the lands and it has quite a short throat.

How are you measuring to the lands?

Tikka T3 .223's are built on a 'short action' 2.8" platform. Technically it's a long action but the bolt stop limits at 2.8".

The stock magazine is designed for SAAMI length cartridges (2.26"). My stock tikka mag will accept 2.275" before it becomes an interference fit.

There are aftermarket magazines available capable of holding longer cartridges. Some individuals have lengthened their factory magazines to accommodate greater OACL.

To find lands I take a guess and seat a bullet way out without any powder or primer in the case. Then gently try to chamber the round while bumping the seating die back incrementally. Once I can chamber the round, I'll seat the bullet half a hair (<.005) deeper. Typically I light a Q-tip on fire and 'smoke' the bullet (turning it in the smoke) at this point. The smoke provides a pretty clear indicator of where the bullet contacts the lands and it wipes off easily with paper towel. From there it's just fine tuning the seating depth until the lands leave a faint impression on the blackened bullet without copper showing through.

Seating a 75gr ELD-M to the lands gives OACL of 2.467" in my chamber.

 

[Kimber7man]

Mountain Tactical is now making billet aluminum magazines for the T3/T3x, or at least taking orders for them. They claim their .223 magazine will handle an OAL of 2.600".

 

[Hand Skills]

Good to know there is a domestic option. I found a couple of aftermarket options, one out of the UK and this guy from australia;

http://www.aihpa.com/Sponsor/Tikka_T3_Mag_Options/Tikka_T3_Mag_Options.htm

 

[ncwg2boatguy]

What's your max mag length? I'm not familiar with Tikka actions, but you should be able to seat the bullets out pretty far. My Remington with 70gr RDF's ends up being around 2.335 to get close to the lands and it has quite a short throat.

How are you measuring to the lands?

Im using a hornady OAL gauge. The Tikka mag is longer than 2.260 Mil Spec. I can stretch them out to 2.548 in the mag no problem feeding.

 

[ncwg2boatguy]

@TMill308 Interesting, I didn't realize 77gr smk was designed specifically with mag length in mind. That's good to know. They list a relatively low BC of .362, so I never considered them. By comparison, 75gr ELD-M has a BC of .460.

It's always windy here, so I've been focusing on 'heavies' w/ BC's >.400, but I should have qualified my previous post with that.

@ncwg2boatguy It's great that you are shooting factory the amax that consistently. At mag length I haven't got them to group better than ~1moa. I'm considering a couple of modified mags so I can use ~2.47 oacl.

Out past 300m, the BC really makes a difference. Here is my range card with 75gr ELD-M (verified)

View attachment 95760

Here is my calculator's guess for a 77gr smk at the same velocity, in the same conditions (unverified);
View attachment 95761

My data is metric, but comparing the two at 550m (~600yd) a 10mph crosswind moves the smk's POI 30% (roughly 12") farther than the ELD-M.

Hand Skills you are the man! I will run these range cards to ground and get back to you.

Jim

 

[Tikka595ll]

I have an older Tikka T3 varmint 8 twist in a chassis that I am running 75 amax in norma cases with Varget at 2.450" coal. In aics mags I also worked up a load with berger 80.5 gr fullbore and Varget coal 2.395" that shot very well. both loads will reach 800 plus I have seen others post of having success with the 80.5 in the Tikka's

 

[Tikka595ll]

 

[No2psi]

Mountain Tactical is now making billet aluminum magazines for the T3/T3x, or at least taking orders for them. They claim their .223 magazine will handle an OAL of 2.600".[/QUOTE


2.600" is awesome!

My load:
LC 2011
CCI BR4
24.1 grains Varget
75 Eldm .007 off the Lands.
2915 FPS
SD 7 for 10 shot string.
26 Kreiger . 223 Wylde 8 twist

H4895 was considerbly faster but shot looser and SD went out the window.

 

[ncwg2boatguy]

Any truth to the myths that if you run moly bullets in barrels you need to stick with them? Im a stickler for cleaning firearms and find this far fetcched but prove me wrong? Why if so...

 

[Kimber7man]

Im using a hornady OAL gauge. The Tikka mag is longer than 2.260 Mil Spec. I can stretch them out to 2.548 in the mag no problem feeding.

I just picked up a new T3X Varmint .223 and the magazine only allows a 2.30" OAL.

 

[Hand Skills]

Here is a cool trick for single feeding - works like a charm with my stock T3 .223 magazine.