Bullet seating depth & oal in 6.5X55SE TikkaT3

[boatbum101]

Have a Tikka T3 in 6.5X 55 . Just measured oal to lands for bullets I have on hand . Was wonder if someone could give me advice on where to start on how far off lands to start with . Norma 156 Vulkan oal to lands is 3.034"
Norma 156 Alaska oal to lands is 3.145"
Norma 156 Oryx oal to lands is 3.055"
Lapua 155 Mega oal to lands is 3.032"
Sierra 160 SMP oal to lands is 3.091"
Horn 160 RN oal to lands is 3.1475"
Horn 140 SP oal to lands is 3.115"
Horn 140 SST oal to lands is 3.156"
Horn 129 SP oal to lands is 3.062"
I'm looking for accurate powerful loads for hunting & have many of the common powders on hand as well . I'd like to keep loads at or below CIP limit of 55K psi / 3800 bar . Some bullets like to close to lands & some like the Barnes like a .030 jump . It's confusing when you look in loading manuals at the coal they developed loads at vs what you measure your rifle at . If I can seat out longer it gives more case space & room for powder . Any suggestions would be appreciated .

 

[FatOldMIHunter]

I'm going through the process of load development on a Howa 1500 6.5X55 SM and finding that my limiting factors are brass length that is below minimum standard and bearing surface of bullet inside the neck, especially with boat tailed bullets. With your long OALs-to-lands, you might find that it is difficult to get close to the lands without risking the bullets falling out of the cases, especially when they are in the magazine during recoil. Sorry that I couldn't be more help on your specific bullets. My plan is to start with a minimum of .150" bearing surface inside the neck and see if the cartridges hold together. Then I'll seat the bullets deeper in .005" increments and see if I can find a sweet spot for jump.

 

[2506]

As to where to seat your bullet will depend on the bullet itself and what your rifle likes. I would start by seating the bullet with a full .264" down in the case neck. I would then find my most accurate powder load then do a ladder of seating depths. I have loaded for a number of the Mauser 96 6.5x55 rifles and they have a throat a mile long. You can't get close to the lands with 140 gr and lighter bullets and allow them to work through the magazine. I have found that the use of a Lee Factory Crimp Die helps in the accuracy department when the bullet has to jump a long ways.

 

[boatbum101]

Yes I've loaded for the Swede military rifles & they do have long throats . My Tikka is definately not in that category . My figures above are with bullets into the throat as far as they'll go with light pressure . I was wondering should I start with .020 jump & do my ladder load tests to find accurate powders & charges & then play with seating depths , neck tension , primers etc. ?

 

[Spin]

In my T3, loaded close to the lands was right at the max magazine length. I’ve read elsewhere and found that the 6.5x55 can like lots of jump. My Tikka shoots lights out and is very forgiving on bullet seating depth.

Is this a hunting rifle or the target version?

Mine likes RL 19 for 120 gr Bullets and 4831 ssc or RL 22 for 140/142 gr Bullets. I believe mid charges provided the best accuracy if I remember correctly. Also, it’s a slow barrel. The 155 Mega’s were under an inch, but moving really slow.

 

[Bigdad123]

Boatbum, you've got the right idea. I would start with a .020" jump, as long as you have =/>.264" neck engagement, and shoot a 10 shot 400 yrd ladder in .3 gr powder increments. Once you find your accuracy node, start adjusting jump from there.

 

[boatbum101]

Rifle is a Tikka T3 Hunter which I upgraded recoil lug to a SS one , pillar & Devcon bedded , free floated barrel . It's a hunting rifle not for paper punching , that's why no SMK , Berger VLD or Amax listed in bullets above . No problem keeping enough bullet shank in the neck as the only bullet I could go to max OAL w/o jamming is the Horn 140 SST & then I'm only .006" off with them . Maybe the Horn 129 SST will be the same but when I ordered Powder Valley had none in stock . The 120's I'll mess with later as unless I'm going for Pronghorn I fail to see them bringing anything to the table that the 129 doesn't .

 

[370bc]

I tried to get constant readings from my stoney point OAL gauge in my Tikka T3x, and only managed to get readings that were all over the place. I cleaned the throat with wipe out for 3 days, then JB bore paste with a brush with a patch on it, connected to a cable that I ran with my cordless drill. This is in a T3x in 270 win., with 110 VMaxes and 110 Pro Hunters.
I have seen videos by Wheeler Accuracy, where they remove the remington ejector. I don't think I can do that with the Tikka.