300 Win Mag COAL - Tikka

Anyone on here played around with seating at longer coal / up close to the lands with a tikka in 300 win mag? From what i have read theres mixed opinions, some say they gained some decent velocity, some say they gained nothing & most tend to agree that the tikkas arent too fussy with running alot of jump & will still be largely accurate and consistent even with a big jump.

I have a t3 in 300 win mag which has a very long throat (seems to be the normal for the 300wm tikkas from what i have read). SAAMI COAL is 3.340, My rifle measures 3.629 at "jam" point, 0.289 jump.

I already single feed with this rifle, as it flattens the tips of the rounds in the mag quite badly (200gr ELDX) so im not worried about having to stay within mag length.

3.619 (10 thou off lands) on left, 3.340 on right. Pretty big difference!

Attachment 214965

It’ll generally be the projectile that determines fussiness of jump, try it but make sure you start low as you’ll likely run more pressure seated long a good way to test it is a know safe low charge and try different depths for accuracy then ramp up the powder at the best depth

I’m running 208s with 77.6 grains of 2217 in my T3-based .300 WM.
It has a Bartlein reamed for 3.5 OAL, which is as long as a 208 can be loaded and still extract.
I’m surprised yours will extract at 3.6”, but perhaps the T3X have bigger ports?

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Originally Posted by Kelton

It’ll generally be the projectile that determines fussiness of jump, try it but make sure you start low as you’ll likely run more pressure seated long a good way to test it is a know safe low charge and try different depths for accuracy then ramp up the powder at the best depth

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I gave this a nudge on the weekend, unfortunately only had a handful of magnum primers so just loaded up what i could to see what would happen. Loaded 6 rounds at 3.340 with 74gr of 2217 and another 6 at 3.614 (15 thou off lands) with 74gr of 2217. The 2 groups of 3 at 3.340 were .7 and .6 moa which is pretty normal for this rifle if i do my part. The 2 groups at 3.614 were right on 1 moa, first one a tick over. Untill i can get my hands on some large magnum primers i wont be able to take it any further but seems it certainly prefers the std COAL compared to 15 thou off lands.

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Originally Posted by Hurricane

I’m running 208s with 77.6 grains of 2217 in my T3-based .300 WM.
It has a Bartlein reamed for 3.5 OAL, which is as long as a 208 can be loaded and still extract.
I’m surprised yours will extract at 3.6”, but perhaps the T3X have bigger ports?

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At 3.6, it wont extract a live round, have to release the bolt and slide it back past the bolt stop a touch.

Are you using a modified case and oal gauge to get your jam? The one on the left almost a looks like I can see lands marks like it’s jammed but it could just be reflections 20thou is a favourite for me with Hornady projectiles. We’re you using 215 federal?

Not using modified case, i loaded up a dummy round and pissed around for about 15 mins slowly moving it out further and further with fresh marker pen on it untill i could see witness marks on the projectile. went 5 thou more to confirm - bolt was tight to close and noticeable witness marks in the copper of the projectile. Went back to the one that had only just contacted the lands, measured it ogive to base, came back 15 thou and loaded up my test rounds. yep was using 215 fed, have none left though so will need to put the 300wm project on hold till i can track down some more.

Sweet thats a tried and true method it did fail me in my 6.5 saum though was getting a false mark from god knows what and I was way back at 150 thou burnt lots of powder chasing my tail until I got the comparator and measured a round that came with the rifle that was 20thou problem solved right away

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Originally Posted by Kelton

Sweet thats a tried and true method it did fail me in my 6.5 saum though was getting a false mark from god knows what and I was way back at 150 thou burnt lots of powder chasing my tail until I got the comparator and measured a round that came with the rifle that was 20thou problem solved right away

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Yeah im fairly confident its correct, the one i loaded up 5 thou deeper was really stiff to close the bolt on and it left clear rifling markings in the projectile. Once i have some more primers will start playing around with different seating depths and see what it likes. :thumbsup:

215s are plentiful down here I can send some if need be it’ll realistically take me a couple of weeks though to get into town then to courier

Thanks for the offer mate, but i think im sorted thanks to another forum member down in christchurch :thumbsup: