Thread: Short action 284win

50900cup with 53.5gr

Just started load dev for my new 284, 22 in Truflite UM bbl 1:8.5 twist built on Tikka ex 2506. Barrel run in and ran a couple of test ladders.
162 AMAX with RL17, 52.5 to 54.5 gns, pressure still ok. 2995 FPS over the chrony at 18ft from muzzle with 54.5 gun.
Happy camper, that’s getting close to Rem Mag speeds !
And 160 TMKs with Superformance , up to 2875 FPS and no pressure signs.
So now time to run some groups to find the sweet spot, fingers crossed it’s close to max velocity.

Originally Posted by chainsaw

Just started load dev for my new 284, 22 in Truflite UM bbl 1:8.5 twist built on Tikka ex 2506. Barrel run in and ran a couple of test ladders.
162 AMAX with RL17, 52.5 to 54.5 gns, pressure still ok. 2995 FPS over the chrony at 18ft from muzzle with 54.5 gun.
Happy camper, that’s getting close to Rem Mag speeds !
And 160 TMKs with Superformance , up to 2875 FPS and no pressure signs.
So now time to run some groups to find the sweet spot, fingers crossed it’s close to max velocity.

Yeah thats good speed alright, I get 3005 fps with the 162 Amax from my 22" 7mm SAUM, with 67.5gr of 2217. Some guys 7RM's are not even getting that accurately.

What is the cost of converting a 708 to a 284? Just curious as could be a good future project.

Originally Posted by GWH

Yeah thats good speed alright, I get 3005 fps with the 162 Amax from my 22" 7mm SAUM, with 67.5gr of 2217. Some guys 7RM's are not even getting that accurately.

I have just got a load going in mine that I'm keen to see how it performs on the animals. I am sending the 140gn Berger VLD at 3050. That's with 57gn of 2209. If I do my bit they can go into the same hole. That is the max in the book however there are no real pressure signs, but the case is at 99.5% capacity I reckon.

Originally Posted by superdiver

What is the cost of converting a 708 to a 284? Just curious as could be a good future project.

There is only the cost of a re-chamber which is not to expensive. It can just be a bit of a chore finding brass, or you can make your own.

Originally Posted by Kudu

There is only the cost of a re-chamber which is not to expensive. It can just be a bit of a chore finding brass, or you can make your own.

And new dies of course

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Hmm always got my mind on the next project. Will see what comes up as thought about a 284 as a replacment for my 308 bushpig

Originally Posted by superdiver

Hmm always got my mind on the next project. Will see what comes up as thought about a 284 as a replacment for my 308 bushpig

If you do it on a t3 708, you can also put the Long action mag and bolt stop in, and run heavy pills seated right out to get max case capacity.

Out of interest, I finished up on 52gr 760 behind 150gr eld x with magnum primer. Met a slightly sticky bolt at book max 53.5. The projectile seated reasonably deep at 3.000 OAL.
Shooting well and still at around 2850 I guess. Being a control round feed I think single loading long ones is off the cards. Still a notch above a 708 I think.

Controlled round feed will still allow the extractor to cam over the rim of the case

Originally Posted by stevodog

Out of interest, I finished up on 52gr 760 behind 150gr eld x with magnum primer. Met a slightly sticky bolt at book max 53.5. The projectile seated reasonably deep at 3.000 OAL.
Shooting well and still at around 2850 I guess. Being a control round feed I think single loading long ones is off the cards. Still a notch above a 708 I think.

Interesting, I'm at 52.5gr of H414 (same powder) with the 162 Amax. But I'm seated out very long. Custom long throated chamber.

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Cool, I didn't know that. I would be interested to try some seated out further and going a bit faster

Have you chronied your load GWH? That's right on book max on my data.
I still have some things to work out with mine..it's fun and I'm learning a bit.

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