Tikka .243 AI

[eric1115]

H4350 is more accurate for me with the 108, but about 75fps+\- slower in a standard 243 chamber. 3000fps+ would be cool, but makes no real practical difference than the 2916fps at 41.3 h4350.

That doesn't suck a bit. Reality for me, neither the difference between .45 to .65 moa groups, nor from 29xx to 30xx fps, make much difference practically. Hoping the lower H1000 temps mean longer barrel life, plus I already have several pounds of it on hand.

 

[SloppyJ]

43.0 grains of n555 (0.7 grain under viht published max) behind a 108 in an 18” creed seems to be pushing 2900 FPS. But , I haven’t been able to justify buying a pile of n555 yet because I’m up to my eyeballs in 4350.

What's the 4350 run? I'm so torn between this and just a straight 6 creed.

 

[justin davis]

What's the 4350 run? I'm so torn between this and just a straight 6 creed.

Seems like 6 creed would be the easier option

 

[BigG]

As said earlier Ackley cartridge needs to be set back so that the parent cartridge can be fired in it with no headspace issues. If you were using a different method to blow out brass such as longer bullet seating it would work but your gain in case capacity would be minimal and negate the ability to fire factory ammo in the rifle.

I never worry about fireforming as I use my best 243 load and shoot it for what ever use intended. Always shoots awsome. When you are done you have fireformed brass and switch to your Ackley load. At least when you go somewhere and loose your ammo or run out you can run factory stuff and have a great shooter. Hardly any trimming and long case life. Anneal cases and get even better results.

 

[wind gypsy]

What's the 4350 run? I'm so torn between this and just a straight 6 creed.

I'd guess around 2800 with same pressure (Edit: meaning below "max"). Maybe a hair less. This is my first 6cm barrel, must have around 500 rounds on it and seemed like it was still speeding up at close to 400 rounds and it's only seen n555 since then.

 

[eric1115]

Did another round today, ran up to 52.5 H1000 (pretty crunchy) and only saw some mild pressure signs at the top (slightly flat primers, light swipe marks. No heavy bolt, no heavy swipes, no craters). Groups were just meh today with both bullets, but the 108 still grouped better than the 106. Magnetospeed on the barrel though, not putting too much stock in a 2 grain span group with the Chrono on.

Big velocity bump from 52.0 (lightly compressed) to 52.5 (moderately compressed. Don't think I'll try to stuff any more in than that). I'm guessing I broke enough kernels to meaningfully change the amount of surface area present, rather than a transition from a "flat spot" or "node" (becoming more and more of the opinion that those don't really exist) to a higher "node" due to charge weight.

I'm planning to try loading 10 at 51.5 or 52.0 and see what kind of groups I get.

 

[pods8 (Rugged Stitching)]

I think I'd go in the 51-51.5 range with those 108s and not bother with a compressed 52, its still a full case and would probably be more stable in variable conditions I'd think. Keep us posted.

 

[SloppyJ]

Did another round today, ran up to 52.5 H1000 (pretty crunchy) and only saw some mild pressure signs at the top (slightly flat primers, light swipe marks. No heavy bolt, no heavy swipes, no craters). Groups were just meh today with both bullets, but the 108 still grouped better than the 106. Magnetospeed on the barrel though, not putting too much stock in a 2 grain span group with the Chrono on.

Big velocity bump from 52.0 (lightly compressed) to 52.5 (moderately compressed. Don't think I'll try to stuff any more in than that). I'm guessing I broke enough kernels to meaningfully change the amount of surface area present, rather than a transition from a "flat spot" or "node" (becoming more and more of the opinion that those don't really exist) to a higher "node" due to charge weight.

I'm planning to try loading 10 at 51.5 or 52.0 and see what kind of groups I get.

Just to confirm, you're running it at 18" and it's the normal 243ai reamer? Didn't know if you sent a dummy round with it or not or if it would even make a difference.

I found a lefty Tikka 1:8 in stock for a pretty damn good deal and I'm thinking that it sure sounds better than dropping another 3k on custom build. I would need to do the exact same as you, send it off to get it cut down and threaded as well as chambered to 243ai. Sounds like Kampfield is the guy for that job but I don't see any chambering info on his page. I'll have to call on Monday. Probably have him flute the bolt as well. It'd give me an excuse to try out a rokstock and those UM rings.

 

[eric1115]

Just to confirm, you're running it at 18" and it's the normal 243ai reamer? Didn't know if you sent a dummy round with it or not or if it would even make a difference.

I found a lefty Tikka 1:8 in stock for a pretty damn good deal and I'm thinking that it sure sounds better than dropping another 3k on custom build. I would need to do the exact same as you, send it off to get it cut down and threaded as well as chambered to 243ai. Sounds like Kampfield is the guy for that job but I don't see any chambering info on his page. I'll have to call on Monday. Probably have him flute the bolt as well. It'd give me an excuse to try out a rokstock and those UM rings.

19" barrel.

Standard (as I understand it) 243AI reamer.

I sent a dummy round (108 seated so boattail junction meets neck/shoulder junction, had him throat that for .020 jump. I don't know how much difference (if any) my throat ended up from where he would have set it without a dummy (guessing shorter throat for a saami spec 243AI since saami coal is 2.700 I think. For sure shorter than the 2.865 dummy I sent.

I have zero complaints about Karl. Good communication, helpful, good work (as far as I'm able to tell). I've heard his fluting and cerakote work is top notch.

I'll be shooting some groups in the next day or two.

 

[SloppyJ]

19" barrel.

Standard (as I understand it) 243AI reamer.

I sent a dummy round (108 seated so boattail junction meets neck/shoulder junction, had him throat that for .020 jump. I don't know how much difference (if any) my throat ended up from where he would have set it without a dummy (guessing shorter throat for a saami spec 243AI since saami coal is 2.700 I think. For sure shorter than the 2.865 dummy I sent.

I have zero complaints about Karl. Good communication, helpful, good work (as far as I'm able to tell). I've heard his fluting and cerakote work is top notch.

I'll be shooting some groups in the next day or two.

Thanks so much man. Going to call him Monday to see if I can get my stuff sent in there. I appreciate you making the thread and pushing me along with all of the info that's been posted.

Only problem is I don't have any formed ai brass but I bet he will know what I want.

 

[eric1115]

Thanks so much man. Going to call him Monday to see if I can get my stuff sent in there. I appreciate you making the thread and pushing me along with all of the info that's been posted.

Only problem is I don't have any formed ai brass but I bet he will know what I want.

Happy to help!

This is what you want...

243 Winchester Unprimed Rifle Brass 100 Count

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[pods8 (Rugged Stitching)]

Only problem is I don't have any formed ai brass but I bet he will know what I want.

The ackley doesn't really change the neck too much you could just make a regular 243 dummy round where you want the bullet. Or just ask if he even needs it or knows what to do based on just doing it.

 

[eric1115]

He said I could send a straight 243 dummy and that would tell him what he needed, before I found some former 243AI brass.

 

[solarshooter]

What's the 4350 run? I'm so torn between this and just a straight 6 creed.

I just started shooting my new Tikka with an 18" Bartlein in 6 creed. Did a pressure test with Berger 108 Elite Hunters, H4350, and CCI 200s, got pressure signs at 44gr, backed off to 43.0 and I'm getting 2930fps with that load. Very accurate too.

 

[SloppyJ]

Y'all rock. Thank you for the help. I talked with him yesterday and he acted like it was no big deal and seemed happy to help. He said "You know, I just did this same thing not too long ago." I told him that's where I got the idea.

I need to go back and read but I'm not sure I want to seat that bullet out as long as it can go to get it chambered so I have some room to counter the throat erosion as the barrel starts to get some rounds on it.

 

[solarshooter]

I just started shooting my new Tikka with an 18" Bartlein in 6 creed. Did a pressure test with Berger 108 Elite Hunters, H4350, and CCI 200s, got pressure signs at 44gr, backed off to 43.0 and I'm getting 2930fps with that load. Very accurate too.

I should mention this is with a saami reamer, 0.183" freebore, bullet seated to 2.800" COAL and is jumping 0.040".

 

[eric1115]

50.5 H1000

Both the 106 and 108 shot fine. 10 rounds each, and suppressor mirage was getting pretty good by the end of both of these, and as far as I can tell both groups started tight and grew at the end. The first 6 106's into a ragged hole is encouraging for sure.

I don't mind these groups at all, especially if the mirage was part of the dispersion. I'm going to load another 50 of the 106's at 50.5 and take them out to distance.

 

[wind gypsy]

Good to see the 106s hangin with the 108s! I haven’t given them a fair shot yet.

 

[Castle Rock]

Yeah just have a concern with availability here in australia on new set and a quick search online shows the roughly $470 ( roughly $310 US) so my initial thought was if may be cheaper to get the die i have altered

You can’t have a die reamed for all practical purposes, they are surface hardened
Simplex will make you a die for a very reasonable price if you need a FLS die
You will probably get away with neck sizing with a Lee collet die for at least 10 loads before you need the FLS die if you use lapua brass

 

[max-x]

I went with a 6mm Competition Match for my T3.

Fireform from 260 brass for an easy false shoulder.

Fireform load shoots .8 moa at 300yd.

3020fps with 47.x of H1000 for any 115gr flavor and groups very well.


To do it again, I'd likely just do a Dasher - that seems to be the 6mm sweet spot