243 Winchester +p

[Thejet]

Any loss of brass yet? Still using Winchester brass and 108 eldm?

Still using the 108s and just retired the Winchester brass. No failures just moving to alpha brass.

 

[HighUintas]

Still using the 108s and just retired the Winchester brass. No failures just moving to alpha brass.

How many reloads did you get on the Winchester?

 

[Thejet]

How many reloads did you get on the Winchester?

Some had 5+

 

[Harvey_NW]

Your starting load for N560 is VihtaVouri's max load. Their max velo is 2749 fps with a 23" barrel.
You don't have a 243 +p, you have a 243 + Unsafe.

VV's load data is garbage, my load in my 6.5 is 11gr over their published max and I didn't even get any signs of pressure on my ladder at 95° besides velocity increase at the highest charge. I'm a very conservative reloader and usually only go a grain or 2 over published max on a pressure test even in custom chambers, but after consulting with some experienced guys that favor VV I took their advice and it yielded great results.

 

[Thejet]

Spending time with this thing lately, 3-5 reloads on the Winchester brass before scraping it. Still pushing 108s at 2850 like a champ.
New brass, powder, and new bullets 87gr Vmax just for a plinking/coyotes load to come. Should be in the 3050 range if it follows suit.

 

[longrangelead]

Spending time with this thing lately, 3-5 reloads on the Winchester brass before scraping it. Still pushing 108s at 2850 like a champ.
New brass, powder, and new bullets 87gr Vmax just for a plinking/coyotes load to come. Should be in the 3050 range if it follows suit.

anything new?

I'm curious how this is going with the +P

 

[HighUintas]

Also, I forgot to ask this earlier. It looks like a factory Tikka. With the p+ throat did it lengthen the throat at all to where you can seat the 108s further out?

I throated my factory Tikka about 0.100 farther out and it shoots lights out but I don't think I was able to gain much if any velocity potential

 

[Chris in TN]

I'm curious, will the 8-twist Tikkas fully stabilize the 109eldm?

An 8-twist Tikka would certainly be the easy-button for a light/short 6mm.

 

[Harvey_NW]

I'm curious, will the 8-twist Tikkas fully stabilize the 109eldm?

An 8-twist Tikka would certainly be the easy-button for a light/short 6mm.

I sure hope so, I have a 6 Creed being built with an 8 twist that I want to shoot them from, lol. I haven't seen any issues though, I think 8 is fine.

 

[Marbles]

I'm curious, will the 8-twist Tikkas fully stabilize the 109eldm?

An 8-twist Tikka would certainly be the easy-button for a light/short 6mm.

I think it depends on your altitude. My 8 twist Tikka had bad results with 112 Match Burners. Handles 108 ELDMs well, but I think the 109 is closer to the 112 than the 108 (if my memory serves, I remember deciding not to try the 109s after comparing).

 

[pods8 (Rugged Stitching)]

I sure hope so, I have a 6 Creed being built with an 8 twist that I want to shoot them from, lol. I haven't seen any issues though, I think 8 is fine.

109s are gonna be marginal depending on conditions/altitude as Marbles noted. It might work at your altitude in summer and then drop off in the COLD. The good news is the 108eldm is the easy fall back.

 

[Thejet]

I'm curious, will the 8-twist Tikkas fully stabilize the 109eldm?

An 8-twist Tikka would certainly be the easy-button for a light/short 6mm.

hunted this season with 115Dtac nose rings so I would say yes. Dtacs fly right at 2800fps backed way off pressure.

 

[Thejet]

Also, I forgot to ask this earlier. It looks like a factory Tikka. With the p+ throat did it lengthen the throat at all to where you can seat the 108s further out?

I throated my factory Tikka about 0.100 farther out and it shoots lights out but I don't think I was able to gain much if any velocity potential

Yes, I have them seated at max length that will fit in a M mag and that seems to be the ideal length for 108s and 115s for this rifle.

 

[Thejet]

109s are gonna be marginal depending on conditions/altitude as Marbles noted. It might work at your altitude in summer and then drop off in the COLD. The good news is the 108eldm is the easy fall back.

The 108s are for sure the easy button, I can’t really find a powder/speed combo the 108s won’t group at.

 

[Harvey_NW]

109s are gonna be marginal depending on conditions/altitude as Marbles noted. It might work at your altitude in summer and then drop off in the COLD. The good news is the 108eldm is the easy fall back.

Well chit, I'll have to do some testing because it will definitely be a go to for some winter coyotes. I have no issue with the 108's either though.

 

[Thejet]

H4350
2.71 long
44.5gr
87gr Vmax
2950

anything new?

I'm curious how this is going with the +P

Load it liked for dogs, could get over 3k without pressure but 2950 grouped stupid well so that’s where I stopped.

Going to tinker with 108s more this winter and see how fast I can really get them.

 

[pods8 (Rugged Stitching)]

Well chit, I'll have to do some testing because it will definitely be a go to for some winter coyotes. I have no issue with the 108's either though.

Plug them into a twist rate calculator for your conditions and see what you're looking at.

 

[Chris in TN]

Thanks guys. Again, I am just sort of planning/daydreaming but the JBM calculator, using published length/tiplength for the .243110ATIP says I'd be good down to high pressure/low altitude/low temp conditions I would likely never shoot in, with an 8 twist.

 

[Marbles]

Thanks guys. Again, I am just sort of planning/daydreaming but the JBM calculator, using published length/tiplength for the .243110ATIP says I'd be good down to high pressure/low altitude/low temp conditions I would likely never shoot in, with an 8 twist.

I doubt it, under 1.5 can start inducing accuracy issues even if the bullet is not tumbling.

This is from AB using standard atmospherics.

109 ELDM


112 MB


You can see the 112 is actually more stable. My velocity was lower than 3000, but I was trying to give more favorable numbers above to see if it would fix the numbers (it didn't).

I've posted the below before. Left target is varying powder charges with 108 ELDMs, right is 112 MBs. The groups actually got worse on the 112s as powder charge and velocity increased.



P.S. Of course feel free to try them and report back. Just sharing/recreating my decision process.

 

[Chris in TN]

I doubt it, under 1.5 can start inducing accuracy issues even if the bullet is not tumbling.

This is from AB using standard atmospherics.

109 ELDM
View attachment 978656

112 MB
View attachment 978655

You can see the 112 is actually more stable. My velocity was lower than 3000, but I was trying to give more favorable numbers above to see if it would fix the numbers (it didn't).

I've posted the below before. Left target is varying powder charges with 108 ELDMs, right is 112 MBs. The groups actually got worse on the 112s as powder charge and velocity increased.
View attachment 978657


P.S. Of course feel free to try them and report back. Just sharing/recreating my decision process.

JBM, using JBM's stated length/tiplength for the 109, shows me in the 1.5x range depending on what pressure and temperatures I put in.

Of course, both models are based on theory and subject to reality. lol.

I'm not even sure it's something I want to do yet. I like the concept of a shorter, lower-recoil 6mm, but I have to remind myself that the 6.5cm is working really well and the marginal gains in shootability between it and a similar 6mm, are small, and only come at the far end of another string of expenses I could do without.

But that's sort of the story of my life, as far as guns go.