IMR 4350 / .243AI / Vihtavouri equivalent / for high temps

[CT10ring]

in 1/8 twist ,.243 AI -loaded some 87 g v maxes w IMR 4350 44.0g first time ( thanks to info here) Wow. great group.

Couple of questions: is IMR 4350 temp ( heat sensitive)? I use Varget & VVN550 for PD shooting high temps. Any info on IMR 4350 being heat tolerant? what would the VV equivalent be? info appreciated.

 

[357Mag]

CT -

Howdy !

IMHO..... VV160 would be closer to I4350, than VV550 is.

What Kaltron-Pettibone told me over the phone, was that their VV500-series powders ( such as VV550, VV560 ) only come into their own; when shooting the heavier/heaviest bullets in the calibre being reloaded. If memory serves, K-P cited testing VV did w/ .308 Win.

I had tried VV560 in-lieu-of VV160, in an attempt to eek-out the max possible vel for 55gr .224" cal bullets; shot from a .224" cal 24"
1-14 barrel; chambered for a wildcat w/ case capacity > .22-250. K-P was apparently right, as the VV560 loads did not even attain the same vel as my standard VV160 loads did.

For a non-VV powder close to I4350 in burn rate, IMHO the surplus " D85" ball powder comes close. I say that, based on my D85 testing in a 29" 6mm 1-8 SS barrel; chambered in a 6mm wildcat w/ case capacity about a nominal 2gr< .243 Win. My 6mm tests tried out bullets of 88- 105gr.

As an aside, don' t forget to try FED LR Magnum Match primers, with any/all of the powders mentioned; above.
They have sure worked well for me, shooting the .224" cal bullets of 55-75 gr; and 6mm bullets of 88 -105gr ( my wildcats, my guns ).

Best of luck in your endeavors !

Regards,
357Mag

 

[Gary in MD]

I would also recommend vv160. It may be just a touch slower burning than imr 4350. I use it my 6mm ai, it's clean burning and has given excellent accuracy with all bullets that I've tried (68gr thru 80gr).
Gary

 

[CT10ring]

Ah, thats great + useful info. So VV160, I will try it. All of the VV powders I have used have been
very clean burning, and I'd like to try another for the .243ai.

FED LR Magnum Match Primers- never tried em. How are they better than the CCI BR2's I use?
obviously hotter, so...more power, better accuracy- reduce charge weight 5% - 10% to start...?

The 1-5 shot group I shot with IMR4350 44.0g 87g v max was great, primers perfect but lots of room left in that .243AI case, and,
I thought why use an AI case, if it's not full of powder...

Thanks for the info.

 

[Steve Blair]

Bill,
I shoot 105 Berger Hybrids in a 6mm Remington which has about the same capacity as your .243 AI. My best results are with H4831 SC although H4350 also produced good results at a lower fill percentage. Neither IMR or H4350 should have much temperature problem. They are both single base powders.

 

[357Mag]

Bill -

Howdy !

As regards your primer question.....

Best thing is to try your best load, with all the different primers you can get your hands on.

I;ve had many loads where just the primer switch, shrank my accuracy load' groups even smaller. Again, with the case capacities and powders we're taling about; you might find the
FED LR Magnum Match will work well for you; also. In my rifles/myu loads, they just happened to help produce more accurate loads, than the same powder/charge/bullet combo mad CCI LR Mags.

You'll have to see for yourself .

With regards,
357Mag

 

[CT10ring]

357 Mag, Gary in MD, sleepygator,
thanks for the info + time spent to reply.

Glad to get more info about this intriguing subject of increasing accuracy & the knowledge of experienced
shooters, esp in the specific area of 243 AI + powders is valuable & appreciated. Now I have to buy new powder & primers to learn more. Darn.