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IMR 4955, anyone using it?

I have a pound of it and was planning to do some load development using it in my 6.5x55 Tikka Sporter- but haven't yet - it's on sale at Cabelas at moment.
 
Great for "mid-weight" bullets for the 308Win.& 30-06 . Approximately 10-15 yrs. ago they pulled down a lot of 30-06 and sold off the components, IMR4895 being the powder .
 
Milo -

Howdy !

Just tried some IMR4955 today, in my " DEEP 6 " wildcat. Its case capacity is 51.2gr H2O. Compare to .243Win @ 54gr, 6mm Remington @ 55gr.

I was simply trying first to determine max allowable charge wt, shooting 95MKs from a Broughton 29" SS 1-8 5-"C" .
Using FED LR Magnum Rifle Match primers, I was suprised that the upper limit on a balmy 67*F day was..... 36.0 gr.

I do seat the 95s fairly deeply into the case' neck. Still, I was expecting a demonstrated " burn rate " closer to the IMR7828 and RL-22 that I have been using.
Instead, to me and in my application... it struck me as being very close to say... H4350. I thought that was a burn rate zone IMR4451 already had covered.

Hmmm...



With regards,
357Mag
 
Instead, to me and in my application... it struck me as being very close to say... H4350. I thought that was a burn rate zone IMR4451 already had covered.

IMR 4955 was developed to be extremely close to 4831, which I'm sure you know. I'm using 4451 in 270 Win as a proxy for 4350, and in preliminary testing 4451 it works great behind 130-gr bullet in 270 Win. While its burn rate may be close to 4350, it develops ~25% more peak pressure than 4350, but delivers max velocity only 3% faster behind lead-core bullets.

PS FWIW (off topic after all, sorry) here's two comparisons between H4350 and IMR 4451, which may have some crossover info WRT 4955 (e.g. temperature insensivity):

http://bulletin.accurateshooter.com/2016/07/powder-comparison-test-h4350-vs-imr-4451/

http://www.chuckhawks.com/imr_enduron_powders.html
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I tried 4955 in a 6.5 slr, and 6 slr, and am currently using it in one 6 slr. I had 2 6slr's at one point, both new chambers, and can say in this application, the burn rate doesn't resemble H4831 at all, it seems way faster.
It seemed to take almost a full 2gr more of H4831 to match the velocity of 4955.
 
I tried it (IMR 4955) in my 22 creed with the heavier bullets, since the RL26 was impossible to find at the time.
I ran into pressure way before case was near full.
It seems to me it burns a little faster than you would think it's listed at. Very close to H4831 or towards H4350, just me.
 
I've yet to try it, but have noted that in the new Sierra Edition VI manual which has some data-sets with 4955 loads, maximum charges and the resulting MVs appeared to be lower than the H4831 equivalents pretty well across the board.
 
It's supposed to be suitable for the .25-06; 270 Win etc. but so is the IMR7977. Seems like it is in the range of suitable powders to be at least worth trying.
 
I shot 4955 in a 25-06 with 115 Bergers with very good results. Check the load data on the Hodgdon website and start about 3 full grains below their max. I ended up with a load at about 3200fps, no pressure and very good accuracy.. Can't really speak to the copper fouling.
 
I won a Fullbore regional shooting IMR 4955 in my straight .284 Win with 180g Scenars.

53.4g shoots really tight at distance with that bullet in my 32” barrel at 2830 fps.

Remember, that is with my setup, usual caveats apply.
 

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