Why IMR 4895 over IMR 4064 for 175 SMKs?

Hunt

Sergeant
Full Member
Minuteman
Jul 3, 2005
651
72
Tennessee
I've seen a lot of talk lately about different powders being used in .308 and with Varget, I'm not feeling the love with 175 SMKs in my rig. There seems to be quite a bit of talk about IMR 4895 as opposed to 4064 and I was wondering why? I would like to use 4064 as I have it on hand but I am willing to buy some 4895 if it's where it's at for 175 SMKs.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

I run 173gr lc match bullets in my M1A DMR.4895 POWDER
I shoots .5 moa 100yds.My FN SPR A2 DOSNT LIKE THE 173GR BULLET WITH 4895 shoots like 1 inch moa 100yds going to 168 gr SIERRA
WITH spr
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

1+ for IMR 4064 in my tube for the 175 SMK. At 44.4 grains, it shoots 3/4 MOA at 800 yards. Love mine. However, I have switched to 155 scenars almost exclusively now.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

IMR 4895 is a faster burning powder. If you still have lots of 4064 powder try some different bullets before you try a different powder. 178 AMAX's, Bergers, Lapuas. SMK's are not always the holy grail.
178 AMAX's will run circles around 175 SMK's in one of my .308's out to 1000 yards.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

DesertHK, what brass, primer and oal do you use for 44.4 IMR 4064 with 175 SMK in .308? Also, have you tried the Lapua 170s and if so, what load did you find worked best with IMR 4064? Thanks, 30calshooter
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

Along with this question - - a general type question -- if IMR 4895 has a "faster burn rate" than say varget of H4895-- what does this mean--
you get more velocity?
you get a dirtier, more fouled bore?
faster burn rate better for shorter barrels?
 
  • Like
Reactions: FNGprobably
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

Custom barrel and what length? What primer are you using? I loaded some up yesterday and started at 42.4 and went up to 43.3 in .3 gr increments with a comparator length of 3.210. I noticed that it felt like the powder was starting to compress around 43 grains. This will be used in a 95 Palma chamber.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AutoVerminator</div><div class="ubbcode-body">Been running 42.5gr of IMR 4064 in lapua brass w/ 175gr SMK's for years with excellent results. If you have it on hand use it! </div></div>
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

I have never shot the IMR4895, but the IMR4064 is really good stuff for the 175SMK. Probably one of the most accurate powders I have used for that bullet.

FWIW, I was shooting a Rock 5R barrel 22", using 43.3 grains in Lapua brass with 210M primers. I was getting an avg of 2720 FPS.

 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SP308</div><div class="ubbcode-body">Along with this question - - a general type question -- if IMR 4895 has a "faster burn rate" than say varget of H4895-- what does this mean--
you get more velocity? <span style="font-weight: bold">It depends</span>
you get a dirtier, more fouled bore? <span style="font-weight: bold">It depends</span>
faster burn rate better for shorter barrels? <span style="font-weight: bold">Some believe that </span></div></div>


With a caliber like .308 that has a massive range of bullets it is necessary to have powders of different burn rates. Light bullets can generally use faster powders, the heavies need slower. Velocity is a based upon average pressure behind the bullet but obviously there is a pressure ceiling we are working with. As an example, if you used a relatively fast powder with a heavy bullet, the pressure curve would have a spike and velocity would suffer. On the other end if you filled the case with really slow powder, velocity would also suffer for lack of pressure. We want something in the middle that will have a nice smooth pressure curve for a high average pressure which makes for high velocities, accuracy can come with any of the above examples. YMMV We are controlling an explosion, it would be nice if we had smart powders that would just go to max safe pressure from the instant that primer was touched off and continued till the bullet exits, but that just isn't the case.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

Thanks for the answer. I was hoping for a general answer just to give me a little bit more understanding.

More specifically, I have Varget, mainly because I have heard from many that it is very stable under a variety of conditions. But, many of the setups I have seen are using IMR4895 with a tiny bit more speed.

I will be loading 155 scenars and 175 SMK using lapua brass and 210M. I have a short chamber set back slightly for less jump when mag feeding. Originally I had 2.839 mag length with facory 700 pss but now have AI mags so I can stretch them out to 2.891 and still mag feed. Now it is a blueprinted action with shilen 1-12 and 25 inch bbl length.

I was curious if a different powder may be better to still get me up to speed if i have to load them to a shorter c.o.a.l. ??? I didn't think this would be as much of the problem for the SMK but more important for the Scenars. ????
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

I just ran the numbers through the old powleys slide rules that us dinosaurs used to use before home computers and with a COAL of 2.8 since I'm shooting a Accuracy International chasis with a magazine. I came up with a case capacity of 48.5 of water converted to 41.6 grains of powder and with a sectional density of .269 and RCBW of .240 the type powder the slide rule suggested is IMR 4064. gives me a Muzzle Velocity of 2330 since I've got a Remington 700 LTR in that AI chasis with a 20 inch barrel. with an effective barrel of about 17 3/4 inches with a cartridge in the chamber. This gives me 2108 of energy and 41000 pressure. I didnt run the flame temperature to see how fast this will erode the barrel.
All that being said, this is the old way to determine optimum loads for a given rifle and bullet. So I can see how this would be a favorite load and its accuracy since it is 86 percent case capacity for that bullet seating.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

Hey Mike1952, can you walk me through the calculations necessary to figure out these numbers? I do not have a slide rule but am interested in the math.


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mike1952</div><div class="ubbcode-body">I just ran the numbers through the old powleys slide rules that us dinosaurs used to use before home computers and with a COAL of 2.8 since I'm shooting a Accuracy International chasis with a magazine. I came up with a case capacity of 48.5 of water converted to 41.6 grains of powder and with a sectional density of .269 and RCBW of .240 the type powder the slide rule suggested is IMR 4064. gives me a Muzzle Velocity of 2330 since I've got a Remington 700 LTR in that AI chasis with a 20 inch barrel. with an effective barrel of about 17 3/4 inches with a cartridge in the chamber. This gives me 2108 of energy and 41000 pressure. I didnt run the flame temperature to see how fast this will erode the barrel.
All that being said, this is the old way to determine optimum loads for a given rifle and bullet. So I can see how this would be a favorite load and its accuracy since it is 86 percent case capacity for that bullet seating. </div></div>
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

In terms of absolute burn rate, and max loads, Varget, IMR 4064, IMR 4320 and IMR 4895 are virtually interchangeable, when you work up from below:


From Hodgdon Load Data Page:

Max Loads with 175 grain SMK

Varget 45.0 Grains 2690 FPS
IMR 4320 45.7 grains 2687 FPS
IMR 4064 45.6 grains 2728 FPS
IMR 4895 45.0 grains 2704 FPS

There is also an H-4895 which is slightly faster burning:

Max Load H4895 42.7 grains 2647 FPS
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

Nobody doesn't like 4064 for its' accuracy. A lot of folks try other powders and some settle on 4895 because it dispenses easier than the 'long rod' 4064.

It's a reloading bench compromise in most cases (no pun intended)... 4064 can be exasperating at the reloading bench for the uninitiated, unwilling or impatient. Of course there are those match-ups between rifle and cartridge that favor 4895, but I think the majority of long-range shooters would choose 4064 for accuracy. 178 AMAX and 4064 is a tough combo to beat for accuracy vs. economics.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: unrepentant</div><div class="ubbcode-body">Nobody doesn't like 4064 for its' accuracy. A lot of folks try other powders and some settle on 4895 because it dispenses easier than the 'long rod' 4064.

</div></div>




Isn't the 4895 rod like as well like Varget? I hate metering Varget.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: alpha6164</div><div class="ubbcode-body">Isn't the 4895 rod like as well like Varget? I hate metering Varget. </div></div>

Yes, it is, but neither Varget nor 4895 are near the PITA to meter like 4064. Not even Harrell will guarantee metering accuracy better than .2gr with 4064.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

4064 meters pretty well out of a Lee powder measure and shoots the lights out for me in several calibers.
I've always trickled to the .1 grain and never relied solely on a thrower as it appears some of the posters above do.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

So anybody tried Accurate 2520 in a 308 for a bolt gun? I have varget and IMR 4895, used both and both come up with good accuracy for the 175SMK. I only asked because I ordered a pound of 2520, which is ball powder, for a Grendel that I used to have. My reloading shop never called until a few weeks after I ordered it and I had sold the Grendel by then. I bought it because I told them I would, but now I gotta find a use for it! Thanks for the above info fellas.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

Lapua brass, 44.5 grains varget, 175smk, remington 9 1/2 lr primer, 2.825" oal. 400 yards measured .991" out of a six shot group. I got a GAP so it's most certainly more the rifle than me.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

J, in a 223AI thread a ways back Jered Joplin endorsed AA 2520 with the 75 AMAX. I doubt that you'd see any loss in performance using it in a 308 as it and the 223AI tend to thrive on like burn rate powders.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

I've got some loaded up, like 6 that I'm gonna try. If it don't work, and from most of what I've read about it's use in semi guns such as M1A and Garand etc, I can use it in my 223 stuff probably. If not I'll see if one my buddies can use it for something they have. Since I sold my Grendel I just don't really need it, but if I can use it successfuly with a 308 load then it's money in the bank. I primarily use Varget anyways and it won't bother me to go back to that! Thanks, Jason
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TacticalJ</div><div class="ubbcode-body">So anybody tried Accurate 2520 in a 308 for a bolt gun?</div></div>

Yes...it's an excellent powder. As a ball powder in that burning range it is on the slower end and one of the better choices...a pound won't go very far though.

TC
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

shot the six today and it was right on par with the remington match premier 168smk's that are factory loads. It was fairly impressive and I think I'll do some more testing with the 2520 and 175smk's as well.
 
Re: Why IMR 4895 over IMR 4064 for 175 SMKs?

One thing no one appears to have mentioned so far is that your chocies may change a bit when loading for a semiauto versus a bolt rifle.

Zediker in his book for example notes that IMR4895 is better for a semiauto than 4064 because the pressure vs time curve makes for pressure at the gas port that is gentler on the rifle.

I guess it makes sense. You can have too much pressure at the port, and that's hard on the rifle. Or, too little pressure, so operation can be inconsistent enough to affect accuracy.

I suppose someone running Quickload software, and knowing the distance from bolt face to port, might be able to compare port pressures.

Jim G