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.308 win 175smk 20" 2650fps Powder Charge?

F

FingerlakesFeetPerSecond

Private
Minuteman
Mar 10, 2022
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2
Watkins Glen New York
Howdy all, Im looking to push a 175gr SMK to 2650fps out of a 20" Remington 700 short action so my ACSS Apollo BDC is accurate past 800yds. Bit of an ask out of an 20" I know but i believe its doable. My question is has anyone produced loads that replicate the performance I'm looking for? According to GRT Lever Evolution and BL-C(2) are my prime candidates. I don't entirely trust GRT yet so im looking for some real world input?
Loads im looking at on GRT for a 2.005 case length, 2.83 overall length, 55.4H2O case capacity.
LeverEvolution at 45.8 grains puts it at 2650 at 57,000psi
BL-C(2) at 46.8 grains puts it at 2644 at 61,000psi
Now Hodgdon lists their max charge for BL-C(2) at 46.0 grains for a 175 grain projectile. As you can tell the GRT Load is a little spicier than that(should go without saying to start lower and work up). As for LeverEvolution my only issue with it is temperature sensitivity. Some other options i've considered are Varget, H4895 and IMR4064 (pressure curves look a little sketchy for the 4064 according to GRT at 70k psi for 2650 out of a 20) but iv heard thats whats used for the M118LR round so who knows. Again Would love to see if anyone has pushed a 175 grain out ofa 20" 308 at 2650 or better and if so how did you do it? Thanks!
 
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I’ve pushed about 2625iah from a 16” barrel with 2000mr under 175/178 class bullets. Somewhere around 48gr in FC brass and primer pockets are still going at 4 firings.

That was a desert tech and a Remington factory tube may be slower. 2000mr will probably do it but it likes to be pushed hard before accuracy and es/sd tightens up.
 
42gr H4895 2650 fps from 18” barrel Seekins AR but high pressure signs
 
nn8734 said:
Just curious, why specifically do you need to hit 2650? What’s the application(s) for this rifle?
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The BDC in my reticle is calibrated for a 175 Sierra Matchking with a muzzle velocity of 2650. The manufacture probably designed that velocity with a 22 or 24" barrel in mind, not too many crazy bastards like me trying to push that out of a 20". I will be taking it to shoot steel at 1000yds occasionally (once or twice a year maybe) and really i only need the 2650 for when I'm going to be shooting that distance. Otherwise its going to be a plinker inside of 700yds for the rest of the year, in which case I can adjust the zero to make the BDC hit "close enough" out to 700yds with M80. So given ill only be shooting these hot rodded loads a couple times a year i dont mind pushing them a little hotter than most would (so long as i dont shooting primers into my bolt). I am indeed aware this is at the ragged edge of what a 20" 308 is capable of doing
 
FingerlakesFeetPerSecond said:
The BDC in my reticle is calibrated for a 175 Sierra Matchking with a muzzle velocity of 2650. The manufacture probably designed that velocity with a 22 or 24" barrel in mind, not too many crazy bastards like me trying to push that out of a 20". I will be taking it to shoot steel at 1000yds occasionally (once or twice a year maybe) and really i only need the 2650 for when I'm going to be shooting that distance. Otherwise its going to be a plinker inside of 700yds for the rest of the year, in which case I can adjust the zero to make the BDC hit "close enough" out to 700yds with M80. So given ill only be shooting these hot rodded loads a couple times a year i dont mind pushing them a little hotter than most would (so long as i dont shooting primers into my bolt)
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It should still work if you get 2600 which is doable out of your rilfe (i get 2575-2590 out of my mk11 with the 175 and it has a 20” chrome lined barrel and dont have problems making hits at 900m in reasonable conditions).

I also use bdc reticles in a couple rifles including the aforementioned mk11 and it’s still effective/tracks accurately even though its also calibrated for 2650 so know there’s wiggle room meaning you can be a little strong or short and still have it keep accurate. You don’t need 2650 to make hits at a grand with a 175, just good wind calling and fundamentals. Beyond that your algorithm, once trued, will work fine.
 
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nn8734 said:
It should still work if you get 2600 which is doable out of your rilfe (i get 2575-2590 out of my mk11 with the 175 and it has a 20” chrome lined barrel and dont have problems making hits at 900m in reasonable conditions).

I also use bdc reticles in a couple rifles including the aforementioned mk11 and it’s still effective/tracks accurately even though its also calibrated for 2650 so know there’s wiggle room meaning you can be a little strong or short and still have it keep accurate. You don’t need 2650 to make hits at a grand with a 175, just good wind calling and fundamentals. Beyond that your algorithm, once trued, will work fine.
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Indeed 2600 is my target minimum if i cant get 2650 safely. I can get the BDC at 1000 to get within half a Mil i believe at 2600 if i zero it a half inch high, good ole kentucky windage can take care of the rest.
 
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Yeah 2000MR might get you there. I chased the 2900 with 155's and while I got it and the load shoots lights out. My brass life is pretty shit. Primer pockets are getting loose after 3 firings..
But a case with more capacity may help. My cases have similar capacity to LC brass.
I've got to the point I'd rather have a slower accurate load and learn it's dope then have a Laser and buy brass every 3 months.
 
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MK20 said:
SB or Fed match primer
LC LR case
47.7 PP2000mr
175 smk or 178 hornady

This combo will do it in any decent rifle and should shoot pretty well. It can be near the upper edge in some rifles so work up. It should leave enough room for safety with temp swings.
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47.7 of 2000mr? Thats gotta be getting pretty close to touching the base of the bullet.
 
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MK20 said:
I just saw that you are doing this to match the BDC in a scope. Easy fix. Stop living in the 1980's and buy a mil/mil scope. You can get a decent one for cheap now.
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Tried my hand at Primary Arms ACSS Reticles a few years back with one of their LPVO's. Bought several other of their acss reticle optics now and they have yet to let me down long as you zero them according to the book. Havnt touched one of my Mil scopes in a couple years now.
 
I get 2670 with a 178 ELD from a 22.5" DT barrel; the key is hornady brass, loading long, and RL-15
 
918v said:
That’s a retardedly stupid load.
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Ehhh what am I missing here? I went to Hodgdon reloading because of your comment to check it out. According to them H4895 with 175gn bullet the range is 40.0 to 42.7gns. They claim at max charge you will only see 2422fps though
.
 
Im2bent said:
Ehhh what am I missing here? I went to Hodgdon reloading because of your comment to check it out. According to them H4895 with 175gn bullet the range is 40.0 to 42.7gns. They claim at max charge you will only see 2422fps though
.
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Interesting, This is what GRT puts out for Hodgdon's max for H4895. Fascinating the differences in pressure and velocity reported here.
 

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Went and rechecked the 2422 was under pistol(Doh) under rifle they give the same load range but 2647 fps out of a 24 inch barrel. 49000CUP
 
FingerlakesFeetPerSecond said:
How many grains of RL-15 and what depth are you seating at?
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2.840"; the Hornady match brass is from factory match ammo I bought in 2008 (for like 75 cents a round on sale if you can believe that); some of them have 12 reloads on them. I don't know the water capacity on those but I know that once a Norma case got mixed in and it was hot AF with a bright ejector mark. This load will not work in Norma/Lapua etc heavy duty brass. I also know it's near max at 44.5 grains; my neighbor was helping me reload a couple of batches and he spaced it and programmed 45.5 into the scale, and those pockets were loose next time I reloaded.
 
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Im2bent said:
Ehhh what am I missing here? I went to Hodgdon reloading because of your comment to check it out. According to them H4895 with 175gn bullet the range is 40.0 to 42.7gns. They claim at max charge you will only see 2422fps though
.
Click to expand...

Hodgdon data is based on Winchester commercial brass which is the thinnest brass on the market. Their max load makes 2650 FPS out of a 24” barrel.
 
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Instead of trying to make it work with 175SMK and risk issues when it gets hot why not instead get a lighter bullet with a better BDC.
SMK 175 G1BC is .496

The new SMK 169 is .505->.527 and it'll go faster than your 175 SMK.
same with the 168 ELD-M

You're not coal limited due to magazine so it's not like you really need to use 175 SMKs

edit: I just looked up the numbers and with 169 SMKs at 2600FPS depending on the environmental (which will affect your numbers past 800 yards) it matches up fine.
 
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st1650 said:
Instead of trying to make it work with 175SMK and risk issues when it gets hot why not instead get a lighter bullet with a better BDC.
SMK 175 G1BC is .496

The new SMK 169 is .505->.527 and it'll go faster than your 175 SMK.
same with the 168 ELD-M

You're not coal limited due to magazine so it's not like you really need to use 175 SMKs
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I’ve switched over to the 169smk for my 308 bolt gun; its 2.4-2.5 mils flatter to 1000m vs the 175 but i think the OP’s scope he wants to use has a bdc for the 175 otherwise the 169 is def the better choice.
 
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I understand the desire to use existing equipment but myself I have fallen victim to "penny wise and pound foolish" so many times I couldn't count. Maybe the best option is get a new scope. Like it's a $500 scope; how much money are we going to have wrapped up in brass, bullets, misses, and blown primer pockets?
 
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Shit, use the scope. BDCs are never accurate anyway. You’re always going to need to map the reticle to your load, unless you’re never going to use the hold overs. Might as well just map it to what you shoot rather than try to recreate a Goldilocks load that isn’t. And, if you’re not going to use the hold overs, why try to recreate the load? You can even do most of the leg work beforehand with a schematic of the reticle (giving angular sub tensions) and a ballistic calculator. The hold overs in that reticle are not even labeled in the scope, they can be whatever range you want them to be...
 
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nn8734 said:
I’ve switched over to the 169smk for my 308 bolt gun; its 2.4-2.5 mils flatter to 1000m vs the 175 but i think the OP’s scope he wants to use has a bdc for the 175 otherwise the 169 is def the better choice.
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My point is that he can’t reach the BDC curve with the 175 but he could with the 169 and be much closer.

I’ve ran these experiments back in the mid 2000s with my “tuned” M1A in a DMR style stock with a Burris scout style scope with a BDC that was calibrated for some kind of generic hunting style ammo and I tuned my 308 load to match that curve rather than try to blow primers to use the exact same bullet. Sure maybe I was 3-4in high at 200-300 but I was also pretty close at 400-600. A bdc isn’t a precision tool no matter what quigley Ford says.

I do the same thing with the Acog BDC - say your acog bcd is calibrated for a 62gr green tip out of a 16in barrel - well you could make it work with a 55gr bullet with a better BC out of a 14.5in barrel. Is it going to be 100% dead on? No but it’ll be within minute of chest all the way to 600 yards.

Anyhow it doesn’t matter because environmental will fuck you up past 800 yards on any bdc and that increase of velocity and increase of DA and temp will make that 900 yards hash line poa, a 1000 yard poi.

But yeah it’s foolish to try to match a bdc by loading hot so that you will match a bdc past 800 yards.
 

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st1650 said:
My point is that he can’t reach the BDC curve with the 175 but he could with the 169 and be much closer.

I’ve ran these experiments back in the mid 2000s with my “tuned” M1A in a DMR style stock with a Burris scout style scope with a BDC that was calibrated for some kind of generic hunting style ammo and I tuned my 308 load to match that curve rather than try to blow primers to use the exact same bullet. Sure maybe I was 3-4in high at 200-300 but I was also pretty close at 400-600. A bdc isn’t a precision tool no matter what quigley Ford says.

I do the same thing with the Acog BDC - say your acog bcd is calibrated for a 62gr green tip out of a 16in barrel - well you could make it work with a 55gr bullet with a better BC out of a 14.5in barrel. Is it going to be 100% dead on? No but it’ll be within minute of chest all the way to 600 yards.

Anyhow it doesn’t matter because environmental will fuck you up past 800 yards on any bdc and that increase of velocity and increase of DA and temp will make that 900 yards hash line poa, a 1000 yard poi.

But yeah it’s foolish to try to match a bdc by loading hot so that you will match a bdc past 800 yards.
Click to expand...
I just reiterated the OP’s reasoning, that’s all; nothing is stopping him from switching as the same powders and charge weights are interchangeable for the most part.

I’ve always viewed the 308 as an 800m-and-in cartridge whereas the win mag (1200m) and Lapua/Norma (1400)m for reliability high hit probability in reasonable conditions, all other things equal.

I will say that 308 BDC reticles calibrated for the 175smk do correlate fairly well to 500m which is where speed is arguably more important than extreme precision, anyway. Beyond 500m they tend to break down due to the factors you mentioned above as well as others. Speed isn’t quite as critical as pure precision/accuracy beyond 500m.
 
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I shoot a 155 Berger out of my 20" 1:12 FN. It doesn't have any issue getting to 1000 at 4400' elevation. I don't remember my exact velocity, somewhere around 2600, but I'm running 41 grains of 8208XBR.

It doesn't have the BC of the 175 but it's super consistent.
 
Those speeds are definitely possible with a 175 class bullet.

Post 38 of the below linked thread shows MontanaMarine claiming 2600s MV from a 20.5" 308 using a 208 AMAX.

www.snipershide.com

Question on 208 Amax, RL17 - Updated 8/19/11

Just had my rifle re-barreled from a factory SPS 20" 1:12 twist to a 24" Rock Creek 5R 1:10 twist. I'm going to break it in with my go to load of 178 Amax and 44 grains of RL15. However, with the longer barrel, and tighter twist, I bought the fixens to experiment with the 208 Amax. Here comes...
www.snipershide.com www.snipershide.com

I know it's a very old thread but I always find it intriguing how much they were pushing the 308. I say they because I believe @LawnMM and Shortbus (I could be wrong) were also experimenting back then with heavies in 30 cal cartridges.
 
46.5 2000 MR in a Federal GMM case / 175 Nosler CC / @ 2769 FPS. In a 24" Hart barrel. With a thinner Winchester case, I use 47.5 to get to about the same velocity.

I do agree with others that say the 169 SMK, the new Nosler 168 RDF and 168 ELDM will get you there with other powders.

What powders do you have on hand?
 
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stello1001 said:
Those speeds are definitely possible with a 175 class bullet.

Post 38 of the below linked thread shows MontanaMarine claiming 2600s MV from a 20.5" 308 using a 208 AMAX.

www.snipershide.com

Question on 208 Amax, RL17 - Updated 8/19/11

Just had my rifle re-barreled from a factory SPS 20" 1:12 twist to a 24" Rock Creek 5R 1:10 twist. I'm going to break it in with my go to load of 178 Amax and 44 grains of RL15. However, with the longer barrel, and tighter twist, I bought the fixens to experiment with the 208 Amax. Here comes...
www.snipershide.com www.snipershide.com

I know it's a very old thread but I always find it intriguing how much they were pushing the 308. I say they because I believe @LawnMM and Shortbus (I could be wrong) were also experimenting back then with heavies in 30 cal cartridges.
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I played with the heavy 208 amax and RL17 back in the days and the recoil, mediocre accuracy and short brass life killed that idea.
 
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FLIGHT762 said:
46.5 2000 MR in a Federal GMM case / 175 Nosler CC / @ 2769 FPS. In a 24" Hart barrel. With a thinner Winchester case, I use 47.5 to get to about the same velocity.

I do agree with others that say the 169 SMK, the new Nosler 168 RDF and 168 ELDM will get you there with other powders.

What powders do you have on hand?
Click to expand...
2769 is cooking. Right now all i have on hand is LeverEvolution, AA2520, BL-C2, and H335. Slim pickings but im on the hunt at local gun stores for other powders.
 
st1650 said:
I played with the heavy 208 amax and RL17 back in the days and the recoil, mediocre accuracy and short brass life killed that idea.
Click to expand...

Yeah that's really pushing it for sure. I'm just saying in response to this post, if it was possible to do it with a 208, the 175 class bullets the OP wants should be able to get there.
 
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running 8208xbr I'm getting 2670 with 175 RDF's out of a Savage MSR 1O LR with a 20" barrel.

Bullets are seated long 2.850 +/- and fit in magazine. Averaging 1 moa.
I hope to work with it shortly to get tighter groups by working with seating depths

This is with LCLR brass.
And NO it hasn't been hard on the brass

YMMV so be careful and work up.

I've done work on this rifle as far as buffer and spring go so that it cycles very smooth.
 
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GONE BAD said:
running 8208xbr I'm getting 2670 with 175 RDF's out of a Savage MSR 1O LR with a 20" barrel.

Bullets are seated long 2.850 +/- and fit in magazine. Averaging 1 moa.
I hope to work with it shortly to get tighter groups by working with seating depths

This is with LCLR brass.
And NO it hasn't been hard on the brass

YMMV so be careful and work up.

I've done work on this rifle as far as buffer and spring go so that it cycles very smooth.
Click to expand...

Your chrony is lying
 
Funny its right about all my other loads
But........................................................
 
GONE BAD said:
running 8208xbr I'm getting 2670 with 175 RDF's out of a Savage MSR 1O LR with a 20" barrel.

Bullets are seated long 2.850 +/- and fit in magazine. Averaging 1 moa.
I hope to work with it shortly to get tighter groups by working with seating depths

This is with LCLR brass.
And NO it hasn't been hard on the brass

YMMV so be careful and work up.

I've done work on this rifle as far as buffer and spring go so that it cycles very smooth.
Click to expand...
How much 8208?
 
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