4007ssc in 308

[mao0720]

Has anyone used IMR 4007SSC in a 308 with 185gr bullets? Im trying to find and alternative to my usual Reloder 17 and 4007ssc seems to be pretty close. My current load is: Win brass, Fed 210 primer, 185gr Lapua D46, 47gr Reloder 17, 2.246 CBTO in a 24" barrel yielding about 2580 FPS. Id like to find something that will get me close to this velocity and maintain accuracy at 1/2 MOA or better. Just wondering if anyone has any real world experience with this combo. Reloder 17 has become too hard to come by so I'm out to find an alternative.

 

[Laurie]

Yes.

Reasonable groups - disappointing velocities. I don't consider Re17 great for the 185s either - excellent velocity, but couldn't ever get this combination to group really well with the bullet weight. It comes into its own in 308 with 210s, especially in small primer Lapua 'Palma' brass.

I'd advise you to try Viht N150, and if you don't mind the reduced barrel life, Viht N550. Ramshot Big Game works well with 180-190gn bullets and Hunter looks a possible too, but we can't get 'Hunter' in the UK as it's not CE certified.

 

[mao0720]

Thanks for the help. I've found RL 17 to be ok with my 185gr D46s. Got it down to around 1/2 MOA at 200yds. This isnt a comp. rifle, just my do all 308 that I use for punching steel. If I ever get a chance to do a practical/ Tactical rifle match, though, this would be the rifle/ load I would use.
I do occasionally see Viht 150 around my parts, so I may have to pick some up next time I see it.

 

[Down South]

Yes.

Reasonable groups - disappointing velocities. I don't consider Re17 great for the 185s either - excellent velocity, but couldn't ever get this combination to group really well with the bullet weight. It comes into its own in 308 with 210s, especially in small primer Lapua 'Palma' brass.

I'd advise you to try Viht N150, and if you don't mind the reduced barrel life, Viht N550. Ramshot Big Game works well with 180-190gn bullets and Hunter looks a possible too, but we can't get 'Hunter' in the UK as it's not CE certified.

+1 on N-150

 

[boltgunluvr]

Let me know what the results are. I've had decent groups with IMR 4350 using 168 &175 SMKs. And we all know folks say no way it'll work.

 

[J-rod]

Long long time lurker, finally registered so i could post.
This powder was recommended to me by McCourt Munitions. Excellent powder between varget and h4350, very similar burn rate to PP2000mr from my testing.
I don't have my load book in front of me but i do remember fps. 185 lrbt and hybrids over 2900fps with 30" barrel. 230 hybrids 2530fps with 45 gn, win brass, zero pressure sign. 200hybrids at 2750fps, 47gn. Powder is very forgiving on pressure, fairly temp stable due to being single based, ~.7fps per deg F. Likes compressed loads. Burns clean when pressure is up.

 

[J-rod]

PS h4350, 52.5gn, 185 hybrids, 2.288 to ogive, win brass, cci br2's gives me 2950fps and excellent accuracy. So yes it does work

 

[Down South]

PS h4350, 52.5gn, 185 hybrids, 2.288 to ogive, win brass, cci br2's gives me 2950fps and excellent accuracy. So yes it does work

Wow, thats smoking!

 

[amlevin]

PS h4350, 52.5gn, 185 hybrids, 2.288 to ogive, win brass, cci br2's gives me 2950fps and excellent accuracy. So yes it does work

In a 308????

 

[Laurie]

PS h4350, 52.5gn, 185 hybrids, 2.288 to ogive, win brass, cci br2's gives me 2950fps and excellent accuracy. So yes it does work

In a 308????

My thought too! A 185 at 2,950 fps produces 3,223 ft/lb ME, the same as a 155 at 3,223 fps MV and the 230 Hybrid at 2,646 fps MV.

A general rule of thumb is that a rifle / barrel / cartridge combination will produce similar muzzle energies with different bullet weights assuming the chamber is appropriately throated and the correct grade of propellant used for the bullet weight + usable case volume. So, this puts a 185 at this claimed MV into perspective.

I know people who produce some impressive MVs / MEs from 308 Win, but combinations that produce over 3,200 fps MV safely with 155s are in the rarely seen to fairytale category, and the few who get close to there spend a large part of their income replacing barrels and cases.

ESPECIALLY when it's claimed from a relatively slow burning single-base powder where it'd be difficult to get enough into the case even to simply produce enough energy to achieve that velocity and muzzle energy.

I know QuickLOAD isn't anything like 100% accurate, but I thought I'd have a play to see how the most optimistic scenario might model in this case. To wit:

Very thin-wall case in a very slack chamber - 58.0gn overflow water capacity. (Winchester is 57gn after firing in my 'minimum SAAMI' chamber).

34-inch barrel

throat such that the bullet is barely nipped into the case - 3.100" COAL, only 67 thou' of shank held in the case-neck.

54.0 gn H4350 which is calculated as 111.6% fill-ratio. In practice, such a shallow seated bullet wouldn't stay in the neck most likely with that degree of powder compression, but we'll imagine it does.

Since my version of QuickLOAD doesn't include the Hybrids, I've used the 185gn Juggernaut, but I doubt if the findings are overly affected.

And the result? ........ 2,954 fps from a 34-inch barrel, so getting there or thereabouts, BUT at 66,068 psi chamber pressure or a 10% overload. In other words, proof cartridge pressures.

Incidentally, because powder A is shown as having a similar burning speed to powder B, this emphatically DOES NOT MEAN THEY WILL PERFORM THE SAME IN ANY CARTRIDGE / BULLET SITUATION, OR EVEN GUARANTEE PERFORMING SIMILARLY.

 

[J-rod]

Laurie, i have seen/read enough of your posts to know you are VERY knowledgeable and i greatly respect your input. I knew i would create a firestorm with my response.
I am traveling for work so have to use my phone for responses. Forgive the shortness.
This load was tested over a magnetospeed and dope verified at 1,000yds. Based off of the primers and zero ejector marks, it looks to be less pressure than my varget loads: 45.5 var in win 2800fps, 44.5 var in lapua, 2800fps.
It is a compressed load and i have to use a long drop tube to get it in there.
For ease of loading, i also have been using 51gn in lapua, 2885fps. Lapua is obviously more consistent so i get better es/sd with less work than win.
I usually shoot at quantico and butner....and because i can't read the wind, my pursuit of the magic fast load never ends.