308 is this load safe

[Deerhunter#1]

loading some 150 grain nosler bt. The data they show and powder I am using is imr4831. Trying to stay on the low end of the speed spectrum and reduce a little of the recoil. The start load is saying 42 grains and that is a 103% casr capacity load. In your opinion would I be safe taking that down 1 grain to 41 and be around 95% capacity or am I asking for trouble.

[LanceR]

Although some folks may have done such things and gotten away with it every powder maker will tell you not to go below the published minimum charge due to erratic ignition, significant pressure spikes etc.  It is important to note that reduced powder charges result in lower velocities and recoil but often are at maximum pressure and the pressure can increase dangerously as the powder charge gets lower.

Hodgdon, who markets IMR powders, no longer recommends any IMR powders for reduced loads below those found in their latest published data.

They have tested H4895 as a reduced load powder and since it is the most uniformly igniting and burning powder in reduced loads it can be safely use down to 60% of the published max charge in any cartridge for for which it is listed.  They caution to not use that formula in any cartridge for which H4895 is not listed nor with any other powder.  My experience has been that the velocity changes are pretty linear with the powder changes.

The Hodgdon home page has link to reduced loads at    http://hodgdon.com/PDF/H4895%20Reduced%20Rifle%20Loads.pdf

Those loads are all designed to cleanly take deer sized game at 200 yards.

And there's an article on reduced loads at   http://www.chuckhawks.com/reduced_recoil_H4895.htm

You can dial the 150 BT back to 27.3 grains of H4895 safely.  Nosler states that the BT needs 1800 FPS to fully function as designed so you can fairly easily predict how low you could go if you want to work up a reduced hunting load other than what's on Hodgdon's site.   As a starting point I'd guess that each grain drop in a .308 150 grain BT load with an H4895 charge will result in 50-60 FPS less velocity.

H4895 work from 204 Ruger to 458 Win Mag and beyond so it's a handy powder to have around.

Hope this helps.

Good luck

Lance

[Nobade]

That is a very low velocity load, well under 2000 fps. Should be safe enough, but probably would be more accurate with a faster burning powder if you want to shoot that slow. It should leave a lot of unburnt powder in the bore and have wide velocity variations.

[Deerhunter#1]

I have the h4895 powder. I just was thinking this powder was listed on Nosler book and the accuracy load was the min load of 42 grains at 2700 ft second from a 24 inch barrel. Mine is a 22 so I should be at around 2650. I want to be around the 2550 to 2600 mark. I just liked the idea of a more full case then using 4895 which is why I was looking at the imr4831. I will try the starting load of 4831 and also some reduced 4895. In your guys experience does a fuller case of powder in the 308 usually perform better or does it really not matter?

[shot1]

IMR 4831 is really too slow burning for the 308 Win. The latest Hodgdon manual, Hodgdon owns IMR now, does not list either of their 4831 powders with 150 gr bullets. If you have H-4895 I would suggest you use it. Either H or IMR 4895 are about perfect for the 308 Win. Start load with H-4895 is 43.0 grs and max is 45.5 for 150 gr Nos BT as listed in the 2011 Hodgdon manual. I would load up some at 43 grs and some at 44 grs to see which is more accurate. My accuracy load for most 308 Win rifles with 150 gr bullets has been 43 grs IMR 4895 for years. If you want a real deer thumping drop them in their tracks light recoil load try you some 125 gr Nos BT with 46 to 47 grs of your H-4895. I have been using 46 grs IMR 4895 with the 125 BT for a number of years on deer and it is awesome.

[LanceR]

The ignition and burning characteristics of each powder can be quite unique and especially so in lower charges.  Despite generalizations by many folks you just can't make general statements about case capacity versus powder charges except in certain very narrowly defined cases.

H4895 will ignite and burn with predictable pressures in a case nearly half empty.  Some powders explode under those conditions.  Some won't ignite and burn  under those conditions and can even result in a bullet stuck in the bore.  So, the question about whether a more full case of powder performs better can only really be answered by setting the parameters of what bullet, what case, what powder and what primer.   H4895 is comparatively very insensitive to where along the 60% to 100% curve of the max charge you use it..  Whatever charge your rifle likes best is the correct optimal accuracy load for your rifle.  It is also has about as much drama as watching paint dry which is one of it's great virtues.  It generally does not care what primer you use a long as it is a standard large rifle primer where some powders can vary the group size pretty dramatically with primer changes.

One thing most folks don't appreciate is that you can forget about the "most accurate" loads in loading manuals.  All firearms are individuals.  If you take five identical rifles in sequence as they come off any production line the odds of even two of them getting the most accuracy with the same load are slim indeed.  That "most accurate" load was fired in a standard test barrel fixed in a ridged mount while you and your rifle make up a living, breathing dynamic system.

The .308 is one of the most predictable cartridges in existence at the reloading bench so I wouldn't over think this as long as what you are doing is within the range recommend by Hodgdon.  For what it is worth, I take the advice of a powder manufacturer over that of a bullet manufacturer when it comes to conflicting data in minimum or maximum powder charges. 

I would note that a drop in velocity from 2650 to 2550 is only going to drop the recoil of an 8 pound rifle from 13.8 to 13.1 pounds.  I doubt your shoulder is calibrated finely enough to feel the difference.

Lance

[Dave in WV]

The only rifle gun powders that are normally suggested for reduced loads are H4895 & IMR 4895. Hodgdon has reduced "youth loads" listed online. I have loaded for the 243 and 270 using their data with success. If you load with too little amount of powder for a cartridge you can get detonation "catastrophic firearm blow up".

[ceadersavage2]

A safe load for low recoil would be to load the 308 down to 300 Savage loads.I have both guns an they work great on deer an recoil. I would try a difference powder or lime savor pad on stock

[1armoured]

I've only used H4895 in my .308, for all bullet weights from 110gr V-Max to 175gr Sierra HPBT.
The IMR4831 is really too slow in the .308 except for maybe the top end 190grs+
I don't shoot reduced loads as such, but I did a bit of experimenting with shooting the 110gr for reduced recoil with less powder.
I found I still needed as much as I would normally use, 43.5grs for a 155gr Sierra HPBT, to get the best accuracy out of the 110gr V-Max. As good grouping as the Sierra Match bullet. Not much difference in velocity. A mild 2,800fps.
Recoil was probably a couple ft/lbs lighter, but not significantly.
I find that the 43.5grs fills the case plenty enough in my Lapua cases.

I don't think absolutely filling them any more using 4895 would have any advantage in accuracy. Velocity yes, (and pressure probably !)
My Sako 75 has a 22" barrel with 1:11 twist.

The way to go maybe is to shoot cast lead and a reduced load.
A lot cheaper per round, but quite a bit of work involved in finding the right bullet and load to get reasonable accuracy, and much less recoil. Good fun though.
cheers,
SS

[Val]

Have a look at the Speer reloading manual. They list a lot of reduced loads which are tried and proven.

[Lloyd Smale]

I agree!

IMR 4831 is really too slow burning for the 308 Win. The latest Hodgdon manual, Hodgdon owns IMR now, does not list either of their 4831 powders with 150 gr bullets. If you have H-4895 I would suggest you use it. Either H or IMR 4895 are about perfect for the 308 Win. Start load with H-4895 is 43.0 grs and max is 45.5 for 150 gr Nos BT as listed in the 2011 Hodgdon manual. I would load up some at 43 grs and some at 44 grs to see which is more accurate. My accuracy load for most 308 Win rifles with 150 gr bullets has been 43 grs IMR 4895 for years. If you want a real deer thumping drop them in their tracks light recoil load try you some 125 gr Nos BT with 46 to 47 grs of your H-4895. I have been using 46 grs IMR 4895 with the 125 BT for a number of years on deer and it is awesome.

[BBF]

Don't forget Ball Powders in that cartridge. 

[swifty22]

One can use slow burning powders in smaller cases such as the .308 win. What must be done (AFTER CONSULTING ALL RELODING MANUALS AVAILABLE) is to make sure you have a full case (if the powder is suitable-NOT BULLSEYE!) I have been using a FULL case of H-870 in a 308 Win. w/175 gr. cast bullets and magnum primers to full satisfaction and good accuracy. This is common practice with cast bullets but note that the case MUST be full (at least slightly compressed) and a HOT primer used and the heaver the bullet the better w/the slowest burning powders. Speeds are not fast ( that load is probably not more that 2000 fps) but it is specifically for heavier cast  bullets as it starts them slow w/little smashing of the gas check into the lead and builds enough pressure to burn the powder at least into the lower end of its efficiency range (heavier bullets are better depending on the twist). I just checked my Hodgdon manual #26 and it give loads with  H-4831 for jacketed  bullets from 110 gr through 225 gr in the 308.  It is probably not the most efficient but you can sure use it!  OK If I'm loading a 308 for lighter bullets and lower velocity and recoil I would use H-4895 or H-4198 per whatever the Hodgdon book says. I'll bet the Nosler 150 Partition @ 2500 would be a great deer load from here to 150 yds and be really effective, but the 180 RCBS FN Cast air dropped 50/50 Wheel weights/PB + w/a full case of H-870 and a Fed. 215 Mag. primer will be just as good @ 2000 fps -Muddy