If you use 41.5 gr of H4895 for 168 smk.

[rocky_creek]

If you use 41.5 gr of H4895 for 168 smk in your gas gun, what load of H4895 do you use for 175 gr A-Max ?
I am interested in limiting the damage to the gun and I agree with the 41.5 for 168 gr as an upper limit. I am looking for an equivalent load as far as pressure.

 

[Ratbert]

Re: If you use 41.5 gr of H4895 for 168 smk.

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=323517

 

[rocky_creek]

Re: If you use 41.5 gr of H4895 for 168 smk.

No answer there. I am looking for a gas gun load using H4895 and a 175 gr a_max that will give similar results in the gas system to 41.5 H4895 and 168 smk. I guess I'll stick with my 40 gr load.

 

[Grump]

Re: If you use 41.5 gr of H4895 for 168 smk.

Oversimplification is dangerous, but....

175 grains is 4-1/6 % heavier than 168 grains.

41.5 grains minus 4-1/6 % is 39.78 or so.

40.0 sounds about right, but years ago, lots of HP shooters used the same charge for 168s and the old USGI 173s, which actually ran abut 174...

Why don't you run QuickLOAD on that? The results might be surprising.

 

[Rob01]

Re: If you use 41.5 gr of H4895 for 168 smk.

http://data.hodgdon.com/cartridge_load.asp

Put in Rifle for Load Type and .308 Winchester for Cartridge and then use you will have the min/max for H4895 and the 175/178 bullets as well as many more powders and bullets. You can use the 175grn loads with the 178. Start low and work up for safety.

175 GR. SIE HPBT Hodgdon H4895 2.800"
Min-40.0 2489 39,100 CUP
Max-42.7 2647 49,000 CUP

 

[KaiserNorton]

Re: If you use 41.5 gr of H4895 for 168 smk.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rocky creek</div><div class="ubbcode-body">No answer there. I am looking for a gas gun load using H4895 and a 175 gr a_max that will give similar results in the gas system to 41.5 H4895 and 168 smk. I guess I'll stick with my 40 gr load. </div></div>

You could give Sierra a call on their hotline, and get their recommendations for their 175gr Matchking, then extrapolate from there.

The Kaiser

 

[Ol' RD]

Re: If you use 41.5 gr of H4895 for 168 smk.

I guess I'll scare you, I use the same load for both! LOL!

 

[Fatelvis]

Re: If you use 41.5 gr of H4895 for 168 smk.

Rocky, after studying the Hogdgon load chart and it's recorded pressures, a 40.0 grn load of H4895 seems like it would only create a little more pressure than the 168 load. I think the pressure would be fine for a M1A, I say this because I shoot 175SMKs over 40.0 IMR4895 in my match M1A, and the load doesnt seem like it is over working the gas system. I use how my rifle ejects the empties, to indicate how hot the loads are. The 40.0/175 loads land in the same area on the ground as my 41.0/168 loads.