178 gr AMAX

vaeevictiss

Sergeant
Full Member
Minuteman
Dec 4, 2012
175
2
41
Virginia
I just got into reloading...finally lol. I worked up 100 rounds for my .308 this weekend and im not happy with the accuracy. I shoot better with factory hornady rounds.

What i used was hornady cases, 178gr AMAX, WLP primers, and 41gr of varget, COL 2.800.

the rifle is a rem 700 sps varmint (1:12). I had my 'smith cut the bbl down to 22", thread, and got a break for it.

I was reading the 178s were not good for the 1:12 twist, then i found a thread on sniper central where guys were getting outstanding results with them, but they were using anywhere from 43-45 grains of varget, and some were even setting the COL to 2.925.

the Hornady book i used to get my load from said 41gr, but also says 43.5 would be too high pressure.

Is the book just being safe and i can use 43-45gr safely?
 
Re: 178 gr AMAX

Just to compare to the above, Horn brass weighs about 15 gr less than my '91 LC, so you have a little more room in there (maybe a gr worth of varget).

Rem barrels are typically long throated and if you're loading to book 2.8", that's probably a pretty big jump. I would lengthen the coal to be ~0.050 off lands and start working up the charge (slowly) toward 44 or 45grs.
 
Re: 178 gr AMAX

Hodgdon data for the 175/178 and Varget is Minimum 42grns and Maximum 45grns. Most find a good load between 43 and 45grns.

The 178 AMAX usually works fine in 12 twist barrels. The box says 10 twist but its not the only twist the bullets work with.
 
Re: 178 gr AMAX

Im running a nice FGMM clone load of 43 Varget under the 175 SMK and 178Amax. the are identical loads from a performance and drop perspective and I even load both of the with the same OAL (measured at ogive.)
 
Re: 178 gr AMAX

Works great for me. I get the veloicty I like out of 44g of varget, but it shoots almost as well as that did.

43.5 Varget
Hornady Match Brass
FGMM primers
2.825 OAL
2.205 OGIV
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Re: 178 gr AMAX

Picking a single load at random will very rarely result in satisfactory results. Proper load development should improve your results over factory ammunition.

You have a good set of components. Now just decide if you want to do a ladder test or OCW.
 
Re: 178 gr AMAX

44-45 of varget seems to be where people usually end up.

Are these the first rounds after having the barrel cut? Have you tried the factory rounds since shortening the barrel?
 
Re: 178 gr AMAX

Doesn't matter ... take some factory loads & shoot for group. Especially if you have had barrel cut, did you check muzzle for burrs or anything like that ? I usually take a marble with Flitz/Simichrome on a drill (attach to a tee w/ adhesive) and clean up the muzzle if it wasn't already done by gunsmith. What works for others may not work in your rifle . EACH RIFLE & barrel is different.
 
Re: 178 gr AMAX

thanks for the great info! i actually just read about the OCW 12 round method in a magazine and was thinking of trying that out. So ill get on tearing these rounds down and starting over. I suppose ill make a batch starting at 43 up to 45 and see how that turns out.

Is half a grain separation between loads good? or should i go less.

And actually i really havn't shot the rifle for groups after the barrel job, thats a good point. I just had it out recently shooting 1/2 lb tannerite jars at 100 yds and never missed one so thought nothing of it.

Hes a pretty good smith tho, him and his business partner build some really serious bench rifles.

I just really need to find a local range cause all i have on my property is about 75 yds of strait line
frown.gif
. A friend has 100 so thats a good starting point but i would really like 200.

Im planning on junking the factory stock in a couple months for a B&C A5 so im sure ill have to do it all over once i add a stiffer base to the rifle lol.
 
Re: 178 gr AMAX

I also run the 178's in a 12 twist LTR 20" barrel. I run Hornady brass/ br2 primers/ RL15 at 44.5 gr's. Shots moa or better if I do my part. I'd say just start working up in .5 gr incerments up to about 45 gr's stop if you fell heavy bolt lift you'll find one of the loadings shoot better than the other. Now take that charge weight and work .1 grain up and down until your at .5 from the best weight you had. Then shot them and take the best group for your charge weight for that rifle.
 
Re: 178 gr AMAX

So I broke them all down today and weighed out the charges from 43-45 in half gain increments. i then decided to look more into the cartridge length. I had it at 2.825 to begin with and I'm able to get to 2.925 closing easily. At 2.93 i felt some resistance so I backed of to 2.915. Is that normal? That seems like a huge difference. Also, how will this affect my powder charge? Should i start higher than 43gr?
 
Re: 178 gr AMAX

Just finished working up this load for my SPS Tactical. Using FL sized once fired FGM brass- trimmed and cleaned, Win primers. I started low on the charge (41.5) and found that as the charge went up the group size came down. Finished at 44.5 Varget with OAL of 2.825. Shot groups today of 0.59" and 0.29" (those are 5 round, 100 yard groups out of a factory gun).

The OAL on mine could go out to about 2.837- but the shorter did better. 2.9+ doesn't sound right to me.
 
Re: 178 gr AMAX

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vaeevictiss</div><div class="ubbcode-body">

Is half a grain separation between loads good? or should i go less.

</div></div>

I think 0.5 grain is too great an increment for an OCW test. Most shooters will use 0.3 grain, which is what I recommend.
 
Re: 178 gr AMAX

So I got out to a local range today to try these out. Cold and rainy but I made the best of it lol. I also found out I'm not comfortable shooting from a bench lol. My whole life I would lay prone when shooting rifle. Anyway, that being said I had some odd results.. but again, not used to shooting from a bench so I'm sure a lot of it was me. The group sizes were...

43.2 gr - .81
43.5 gr - .81
43.8 gr - .90
44.1 gr - .85
44.4 gr - 1"
44.7 gr - .45

At 45 gr i barely started seeing some cratering and a slight noticeable tension when lifting the bolt so I didn't even go to the 45.3 gr.

Is that normal to get a consistent group size then just a drop to .45?

I feel the factory stock is an issue too because it seems to flex a ton. I plan to pick up a B&C A5 soon tho. Also, should i be sighting in with a front bag, or bipod? Im currently using rear bag and bipod.
 
Re: 178 gr AMAX

I use 44.0 of Varget in virgin LC 70 brass and its a hammer. Cases are fully prepped to include neck turning and annealing. With 44 grains I hear powder being crushed.

Edit to add: I'm running .02 jump in a .308 tac match chamber
 
Re: 178 gr AMAX

The 178gr A-Max's are great. They ARE more sensitive to OAL though so it will take some adjustment. Do an OCW test for powder charge then play with OAL, first in .010" increments, then +/- .005" on your best length. To validate then shoot a slightly heavier and slightly smaller charge.

Make sure your seater plug contacts the bullet in the same manner every time. Length will be more critical than with the SMK's or Nosler Custom Comps.