.308 starter load

[m1ajunkie]

I am about to load up my first batch of 178gr amax's, but I'm not sure where to start on powder.

My hornady reloading manual 7th edition says max load for imr 4895 is 40.1gr.

However the hodgdon website says max load for imr 4895 is 44.7gr using a 180 gr bullet.

I was planning to start at about 40gr and work my way up to 43gr or so to use in a semi auto ar.

Where should I start?

 

[FCS]

Re: .308 starter load

40 and work up is reasonable plan.

Which 308 AR are you using? Factory or custom?

 

[m1ajunkie]

Re: .308 starter load

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: FCS</div><div class="ubbcode-body">40 and work up is reasonable plan. </div></div>

Thanks for the quick reply.

Just curious, any one have any idea why the hornady manual says that 40.1 gr is the max load when .308's usually have well over 40 grs?

Using an lmt mws with 20" SS barrel with 5r rifling.

 

[black_ump]

Re: .308 starter load

i load 175 smk's and before i sold my scope i was doing good with 41.0 out of a 26" barrel and imr 4064

 

[Boogyman]

Re: .308 starter load

I agree with FCS, Amaxs have very long bearing surfaces, thus the difference in loads with a standard 180 grn. Start at 40 grns and work up cautiously.

 

[m1ajunkie]

Re: .308 starter load

I loaded up some rounds tonight starting at 37gr of imr 4895.

I loaded 10 rounds at 37gr, then moved up to 40gr. From there I loaded 10 rounds at each half grain amount to start my testing. I didn't load any rounds higher than 42.5grs because I was thinking the cases were getting more full than I like.

All the rounds have an oal of 2.800.

I plan to get out this weekend and see what happens.

 

[m1ajunkie]

Re: .308 starter load

I called IMR today and ask my question just to be safe.

The man who answered said the I should be fine starting at 40grs and working up. He only had data for 180gr bullets so thats what he used as a reference. He was guessing that hornady used hornady brass for there test and they could not hold as much powder as the winchester brass used in IMR's test. He said even though they used a bolt gun for testing, I should be safe to start my load at 40grs in an autoloader.

40gr is the max load in the hornady book, but less than the min load listed on the imr reloading data center.

This has me wondering, how do I know when my case's have reached max powder capacity for the length bullet I am using?

 

[lightman]

Re: .308 starter load

Every recipe,ie bullet,powder,case,even primer can be different.Case capacity,bearing surface,bullet hardness,all can change pressure.You just have to watch for pressure signs.The data reported in loading books is from the exact components and rifle that they tested,yours can be different.Most of us have several books,so that we can check and cross check data. Pete

 

[BCP]

Re: .308 starter load

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m1ajunkie</div><div class="ubbcode-body">
This has me wondering
</div></div>

Don't wonder, just use 175 SMK data.

 

[EXSOCAL]

Re: .308 starter load

As others have stated, I found that 175 SMK data and desults are almost identical to those obtained from 178 AMAX loads. My two go to bullets for LR 308 shooting. Good luck and be careful!