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Discussion Starter #1
So I just loaded my first 20 rounds, 4 different loads. They are all imr4895 using sierra #2200 and oal 2.995. I was using the lyman book for load info. It said starting was 38gn and max was 42gn. I was told since military brass is thicker that I should subtract .5gn off the loads. So I loaded 5 rounds of 37.5gn, 39gn, 40.5gn, and 42gn. In the speer reloading manual I see the starting is 40gn and max is 44gn. I am reading that most people are above 40gns for their loads. I haven't shot these rounds yet. Should I shoot the 37.5gn and 39gn rounds? Or is it not going to shoot well? Thanks for any pointers.
 

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So I just loaded my first 20 rounds, 4 different loads. They are all imr4895 using sierra #2200 and oal 2.995. I was using the lyman book for load info. It said starting was 38gn and max was 42gn. I was told since military brass is thicker that I should subtract .5gn off the loads. So I loaded 5 rounds of 37.5gn, 39gn, 40.5gn, and 42gn. In the speer reloading manual I see the starting is 40gn and max is 44gn. I am reading that most people are above 40gns for their loads. I haven't shot these rounds yet. Should I shoot the 37.5gn and 39gn rounds? Or is it not going to shoot well? Thanks for any pointers.
Discus,

I just doubled checked my Sierra manual & it's states.

IMR 4895 using Sierra 168HPBT #2200 to start 38.2gn & max as 41.3gn with a OAL of 2.800 it doesn't say if it was using Military brass or commercial.

Also my Lyman book states that the OAL for your loads is 2.775, it's the 47th edition page 275
 

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For 308Win, an OAL of 2.995 is quite long, and may not fit/feed through a magazine.
The typical max OAL for mag feeding is about 2.83 inch.

Typical 308Win commercial cases and 7.62 GI cases weigh about 180-185 grains.
If the cases you are using are in that range, then it is probably not necessary to reduce the powder weight.
Some Winchester cases are quite light (~160 grains), and those case need a little more powder.

Don't use the MAX loads from manuals in an M14/M1a - those loads are usually for boltaction rifles - not semi-autos.

The loads you mentioned will probably all work ok at 100 yards.
If you plan on shooting longer distances, then 40.5 - 41 grains will probably work best.

If you shoot your 2.995 loads, be VERY CAREFUL to check every time that the bolt has rotated fully closed into the locking lugs.
I would re-seat the cartidges to an OAL of 2.83.

Jay Kosta
Endwell NY USA
 

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CAUTION
Your overall length is most likely way too long. Of the three M1As that I own all have a max COAL of about 2.88" to the lands. Your dimension of 2.995" could cause a couple of dangerous safety issues; the bolt not going in to full battery and/or very high chamber pressures.

I would seat the bullets a little deeper, an overall length of about 2.83" is a pretty common dimension that works for a lot of us.

The powder charge weights are within reason, once your COAL is corrected, but I would recommend trying 40.0 to 41.5gr depending on whether you want the smallest group size at 100 yards or higher speed for longer ranges. Most often 40.0gr or 41.0gr works very well.

You could test other charge weights by adding or subtracting a half grain initially and then making 0.3gr changes and finally 0.1gr changes until you get the absolute best load.
 

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Discussion Starter #5 (Edited)
$hit I'm sorry about that. My oal is 2.795 not 2.995. It was late last night. Sorry for the confusion.

Anyways, About those loads, any recommendations?

So I should pull the 42gn loads?

I am going to shoot them at 100yards and see what is giving me the best results, but eventually I'm looking for a load that will be best from 100-500 yards.

Does seating depth of your bullet affect how much powder you will need to use?
 

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Seating depth will affect chamber pressure, each chamber is unique in that respect.

Same goes for the 42.0grns IMR4895... work your way up through your handloads, if you get to the 42.0grn loads and you are not seeing pressure signs, you are probably OK. As I mentioned, every chamber is it's own character... you may see pressure signs before you ever get there... you never know.

Also, the Hornady manual has a specific 'service rifle' section as does, I'm told, the new Sierra manual. You may want to check those out.
 

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Discussion Starter #7
I was told to take off .5gn the max load for gi brass. In the lyman and sierra books it says to take off 1-2gn for the thicker gi brass. I am assuming the military brass with the primers crimped is the thicker brass? All these manuals have different minimum and maximum loads. I just don't get it.

I have 37.5gn, 39gn, 40gn, and 40.5gn loads for the range monday with an oal 2.795. I will start with the lower loads and check my brass after. What should I be looking for exactly and where?
 

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42.0 might be a tad hot !! I run with 41.5 and that's about as warm as I want in milsurp cases
 

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I was told to take off .5gn the max load for gi brass. In the lyman and sierra books it says to take off 1-2gn for the thicker gi brass. I am assuming the military brass with the primers crimped is the thicker brass? All these manuals have different minimum and maximum loads. I just don't get it.

I have 37.5gn, 39gn, 40gn, and 40.5gn loads for the range monday with an oal 2.795. I will start with the lower loads and check my brass after. What should I be looking for exactly and where?
Yes it is confusing but with a little time and experience it will all start clicking together. We have all gone through this and to some extent we are all still learning. None of this reloading stuff is exact science and that is why most people avoid giving out their reload recipes, they don't want to be blamed for any accident that may occur.

In general military brass has less volume because they have thicker walls (that's why they usually weigh more but the volume is the important factor not their weight). That smaller volume causes there to be more pressure with any given amount of powder as compared to a larger volume commercial case. That is why everyone says that you need to reduce your load, but how much you reduce the load will depend on what commercial case you are comparing the load to.

Then all bullets have different overall lengths even if they weigh the same. A longer bullet seated to the same COAL will result in less volume inside the case so again this will increase the internal pressures when the powder burns.

This is why I always ask what case, bullet, and COAL a person uses when they reload because all of those things will have an effect on the internal pressures. Once I know that data I can compare their recipe against mine and make an educated guess as to whether their load is safe or not.

In the case of your COAL being 2.795" vs. 2.83" your cartridges, with everything else being equal, will produce higher pressures. I don't think that they will be dangerous but they will be higher. The other disadvantage is that seating a bullet deeper will move it away from the lands of the barrel. The farther away the bullet is from the lands the less accurate your shots will be, normally that means that your groups will be larger. There is a sweet spot for the COAL and it usually puts your bullet's ogive (the spot on the bullet that touches the lands, normally it's the spot where the bullet begins to curve toward the tip) about 0.020" away from the lands. For most 168gr bullets that puts the COAL at just about 2.83".
 

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Discussion Starter #10
Thank you for that. It makes sense, it is just frustrating.

I am using lithuanian brass ggg 03, imr4895, sierra mk 168 #2200 and cci#34 primers.

So if I have loads 37.5, 39, 40, 40.5gns, with my seating depth of 2.795, am I going to run into any dangerous problems?

Which loads should I not shoot? Should I load mre rounds and seat the bullet for an oal 2.81 with these powder charges?
 

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Discussion Starter #11
Also I have the bullet comparator to use with my calipers but I am confused to all holy hell how to use it. With the comparator my measurements are coming out to 3.211. How do I know what is an coal of 2.81?
 

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Thank you for that. It makes sense, it is just frustrating.

I am using lithuanian brass ggg 03, imr4895, sierra mk 168 #2200 and cci#34 primers.

So if I have loads 37.5, 39, 40, 40.5gns, with my seating depth of 2.795, am I going to run into any dangerous problems?

Which loads should I not shoot? Should I load mre rounds and seat the bullet for an oal 2.81 with these powder charges?
Discus,
You should be good to shoot the loads you have listed. At the 39 gr mark and above shoot them slowly, checking the fired brass for pressure signs after each shot. With the GGG brass you will build up pressure quicker than any other brass.
If you are not sure about any rounds you have, Dont shoot them!
Do the next round of reloads at 2.810" OAL and you should be OK.

With the bullet comparator you need to reset the caliper at zero with the comparator closed. The Over All Length (OAL) is measured with a caliper from tip of the bullet to the base of the case. With a Hornady bullet comparator and size 8-30 bushing with the caliper zero when closed the ogive should be between 2.178"- 2.230". I do not have any Seirra 168 gr bullets to give you an exact number, only MK 173 gr and Nosler 165 gr . With the caliper the way you have it set that's between 3.181"- 3.233" .

Glenn
 

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My favorite load is 40.5 gr of H 4895 Sierra 2200 168 gr hpbt Match LC brass WW standard primer 2.810 overall length.

shoots moa all day long.
 
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