7.62 Handloads built on the .308 win

slushee

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Okay, I bought the lee Breech Lock Challenger Press Kit .. loading for an M14. I found some really old reloading articles (much thanks to RePete if i remember correctly for sending me SO MUCH DATA on that), that basically tell of "the load" for M14's.

41.5 grains of IMR 4895, 168gr Sierra Matchking, Winchester Brass and CCI primer #200.

I know I know, "work up a load" .. but I decided I wanted to make the M852 load used in Vietnam. I read a quote stating, "If I know anything in life, its 41.5gr 4895 + Sierra 168gr HPBT".

Well after loading up my very first hand loads, I shot them to find I had reduced my 3" @ 100yards to 1" @ 100 yards!!!!!!!!!!! :D:D It just so happens that the M852 load is on the lighter end of the recipe so I was not overly concerned about 'working up a load' as opposed to starting with the one that I did instead. I checked for flat primers, extractor marks and any other signs of high pressure; there are none.

Now on to my questions. Those of you who load for an M1A/M14, what are your tolerances for your case trimming? I currently have 2 sets of brass (to be reduced to one to avoid confusion soon) .. the OAL of my trimmed brass is as follows:

Set 1
2.015" (+.000/-.005)

Set 2
2.020" (+.010/-.005)

I trim after every full length resizing, the above tolerances are what I get using the same trimmer and lee guage on both batches.

Set 1 brass shoots the most accurate (Winchester brass) at 1" @ 100 yards, Set 2 (Remington brass) shoots about 1" higher with a slightly more open spread (1 1/4" @ 100 yards). I am assuming that the longer neck on Set 2 brass is putting more pressure (and allowing more surface area for my factory crimp) on the bullet, causing higher pressure (the 1 inch higher shot) and slightly less accurate groupings.

I am curious what you all use for your brass tolerances when working 7.62 loads? Also, I am currently married to the Sierra Matchking #2200 HPBT 168 gr bullet. I noticed in my new canadian cabela's magazine that Hornady makes a 168 gr HPBT for $10 cheaper. Has anyone tried these and found them to be more or less accurate then the Sierra's?

Another question, has anyone used CCI #34 Large Rifle Primers as shown in Handloader Magazine, August 2008 issue, page 47? It shows these primers being used for 7.62 NATO rounds. I would love to hear any success or horror stories regarding these primers. Will they work in .308 brass? If worthwhile, I would change out to them.

Anyways, I wont bore you to death with my novel, but I am just so excited about how well this handloading went. I have shot about 4 batches so far and the rifle has really shined! I CANNOT believe how much more accurate handloading is compared to factory ammunition.

Thanks again for everyone who responded to my other posts when I was asking some rather silly "newbie" questions. :redface:
 
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#34 primers are hard primers used to prevent slam-fires from bolts with floating firing pins, like the one in your M14.
They should not alter performance in anyway.
The #34 primer is a military primer and is still in use by the military. So as the rest of the war supply goes....good luck finding any quantity of them.
They pretty much do not exist. :(
 
Okay, I bought the lee Breech Lock Challenger Press Kit .. loading for an M14. I found some really old reloading articles (much thanks to RePete if i remember correctly for sending me SO MUCH DATA on that), that basically tell of "the load" for M14's.

41.5 grains of IMR 4895, 168gr Sierra Matchking, Winchester Brass and CCI primer #200.

I know I know, "work up a load" .. but I decided I wanted to make the M852 load used in Vietnam. I read a quote stating, "If I know anything in life, its 41.5gr 4895 + Sierra 168gr HPBT".

Well after loading up my very first hand loads, I shot them to find I had reduced my 3" @ 100yards to 1" @ 100 yards!!!!!!!!!!! :D:D It just so happens that the M852 load is on the lighter end of the recipe so I was not overly concerned about 'working up a load' as opposed to starting with the one that I did instead. I checked for flat primers, extractor marks and any other signs of high pressure; there are none.

Now on to my questions. Those of you who load for an M1A/M14, what are your tolerances for your case trimming? I currently have 2 sets of brass (to be reduced to one to avoid confusion soon) .. the OAL of my trimmed brass is as follows:

Set 1
2.015" (+.000/-.005)

Set 2
2.020" (+.010/-.005)


I trim after every full length resizing, the above tolerances are what I get using the same trimmer and lee guage on both batches.

Set 1 brass shoots the most accurate (Winchester brass) at 1" @ 100 yards, Set 2 (Remington brass) shoots about 1" higher with a slightly more open spread (1 1/4" @ 100 yards). I am assuming that the longer neck on Set 2 brass is putting more pressure (and allowing more surface area for my factory crimp) on the bullet, causing higher pressure (the 1 inch higher shot) and slightly less accurate groupings.

I am curious what you all use for your brass tolerances when working 7.62 loads? Also, I am currently married to the Sierra Matchking #2200 HPBT 168 gr bullet. I noticed in my new canadian cabela's magazine that Hornady makes a 168 gr HPBT for $10 cheaper. Has anyone tried these and found them to be more or less accurate then the Sierra's?

Another question, has anyone used CCI #34 Large Rifle Primers as shown in Handloader Magazine, August 2008 issue, page 47? It shows these primers being used for 7.62 NATO rounds. I would love to hear any success or horror stories regarding these primers. Will they work in .308 brass? If worthwhile, I would change out to them.

Anyways, I wont bore you to death with my novel, but I am just so excited about how well this handloading went. I have shot about 4 batches so far and the rifle has really shined! I CANNOT believe how much more accurate handloading is compared to factory ammunition.

Thanks again for everyone who responded to my other posts when I was asking some rather silly "newbie" questions. :redface:

might just be me but there is no difference in your brass (given the tolerances you have stated)
 
Just to clarify,

Set 1
2.010-2.015"

vs

Set 2
2.015-2.030"

I know 15 thou is not much, but I was concerned because I notice the extra 0.015" is mostly in the neck length. I do not have much knowledge in the proper dimensions, thus I'm hoping someone can say "those are both within tolerance", or tell me what I should be aiming for :) When I trim, should I strive to keep it towards 2.015 or 2.030??

And those #34 primers sound EXACTLY what I would love to use for my loads. Now the hunt begins for a supply :runaway:
 
"...The #34 primer is a military primer..." The CCI #34 "milspec" primer is nothing more than a marketing gimmick for magnum rifle primers.
Properly seated regular large rifle primers will work just fine in any semi-auto. Thousands, if not millions, of .308/7.62(and .30-06) ammo was loaded and fired with no fuss long before CCI saw another way of making more money.
The trim-to length for .308/7.62 is 2.005". Do that and don't forget to chamfer the inside and deburr the outside of the case mouth.
 
I trim mine to 2.000" and have no problems in a bolt gun. If you trimmed to 2.005", you should be able to go 5-6 loadings before having to trim again, providing your brass lasts that long out of your M14.
 
Trim to .2005 like Maynard said and others, you might want to go down to as low as 39gr with the 168 Sierras and work up to 41.5 grains, also another good powder 4064 40gr to 41gr don't change bullets the Sierra's are very good. I have tested in a Match grade benchrest rifle.308 Nosler, speer, Hornady's the sierras perform the best.in 168gr
 
The trim-to length for .308/7.62 is 2.005". Do that and don't forget to chamfer the inside and deburr the outside of the case mouth.

Oh wow! My Lee gauge coupled with the Lee trim tool is trimming WAY too long :( .. Do you have any suggestions on a good upgrade for a case trimmer? I've seen some of those nifty hand lathes .. or could I gently take a little dremmel and shorten my gauge until it produces a 2.005" trim? Is a 0.010" tolerance on that trim to lengh okay, or should I strive for a 0.005 tolerance?

You trim your brass after everytime you FL resize?

Yup .. from everything I've read about M14 reloading, you wash up your brass, you full length resize (and deprime at the same time), and then you trim your case. Now, sometimes the trimmer takes nothing off .. so i measure to be sure .. but I always go through the motions of putting every case in the trimmer after resizing. I also take the time to inspect for case failure marks during the trimming phase, and any with large dents or dings that did not get resized out, or indications of case seperation, get crushed in my handy bench vise.

I hope I'm doing things correctly :) Again, I am new to all this .. thanks for all the info! I'll curb my search for #34's .. the #200's seem to be preforming well, and if it ain't broke ;)
 
I am always amused at these people discussing trimming their cases. Should it be this .005 longer? Or maybe that is too much.
I reloaded for years and years, using the comparitive method. I had a new case, either a factory loaded cartridge, or a new case, of the calibre I was loading for. From time to time I would put my new case beside the one I was loading and compare the length. If the case appeared to be a bit longer, I filed it down, then reamed the neck with my jack knife.
I used to size 30-06 cases down to 270. The old 30-06 case worked just fine in the 270, but if anyone measured it, they would find it .100" shorter than the specs on a 270 case.
By the way, I did OK in the shooting matches I entered with my home built ammo and have the trophies to prove it.
 
I should add that I didn't put with a file and jack knife too long for trimming. I made an automatic length trimmer myself. It was based on a cut out piece of 2 x 4, a drill ground away to cut a square shoulder on the case, while the centre of the drill actually chamfored the neck. A handle turned the drill and a stop allowed for only excess neck to be cut off.
However, it was only good for one calibre.
 
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