Im currently developing loads for a semi auto .308, I've backed off maximum charges by 2 or 3 grains of posted data. I'm using federal and Winchester brass I find federal to create a better gas seal than Winchester at least before being fire formed. I'm shooting out of an fnar chambered for 762 NATO. My question pertains to charge weights; is the only difference between the .308 and 762 NATO brass case volume? This being the reason why pressure spikes with lower charge on NATO brass and published load data is lower for it? I'm new to reloading for semi autos and I would appreciate any comments on this matter or suggestions for this application.
Reloading for Bolt vs semi-auto action
- Thread starter patagon2
- Start date
Thanks! Does this mean I can use Lyman data for an auto loader the same I would for a bolt action? I'm aware that a bolt action is stronger and can withstand higher pressures, not sure where to start with auto loader? I usually start at halfway mark when reloading for bolt.
Funny you mentioned trimming brass because I've noticed some of Winchester brass has come at 2.000 ans a couple at 1.995 out of the bag they get longer after a couple firings then get trimmed, never believed this was an issue. Brass that is to long on the other hand is dangerous!
You need to trim your brass for pretty much any action/calibre if it gets too long not just autos.
Loading data is usually not listed seperately for Auto and Bolt guns. It is by calibre and the idea is you would work up from starting load in any given rifle. In the case of an auto loader you would be looking for reliable auto cycling on top of all the other things like pressure accuracy etc. In my M1/M14's I found starting loads cycled the guns perfectly.
Some manuals do note powders appropriate for .308 and .30-06 gas guns like M1/M14 but those are the same loads for any gun in these calibres.
I would suggest using starting loads and going up from there with some common powders listed in your manual until you get the accuracy and reliabiliy you want.
Loading data is usually not listed seperately for Auto and Bolt guns. It is by calibre and the idea is you would work up from starting load in any given rifle. In the case of an auto loader you would be looking for reliable auto cycling on top of all the other things like pressure accuracy etc. In my M1/M14's I found starting loads cycled the guns perfectly.
Some manuals do note powders appropriate for .308 and .30-06 gas guns like M1/M14 but those are the same loads for any gun in these calibres.
I would suggest using starting loads and going up from there with some common powders listed in your manual until you get the accuracy and reliabiliy you want.
just having some fun
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Powder selection is more critical in a semi (port pressure)
Bullet selection is also more critical
In A bolt gun you can use a lot faster powder and alot slower powder than the semi
for instance trail boss & Unique you would never use in a semi
(under special conditions you can use them in a bolt gun)
Bullet selection is also more critical
In A bolt gun you can use a lot faster powder and alot slower powder than the semi
for instance trail boss & Unique you would never use in a semi
(under special conditions you can use them in a bolt gun)
hometownhero
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IN my hornady loading manual it has data for 308 winchester as well as data for 308 winchester service rifle
Another issue is reloading commercial .308 brass for 7.62 chamber, I discovered after firing com brass once case length had shortened!? Discovered that it is a head spacing issue in the 7.62 chamber is slightly longer therefore brass had to stretch into that excess making the case shorter, confirmed this with Winchester brass had more gas marks on shoulder, federal brass that had not shortened significantly had none. I curious as to the integrity of the once fired win case? It measure from 1995 to 2000 some came out of the bag at this length (2000). Has the excess headspace worked the brass too much to the point it is unreliable? I will reload a few at lower charges, the cases look fine just short and slight rounding at shoulder. I would appreciate any input on the matter!
Anyone here use the Lee FCD for .308 semi-auto?
There seems to be this huge debate on gun forums...
Neck tension vs. Crimping.
I am going to experiment with both when I do some loading for semi-auto .308 this Spring.
There seems to be this huge debate on gun forums...
Neck tension vs. Crimping.
I am going to experiment with both when I do some loading for semi-auto .308 this Spring.
I usually use the Lee Factory Crimp Die on my .308 M14 loads and ,y .30-06 M1 Garand loads. Many people shoot these without crimping too.
hometownhero I now notice what you mentioned in the Hornady Manual. I believe the service rifles refered too are the M1 and M14. Also Speer notes the powders for these with a + cross symbol in their normal .308 section.
I have noticed straightwall low pressure cases that do not grow or even shrink to shorter lengths with .45-70 and .45 ACP etc. But had not witnessed this with bottleneck rifle cases like .308 Win. Interesting. I would think a larger/looser/longer chamber would really cause a bottleneck round to grow in length thus thinning out. Sizing in a FL die would do this a bit more too.
hometownhero I now notice what you mentioned in the Hornady Manual. I believe the service rifles refered too are the M1 and M14. Also Speer notes the powders for these with a + cross symbol in their normal .308 section.
I have noticed straightwall low pressure cases that do not grow or even shrink to shorter lengths with .45-70 and .45 ACP etc. But had not witnessed this with bottleneck rifle cases like .308 Win. Interesting. I would think a larger/looser/longer chamber would really cause a bottleneck round to grow in length thus thinning out. Sizing in a FL die would do this a bit more too.
