7.62 and powder questions

[DevilWillCry]

I've been loading 5.56 for a while and just got set up for 7.62X51. I'm planning on using Varget with a 168gr Nosler. Is Varget one of the better choices in 7.62 like it is with my 77gr Nosler load in 5.56? I pick up 1lb of XBR to try, any other suggestions?

My other question is regarding known temp sensitive powders like W748. I found a good plinking load using W748 and 55gr Hornady's but haven't used it on anything warmer then a 70 degree day. Factory manuals are said to be on the conservative side, but do they account for temperature? I don't think so, but I'm not sure how much a hot day will effect my load. I'm almost a full grain from max, I'm ok with lower velocity in cooler weather but I was going to give some to a friend to try, and if he shoots them on a 95 degree day will that be a problem? If I were with him I'd do my usual routine of inspecting cases after firing, but if I'm not...
I know a bigger deal is made over this but want to err on the side of caution.

Devil

 

[recarga]

Re: 7.62 and powder questions

Hello newB here

On your 7.62 or 5.56 or any other military brass don't you need to lower your filling % to at least 90% to be on your safe side because off pressure issues .

Now on recipes I can say this 7.62 or 308win in SEMIAUTO rifles like AR platform love IMR 4064 AND VIHT N-140 .

My best groups I've gotten on my Armalite AR10T with (308 brass ) are from 1.000" to .350" MOA @ 100yards. With n-140 I know this powders are price ZZZ but if you by it by the 9#' s It's a good bargain.
IMR 4064 is also a fantastic powder for you semi I've had .500" groups with this one to but it doesn't burn as clean as the Viht n-140 does.

Hope I've been on helpful and good luck.

 

[MtnCreek]

Re: 7.62 and powder questions

IMHO, Varget is The choice for .308.

If you're not showing pressue issues with the load now, shooting them on a hot day won't do any harm in your rifle. Unless you shot them through your friends rifle, you don't know. Either way, I really doubt anything bad would happen, but I wouldn't want to use a load that was un-tested in my rifle under extream conditions (like a rd worked up @ 50deg, firing it @ 95deg). The AR's I've loaded for don't seem to peek at different charge weights; they tend to operate with similar pressures. I can't say the same for some of my bolt guns.

 

[Beef82]

Re: 7.62 and powder questions

Varget is an excellent choice. RL15, 2000MR, Tac, and the list goes on all work well, some more temp sensitive than others. Temp sensitivity tends to be somewhat overstated, it exists, yes, and it matters, but if you are not loading just shy of showing pressure you won't likely jump into danger territory because the temp gets into the 90s. Now if you developed your load with mittens on, its in the hundredds or you leave your ammo to cook in the sun a while you might see some pressure, it might even be severe, if you're worried, don't give them to anyone, rifles behave differently, and try them as it warms up rather than when it hits 120*.

FWIW 5.56 brass is really no different than commercial 223Rem downloading for it is not neccesary. 7.62, if it is in fact 7.62x51mm NATO brass, does generally have a smaller internal capacity than 308Win and requires its own load development and will generally show pressure below book max loads.

 

[Shoots 700's]

Re: 7.62 and powder questions

+1 for Varget in .308/7.62 I use 175 grain bullets to 1000 yards

 

[DevilWillCry]

Re: 7.62 and powder questions

Nice to hear Varget is good for my application as i already have some. I was pretty sure temp sensitivity was overemphasized more then it needs to be. Also aware it is a factual thing, I just don't have the experience to know how much it comes into play. I never really experienced enough difference in case capacity between .223 and 5.56 to make any real difference. Then again I use primarily 1X fired LC brass because it's good stuff and cheap. Thanks for the heads up on .308 vs 7.62 capacity Beef! I have LC 7.62 brass, and I was going to start middle road. Is that a good idea, or do you recommend starting lower?

 

[JohnTlag]

Re: 7.62 and powder questions

Hi so this is an interesting issue for me as well. I was between varget and BLC-2. I originally decided on varget to make an mk262 reproduction even though I was able to get more velocity and a lower chamber pressure with BLC-2. Supposedly the problem with the BLC is that is give pressure and velocity swings as the outside temp changes. Now, I'm not sure what your setup is but varget will not run out of a power bar/measure as well as blc does because of the shape of the power granules. So what I found was that BLC-2 throws incredibly accurate powder charges out of my 650, while varget is sufficient but less consistent out of the same powder bar. The end result SEEMS to be, through a chronograph, that BLC is just as consistent as varget, and gives more velocity.

 

[DevilWillCry]

Re: 7.62 and powder questions

I'm running a RCBS Pro2000. Ball powder meters like a dream in it. I get a consistent crunching with Varget and other stick powders, but it meters +/-.1gr which is good enough for me. I picked up some XBR and H322 but haven't used BLC yet. What kind of velocity are you getting for your MK262 load, and does accuracy suffer? I'd rather have more accuracy then miss with a hotter load. If I need to hit something harder I'll just use the 7.62.

 

[Paladin2147]

Re: 7.62 and powder questions

I get good accuracy with XBR out of my Dillon. But, I also do not run hot with those loads.

 

[Drgonzo_1981]

Re: 7.62 and powder questions

I use r15 at present and get fantastic accuracy. I have been chasing on load development as far as velocity. Is due to temp changes and has thrown me way off. Today I started at about 2500fps with rounds cool and coming out of the truck at about 65-68F. After being out shooting for a few, rechecked velocity and was right at 2600, this is with a 20" rem 700 1in10 and the temp at 100F.
It is enough to throw yOu off, I just need to shoot different temps between and calculate the fps/degree of change, that way I know what vel. To use. I hear a lot about argent, anybody have data on it's temp stability?

 

[BCP]

Re: 7.62 and powder questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WestTxMarine</div><div class="ubbcode-body">I hear a lot about argent, anybody have data on it's temp stability? </div></div>

I'm going to guess that means "varget".

Very temp stable. Going from freezing to 100+ you'll see maybe 30fps change depending on caliber and how well developed your load is.

I use it for all my target and hunting loads because of that.

 

[Drgonzo_1981]

Re: 7.62 and powder questions

Yeah varget! Fucking auto correct! Ha! Well that is something to chew on, will have to buy some when this 5# jug is out. Thanks