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Posted: 12/23/2015 12:00:27 AM EDT
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So, I got 200 of the once fired LC brass prepped, going to make up some loads. I found some IMR 4064, read an awful lot of good things about it, going to start there.
Sierra's manual lists a starting charge of 37.8 then 39.7 then 41.5 then a max charge of 43.4, for the SMK 168gr HPBT, loaded to 2.800. Since this is MIL brass, I know the reduce the max charge by 10%, then another 10%, which comes out to 34.7gr, for a starting charge. So My main question is by what amount would I move the charge weight up for My ladders? In My other thread, several members mentioned good results around 42.0gr, in a commercial case. From what I have read, it would seem that between 40-41gr is the general area that I think the load is going to come in at. Anybody loading SMK's in LC brass? I got some 168's and 175's I'll be working with. I also have some RL-15, Varget, H-335 to try if needed, read good stuff about the RL-15. Thanks, Dave |
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Start with 40gr, and work up from there with the 168 with 4064.
The lighter 40'ish charges will sleep fast for short 100 yard work, but for pushing out to 600yards plus, forget about sleeping fast, and work on speeds to buck the winds instead (into the 41gr'ish loads instead where it may take 200 yards or more until the bullet sleeps). Note, if this is for a bolt gun, the use some cheap powder and bullets to first fire form the brass to the chamber, then neck size only and start working up the real loads. |
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I forgot to add, this will be for My Ruger Precision Rifle, bolt gun.
I thought maybe loading up some of the cheaper 147gr FMJBT Mil spec I got with some of the WC844 powder to fire form. WC844 uses the same data as H335. So it would be best to fire form, and neck size for the real load work up? |
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Quoted:
Start with 40gr, and work up from there with the 168 with 4064. The lighter 40'ish charges will sleep fast for short 100 yard work, but for pushing out to 600yards plus, forget about sleeping fast, and work on speeds to buck the winds instead (into the 41gr'ish loads instead where it may take 200 yards or more until the bullet sleeps). Note, if this is for a bolt gun, the use some cheap powder and bullets to first fire form the brass to the chamber, then neck size only and start working up the real loads. I have never heard the term sleep in relation to firearms... Please explain... |
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Quoted:
I forgot to add, this will be for My Ruger Precision Rifle, bolt gun. I thought maybe loading up some of the cheaper 147gr FMJBT Mil spec I got with some of the WC844 powder to fire form. WC844 uses the same data as H335. So it would be best to fire form, and neck size for the real load work up? Yep, fire form the brass to the chamber to being with with cheap loads, then work on your match load with neck sized brass instead. |
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Here are a few good reference points for Match Loads for gas guns like the .308 Garand and M14.
http://www.radomski.us/njhp/cart_tech.htm http://www.accurateshooter.com/cartridge-guides/308win/ Ladder testing has suggestions for how to set your charges. http://www.accurateshooter.com/technical-articles/long-range-load-development/ http://optimalchargeweight.embarqspace.com You will likely find a match to the old Federal Match Ammo loads that comes close to being right for your rig, plus or minus a little. http://rifleshooter.com/2015/02/308-winchester-175-sierra-matchking-ladder-test-with-varget-and-imr-4064/ https://www.ar15.com/archive/topic.html?b=6&f=42&t=270297 Good Luck, can't wait to hear how it turns out. |
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Bullet sleep,
http://www.longrangehunting.com/articles/bullet-pitch-yaw-1.php https://youtu.be/4pF8W5liSRc Or the short version, the distance that is take a bullet to spiral perfectly with no pitch or yaw from the nose to the base in flight once it leaves the barrel. |
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Rat, thank you, this one article is very helpful to Me.
http://rifleshooter.com/2015/02/308-winchester-175-sierra-matchking-ladder-test-with-varget-and-imr-4064/ This is the test ammo I will be using, so it is really valid info to Me. I think it is a good starting point. 
I think all I am worried about right now is hitting the paper consistently. And this article is VERY interesting, suggesting that FGMM works so well in so many rifles, due to the fact they have timed the exit of the bullet at the moment of least obturation is very interesting. At least that was My take on it. 
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FYI . . . If you like the FGMM 175s out of your rifle, save one and open it up. I believe you will find 41.75gr of IMR 4064.
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Quoted:
FYI . . . If you like the FGMM 175s out of your rifle, save one and open it up. I believe you will find 41.75gr of IMR 4064. Quoted:
FYI . . . If you like the FGMM 175s out of your rifle, save one and open it up. I believe you will find 41.75gr of IMR 4064. Depending on how the FGMM 168's and 175's perform in My gun, I was going to try to match the velocity, then bump the charge up and down to see what happens to accuracy. Then try adjusting the seating depth to see what it likes. |
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So, here is what Sierra has for H335 and a 150 FMJ BT. 39.5gr 40.9gr 42.2gr 43.6gr 44.9gr So, If I loaded up some cases at 40.0gr, 5gr below max, it would seem to be a safe middle of the road charge, just to fire form? So, I feel that 40gr of WC-844 is a safe charge to start at, I just wonder is it going to be enough of a charge to Fire Form the brass properly? Not coming up with too much specific data on Fire Forming, beings that I've never done it before, would really appreciate some input. Thank You, Dave |
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Quoted:
Depending on how the FGMM 168's and 175's perform in My gun, I was going to try to match the velocity, then bump the charge up and down to see what happens to accuracy. Then try adjusting the seating depth to see what it likes. Quoted:
Quoted:
FYI . . . If you like the FGMM 175s out of your rifle, save one and open it up. I believe you will find 41.75gr of IMR 4064. Depending on how the FGMM 168's and 175's perform in My gun, I was going to try to match the velocity, then bump the charge up and down to see what happens to accuracy. Then try adjusting the seating depth to see what it likes. Nope, you should be working with about .003" to jump to lands from the start. Hence BTHP bullets do not do well with jumps past about .010" before they start throwing fits. Note, flat base bullets can just much farther before they start acting up instead. So cases blow outs to fire form the prepped weight selected brass to the chamber, neck size only, bullet jump to lands about .003", then start working with your powder amounts to get the bullet to leave the muzzle on one of it's barrel harmonics oblong end points. Hence your going to hit one of these points with your short distance loads for quick bullet sleep, then when you start pushing the speeds to dope wind, it's the bullet exit at one of the muzzle oblong end points that you trying to achieve again for the faster loads. Also, Use Federal 210M primers from the start. |
Congrads on your Ruger , got to get one soon.
Anyhow I like Varget for accuracy,prescision rifles due to it's ability to flow through my powder measure (Lee Perfect) and relative insensibility to temperature and case position. LC Cases are OK even the match cases but real sub minute loads will be found with commercial cases like Federal,Winchester,Remington You can get good accuracy from lake city, but your rifle should have the most perfect ammo you can make. I used to shoot benchrest in the 90's and case prep is very important for those tiny groups,depends on what type of accuracy you want,how much you want to spend and how much time you want put into it. Later John |
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when you work your load up it will probably be close to these US Military load is-- 308 Lapua case Sierra 175 MK 41.75gr IMR 4064 My load is-- 308 Lapua case Sierra 175 MK 42.2gr IMR 4064 CCI # BR 4 primer ( is in the sweet spot for-- Rem. 700, Israeli Mauser, Indian Enfield, M1A1, ) |
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So, a little change in direction. I went over to the LGS, and talked with the Owner and the Purchaser for awhile. Both very knowlegdable reloader's, I'm just going to skip the fire forming, and do some load development.
After that, I'll have fire formed brass.  After talking with them, I realize that I probably don't need to waste the time or materials worrying about it.
If People can get MOA out of FGMM, that isn't formed to their chamber, I'll probably be OK with My loads to start with. 
So, carry on, nothing to see here. So, those of You Who get a kick out of My mindless OCD rants, just wait, I'll be along with another one shortly. 
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