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Posted: 6/8/2014 10:39:37 PM EDT
If you load for this rifle, what MV's are you getting with API's and M-33's? I'm stuck at 212 grains of WC867 and getting MV's in the low 2,700's. I seem to be running less powder than anyone here and still I get an occasional sticky bolt or heavier than normal bolt lift I was able to get 2,850 out of M-33's using Reloader 50 but they printed terrible because they were too light. Is 2,700 the limit for this rifle and bullet/powder combo
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Peak muzzle velocity tells you NOTHING useful except how much drop for your projos BC you will get.
That's it. I have no idea why some people are fascinated with it. Go searching for your velocity nodes. THEN you will have found something which will greatly increase your accuracy and be worth your time. And don't worry about a sticky bolt. It's an AR50. Keep an eye on your primers. If they get FLAT and shiny then you've gone too far. |
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Quoted:
Peak muzzle velocity tells you NOTHING useful except how much drop for your projos BC you will get. That's it. I have no idea why some people are fascinated with it. Go searching for your velocity nodes. THEN you will have found something which will greatly increase your accuracy and be worth your time. And don't worry about a sticky bolt. It's an AR50. Keep an eye on your primers. If they get FLAT and shiny then you've gone too far. this is the truth ...MV is there to get your dope, After you find the right load ... YOUR GUN LIKES. |
| Accuracy wise...my rifle likes the load and my primers are doing just fine. However, I'm puzzled how some here can run 225 grains of 867 with the same rifle and I can't get anywhere near that. The other thing I find odd is that @ 205 grains I smoke the necks and at 212 grains I appear to be at max load. That's a pretty thin window for such a large powder charge isn't it? |
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Accuracy wise...my rifle likes the load and my primers are doing just fine. However, I'm puzzled how some here can run 225 grains of 867 with the same rifle and I can't get anywhere near that. The other thing I find odd is that @ 205 grains I smoke the necks and at 212 grains I appear to be at max load. That's a pretty thin window for such a large powder charge isn't it? You do not understand what a node is or how to find one yet. That's why you don't understand why different guns get different velocities or what you are seeing. The standard deviation is trying to tell you something! ;) (You are not at node!) Unless your primers are FLAT you are nowhere near max load (unless you're shooting 800gn bore riders you probably aren't there with 212gn of 867 ) |
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Just my 2 cents and others are welcome to comment and tell me I am wrong. I am thinking there are a few things besides max load that will cause a bolt to be sticky. Work hardened brass that does not shrink back after it cools some. case that has a long neck that should have been trimmed back some while prepping the brass or when it was commercially loaded. I dont have a neck only die, so I back off my FL dies. This then does not set back the shoulder. Every once in awhile I have a stiff closing bolt with an even stiffer opening bolt. Wonder if this is part of your problem? How are you sizing your brass? How easy does the bolt close? A few stiff ones now and then? What do your primers look like?
Have to agree with the majority. Those 212 grains of powder sound weak. Though I do not use your powder, I use good old H50BMG. I did by some 5050 back when I first got started. Never had bad powder before. This stuff when I first got it smelt different but not really strange. But the next year is smelt like a pool that had a shock charge of chlorine. I had a few loads left over from the year before. Shot one and it kicked like a SOB. pulled and threw away the power that was clumped and the brass was real badly blue green. Brass got tossed also. I bring this up to ask what does your powder smell like? Sorry to ask, I might be the only one that does not know what bad powder smells like, or there might be others, if it smells slightly off, get rid of it. |
| All my brass is LC 2006 thru 2013. I trim all brass to 3.90". I full length size every case and yes, I do sometimes think the bolt is a bit tight when closing. As for the powder...I got it recently from Widener's and it's virgin and smells like it should. Primers are perfect after firing. |
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All my brass is LC 2006 thru 2013. I trim all brass to 3.90". I full length size every case and yes, I do sometimes think the bolt is a bit tight when closing. As for the powder...I got it recently from Widener's and it's virgin and smells like it should. Primers are perfect after firing. You want the bolt closing to be snug and consistant. If your dies are clean and you've tried a variety of brass, talk to CH4D about getting a die from them for your press. There is a reason for the inconsistency and you need to find it. Another thing is I think you are over apreciating bolt lift as THE sign of overpressure. It certanly can be a sign, but like was mentioned above, brass geometry, fouling, and lots of other things can cause it too. The true sign is distress of the brass and primer. You need to more use "stiff bolt lift" as a clue to check your brass, not as proof of overpressure. If you can't catch the gap between the primer and casehead with your fingernail after firing And the casehead is picking up machine marks from the bolthead: "you are there". (Edit) The AR50 is an amazingly robust gun. One of the most stout 50Bmg's built... It's the Ruger Blackhawk of the 50 world. Don't be foolish, but at the same time, you can trust it. |
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It is important to use a chronograph while developing loadings for your rifle, not to just read your best velocities, but to allow you to see where the different plateaus exist with different powders and different projectiles. Matching the correct powder with the correct projectile weight will definitely become obvious during your testing. Barrel length sometimes upsets the normal expectations.
My AR-50's original barrel was shot-out at about 1800 rounds, but I continued to use it until over 3800 rounds. After moving to a new-to-us home, I purchased a large toolroom lathe and Bridgeport mill. One of my first projects was re-barreling my AR-50 with a 35" Feddersen rifled barrel blank. I decided to use it near full length and only put a slight taper on it after threading both ends. I also chambered it with a Match specification reamer using a 0.554" neck diameter. This now requires that I turn the necks to ensure a maximum loaded neck diameter of 0.552". (Note: some, but very few, surplus will fit but measure before using.). Using the new barrel at a 34" finished length from chamber to muzzle, allows for the use of cannon grade powders such as V. V. 20N29 and others including Reloder50 to achieve best velocities (2860fps) and accuracy using the 815 grain brass bore-riders I prefer for 1000 yard Match Competition. I can't tell you the loading but will tell you that I don't get 28 loadings per pound of powder. Hodgdon H50BMG is way to fast for my bullet barrel combination although Hodgdon does list a maximum loading on their powder bottles. My best grouping so far was 5 shots under 5 inches at 1000 yards. A newly developed loading using a tungsten disulfate coated 800 grain Barnes LRS shows very good indications of great accuracy. Testing was done at 200 meters and groups were 3-shot cloverleafs. I will be attending a 1000 yard FCSA Match this coming weekend at Alliance NE, a place with terrible wind conditions for achieving great groups. I will be using 815 grain Lehighs there, saving the coated bullets for the World Championship at Raton NM in July. Come shoot with us again ED. |
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