Loads for High power/national match.

[ordnancemarine]

Just wanted to get some opinions on loads for high power/ national match style shooting. I have a Rock River NM AR 1:8 20 inch barrel. I'm mainly looking for powder/ primer combos for use with Lapua brass and Sierra 77 and 80 grain moly-coated projectiles. Please let me know if you have any suggestions for powders to start with. Thank you in advance.

 

[RegionRat]

The Sierra Manual is the best place to start. There is a link to a pdf version on the cartridge guide main page. You can also see several club pages with pet loads. For example:

http://www.njhighpower.com/

http://www.6mmbr.com/223Rem.html

Try starting with RE-15. Without MoS2, the basic magazine length load is 24.0 gr 77 SMK Rem 7 1/2
LC , Win, or Lapua brass all comes close. You will have to adjust for MoS2.

The SMK 80 will be at a length that depends on your chamber reamer, which I am not sure about for a RR NM rig. The process for determining the length isn't difficult if you have something like the Stoney Point comparator. The WOA loads are shown on John's web page. Mine goes to 2.465 with the same load as the SMK77 using the SMK80. I don't run MoS2 so I can't get you any closer, but those are decent starting points. Always back down when you start out and ease into the 24.0 so you don't load up too many before you find your sweet spot.

 

[KevinThomas]

Ordnancemarine,

Varget and RL-15 are the "go to" powders for this game, and probably account for about 95% of gthe powder used on any given line, divided about 50/50 between them. There's other good options as well (N135, N140) but these are the two primary choices. Most shooters are probably running right around 24.0 grains with the Varget, for both 77s and 80s. Used that load for many years, and it's like the old 4895 load in the M1As; if your rifle doesn't shoot it, you've got a gun problem. The RL-15s just as good, but the charge weight will be a bit different. That's with uncoated bullets. I'm completely with Regionrat about using naked bullets, the moly's just another variable to deal with.

Mag length for the 77s (of course) and the 80s are usually right around 2.440"-2.450" with a Wylde chamber. Check it out in your rifle with a comparator, since off the top of my head I'm not sure what reamer RRA uses in their factory guns.

 

[FroggyOne2]

I agree, don't bother with the moly, you can't get enough powder in the case to justify using moly in my opinion.

 

[ratguner]

Ordnancemarine,

Most shooters are probably running right around 24.0 grains with the Varget, for both 77s and 80s.

Mag length for the 77s (of course) and the 80s are usually right around 2.440"-2.450" with a Wylde chamber. Check it out in your rifle with a comparator, since off the top of my head I'm not sure what reamer RRA uses in their factory guns.

Right on the money.
Used 23.5 gr Varget for 77s and 80s. CCI BR-4 primer, LC case.

 

[Taildrag15X]

Single loading with 77 or 80 gr, Sierra MK's I'm at 24.50 grs. Varget with the bullet jumping .015.

 

[johnu]

RRA uses a Wylde chamber in their NM and varmint uppers. Most of their tactical uppers use the 5.56 chamber, at least in their carbine length.

John

 

[flatlander]

Unless I miss my guess, your RRA SR bbl. was chambered with a Wylde reamer, which is pretty close to what John uses for his match bbls. No matter which reamer was used, your 200&300yd ammo will all be loaded to magazine length, whether you're shooting 69s or 77s. The S80MK is very tolorant of various seating depths, usually shooting quite well whether jumped to the lands, or jammed.

Good results can certainly be expected with Varget, but I've never liked compressed charges. H4895 will give accuracy at least as good as Varget, with a little less compression. Going a step further, IMR8208 meters better than either Varget or 4895, and is also compressed less than either of the other two powders.

 

[ordnancemarine]

Thank you for the reply's! I think I'll go with the varget. I've been using that with my .308 for a few years now. The RR upper is wylde chambered and I do have a comparator on the way to measure for the 80 grain SMK's. My reasoning for using moly coated projectiles is to further the time between cleanings during a match. I haven't decided which way I'll go just yet, but I appreciate the input from everyone.

 

[Shootinstick]

You certainly shouldn't need to worry about cleaning during an 88 round match (80 record shots and 2 sighters per position). In fact I don't think moly is a good idea for an XC gun at all. It doesn't eliminate cleaning completely, and when you do clean it can take more than a few shots to get the rifle to settle down again. Not a good deal when you show up at a match with a clean barrel and only get 2 sighters. If you are shooting leg matches with no sighters it is even worse. When I was chasing leg points, I would always put a fowling shot down the bore before I arrived at the range so my first shot offhand wasn't on a clean barrel. Like many, my standard XC service rifle loads are 24 grains of Varget behind a 77gr SMK seated mag length for 200 and 300. 24.5 gr of Varget behind an 80gr SMK seated .005" off the rifling.

 

[Killshot]

I found my best long-line load to be 24.5gr of Varget under a 80gr JLK VLD, seated .001" off the lands.

But you can't go wrong with 77gr SMKs over 24gr of Varget for the magazine-length distances/rapids.

 

[boltman13]

My RR National match Rifle loves Winchester brass, Rem 7 1/2 Primer, Sierra 80 gr Match, and 24.5 gr of Varget. I avoid molly like the plague, could never get consistant results, probably due to neck tension issues. My load jumps 0.01".

 

[jonbearman]

If you run .004 tension on the neck you have no problem with moly. The problem with moly is application and polishing after application so you hardly get any on your fingers.This way you get the lubricity without the build up. I have been using it for years without any problems with initial flyers. Too much is bad and a highly polished bullet with light application will do the trick. The spray bombs are a joke. Just my .02 cents.

 

[ordnancemarine]

I shoot moly with my .308 and I love it it. I do buy the pre coated moly projectiles from sierra though so I don't have to mess with the application. If I do go the moly route, I'll do the same thing. I use to shoot on the MCAS Miramar rifle team for a little bit before I got out. We were given special match rounds that were moly coated. I liked the way they performed but I have never reloaded for this yet. I think I will take the advise I've recieved so far and use it as a good starting point for load development. I think the majority says 24 grains for the 77SMK's and 24.5 for the 80's. Thank you again for the advice on where to start.

 

[KevinThomas]

Orndancemarine,

Don't sweat the .001" jump business, it's an illusion in a Service Rifle. I've explained this elsewhere, but when you trip the bolt those bullets are going to seat themselves into the rifling to some degree if you're anywhere near that close to the throat. Virtually ALL ammunition is subject to this, and I've even seen some jump (.001"-.003" or thereabouts) in military ammunition complete with cannelure, crimp and asphalt sealant. In match ammunitioin with considerably less neck tension, oh yeah, they're gonna move. Basically, what we've got here is the largest and most expensive kinetic bullet puller in the world. Bullets jump measurably under the forces of chambering in an AR. The fine details like this apply to bolt guns, not to Service Rifles. Try it and see. Load up some dummies using your normal, match ammo neck tension and measure them individually, recording the results for each round. Chmaber them normally, droping the round into the follower and tripping the bolt to close. Extract the round and remeasure it. I'll guarantee you, it will have moved. Just a fact of life with the Service Rifles, and yes, they still manage to shoot quite well. Don't sweat it.

 

[fdshuster]

Same load as Taildrag15X: 24.5 of Varget, 80 gr. SMK, seated to touch or .020" of jump, doesn't matter, CCIBR4 primers, Lapua brass. For my bolt guns only, not the AR's. Chambers cut with my reamer, .253" neck, .074" freebore, 1-8 twists. Excellent combination.

 

[ordnancemarine]

I think I may just try that experiment. Not that I don't believe you, just for shits and grins.

 

[westerngrizzly]

When I was on the California Grizzlies we shot 24.5 grains of varget almost across the board. When we won rattle battle we shot 24.5 grains of varget with a 75 grain HPBT. One person on the team shot TAC until he ran out and then switched to Varget. Most of us shot the 73 and 82 Berger bullets. Some shot Hornady, others Sierra.

So use 24.5 Varget with your choice of bullet (except the 69. Its too light for 300) and a Rem 7.5 primer.
Best wishes,
Matt C.

 

[ava123]

I have taaken the loads and advice of matt above, and shoot 24 of varget, 77 or 80 grain smk, but my match barrel was set up by Kreiger barrel, and they use a match reamer that leaves the chamber 2.50 long, for a good 80 smk fit. and like everyone finds out, this barrel and bullet combo shoots the lights out. I have been using refined LC cases, worked over at both ends, and my third trip to the range, shooting this load, with about 010 thousands off the lands, shot a hunter target with 49/ three x's. and then shot my only group for the day, and measured it big, at .140/ which blew me away. thanks kreiger barrels, who put the complete upper together for me.