Sierra 69 gr MatchKing accuracy load?

[LRRiflemanSNJ]

I am looking to develop a .223 load for 300 yard F class matches using the Sierra 69 MatchKing and Target. Does anyone have a load they would recommend?

I am shooting a 26" barreled White Oak match upper with a Wilson 1:7 that I I shoot out to 1000 yards with appropriate loads.

Thanks!

[wncchester]

Ah, if only life were so simple.

[NWPilgrim]

Well, every gun can shoot the same load differently, and you should double check anything mentioned against your own manuals.

Given that disclaimer here is what I have found. Although Varget can be accurate with 69 SMK, it is mot the most accurate for me. Here are my best loads in order of preference, ranging from 5-shot groups of 1/2" to 1":

- 25.1 gr BLC2, my favorite powder 55 gr up to 69 gr bullets

- 23.5 gr H335 is very consistent

- 23.0 gr H4895

- 24.9 gr Varget

I've found any of the 68-69 gr BTHP bullets are just flat out easy to find a great load. For me at least the Hornady and Nosler shoot just as well as the Sierra so I buy whichever is available and at best price in bulk when I need more.

I have not tried IMR 4064 yet but since it very close to Varget I suspect it would be good, too.

[stnosc]

Just quoting Sierra here, but they say the accuracy load for that bullet is 26.5 gr of Viht N540.

http://accurateshooter.net/Downloads...223rembolt.pdf

Personally, I use 24.9 gr Varget with that bullet. It produces sub-MOA groups.

[Unclenick]

I am looking to develop a .223 load for 300 yard F class matches using the Sierra 69 MatchKing and Target. Does anyone have a load they would recommend?

Just to be clear, I assume you mean Varget and not Target?

There are any number of loads possible, but Sierra's AR-15 listings says 25.3 grains of Varget proved most accurate in the AR platform, so that's a place to start.

That said, you may want to rethink your bullet choice. The 69 grain bullet is short enough that it is somewhat overstabilized by a 7" twist. The stability estimator at the JBM site suggests that bullet would be happier with a 9" twist, as the 7" takes the stability factor to about 2.8. Sierra gives the optimal gyroscopic stability factor for match shooting as 1.4-1.7, and hunting accuracy as 1.3-3.0, so you'd be up in the high end of the hunting accuracy recommendation with that bullet.

The 7" twist was designed originally for the military to stabilize tracer bullets that are light for their length, and thus more easily turned into a tumble by air pressure on their nose. The only bullet I spy with enough length to be optimal for that twist is the 90 grain Berger VLD, though it's long enough that you'll end up with a long round and need to load it singly. But even the 80 grain Sierra should be happier with the 7" twist than the 69 grain bullet is, and it can be forced short enough for magazine feed (though that costs you some powder capacity and velocity).

That said, the proof is in the pudding, and Sierra bullets are well made and can tolerate some degree of over-spinning. So if you already have some 69's, I would start at Hodgon's 24 grain starting number for Varget and work up to Sierra's 25.3 grain recommendation and see how it shoots? The OCW load tuning method is simple and should work for you with any of the bullets mentioned.

[LRRiflemanSNJ]

Thank you for the recommendations. I have reloaded since the mid 1970s, and for competition since 1988. I realize rifles can (and do) shoot the same load differently.

The range where I do my load development is 3 hours away. Typically, book recommendations are for 20" barrels, not 26". Typically, I pick a load at random and develop about 10 loads of a given charge, then repeat that at 0.2 gr increments. The problem doing it this way is the time consumption and "wasting" of hard to get components.

I am finding this barrel is showing excellent accuracy with 77s in the mid to high 2700s, and 80/85s at 2800-2850. I was hoping someone with a comparable barrel and components could share their experience.

[LRRiflemanSNJ]

You are correct, I should have proof read my post, I meant Varget (my computer auto corrected). Additionally, I should have identified my barrel as a 1:8 twist.

I am saving my 80/85 HPBTs for 800-1000 yard matches. I can get 77s, which I am shooting at 600. I have a couple thousand 69s, which I hoped to use in 300 yard F class matches.

Just trying to use what I have on hand prudently.

[Unclenick]

The 8" will be easier on the 69's and probably will do OK. It's pretty common for 10" twist .30 cal barrels to do fairly well, despite over-spinning the 168 grain MatchKings. The issue with over-spinning, aside from slight loss of BC due to increased yaw of repose in flight, is just wobble. The faster you spin a bullet the more any asymmetry in the mass distribution will cause eccentric wobble. But the MatchKings are pretty uniform, as I said, and can often withstand more spin than is strictly optimal.

If you assume the load Sierra shot was tuned to the 20" barrel, then you'd be right. But if you read through Dan Newberry's OCW concept, you'll find he's interested in identifying loads that do well over a range of barrel lengths, and his approach seems to find those. Whether the Sierra load would work out to be one or not, I can't say. The round robin Newberry uses tends to compensate out changes in bore fouling, temperature, light conditions over the course of the shooting, or anything else that might make you shoot differently from one time to the next. I find it a useful method and it can identify useful loads even where the old Audette ladder fails.

[stnosc]

Oops....sorry about the Sierra recommendation for a bolt action. I read "F Class" and automatically assumed "bolt action" without reading further.

[snooze]

I guess I'll echo what everyone else has said: 24.9gr of Varget produced the most accurate groups for me. I shoot with a 16" 1:7 barrel, though.

[mohr308]

I just started with some 69gr match bullets and used BLC2, so far so good, but still plenty of work to do if I want sub moa at 200yds+