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No love for the AR-10T Magnum (RSAUM)?

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Replied by JustMe on topic No love for the AR-10T Magnum (RSAUM)?

Thanks. Looks like the RSAUM is a little fatter than the .308. I like that it is still a .308 bullet so you have a lot of bullets to choose from. I load a 155gr Palma Sierra Match King with about 46 or 49 grains of Varget in my .308. I get equal 100 yard, .5 inch group accuracy with both powder loads. How many grains are loaded in a RSAUM? Try the 155gr Palma Sierra Match King, it's a real good long range bullet. I think you'll like it better than the 168gr or 175gr SMK. I find the 155gr is more stable in a 1 in 11 inch twist barrel than the 168 and 175 gr bullets. These heavier bullets I feel are more suited to the 1 in 10 inch twist barrels.
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10 years 11 months ago #23877

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Replied by SOC on topic No love for the AR-10T Magnum (RSAUM)?

Here is my load data. These are very hot loads for the RSAUM and if you want to use them start 10% low and work you way up. I have been getting some pressure sign and am on the edge with the following load.

Bullet - Burger 210vld hunting
Powder- 60gn RL17
Primer - Federal 215
Brass - New Remington trimmed to 2.004"
COAL - 2.860 (Just fit in mags about .088 off lands)
MV 2925fps
G1 0.631 G7 0.323

My accuracy at 100yds is not all that impressive as the bullet hasn't setteled down (gone to sleep) tell 300-500yds. It really shines the longer range you shoot.

ETA The rifling twist for my rifle is 1-10". Berger recomends this twist for their 210vlds.
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Last edit: 10 years 11 months ago by SOC.
10 years 11 months ago #23880

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Replied by Lizardette on topic No love for the AR-10T Magnum (RSAUM)?

SOC: Always happy to see a 24" barrel on an AR10. I wanted to get a 24" 1 in 10 twist .308 SI Defense chrome moly heavy barrel (not a bull barrel) to build another upper with, but when I got the money together it wasn't available anymore (at least at midwayusa.com). Anyway, your rifle is going to look great.

JustMe: The 155 grain Sierra Palma Match King is seriously my favorite bullet ever. Haven't tried them in my LR-308 yet, because I keep shooting them in my Saiga .308. The best groups I've ever gotten out of that rifle were with that bullet and 42grains IMR 8208 powder, in Federal Cases, with either CCI BR-2 or Federal Gold Medal Match primers.
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10 years 11 months ago #23926

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Replied by SOC on topic No love for the AR-10T Magnum (RSAUM)?

I have a new AR-10 Carbine 16" 308 that I'm going to make into a DMR. I'll have to try that bullet when I start shooting it.
10 years 11 months ago #23928

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Replied by marios5469 on topic No love for the AR-10T Magnum (RSAUM)?

Ive got a Magnum lower that I plan on building into a SASS upper, but have been on the fence whether to go RSAUM or go .308. How much of a difference am I really going to see performance wise at long range?
10 years 11 months ago #24027

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Replied by SOC on topic No love for the AR-10T Magnum (RSAUM)?

The 300 RSAUM is supersonic to almost a mile with my load.

The 300s are also more accurate in general than the 308s. Ballistically you have to look at 338 Lapua to give my 210 vld load a run for it's money. The 338 Lapua has about 10% less wind drift and slightly more energy at any range when compared to the RSAUM due to a 250 gn bullet compared to a 210 gn.

With a capable shooter you should be able to shoot under 8" at 1000 yds and 15" at 1500 yds with a factory RSAUM and good handloads.

A 308 might be able to push a 210 vld to 2400 fps.
A 300 RSAUM is capable of over 2900 fps.
The two rounds are really not in the same catagory.
10 years 11 months ago #24031

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Replied by marios5469 on topic No love for the AR-10T Magnum (RSAUM)?

So what would be the ideal barrel twist to squeeze out max accuracy from this round?
10 years 11 months ago #24033

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Replied by SOC on topic No love for the AR-10T Magnum (RSAUM)?

1-10" or faster. Factory Armalite RSAUM barrels are 1-10" and very accurate.
10 years 11 months ago #24036

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Replied by marios5469 on topic No love for the AR-10T Magnum (RSAUM)?


What about the 1:11.25 they use on the SASS? Any better in accuracy?
10 years 11 months ago #24048

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Replied by SOC on topic No love for the AR-10T Magnum (RSAUM)?

I don't know about the barrel particular to the SASS but Berger recomends a 1-10" twist for the 210 vld. IMHO 1-11.25" is a little slow for weights over 190 gn.
10 years 11 months ago #24051

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