.270 Win. and 130gr SGK COAL?

S

SEHunter

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Just started prepping for loading for a .270 Win. This gun uses a factory Remington 700 barreled action. I'm going with the 130gr Sierra Game King and H4831SC. I have my brass prepped and in the tumbler as I speak. So, I pull the gun out of the safe to measure the max COAL to the lands and found out that this chamber has a long throat. When touching the lands, the 130gr SGK has maybe about 1/8" at most of bullet in the neck, not counting the boat tail portion.

This is obviously not enough contact to ensure good bullet to case straightness. My stock is an aftermarket piece with a DBM that can hold a round with a longer COAL than the chamber can, so I can't use the mags max allowable length either. My only option is to determine the max COAL that maintains good bullet-in-case straightness. I may can pick up good velocity with this chamber (Weatherby's philosophy) but I want accuracy. Is there a known sweet spot in this chambering with 130 grainers when you do not have the option to seat the bullet close to the lands?
 
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Just start with the factory COALand see how it goes. My load with that caliber and bullet is 59 gr of that powder. That's a max load, so work up to it.
 
Do you get good accuracy and velocity from your gun at that COAL? Have you tested other COALs with all other variables being equal?
 
Making the bullet touch the lands is desirable at times but often unnecessary and inconsequential. Bullet to bore alignment on the other hand is a biggie and with only an eighth of the neck filled your odds of good accuracy are low. With vlds and stuff like that it's a different game but with hunting bullets ots really not so important to kiss the rifling
 
I know the only way to know for sure is just test. I was just curious what everyone else has seen with similar components in this chambering. I use heavier bullets in other guns, relatively speaking, and I've been able to get within .020"-.050" in them due to the longer bullet. This will be my first time having this much free bore, so hopefully it will still be a shooter. I really hope to settle on at least MOA. I don't like being over that, even with a hunting round. I know the deer won't know, it's just an OCD thing I suppose. I could move to a 150gr bullet but I want to keep it as fast and flat as possible as long as accuracy doesn't suffer.
 
Barnes did an article a few years ago on OAL vs Accuracy and Pressure.

What they found was the there are more than one OAL accuracy nodes, one on the long end and at least one on the short end. So, just because you cannot get up close and personal to the lands does not mean that you cannot find an OAL accuracy node.

I saved the article in my favorites, just for occasions like this. Unfortunately, when Barnes updated their web site, most if not all of these article were lost. I contacted them and they said they are gone.
 
I load my 130 GK's at factory COAL( I don't have my data in front of me right now). I play with the OAL with Bergers and SST bullets because they have a secant ogive. My 130 gn gk load is my most accurate load I have found for my .270 with no need to get closer to the rifling. For me this combo needs plenty on run out.
 
That's interesting about the study Barnes bullets did. Wish the article was still available.

Jersurf101, that's the kind of real life info I was hoping to come across. That's not the first time I've heard the recommendation to start with the factory COAL. I think that this is where I will start also. As you mentioned, I do worry about runout because I don't neck turn and I use bushing sizers. I do all other case prep steps known to man with that one exception.
 
If you are using Bushing dies with Lapua, Norma, or Nosler brass, probably no need to turn necks. If the brass is something else, I'd do a light neck turn and just skin off the thick areas.
 
What kind of rifle and has the headspace been checked?

Pretty odd for a new age rifle to be that way, some of the old 1903 and or A3 with a different barrel I have seen that long (30-06 of course not 270)

Sako at least to push their throats pretty long.

As noted, you can try with a rational length and see or go to a longer bullet.

Copper bullets are much longer for their weight (a lot more expensive but if only hunting that can be managed due to low volumn.
 
I suppose discussing COALs between our different guns and components can be a moot point to some extent. Unless it's to fit the cartridge in the mag, I usually am concerned with the cartridge length to the bullets ogive.

I did extensive load development yesterday and my final CL to the ogive with a SGK is 3.800. This is a little longer than average but I still have a good .250" or so of bullet in the case.
 
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