6.5 - 284 velocity ?

[bobinpa]

I have a 28" SS Krieger barrel and I am loading 47.3 grains of H4831sc with a Rem 9 1/2 primer. I am using 140 A-Maxs and 142 SMKs. I am only getting 2680 - 2690 with the AMAXs and about 40-50 fps less with the SMKs. Why? To me this is a little slow according to what I have been reading and what I am told. I was getting hard bolt lift at 48.5 grains and a little stiff bolt lift at 48 grains, so I backed it down and then chronographed it. I don't know what velocity I was getting with the other charges. I am shooting in cool weather too, 30 - 40 degrees. Will another powder get better velocity? I would like to get to 2800 - 2850 fps.
Thanks Bob

 

[Dubya]

Yes, your velocity is slow and your powder load is not high,hot) enough. Go to home page,this site) and look nder 6.5x284 Load info.
Good Luck & Good Shooting,
Gary,aka dubya)

 

[jofus]

Is this a tight neck chamber if so you may not have the necks turned enough.

 

[bobinpa]

This is a no turn neck. I've read the info page multiple times...... I know that the velocity is low but if I bump it up, I get hard bolt lift......

 

[memilanuk]

Bob,

Couple basic things to look at...

1) Run some ammo that is 'known good' out of one of your rifles across your chrono and see if it clocks good, or borrow a chrono from a friend and run your loads across both units back to back. It's possible your chrono might be off.

2) Check your scale calibration. Might be possible it's reading screwy.

Monte

 

[jofus]

do you get hard bolt lift on new cases or used cases

 

[jofus]

Iam getting 2850 out of 48.5 grns 4831 and 142s. rl-22 i can shoot 140 bergers at 2975. Who put this rifle together for you I would ask them what could be wrong.

 

[bobinpa]

This is all out of new Lapua brass. I am thinking that could be part of the problem but do you think it is all of the problem?

 

[bobinpa]

I didn't mean Lapua was the problem but the fact that it is all new and unfired. Will I get better velocity loading in brass that has been fired in my chamber? Will RL22 give better velocity than H4831sc?

 

[memilanuk]

Bob,

Not 300fps worth, which is about how much you're shy of the norm.

~48gr seems to be several grains lower than normal compared to what most folks report for H4831SC to get 2950-3000fps - I think I was in the 52-53gr range. Granted, my gun has a *really* long throat, but you get the point. Either your scale and/or your chrono is off, or there is something else drastically wrong. I highly doubt changing powders is going to magically fix your problems.

Monte

 

[jo191145]

Your not using coated bullets are you? Most likely not or you should have no pressure issues.

Make certain your getting the throat clean. Even though its a Kreiger if the throat is collecting carbon/copper you'll peak pressures much sooner.
A new chamber will usually leave some small burrs in the throat that can cause fouling even in a hand lapped tube. If your cleaning regimen has been missing this fouling from the start it will accumulate.
The 6.5 x 284 is supposedly notorious for fouling throats.

 

[Sooner04]

This looks like an old question; but it caught my eye so I thought I would throw in my .02.

I had the same issues with 4831SC using 142SMK's -- solution -- I stopped using the 4831 and switched to H4350 and RL22 and never had a problem since with getting 2900-2950 with either powder and no pressure signs. 30" Lilja Barrel.

My rifle just wouldn't shoot the 4831SC -- the pressure signs starting showing up almost right away at the lower load levels when I started. I use Lapua brass.

Your story sounded so identical that I thought I would throw that in.