SL8 range report

[General Ripper]

Had the gun for a while now and started developing a load. It has a 1:7 twist so the 55 grain ammo I tried first was all over the map. Found some 69 g Federal Gold medal SMK and it shot pretty well. Thought I should go heavier though. A previous owner shot this rifle sub MOA at 300 metres. So that is my goal. Another member recommended 75 g A-Max. I started the load at 20.5 grains of benchmark and I'm at 21.3 right now. One thing I'd like some help with is the oal. I can't get it short enough to load a mag. Is there a way to crimp on the area above the parallel surface without popping the bullet into the case? This is all at 100 yards to start. My scope is an inexpensive Leapers 3-9 x 40mm mil-dot LP-SCP-394FDRL3. I find it difficult to use. (That's my excuse!)
So yesterday I tried the Federal 69 g SMK, the Hornady 75 g TAP and my 75 g A-Max handloads. I'm new to rifles and the Harris bipod but the groups are tightening up. I'd like a new scope but for now its not too bad.

The rifle

Me

My handload in a mag....can only use 1...in a 10 rnd mag

Targets (Had to adjust scope after 1st 5)

I guess I could have posted in several other areas...hope this ok here

John

 

[agent_mango]

A couple comments:

1) I don't know if crimping is 100% necessary. I've heard that even for semi-autos neck tension should be good enough to hold the bullet in place. The general opinion about whether crimping helps or hurts groups is up in the air, but I've read some evidence saying it might give a slight improvement. So anyway, maybe you could get mag length by avoiding crimping, except...

2) I've never read on here about anyone loading anything bigger than 69 gr SMKs to mag length. They happen to work great in my savage with varget at 2.250 OAL, and of course the Federal ammo you used is the same idea.

However, I've heard about soldiers in Iraq using 77 gr loads, which I think might be the SMK 77 gr. If somebody could confirm I'd appreciate it. So anyway you might have an option to go with that if you want a heavier mag length load.

3) If you want to shoot tight groups then a bipod, while ok, isn't the greatest. I'd recommend getting some sort of shooting rest. On the cheap you can try a block of wood with a sock full of rice, or if you want to go a bit more expensive (probably about $300 total) find a caldwell BR rest and get some protektor cordura front & rear bags.

 

[beltfed]

There are a number of the heavier bullets that are physically too long to be pushed into the case to an overall length of 2.260", and still allow enough room for powder and seating depth optimum for ignition. Many of the bullet manufacturers and loading manuals advise against loading these bullets past a certain length. The Hornady 75gr. Amax and Sierra 80 gr. Match King are two popular bullets that should not be loaded to mag lengths.

Good heavier bullets to try in autos (at mag length) include:
- Hornady 68 & 75 gr HPBT
- Sierra 69 & 77 gr. Match Kings
- Berger 70 & 73 gr. LTB match bullets
- Nosler 77 gr. J4 (although I've never tried them, nor seen them sold around me)

I recommend (and do) Crimping for autos, even the bullets that don't have a canalure (all of the above with maybe the exception of the Nosler -I've never seen one). I've fired all of the above bullets in my ARs and my PE-90, and can say for sure crimping helped in consistancy. As always, ymmv.

 

[General Ripper]

Thanks for the input.

The 77 SMK is a much shorter bullet so I think that might be one to try. I got this from a reloading web site and I can't remember where. Very useful for comparing.

John

 

[agent_mango]

That's from here:

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

 

[edon]

If you want maximum OAL, maybe switch back to the HK mags (looks like they handle about 2.300" max OAL) - might be up to .030" longer depending on which AR mags you compare them to. I'm not a reloader so I don't know if this amount is significant or not.