1x7 AR barrel - competition load help

[Lovesbeer99]

I've was shooting NRA Highpower with an Hbar 1x9 twist and my pet load was 52gr BT HP Match rounds with 26.5 grains of 748. They were pretty good. Now I have a White Oak Service rifle barrel 1x7 twist and my 52gr rounds are shooting very well but when I try match 69gr rounds or 75gr rounds I'm getting not so great results. I've been using Win748 and RL15 but I can't find a pet load for it.

Any suggestions as to the velocity I should be trying for?

 

[taliv]

dunno, but 69 and 75g bullets should shoot a lot better in the faster twist. usually, seating depth and neck tension and how straight you seat the bullet (concentricity) have a LOT more to do with accuracy than velocity

 

[mc223]

What Taliv said and you might want to try VV-N-540 with BR4 primers. And sometimes you have to push them a little harder.

 

[Mags]

I like 69 grainers in my 1-7 twist rifle for 3-gun.
IMR4895, RL15 and TAC have all worked well behind the bullets.

 

[TonyAngel]

All barrels are different and just because it's a 1:7 twist, it doesn't necessarily mean that the heavies are what it's going to shoot the best.

In any case, I've always found Varget and Reloader 15 to give the best accuracy performance in all of my rifles (that is, of the powders that I've tried). I've always just seated to .010" shorter than max mag length. As for the powder charges, 24gr of RL15 with a 77gr SMK is a pretty standard load. Of course, you can play around with the charge weight a bit to see if you can tighten things up a bit.

Now, I'm not looking to get into an argument over the subject, I'm just going to share what I did with stubborn rigs. I find a load that gives me the best accuracy. If that load is the best that I can get (with a bullet that I want to use) and I still don't think it's satisfactory, you can try applying different amounts of crimp using a Lee Factory Crimp die. I actually had two barrels that showed a vast preference for crimped rounds. Go figure.

If you are getting super results with the 52gr load, you may not be able to attain that with the SMKs in your rig. Still, you should be able to find a load that shoots MOA and shooting the heavier bullets, even if they aren't as accurate at 100 yards, may get you some benefits in terms of bucking the wind at longer ranges.

 

[Lovesbeer99]

Thanks for the feedback. I would appreciate if you list the powder and charges or the velocity and I'll work backwords. I understand that each rig is different and you never know but I'd like to get some sort of standard and work a little up and a little down to see what happens.

In the end if the 52gr are working I'll just stick with them. But I have a feeling I just need to work on these loads a little more.

 

[mc223]

Maybe you should drop this thread and start a new one in reloading.

 

[P-32]

Here is what I refined into my loads...http://www.whiteoakprecision.com/info-reloading.htm.

I use Rem 7 1/2's. CCI will do in a pinch and shoot to about the same zero. I will not use Federal primers in a gun with a free floating firing pin.

Tony, the upper lovesbeer has is a top shelf upper. White Oak knows how to build a service rifle. Both of my White Oak Precision upper's love the 77 and 80 gr SMK's. Both also shoot the 52 or 53 gr SMK very well. (WOP and WOA are the same company, it depends on who is building the rifle, John or Mike) WOA uses Wilson barrels with a Wylde chamber. RRA NM uses a Wilson barrel with a Wylde chamber. WOP on the other hand John will build on a Norpac. (or Pac Nor I can never rember) (popular with the bench resters) My first rifle was the NorPac in 6 1/2 to one as I had dreams of shooting 90 gr bullets out to 1k. Never happened. John also uses the Wlyde chamber. My newest upper has a 7 to 1 Kreiger. Like I said they both shoot when the nut behind the trigger does his job.