243 LBC?

JTPinTX

JTPinTX

Custom Call Maker
For years I did a lot of daylight coyote calling with bolt guns in open country. 22-250, 220 Swift, 243, 25-06. I like to put coyotes down hard. Fast flat bullets that open up. I don't save fur, most of ours aren't worth anything anyways.

Last few years I have been doing a lot more hunting with AR's, a fair amount of it in closer cover. My 556 piston gun with 65 SGK's does OK, even with a 14.5" barrel. Doesn't have that serious bang flop of what I am used to, but not much gets away from it.

Started doing a lot of night thermal hunting this year. Also got more into pig hunting at night as well. Been shooting a 6.5 Grendel for a couple years. Good on deer and pigs, but honestly I just have not been that impressed with it on coyotes. I shoot suppressed so I like to keep a pretty short barrel (16") and would like to stay with that length. I keep going lighter with bullets trying to get back to dropping coyotes like I am used to. Currently shooting a 95 VMAX, and it is killing coyotes, but still seems like I am shooting through them and not opening up as fast as I like.

So my thought is same powder capacity but faster, flatter and more pop. 243 LBC caught my eye because I can use most of my Grendel stuff but get a new barrel, sizing die, and new brass, and have minimal swapover of parts. My thought is a 60-70 grain bullet as hard as I can push it out of a 16" barrel, something that will open fast. I never shoot over 300 at night, honestly nearly everything within 200.

Seems to me the 6mm variant would let me get bullet weight down and speeds up, yet have more powder burn efficiency in that bullet weight range than going on down to 22 cal.

I know lots of you guys know tons about this. Give me your thoughts.
I can get a Grendel bushing die with .269 bushing, and new brass. Barrels? What else do I need to think about?

Most importantly, is this going to be a significant step in the direction I want to go?

Thanks in advance for the help and advice.
 
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I think you'll find that pushing a 58 VMAX or 70 TNT will do everything you are looking for coyotes. Ritch designed it with that area if bullet weights in mind specifically for the task.

Greg
 
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It's about as good as it gets, I used one for a few years but used 87 vmax. The 6mm Arc is basically a factory clone also.

Honestly though for the light bullets you want to use I'd look hard at the 6x6.8. But they will all be neck and neck.
 
I think the first two responses cover everything you need. I'm a 6.8 variant guy, but those two have pretty well shot everything in the world of cartridges you're looking at.
 
I shoot the 87 VMAX in my 243 and really like it there. It is a real hammer. But 12-13 more grains of powder behind it than the LBC, it should be. That is the kind of performance I am looking for. I know I can't make the LBC match the 243, but would like to get as far that direction as I could.

My initial thoughts were either the 58 or 70 VMAX. Probably the 58. So from what you said GL, the throat should be fine for that. I didn't know if lots of folks might be trying to get into the high BC bullets for long range and therefore the throat be kind of long.

I do shoot some LR, but don't plan to with this at all. Debating on whether to go with 8 twist (I don't really see a situation where I would need it) or stay with a 10. The 10 would match lighter bullets better and "maybe" give a touch more speed.

My 6.5 Grendel seating die is a Forester Benchrest seater with the sliding sleeve. Any way I could use that to seat bullets since the sleeve would be holding the case in line? Or am I asking for trouble on runout?
 
The chambering is perfect for the 58's and it is Ritch's pill of choice. I like the 70 TNT's. I shoot an LBC in 500 yard matches using a 95 Sierra MK and do very very well with it. We've found the 95 with the extra velocity does better ballistic ally than the 105's in this case. I have not tried the new whiz bang 103 stuff floating around. For the really long bullets I would recommend a windowed mag in the AR15 as that will give you about 2.40 for max OAL. In my regular stuff it is ASC mags all the way as you can get a 2.216 nominal length on them.

I would talk to Ritch about twist rate as I have 8's and 9's and they both shoot the 58-95's well. I tend to go one twist faster than what I anticipate as my bullet weights so the 8 gets most of my work and I have seen no detriment at all.

As for the 10 twist I just got in a Tactical Ordnance Rugage barrel that is 1:10 and loaded my first batch of ammo for it from 58 to 95. With luck I will have some idea how it does on Thursday. It is a five groove polygon barrel replacement for my Grendel RAP.

I have seated the 6MM with a 6.5 set up but I use the generic Hornady sliding seaters for 95% of my loadings. With the addition of a micrometer top I can move them around from 6X45, 6X6.8 243 LBC and 243 Win very quickly and it saves me worrying about alignment and I don't have four dies laying setting in the box on the bench. My suggestion is try it out for run out. It could come down to how your press tolerances are even vs. the die set up as to your success there.

Greg
 
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Let me know when you jump on the wagon. I have more than enough data to clog your brain with. Give Ritch a call in the early morning during the week or the afternoon on the weekends and jaw with him a bit. He is the encyclopedia on the design minutia.

Greg
 
I shot the 1:10 243 LBC from Tactical Ordnance last week. This is on a Ruger switch barrel but the results should hold pretty close on the AR version based on our experiences with both bolt and auto platforms.

I won't post up all the targets but Cliff Notes:

Total groups fired was 26. Total over 1 MOA was two. Average group size for three different bullets and six different powders was satisfying a 0.696. Across the board this was below my 0.750 baseline. The 70’s need some work as they blew the average up with their 0.846 as compared to 0.6375 for the 58's and 0.599 for the 95's. Personally, I’m convinced that these could all be cut by a solid 0.1 or 0.2 with the right guy behind it. Unfortunately, unless a long-lost doppelganger drives up to the house I am stuck with my trigger finger digit.

The 95's had some screamers comfortably below 0.2 and the others had several under 0.5. Across the board it showed pretty good behavior with no surprises using 6 ARC data as a baseline and moving up.

With the deep hole drillers running behind getting blanks drilled has been a challenge for several companies even though they are feeding the steel to them. If you want to look at one of these chat with Ritch as he has a good feel for the status on the in-house blanks at this point.

Greg
 
I had one years ago and it was accurate, but I never got the internet claimed speeds before it started trashing brass. In the end, I sold it and kept the grendel for the increased ft/lbs of energy at longer range,
 
If I was looking into a new round for the AR and I was starting from scratch I would look at the 6 ARC, just for the fact it has the weight of Hornady support behind it. However, since you are already set up for 6.5 Grendel, the 243 LBC is a great option. I had a 20in Black Hole and with a 90 STMK, it would ring steel with authority at 600 and do it flatter than my Grendel. If you dont mind fire forming, there are varieties like the Turbo 40 that get some more FPS
 
I just shot a good test on the 243 LBC in a RUGAGE that covered 58-70 and 95's. The speeds were up thanks to the polygon TO barrel and it was in a bolt gun. Accuracy was way more than adequate for most uses and down right scary on occasion. Here's a link to the long and pic heavy production:

RUGAGE 243 LBC


Greg
 
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