Reloading .223 Match for AR

[usmcmba]

Hi All,

I am shooting a Compass lake Ar-15 with a Krieger 1-7.7 twist barrel for high power matches. I am planning on shooting leg matches next year. Currently I shoot 77 gr. Lapua Scenars with Lake City brass with VV N135 and CCI Br-4 primers for practice at 100 yards. For the 600 yard leg match, I expect to use Lapua Match Brass.

Here is my problem. With the Lake City brass I can seat the bullet to achieve an OAL of 2.460" for the single load events. This load is highly accurate out of my AR- however when I try to replicate the same OAL on Lapua brass (this is first loading), a 2.460 OAL will not chamber and I have a stuck round issue. I would have to seat the bullet around 2.360" with the Lapua brass for it to chamber properly. I have noticed that the neck diameter of LC brass is approx .245-.246" while Lapua is a little thicker, .249-.250".

I am at a loss, why would the LC brass chamber with a longer OAL than Lapua. My initial theory is the case neck thickness, but that shouldn't matter in this situation right? Anyone have any thoughts or insight into this? Also, would it be recommended to turn the neck for the AR? I would imagine a Compass Lake would have a tight chamber as well even though it is a semi-auto.

Thank you in advance for any info you can provide.

 

[Klong]

No need to use Lapua 223 brass. Lake City sorted by weight will provide all the accuracy you will ever need to win a LEG match. It is very important to know your sight setting at each distance and position, plus being able to compensate for wind and light conditions. Not getting rattled on the firing line is a key to getting LEG points. Good practice helps. Dry firing in position in full gear will help a lot also. I would not use 77gr bulle5t6s at 600 yards since it is a disadvantage. I use 80 gr bullets. I Legged out years ago!

Good luck!

 

[7x57]

Just shoot the Lap 77's with LC brass, sort them to the same year if you want. All the weight sorting of the brass, etc isn't going to make a difference. This is not short range benchrest. The points you'll lose at 200/300 are up to your position and ability to shoot offhand. Need to make the correct wind call at 300 or a lot of points are going down in 70 seconds. 600 prone is up to your ability to make wind call and hold tight. The Lapua .223 brass came in two flavors, one where the brass was about 94 grains another where the brass was aroung 115 grains. The heavier brass will affect your loads. Save your money on the Lapua brass and shoot more instead.
Nothing wrong with the Lapua 77s across the course. I was squadded next to Shawn McKenna 3 years ago at Camp Perry and watched him win the NITT/LEG match shooting L77s. I believe that he was the second civilian shooter to ever win the NITT. It was impressive shooting.

 

[distinguished]

You might want to try N140 or re15 powder. I found that I had better results with these than with N135. Take another look at your brass because the distance from the bolt face to the rifling doesn't change just because you change brass. You can shoot the 77gr bullets at mag length with no problem at 600yds. I scored for a marine who shot mag length 77gr bullets during the P100 and did very well. Said it uses 1/2 min more elevation than 80gr bullets.

 

[flatlander]

First, you can save a considerable chunk of change in component cost by using a less expensive, but still very accurate 52-53gr. match bullet for 100yd. practice. Load 'em with any of the usual ball powders (W748, H335, AA2460, etc.) for smooth & accurate metering, which will save you a lot of time at the loading bench. The lighter bullets will also be slightly easier on your barrel's throat than a steady diet of 77s.

I've had several AR bbls. from CLE, and IIRC, Frank used a reamer similar to the Wylde. My Wylde reamer print shows a neck dia. of .2558", which should be large enough to save you any problems with the Lapua. Seems odd - you might want to give CLE a call and ask about this.

Whatever - I used to dink around with neck turning LC brass, taking just enough of a cut to clean it up, or taking off the 'high' spots. That stuff shoots lights-out at 600 in every rifle I've tried it in - but so have several other brands of non-turned 5.56 or 223 brass. Most likely, it's a case of "If you think it's going to help, then it probably will.", also expressed as "It's all in your head." Spend the time it'd take to neck turn shooting or dry-firing instead, unless you've got a lot of the Lapua that needs turning to fit your chamber.

 

[anyrange]

Interesting. Don't make sense. Your chamber neck is around the .256 range and do not see how a little more neck clearance would affect overall seating issues. Check the shoulder dimenisions on both brass also. They should not be an issue ether. Is runout okay. Compressed load and growing on you?

 

[KevinThomas]

Can't quite see where a length difference with the same bullet would be giving you chambering difficulties between LC brass and ours, so I suspect there's something else you haven't quite tumbled on to just yet. The 77 Scenar has seen some very sucessful use as a full across the course bullet, since it runs an unusually high BC. The N135 is a good choice, but you might also consider N540; a bit better velocity can be had there. The Lapua 77 is a bit longer than most of the other 77s, and they eat up a bit of the powder capacity at the same OAL. Varget and RL-15 are generally the "go to" powders for a 77 grain XC load, but don't seem to be the optimal choice for the Scenars due to the length issue. That's where the N540 comes in, if you want to give it a try.

Let me know if you don't get the chambering issue worked out, and you want the brass checked out. Be glad to help with that, no problem.

Kevin Thomas
Lapua USA

 

[anyrange]

Same Box, Lot, Batch of bullets?

 

[jonbearman]

What is the neck diameter after bullet seating into each kind of brass.When you chamber does it stove the bullets into the case,chamber and check that. I would also call CLE and find out what reamer they used and there neck diameter. I crimp lightly and sometimes it actually has stoved the neck junction and they wont chamber. I know that this is not the approved method for precision shooting but it works good for me.

 

[Taildrag15X]

I think you'll find that Frank uses a JGS 5.56 Compass Lake Reamer, not a Match .223 Rem.

 

[usmcmba]

Hi all,

First of all, I would like to thank everyone who have contributed to this thread. I value each and every one of your feedback. From reading some of these replies, it made me realized that I shouldn't be focusing on producing ammo that can shoot one hole groups like I am used to (I used to shoot a lot of benchrest), but rather I should be concentrating on the techniques to be an exceptional position shooter.

With that said, despite over a decade of reloading all sorts of and including some odd calibers, I am still baffled at why two rounds with same OAL but with different brass, why one can chamber and other cannot. In reading your all's posts and having thought all the possibilities, I have to wonder if the LC brass held the bullet just tight enough that it allowed the bullet to seat further when the round was chambered. I use bushing dies for the case so the grip on the bullet isn't as tight. The Lapua brass on the other hand were virgin brass straight out of the box in which probably griped the bullet tightly and would not allow any bullet movement when it was chambered, resulting in a stuck case. I wish I had the Sinclair AR bullet seating depth gauge (I only have for the bolt action rifle) to test the theory, but I understand that an AR like Compass lake should chamber bullet up to 2.460"? (If I recall, even Frank White says in the instruction sheets he provided with the rifle that you can seat that long for single shot purposes). I have measured the neck diameter on a seated round, the neck diameter is .250 (very consistent). Either way, this is an interesting situation.

I think I maybe getting a little too worked up with trying to figure this out as it has been a long time I shot at ranges over 100 yards and my concern is the accuracy of the load at 600 yards. I have to remember that when I was in Marine Boot Camp in Parris Island, we qualified with some pretty awful M-16's with no shooting coats and standard issue ammo. Despite all these handicaps, I was still able to put round after round in the black at 500 yards (silhouette targets). With the shooting coat, an accurate AR and the Lapua 77 loaded at 2.360" which shoots less than 1/2" at 100 yards, I think maybe I should just spend more time concentrating on techniques. Although, this does still pose an interesting reloading question as to why it wouldn't seat.

Again, thank you all for your time and inputs.

 

[p17enfeild]

have you cheacked your nech tenion? it may be the the lc brass load is in to the land and is soft seating , and the lapua brass with thinker neck will not let the bullet move?

just my thought as i read your post

 

[KevinThomas]

"In reading your all's posts and having thought all the possibilities, I have to wonder if the LC brass held the bullet just tight enough that it allowed the bullet to seat further when the round was chambered."

Have to believe you're not thinking in the wrong direction here. Just one of the many differences between the BR stuff you're used to and the world of Service Rifle reloading. In the case of the AR-15 family of Service Rifles, the problem is keeping the bullets from pulling OUT, rather than seating them deeper upon chambering. We're usually using a full enough charge that the powder itself will keep bullets from setting back more deeply. In the other direction, what you've got in an AR chamber is basically the world's most expensive inertia bullet puller. Drop that bolt sometime, and extract the chambered cartridge. Measure the round first, and then measure again once it's pulled out of the chamber. Almost invariably, it'll now be several thousandths longer. I suspect that those using insufficient neck tension are in effect (and totally unintentionally), soft seating their bullets when the bolt goes home. Still don't see where that would create the chambering situations you've experienced, so that's just info only. When you're dealing with the Seervice Rifles, forget 95% of what you learned in Benchrest reloading; whole different world here, and it needs to be treated differently.

Kevin Thomas
Lapua USA

 

[usmcmba]

Kevin, thank you so much for your input! Love your products by the way. I use Lapua and Vhitavuori almost exclusively. Take care and happy holidays!

David