.223 Heavy Bullets.

[kochie]

How far until the 69s start falling out?

To me the 223 is a mid range rifle . If I want to get out there with any energy at 600 I will go with my 22 Creedmoor or my 6 x 47 lapua.

 

[topclass2017]

I shoot 77 SMK's over H4895, Varget, or CFE 223 in my 1:8 twist 5.56 AR

 

[kochie]

I shoot 77 SMK's over H4895, Varget, or CFE 223 in my 1:8 twist 5.56 AR

Yes I think 8 twist is a good twist for 223 . Can shoot 53 to 77s

 

[JSH]

How far until the 69s start falling out?

It was kind of an accident. Buddy was on my Badrock with the wrong mag of ammo, had 69’s and 75’s laying out. His comment was it shot darn good, after he put some elevation in it, lol. Target was short of 700 yards. Load was Sierra’s 5.56 data

 

[DHD]

ASC and PRI make magazines with internal dimensions longer than 2.260.
The PRI ones I've got measure just at 2.3. The ASC ones seem to have some number that have what looks like a faulty weld that causes an edge to protrude a bit reducing the max COAL to something under 2.29.

There is another supplier that cuts out the front of the mag so the max COAL is determined by the inside of the mag well.

Cavity Back (they make monolithic bullets) is the company that does the modification to PRI magazines. More often than not they are out of stock.

It is not hard to modify PRI magazines yourself. I've done 4 or 5 myself and have them in 223 and 6.8 (grendel and ARC using ASC followers). The limit then is your magazine well and bullet choice. I don't find the 77 grain SMK style bullets to need the extra room for great accuracy but for VLD's and long throats it's nice to have. I consider these modified magazines best for 10 rounds maximum and typically use them for 5 round groups.

My shooting partner is a welder and fabricator and he modifies ASC and Dura Mags the same way. They work just as well and $15 compared to $40 is a heck of a difference.

The Hornady 75 grain HPBT bullets have been memtioned a few times here. I also find they can shoot very accurately. Maybe not quite as well as a SMK but still smile worthy if your rifle will shoot them. I've been lucky as my AR's do shoot them well.

I'm a 7 twist guy with the exception of 1 Craddock gain twist Bartlein. If you already have an 8 twist or a 7 twist isn't available in the configuration you want is about the only reason to go with an 8, IMHO.

 

[cmillard]

I agree with the 77 TMK! I have shot that out to 1431 yards and was pleasantly surprised. Shot out of a 1-7" twist 18" Mk12 rifle with MR2000 powder. I would recommend a 7" twist as some more spin on the bullet won't hurt.

 

[riverside jeep]

I run a 8 twist on my AR, 43 grn TNT over H335 for squirrels etc. and 77 SMK over Varget for longer range and both get very small groups out of my economy 18" Green Mountain barrel.

 

[4xforfun]

I am New to 223 and also to gas guns. Last spring I was prepping for a match that had 6 different rifle classes...one being an AR 15 class. I barrowed a friends Rock River (8 twist) and my shooting buddy also has a RR...also 8 twist. I picked up some Berger 85.5's, dies, powder ,etc and went to work. First thing i noticed was how deep the bullet needed to be seated to fit the mag. Like I said, new-bee. I started below book with H4895. 2nd thing I noticed was how GREAT it shot. I was about a grain above the starting book load and it shot tiny at 100. Did the same test with my buddys RR and same thing...tiny at a grain over start.. No chrono data and health issues took over my life at that point, but I now have my own RR and am going to start testing again this spring.

 

[Lefty2506]

Most of my ARs have 1:8 barrels with 223 Wylde chambers, including my first which had a heavy 22" stainless Wilson barrel that was purchased from Rock River back around 2002 or 3. It hasn't seen a ton of use, but it still shoots well. I had several loads that would put 5 rounds in a ragged hole. Back then I shot a lot of 40gr and 50gr Nosler Vmax over Varget, N135, and N530. For NRA Highpower, I worked up various 75gr loads using Hdy 75gr BTHP, 75gr A-Max, and Berger 75gr VLD projectiles with RL15, N140, and N540 powders. Out of my Rock River DCM service rifle upper (20" stainless with Wylde chamber), the max charge of N540 from VV's load data gave me a MV of 2950 with 3/4 moa groups or better using irons. I also developed loads for some 69gr Nosler J4s that were really accurate, but I don't remember what powder I used, and the J4 bullets have been out of production for a long time now. I use TAC and BLC2 for my midweight plinking ammo, but both of those should also have good potential for 75gr bullets.

 

[karrarararararar]

I am New to 223 and also to gas guns. Last spring I was prepping for a match that had 6 different rifle classes...one being an AR 15 class. I barrowed a friends Rock River (8 twist) and my shooting buddy also has a RR...also 8 twist. I picked up some Berger 85.5's, dies, powder ,etc and went to work. First thing i noticed was how deep the bullet needed to be seated to fit the mag. Like I said, new-bee. I started below book with H4895. 2nd thing I noticed was how GREAT it shot. I was about a grain above the starting book load and it shot tiny at 100. Did the same test with my buddys RR and same thing...tiny at a grain over start.. No chrono data and health issues took over my life at that point, but I now have my own RR and am going to start testing again this spring.

Those 85.5's are not designed for mag length loads. Stick with 77's for mag length.

 

[markm87]

We've been running the 85gr Nosler RDFs in AR mags for a few weeks now. Those will fly far.

I like the 85gr Match Burner too, but it's not as good at 1000 yards as the RDFs. The Match Burners are great to 600-700 yards.

 

[RegionRat]

Does the Nosler 85 just go down deeper into the case?

I am wondering how they got 10% more bullet weight into this one while there is hardly any margin on a 77 grain?

 

[karrarararararar]

Does the Nosler 85 just go down deeper into the case?

I am wondering how they got 10% more bullet weight into this one while there is hardly any margin on a 77 grain?

Has to be eating up some case capacity, if the ogive isn't below the case mouth. The 85gr RDF is 1.135" long per JBM. The 77gr Custom Comp is .973" and 80gr SMK is 1.066"

 

[RegionRat]

I'll have to get my hands on some and see how they compare.

With the mag length max of 2.260" minus case length of 1.760", we have a maximum nose length of 0.5" for keeping the curvature out of the neck.

With the Rt/R of the Sierra being 0.96, it makes me want to wonder what the shape of the nose on these Nosler 85 RDF will run?

Thanks for mentioning these folks, I have not considered them a magazine length bullet before tonight.

 

[bpm990d]

I thought the OP had an AR. Why are people talking about MDT mags for boltguns?

 

[Dolomite]

I thought the OP had an AR. Why are people talking about MDT mags for boltguns?

ADD lol

 

[Herzo]

I have a 24" AR with a 1:8 twist that will produce 1/4 MOA with the Barnes 85 gr Match Burner and VV-N530 at magazine length.

 

[markm87]

Does the Nosler 85 just go down deeper into the case?

I am wondering how they got 10% more bullet weight into this one while there is hardly any margin on a 77 grain?

Yeah. These are pretty long bullets and probably better off loaded long. Here's some from a bag full of mag length I loaded. The Ogive does just start to go into the neck a little. I leave my trim length on brass a little long too. When I first saw the test load, I thought these bullest would be 3-4 MOA the the amount of jump to the lands, but they shoot mag length and stay sub MOA.

I'm not sure what you mean by "margin" on a 77 grain. I also loaded some of these longer than mag length with Varget, and they shot really well too.

 

[RegionRat]

I'm not sure what you mean by "margin" on a 77 grain.

Thanks for the photos of your mag length loads.

What I meant by margin, was how close the line on the bullet that transitions from bearing diameter to ogive will stick out of the case neck when loaded to mag length. When it goes negative on margin, that means there is a gap under the edge of the neck that can collapse or snag and bend.

I suppose you could taper crimp the necks to avoid the gap and in order to prevent them from a snag. The other issue becomes case capacity since there is so much bullet down inside the case.

I guess at some point we are trading between BC versus powder at mag length and a person will just have to run a side by side test to see if these run better than a typical 77 grain.

Thanks again for the snapshot.

 

[nmkid]

I thought the OP had an AR. Why are people talking about MDT mags for boltguns?

Yeah, I gave up on my post a few days ago.