AR .223 what's too much lands gap?

[TryLikeHell]

I was curious about too much jump to lands. At magazine max or max recommended 2.230 with 52gr HPBTs my lands are at 2.292. Thats 62 thousandths. That seems huge. The rifle has about 500 rnds run through it.
Your thoughts?
Is there a barrel that would close that up a bit that people prefer?
My 2nd post here so hopefully no facepalming as a result.

 

[alamo5000]

Some bullets prefer more jump. Some prefer a lot less jump. In the latter instance I've gotten stuff to shoot but it was beyond magazine length so problems can go either way.

As it is right now, how does it shoot?

 

[Im2bent]

Jump is very subjective in that all rifles are different. As Alamo asked how does it shoot? And even that isn't an answer because it may not like the ammo you are feeding it vs. a problem with jump.

 

[alamo5000]

Jump is very subjective in that all rifles are different. As Alamo asked how does it shoot? And even that isn't an answer because it may not like the ammo you are feeding it vs. a problem with jump.

I concur. Before trying to chase down some tiny spec on the barrel or whatever it's a substantially better use of time to try different bullets and powders until something is adequate for the intended purpose.

On all of my rifles I have no idea how far the lands are.

Given, something could be really out of spec (or not).

"Seems like it's a lot of jump" is not a problem. "It's shooting 3 moa groups" however could be.

 

[diggler1833]

Some bullet/barrel combos will run great at twice that .062 jump.

I agree with the above. Shoot it and let your barrel dictate what it likes. You can also play with seating depth a little here without getting into trouble.

 

[Gustav7]

Some bullet/barrel combos will run great at twice that .062 jump.

I agree with the above. Shoot it and let your barrel dictate what it likes. You can also play with seating depth a little here without getting into trouble.

This ^^

My 6.5 could care less what I seat it at. That being said, it’s 1/2-3/4 moa rifle with me behind it. I settled on 90 thou off based on vertical testing at 300yds and ease of feeding.

My 223AI is 30-40thou off I think.

I wouldn’t worry that much, and unless you’re ONLY shooting 52’s I wouldn’t attempt to get a barrel with that short of a lead.

 

[918v]

I was curious about too much jump to lands. At magazine max or max recommended 2.230 with 52gr HPBTs my lands are at 2.292. Thats 62 thousandths. That seems huge. The rifle has about 500 rnds run through it.
Your thoughts?
Is there a barrel that would close that up a bit that people prefer?
My 2nd post here so hopefully no facepalming as a result.

And what about other bullets? Make a barrel to accommodate one and it won’t work for another.

Bullets can shoot well at different seating depths. You should do a work up at mag length and play with the coal within the constraints of your magazine. Map out your node by powder charge vs coal and use the middle setting.

 

[Molon]

I was curious about too much jump to lands. At magazine max or max recommended 2.230 with 52gr HPBTs my lands are at 2.292. Thats 62 thousandths. That seems huge.

That's nothing for a semi-automatic AR-15. I load the Hornady 75 grain BTHP Match bullet to a nominal COAL of 2.245”. When fired from a Colt SOCOM barrel with a 5.56mm NATO chamber, this COAL will create a jump to the lands of 178 thousandths of an inch. When fired from a Larue Stealth barrel with a 223 Wylde chamber, this COAL will create a jump to the lands of 115 thousandths of an inch and when fired from a Krieger barrel with a 223 Remington chamber, this COAL will create a jump to the lands of 78 thousandths of an inch.

Keep in mind that with a stainless steel AR-15 barrel chambered in 223 Remington the lands can erode 0.0046" for every 100 rounds fired (depending upon variables). Are you going to keep adjusting your seating depth every hundred rounds?

...

 

[Doom]

Rem 700 223 with 53 grain SMK is get sub .4 MOA groups with 2.2 and 2.25 COAL and similar POI. Don't have a clue as to what the jump is.

 

[secondofangle2]

my 50 BMG jumps 1/4" (250 thou) and shoots one hole like my picture. Ignore the "rules" most of them are unfounded. If "jump" were that important, factory ammo would rarely shoot good.

 

[TryLikeHell]

Thanks for all the information. I'll do as many say, try different rounds. My AR just isn't consistent for anything. My bolt actions are tons better. Im just trying to narrow down why this AR is so hard get accurate with. I've been using these recently and they're loaded at just about max length for my cartridges. Im about to load some 52gr so I was curious.

 

[secondofangle2]

for 30 years I have used 55 grain sierra BK or the 52 or 53 grain match options in a COLT AR15 with 1/7 or 1/9 twist and it's always 1/2" about. 24.5 grains of Accurate 2015. Used to be called 2015BR. about 3200 fps depending on barrel length. Loaded to mag length. Works across multiple guns.

 

[OkieMike]

I've got some pretty good groups jumping bullets quite far off the lands... And inversely, I've had some pretty crummy groups with what would supposedly be the ideal distance off the lands.

Sometimes you get lucky and choose a good OAL right off the bat... Sometimes you have to put in quite a bit of work to find the sweet spot.

Best advice is do the work until you find something that you like... Or can live with.

Mike

 

[SporterII]

If you are having trouble with your new gas gun shooting tight and your bolt guns shoot tight, there is a difference to consider right there.

 

[TryLikeHell]

I've got some pretty good groups jumping bullets quite far off the lands... And inversely, I've had some pretty crummy groups with what would supposedly be the ideal distance off the lands.

Sometimes you get lucky and choose a good OAL right off the bat... Sometimes you have to put in quite a bit of work to find the sweet spot.

Best advice is do the work until you find something that you like... Or can live with.

Mike

Got my magnetospeed today and ordered 2 more sizing bushings. The one I have isn't giving a good interference fit. I annealed and sized and I can push the bullet after loading a round, felt almost nothing pressing it . Was like, oops. I'm going to try sets of 5 rounds at different lengths and after that, different grain capacity compared with fps. Thanks for all your feedback.

 

[secondofangle2]

the "annealing state" of your brass can change a bushing by a size or two, so I have an array for each cartridge

 

[TryLikeHell]

the "annealing state" of your brass can change a bushing by a size or two, so I have an array for each cartridge

I hear ya, I've come to consider loading as a fine art with limitless amounts you can learn.