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300 Yards

BIG ALBIG AL Member Posts: 194 ✭✭✭
Using a 1&8 twist 20 inch stainless barrel,77 Gr. match king bullet
how far do I have to push the bullet out of the brass to be accurate.
This is using a custom built AR 15.

Comments

  • wanted manwanted man Member Posts: 3,276
    edited November -1
    You'll have to experiment with seating depth (pushing the bullet out from the brass, as you call it) to find where your barrel likes it.
  • BIG ALBIG AL Member Posts: 194 ✭✭✭
    edited November -1
    If I wanted a smart * answer I will some place else!

    YOU ARE OUT OF LINE, SIR. You asked for and received a reasonable answer to your question. ONLY experimentation with seating depth can determine what will work with your gun. I might add to the answer you received that seating a bullet out too far will cause magazine feeding issues and possibly pressure spikes.
  • dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    And don't forget it HAS TO FIT in the magazine [;)]
    Unless you single shot it [}:)]
  • CheechakoCheechako Member Posts: 563 ✭✭✭✭
    edited November -1
    A 1:8 should stabilize any of the MK bullets. Sierra lists their AR15 accuracy load with the 77 gr at 2600fps. Max load at 2750fps.
  • Ray BRay B Member Posts: 11,822
    edited November -1
    I have found that the 77 grain SMK has only one position for OAL in a .223 and that is right at the maximum OAL. Longer and it won't go through the magazine, shorter and it reduces powder capacity. Hopefully the maker of your custom built AR knew this when it was being throated.
  • MobuckMobuck Member Posts: 13,688 ✭✭✭✭
    edited November -1
    If I wanted a smart * answer I will some place else!"
    Since none of us knows the exact length of YOUR chamber and barrel throat, no one will have the correct answer. Oh BTW, I'm fairly sure you push the bullet INTO the brass rather than other way around.
  • CheechakoCheechako Member Posts: 563 ✭✭✭✭
    edited November -1
    I guess I read his question to ask, "how fast do I have to push the bullet out of the case."

    So, we are left hanging until Al come back.[?]
  • geeguygeeguy Member Posts: 1,047
    edited November -1
    In "Big Al's" defense, I assume he read WantedMan's second line and didn't realize that was a "signature quote" on all his responses. If that was the case, you should edit your post BigAl, if not, be a little nicer on future posts.
  • wanted manwanted man Member Posts: 3,276
    edited November -1
    Mr Big Al; I recommend you do some reading before you venture into the world of reloading. Start with "The ABCs of Reloading". There are NUMEROUS resources available to the beginning reloader, and your original question would have been COMPLETELY unnecessary had you read any one of them.
    As an aside, you may well have mistaken my "signature" line as a part of my answer, but it may ALSO be applicable ;)
  • wiz1997wiz1997 Member Posts: 1,051 ✭✭
    edited November -1
    Big AL. Anything below the bold line in a reply is not part of the reply to your question.

    Many of the forum members put their favorite quotes or "signatures" on their responses.

    It takes a bit to figure it out and I'm sure no one was trying to belittle you.

    Hang in there.
  • BIG ALBIG AL Member Posts: 194 ✭✭✭
    edited November -1
    Sorry for the reply.
    Using 77 gr.SMK
    22gr. of H322
    Single round mag.
    Chamber oal is 2in..250.cheyenne9
  • MG1890MG1890 Member Posts: 4,649
    edited November -1
    If single loading, seat bullet .010" from the throat. You must determine the OAL that accomplishes this.

    BTW, H322 seems a touch fast for that bullet weight... I think H335 might perform a little better.

    Pay attention to your reloading dies. If they have an expander ball, get some that don't.
  • 5mmgunguy5mmgunguy Member Posts: 3,853
    edited November -1
    BIG AL This is how I figure out my cartridge OAL. I use a Stoney Point tool. It uses a modified case that I place in the chamber. Once chambered I push the planned bullet slowly forward until the bullet touches the lands. I lock the rod and then pull everything out of the chamber. I use the micrometer to measure the OAL. I subtract .010 inch and use that number as my max cartridge OAL with the bullet I selected. If you change bullets you will have to repeat the process. Now start to play with powder types and bullet seating depths. Usually .010 to .030 off the lands works the best. PS I wouldn't use H322 I would use something slower unless it provides the best accuracy. Have fun!
  • babunbabun Member Posts: 11,054 ✭✭✭
    edited November -1
    quote:Originally posted by geeguy
    In "Big Al's" defense, I assume he read WantedMan's second line and didn't realize that was a "signature quote" on all his responses. If that was the case, you should edit your post BigAl, if not, be a little nicer on future posts.


    This is at least the 3rd time a newbie/poster has mistaken his sig line as a insult. Maybe the problem lies with the sig line and not the
    person reading it.[;)]
  • FEENIXFEENIX Member Posts: 10,559 ✭✭✭
    edited November -1
    quote:Originally posted by 5mmgunguy
    BIG AL This is how I figure out my cartridge OAL. I use a Stoney Point tool. It uses a modified case that I place in the chamber. Once chambered I push the planned bullet slowly forward until the bullet touches the lands. I lock the rod and then pull everything out of the chamber. I use the micrometer to measure the OAL. I subtract .010 inch and use that number as my max cartridge OAL with the bullet I selected. If you change bullets you will have to repeat the process. Now start to play with powder types and bullet seating depths. Usually .010 to .030 off the lands works the best.

    I use the same set-up and process to determine the best COAL and CBTO.

    - http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-1/

    - http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-2/

    FYSA, Stoney Point is now the Hornady lock and load products >>> http://www.hornady.com/store/LNL-Gauges-Formerly-Stoney-Point
  • Okie743Okie743 Member Posts: 2,567 ✭✭✭✭
    edited November -1
    quote:Originally posted by wanted man
    You'll have to experiment with seating depth (pushing the bullet out from the brass, as you call it) to find where your barrel likes it.

    IMHO: You will have to push the bullet out of the brass 300 yards to check the accuracy!!!!!!!!!
  • wanted manwanted man Member Posts: 3,276
    edited November -1
    quote:Originally posted by babun
    quote:Originally posted by geeguy
    In "Big Al's" defense, I assume he read WantedMan's second line and didn't realize that was a "signature quote" on all his responses. If that was the case, you should edit your post BigAl, if not, be a little nicer on future posts.


    This is at least the 3rd time a newbie/poster has mistaken his sig line as a insult. Maybe the problem lies with the sig line and not the
    person reading it.[;)]

    I had a long, facetious reply to your comment prepared Babun, but thought better of it...guess I'm not much of a keyboard commando. In my 15 yrs (+/-) on these forums my signature line has been mistaken as part of a comment exactly TWICE, by MY count.....Shy of an admin removing it, the sig line ain't goin' nowhere, so I guess you'd best get used to it if you haven't by now; I find that those words apply to any number of situations on a given day ;)
  • Hawk CarseHawk Carse Member Posts: 4,363 ✭✭✭
    edited November -1
    The 77 gr SMK is a "magazine length bullet".
    Load it as long as will fit the magazine and give it a try.

    I would not pick H322 for such a heavy bullet, but if that is all you can get in The Panic, SHOOT THE GUN.
  • The Old SaltThe Old Salt Member Posts: 94 ✭✭
    edited November -1
    Controlling the distance between the bullet O-give and rifling is not as easy as just using a Stony Point tool or home made version of same to determine the desired C.O.L. Factory bullets, even SMKs will have a variance in their O-give. My current box of 175 SMKs has a +/- 0.002" in the length of the O-give, measured from a 0.297" dia to bullet nose. I have SMK factory seconds that have a +/- 0.020" variation. Unless you figure out how to allow for the variances in the bullet profile from one bullet to the next, the gap between the O-give and rifling will vary. I have a method for controlling this so if there is interest i'll post it.
  • MG1890MG1890 Member Posts: 4,649
    edited November -1
    Old Salt is certainly correct. BUT, Sierra MK's out of the box will shoot sub 1/4MOA, even with ogive discrepancy ignored. It just won't matter in your AR.
  • The Old SaltThe Old Salt Member Posts: 94 ✭✭
    edited November -1
    I have a 308 Rem 700 with a Muller Works custom barrel. For this rifle I load to a C.O.L. long enough that each bullet gets pushed back into the case 0.005" to 0.010". That way I have a uniform relationship between the bullet & rifling. The effects of O-give variations are eliminated. For cartridges that are loaded with bullets short of the rifling, I measure each bullet, length & O-give to base. Subtracting the 2 measurements gives you O-give to nose. If done in a spread sheet along with a numbered bullet board you can sort the spread sheet by nose profile and know where in your bullet baord all the bullets of the same nose profile are. Now you can set your reloading dies for C.O.L. and get cocsistant bullet to rifling gap results. Even if you don't have the very expensive compitition dies.
  • MG1890MG1890 Member Posts: 4,649
    edited November -1
    Salt, you are assuming that OAL differences are entirely due to nose to ogive discrepancy. There can be errors in heel location, too.

    Loading to the jam point does eliminate ogive error, but it is above the skills of the average handloader.
  • The Old SaltThe Old Salt Member Posts: 94 ✭✭
    edited November -1
    MG1890 you are correct on bullet discrepancies not all being nose jobs, but the nose it what cuts the air. Consentricity, body dia, and BTs all have micro issues as well. But before one gets into all the micro stuff, getting a good grip on consistant powder measurement (like trickle technique), case prep, and shooting skills will have a bigger impact on group size.
  • MG1890MG1890 Member Posts: 4,649
    edited November -1
  • 5mmgunguy5mmgunguy Member Posts: 3,853
    edited November -1
    quote:Originally posted by MG1890
    Old Salt is certainly correct. BUT, Sierra MK's out of the box will shoot sub 1/4MOA, even with ogive discrepancy ignored. It just won't matter in your AR.
    MG1890 said it all. After setting up your OAL with a stoney point or similar tool, the rest of this interesting discussion is just that, interesting but not really worth the time and energy spent pursuing them.
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