Author Topic: Bullets bigger than 55 gr. (Read 2463 times)

Oldshooter · « **on:** February 07, 2013, 05:07:01 PM »

My old ranch rifle and I'm pretty sure my AR have 1 in 9 twist rate. I 'm seeing some heavy bullets on the market at times. Today I bought 400 at G mountain that are 62 grs. Will my rifling stabilize the heavier bullets? All input is appreciated.

SharonAnne · « **Reply #1 on:** February 07, 2013, 09:11:04 PM »

it should.

Lloyd Smale · « **Reply #2 on:** February 08, 2013, 12:47:00 AM »

the 60 grain vmax bullet is probably the most accurate all around bullet in all of my ars.

Oldshooter · « **Reply #3 on:** February 08, 2013, 01:30:26 PM »

Somewhere in the three brain cells that I have left I had the notion that I needed more twist to stabilize bullets heavier than 55 gr. I do appreciate the replies though. Not much in the way of bullets out there right now so I am getting info so as to be ready should some come drifting under my nose. I just found a good deal on some 62 gr federals so I was checking.
Thanks again y'all.

cjclemens · « **Reply #4 on:** February 08, 2013, 04:03:47 PM »

My 1:9 AR loves 62 grain bullets. That's all I feed it. Mine actually throws 55 grainers all over the place. Not sure if it was just the load or if they're over-stabilized in the tighter rifling, but it sure didnt like em.

rzwieg · « **Reply #5 on:** February 09, 2013, 12:44:15 AM »

I think you'll find that 62 gr bullets will be more accurate in a 1: 9 twist like your Mini 14 than 55s as the 3 I had were. Most of the ones I've seen, including ARs are.

ironglow · « **Reply #6 on:** February 09, 2013, 09:35:21 AM »

Oldshooter;
My grandson is a gunsmith (formerly with Marines) who is now working with a major mfgr and also making custom ARs on his own.
His most recent one shown here: http://www.gboreloaded.com/forums/index.php/topic,274295.0.html
It has a "Wylde" chamber with 1:8 twist ...and loves the 77 gr Sierra match bullets

Scroll down page on the link I sent and see a 100 yd target...

SharonAnne · « **Reply #7 on:** February 11, 2013, 08:31:19 AM »

that is a beauty

Oldshooter · « **Reply #8 on:** February 11, 2013, 02:59:54 PM »

That is a nice rifle ironglow. and one heck of a tight group.

theratdog · « **Reply #9 on:** February 25, 2013, 10:25:30 PM »

+ 1 on the 62 grn most accurate

ole 5 hole group · « **Reply #10 on:** February 27, 2013, 05:07:13 AM »

I don't know about the 62 grain being the most accurate, as a Bushmaster and DPMS AR with 1:9 twist like 68 grain Hornady's and 69 grain Sierra's best. Best I could do was 5-shot groups measuring 0.25" to 0.50" with the 69 grain in the Bushmaster and 0.75" with the 68 grain in the DPMS. The 55 grain Hornady SP would only do around an inch or a tad more in those two rifles while a 55 grain FMJ held closer to 2.5" groups with the best handloads loads.

With my AR's the Winchester factory 55 grain FMJ shot the worse of any ammo tried and that's saying a lot.

In case anyone is interested in those loads:
Bushmaster:
Berger 65 grain with 25.8 grains of Varget produced 0.25" fairly consistently as did 69 grain Sierra with 24.5 grains of H4895.

DPMS:
Hornady 68 grain match with 25.0 grains of H335 and 22.5 grains of H322 did right at 0.75"

When firing 10-shot groups the best I did was with the Sierra's and that was 0.6" with the norm being an inch, more or less, and this was shot prior to 7AM with no wind conditions. With wind conditions, seems like good 5-shot groups are around 1 to 1.5 inches - I suppose wind flags might cut those down some, as going by "feel" sometimes results in one or two really opening up a nice 3-shot group

.

Oldshooter · « **Reply #11 on:** February 27, 2013, 05:23:40 AM »

Quote from: ole 5 hole group on February 27, 2013, 05:07:13 AM

I don't know about the 62 grain being the most accurate, as a Bushmaster and DPMS AR with 1:9 twist like 68 grain Hornady's and 69 grain Sierra's best. Best I could do was 5-shot groups measuring 0.25" to 0.50" with the 69 grain in the Bushmaster and 0.75" with the 68 grain in the DPMS. The 55 grain Hornady SP would only do around an inch or a tad more in those two rifles while a 55 grain FMJ held closer to 2.5" groups with the best handloads loads.

With my AR's the Winchester factory 55 grain FMJ shot the worse of any ammo tried and that's saying a lot.

INteresting stuff 5 hole, Kinda what I have seen with the 55 gr fmj's myself.

JPShelton · « **Reply #12 on:** February 27, 2013, 05:21:22 PM »

I got the best accuracy out of the Mini-14 I used to have with Federal Gold Medal Match ammo tipped with Sierra's 69 gr. MatchKing HPBT or an equivalent handload with that same bullet.

I don't recall mine shooting 55 gr. FMJ loads very well at all.

454Puma · « **Reply #13 on:** April 02, 2013, 06:52:10 PM »

Oldshooter
If you had an old 1:12" twist you'd be in trouble! But that 1:9 will handle everything up tp 70 and maybe even 75 gr- some shoot the 75 gr some don't . My DPMS HABR 1:9" shoots the 75 grs OK.
Absolutely loves 69 gr SMK's! It's a freaking tack driver!

Buckskin · « **Reply #14 on:** April 03, 2013, 02:20:22 AM »

I tried the 55's for a long time, got decent groups but not great in my Remington AR. When I went to 60gr VMax it all changed... Now it is a .5 MOA all day long. Haven't gone over 64 because I want it to be a semi not a single.

Oldshooter · « **Reply #15 on:** April 03, 2013, 10:21:15 AM »

Quote

When I went to 60gr VMax it all changed... Now it is a .5 MOA all day long.

Thats an improvement for sure. I wouldn't have guessed it would work that way, but no one pays me to guess. I'm going to try some 60's and 70'a when I can find em. $:-\$ Thanks fellas.

SharonAnne · « **Reply #16 on:** April 05, 2013, 01:16:46 AM »

the first AR15 barrel twist was 1:14" for the 55gr FMJ. For combat it was not so accurate but a great killer. The twist was tightened to 1:12" since accuracy was lost in frigid winter condition in Alaska. This lost much of the fabled killing power. Why they did not just have the faster twist for Arctic Command I will never know.

The change to 1:7" was made to accommodate the 70gr IIRC tracer since it is very long for weight. Why worry about tracer accuracy over combat effectiveness is something else that eludes me. The 1:7" twist barrel will handle 90gr bthp bullets.

For us sillyvillians 1:8" twist will handle 77gr bullets just fine. 1:9" is good for 69gr bthp.

jmayton · « **Reply #17 on:** April 21, 2013, 05:44:06 PM »

My 1:7 loves 75gr Sierra BTHP's. Best load I've ever shot through it. I get decent accuracy with 55's, but going heavier is better for the fast twist. Some of it depends on the bullet construction. It might stabilize one, but not another even if they are the same weight.

SharonAnne · « **Reply #18 on:** May 03, 2013, 10:10:22 AM »

jmayton what kind of accuracy are you getting? I forgot to ask, is your barrel free floated?

jmayton · « **Reply #19 on:** May 03, 2013, 12:58:27 PM »

SharoneAnne, I just re-measured the group with those 75gr BTHP's just to be sure. It's .269"! That's from a standard Colt 6920 - 16" M4 profile chrome-lined barrel. It still has the original FSB but is free-floated with a Troy TRX rail. Trigger is original Colt but I stoned it a bit to take out any creep. It's still about 5-6lbs, but crisp. Magpul MOE stock. I shot this group with my standard optic for this rifle, a Millett 1-4x DMS with a 1moa dot. I was pretty excited that a shot a group that was 1/4 the size of my aim point. I figure it'll shoot .5moa all day with a good scope on it with these loads.

I generally get right at 1" with the 55grs.

On a side note, I picked up a new lower and plan on building a varmint rig out of it. . .as I have the money. Sad thing is, I might build it and it still might not shoot as good as the Colt!

SharonAnne · « **Reply #20 on:** May 03, 2013, 02:08:40 PM »

that is fabulous accuracy, especially those 55s which are not noted to be accurate. I suppose those are 100yd groups.

.269" is damn fine to anyone not involved in bench rest target shooting. I would be very pleased with such groups. Well done!

jmayton · « **Reply #21 on:** May 03, 2013, 04:50:24 PM »

Yes, all were at 100yds. I was thrilled. The rifle has always shot well, but the best I could ever do before was .75" with the 55's. That 1:7 twist just works magic on those long bullets. I only put 3 on paper (had 10 loaded up) the rest went out a bit further. Our range has steel targets out to 1050yds. I dinged some deer and elk then put a couple on the bison at 535. My scope becomes a hindrance at those ranges on anything small than a human-sized target, but I can easily hit the big targets. It's fun to do that with a 16" barrel and a 4x scope while others struggle with 22"+ barrels and 9x+ scopes.

ole 5 hole group · « **Reply #22 on:** May 04, 2013, 04:33:56 PM »

Must be talking about me,

as the bushmaster has a 20"match barrel and I use a 30X Leupold (24X bumped to 30X with extra fine Xhair). I can't shoot consistent bug hole groups without high magnification and even then sometimes I'm not consistent if the wind is much over 5mph. Nothing wrong with shooting a consistent 5-shot group with an AR off a rest measuring 1 to 1.5 inches with an occasional 0.5"or maybe a 3.5" just to mess with the average.

I'll give my Huldra a good workout tomorrow with that 30X using 77 grain Berger's and then settle down to shooting grapefruit size groups with the Aimpoint - and that's a man-sized grapefruit to boot.

SharonAnne · « **Reply #23 on:** May 04, 2013, 05:43:35 PM »

hmmm, man size grapefruit. Bet you always win a blue ribbon at the county fair!

ole 5 hole group · « **Reply #24 on:** May 05, 2013, 03:52:07 AM »

SharonAnne - That was such a devious reply that I know I'll have trouble getting that out of my mind this afternoon to concentrate on shooting those "tiny" little groups. I'll blame you for messin with my mind causing bushel basket sized groups.

SharonAnne · « **Reply #25 on:** May 05, 2013, 11:11:30 AM »

I do hope the 'messin with my mind' will involve laughter

ole 5 hole group · « **Reply #26 on:** May 05, 2013, 03:33:35 PM »

Quote from: SharonAnne on May 05, 2013, 11:11:30 AM

I do hope the 'messin with my mind' will involve laughter

No laughter - just a sly grin or maybe a snicker or two.

Didn't make it out today, as it rained just a tad and to my way of thinking I'll wait a day or two for drier conditions, as opposed to dragging a little mud home and listen to the War Department belittle my intelligence and threaten to cut short what little time I have left on this planet, as I haven't been fully trained yet in "modern day" housekeeping or whatever it's called.

SharonAnne · « **Reply #27 on:** May 07, 2013, 08:22:05 AM »

just wipe your feet. she will be happy

ole 5 hole group · « **Reply #28 on:** May 07, 2013, 10:50:22 AM »

No she won't - have to wash the damn things. Went out today and with 77 grain berger's in front of 20.5 grains of VV N135 I shot nothing larger than 0.80" with the smallest being 0.515" at 100 yards rested with a 30X scope - all 5-shot groups. At 200 yards half the time I shot 5 shot groups around 1.25" and the other half I would put 4 in 0.7/0.8" and one out so I group usually went 1.5 to 2.25" and the flier was just gun mishandling.

With the Aimpoint micro dot I shot 20 rounds into a 5.5" target at 200 yards and everything was within 3.4", which was a good day, as I normally throw a few with the dot. That smirk on my mug must have settled me down, so I have you to thank for some good looking targets.

Upon entering the castle, I took my shoes off and all is well - until tomorrow at least.

theratdog · « **Reply #29 on:** June 05, 2013, 07:56:38 PM »

MY ROCK RIVER AR WILL SHOOT THRU THE SAME HOLE AT 100 YARDS WITH 62 GRAIN BULLETS AND 55 GRAIN BULLET'S RIFLE HAS A 20 INCH BULL BARREL AND SINGLE STAGE TRIGGER 3X12 SCOPE 1X9 TWIST THE MOST ACCURATE GUN I HAVE OWNED AND SHOT. MY DELTON WON'T SHOOT THAT GOOD 3/8'' GROUPS TIMNEY TRIGGER. 18INCH TAC BARREL.