Old shooter needs help with new rifle

[Admin]

Ok, please explain this one.

Minute of Angle group.

Minute of Mattress group

If you're still shooting Minute of Mattress on qual day you're of to the MTP platoon (Marksmanship Training Platoon).
Commonly referred to Maximum Thrash Platoon. Not a fun place to be.

 

[Mike-Mike]

That's a good one.

 

[bpm990d]

I am using 55 grainers in a 1:7 twist barrel. So that might account for some of the inconsistent groups. I'll try adjust my body some for the NAP.

Negative. 55gr. bullets shoot just fine out of 7 twist barrels.

I'm not exactly sure why this issue keeps coming up? This picture needs to be a sticky. I can tell you from personal experience that M-16A2s and 55Gr. bullets shoot just fine out to 300+ meters. Oh yeah, it wasn't just one or two rifles. We tested over a hundred with M855 & M193 to pick ten that were GTG. The 55gr ammo shot better at 300M than the 62gr. M855.

 

[Cabinetman]

Socratactical, you'll find that some guys feel it's ok to shoot 55 grain through 1:7 barrels. However, that barrel is designed to support a much heavier bullet upwards of 70+ grains. In some rifles, a 1:7 twist will allow the jacket to tear off a 55 grain bullet in flight causing stabilization issues. Can't say for sure that's something you're experiencing but moving to a heavier bulleted ammo would eliminate one of the variables. When the jacket comes off, you tend to see tiny holes in the target along with the bullet hole or sometimes even a keyhole. But, as I said, some guys shoot it successfully.

Rome

 

[Cabinetman]

Sorry! I posted after your post went up and before I read it. I'd bow to someone with more experience with this issue. Thanks for sharing that.

Rome

 

[Socratactical]

Socratactical, you'll find that some guys feel it's ok to shoot 55 grain through 1:7 barrels. However, that barrel is designed to support a much heavier bullet upwards of 70+ grains. In some rifles, a 1:7 twist will allow the jacket to tear off a 55 grain bullet in flight causing stabilization issues. Can't say for sure that's something you're experiencing but moving to a heavier bulleted ammo would eliminate one of the variables. When the jacket comes off, you tend to see tiny holes in the target along with the bullet hole or sometimes even a keyhole. But, as I said, some guys shoot it successfully.

Rome

Thanks again, Rome. It does not appear that I'm getting any jacket separation or destabilization. The impacts are nice, clean little .22 caliber holes. I the truth of the matter is, I'm new to rifles thus, I'm a bad shot and need some training.

 

[bpm990d]

Socratactical, you'll find that some guys feel it's ok to shoot 55 grain through 1:7 barrels. However, that barrel is designed to support a much heavier bullet upwards of 70+ grains. In some rifles, a 1:7 twist will allow the jacket to tear off a 55 grain bullet in flight causing stabilization issues. Can't say for sure that's something you're experiencing but moving to a heavier bulleted ammo would eliminate one of the variables. When the jacket comes off, you tend to see tiny holes in the target along with the bullet hole or sometimes even a keyhole. But, as I said, some guys shoot it successfully.

Rome

What you posted is true. The 7 twist is best suited for heavier bullets and yes you can have jackets that come apart but I'm positive that the problem doesn't exist with 55gr. ball which by spec has a very thick jacket. With something like a 40gr varmint grenade or others, there might be a problem, but I think that is more dependent on the interior condition of an individual barrel (rough spots) and the velocity that someone pushes them at than on the twist rate.

It's also true that small samples of barrels might preform better with one or the other types of ammo but the Army considers the two interchangeable in the M-16A2. In the late 80s we qualified at Ft. Benning with M-193 and A2s.

B

 

[ED_P]

Socratactical,

One other potential issue. As much as I like Bushmaster rifles, 3 of the 4 new out of the box uppers I've had in my life shot very far to the left or right, (Bushmaster is known for this issue), and I ended up sending the rifle back to Bushmaster to be re-indexed. When it came back, I only needed 6-8 clicks of the rear sight to the left or right to be spot on. Out of the box, I needed over 20 clicks. If you are all the way to the right or left on your rear sight, the rifle probably needs to be re-indexed.

Also, once you get the windage issue solved, consider alternative methods of zeroing the height. The way Bushmaster recommends zeroing will result in the bullets being 10" over the target at 100 yards. An alternative sighting method called the "Improved Battlesight Zero", is easily found on the internet, and keeps the rounds within 2-3" of your zeroing distance, out to 230 yards.

 

[Taipan01]

A question for you, if you were showing somebody how to use a pistol, would you have them worry about the actual point of impact or the grouping? It's the grouping that's important, yes?. The sights can always be adjusted to change the point of impact. If that same person had a wide grouping or as you say, a mess, what would you suggest to them. Perhaps, as in the "old corps" expression, they are "chasing the bull"? You may want to use what you know with pistols, by way of grouping, to your rifle. Massbites expressed that first I believe in not so many words along with indexing. You may want to start off on a bench rest, which is just a simple support that goes under the stocks/fore ends, not the barrel. You can buy one or make one. A number of people use sandbags. Draw on your pistol experience for aim, breathing control, trigger hold. A suggestion for you: do not rest your beak on the charging handle. At some point, the charging handle may catch the bolt on the rebound and cause you a mischief. I let mine touch the knuckle of the thumb thats grasping the butt stock, not just on AR's but all rifles. I suggest using a bench rest as a way of determining if it's you or what was mentioned a couple of times before about the indexing. I have a feeling that it may be your newness to rifles. The only addition to what your used to on pistols is what's referred to as cheek weld. That just means a consistent way of how you hold the rifle up against your cheek. If you determine that the rifle is fine by this method, or your groups start to shrink to a nice small pattern, you can adjust the sights to your eye. Again, as in pistols, worry the groups at first, not the poi. Depending on which XM you have, A2 or A3 (one goes to 800, the other 600), there is a difference on the settings. No biggy really, you can look it up on the web for the alts on how to zero. If you can't get it, just say so and I or others will explain it. The thing that no one has mentioned to you is that in the off hand, kneeling and sitting positions, you may want to employ what is called a hasty sling. The idea is that it holds the rifle tight to your shoulder, using your upper arms and shoulders, not the lower parts of your arms. I know when I have a good one is when I can hold the rifle by no more then the pistol grip and it's rock steady. Fortunatly for me, my carry length is the right length for a hasty so I can go straight to the ready by rolling it off of sling arms to a fireing position. You can look up hasty slings on the web also. I couldn't explain it by typing, but I could show you FTF but that's not possible. On the prone, you will be resting on your elbows and that should be good enough for support. Your body should be around 30° offset to your aim. For range work, get either 10 or pre-ban (if that matters in your state) 20's. 30 rounders aren't all that hot for the range. They are more in the way than they are worth.

 

[Jose]

For more modern uppers, the heavier grain round is required and those barrels usually have a 1/9 twist. I may not make a huge difference but one nonetheless.

Rome

Heavier bullets are not requried with faster twists. I've shot plenty of high 190s offhand with WWB 45 grain 223 out of a Wylde chambered AR with a 1/8 barrel. And could easily clean the same target in sitting RF with high X counts using the same ammo.

Unless the lighter-jacketed varmint bullets blow up in flight from being spun too fast, if your barrel likes them they will fly damn tight.

 

[Cabinetman]

Well, I never pretended to be a ballistics "expert" and have learned a few things here. I've see the bullets 'vaporize' in the past because of weight/twist/load issues. And, from what I had read up until now, I was always under the assumption that light 55 grain rounds didn't work well in the tighter twist barrels. Shows what I know!

Thanks for setting me straight here. I'm going to do some experimenting on my own by trying different rounds in my AR just to see the results.

Rome

 

[Taipan01]

Threads vering off into twist rates, maybe this will help. For the heavies:1x7. It is technically too tight of a twist for most of the .224 bullets that are widely available. It was manufactured originally to stabilize SS109 and/or tracer ammo (mainly for the tracers elongated bullet) but upon further military testing, other twists were shown to be superior. Long range shooters using the heavier 75-90's will fair better using this or the 1X8 twist. The 1x8:This twist is great for 69-80 grain bullets. The more common 1x9: This is a good all around twist ratio. It is best suited for 52-69 grain. Though I've used it with Varmint loads about 40 grain going close to 4,000 fps with really good results. For the most part I run with this twist using 55 & 62 grain. The 1x10: Almost the same as 1x9, but favors the lighter side a little more. The 1x12: This tends toward the 40-52 grain bullets. This twist is commonly found on bolt actions that are primarily used as varminteers. They are okay up to 55, but not really the best. 1x14: Use this one if you are into tumbling effects and keyholeing.

 

[Socratactical]

Thanks for your replies everyone. There was some nice advice here. But it looks like we've spun away from my original question, which was the search for an instructor in my area. My problem is almost certainly user error. Part of the problem is I had my rear sight too far to the right. The other part of the problem is that I'm still new to this rifle. The rifle is trying to group, I just can't get out of its way. Yesterday, I adjusted the sights a little more to the left, about 3 clicks left of center line. At fifty yards from a prone position I ran 19 rounds through the rifle. Most of the rounds landed in the 9 ring at about the 3:30 position. Three rounds hit the 10 ring. Two landed in the X ring. All impacts were nice clean holes, except those impacts where two holes were touching. I'm just new to rifles. I'll probably attend a workshop later this summer. In the interim, it would be helpful to have an instructor take me through some basics. That's the way I'd prefer to learn. If anyone knows someone in White River Junction or Woodstock or even Montpelier, I'd appreciate being referred. Thanks again for all your advice. It helped.

 

[Nickle]

Socratactical, I just saw this.

I'm actually in Bristol, not Vergennes, though the shop is in Panton (Vergennes PO).

Ripersnifle is on this forum, IIRC, and he lives in Bethel, almost a stone's throw from you. He's a fellow Appleseed Instructor, an excellent shot and really knows AR's.

As to coming to an Appleseed, we've got them in VT every month from now to October.

July and September, we'll be in Proctor (Rutland area), August we'll be in Jericho (on the same range Burlington Rifle/Pistol Club uses (I know some of those guys), and October, we'll be back in Middlebury.

Watch the Appleseed area in the Training part of the forum, they'll be advertised.

You'll want a .22 with you for an Appleseed, to save ammo money when working on the basics. The good news is that we have some loaners available, or you can bring your own. Just let us know.