Question about surplus bullets and accuracy

[juk]

I finally got a new AR build to the range today for a shakedown run. 3lb trigger, Bushnell Elite 3200 fixed 10x, Burris PEPR, 18" AR Stoner barrel, 1/8 twist, 223 wylde. I did not fire a single factory load.

My "get on paper" load was a bulk surplus 55grain FMJBT on top of 25 grains of IMR4064. These functioned great, but only got me around 2 MOA at best. Most would group in a cluster, then one would fly out low.

Once I was sure that I was on paper, I went to ladder type loads using varying charges of Varget and cheap bulk 62 grain FMJBT bullets. 3 of the charge weights gave me the same results as the 55s, but the two upper charge weights grouped a bit tighter. My best group with these was a 10 shot group at 100 yards that was .25" tall but spread out laterally about 1.75". I am inclined to blame the bullets for most of the dispersion with some being the nut behind the gun.

I am just wondering how much these cheap bullets can affect the accuracy of a firearm. The charge weights were all individually weighed and loaded in identically prepared, same headstamp brass. I admit that I was not expecting stellar groups, but was hoping for around 1MOA. I do plan on finding some higher quality bullets to try.

 

[browningguy]

Bullet quality would be my guess, try some Bergers or Sierra MK's and see how it does. I would guess the bulk FMJ's will have both dimensional and weight tolerances that keep them out of the high accuracy category.

 

[gondorian]

Did you weigh all the bullets? Sometimes there is a significant variation in weight between bulk bullets that has a noticeable effect on accuracy.

 

[rcmodel]

FMJ-BT GI bullets are bad.
Pulled ones are worse.

If you want to test accuracy?
You have to use commercial bullets with the jacket hole in the nose, not the base.
Try Hornady V-Max, Nosler Ballistic Tip, or anybody's HP varmint or match bullets.
Even cheap lead Soft-Point hunting bullets will shoot better then GI FMJ-BT!

It makes a 2" difference in a lot of cases.

Here is the same load in the same Colt SP-1 carbine at 100 yards.
Only difference is the Winchester 55 grain FMJ-BT vis the 55 grain Nosler Ballistic-Tips.

 

[wanderinwalker]

It's your bullets. My experience is that even factory-first FMJs in .223 will only do about 2-MOA or just under; I wouldn't expect pull-down surplus to be any better. If you want to shoot little groups at 100-yards, find yourself some 52gr match hollow points. Also good in a 1/8" twist barrel are 69gr Noslers and Sierras, as well as the 77gr version of the same bullets (fuel with Varget or RL-15, thank me later )

Years ago I used to think 55gr FMJ was "good enough" for practicing at 200-yards. At some point I decided it wasn't worth using up good match barrel life on ammo that wasn't up to X-ring accuracy. If I had to wager, I'd say you'll get similar accuracy with thrown charges with those bullets as you did with weighed charges.

 

[juk]

I was thinking right along the same lines as yall. Like I said, I wasn't expecting much from them. I pretty much just bought them to function test and for break in. I will probably end up getting 65-69 grain match bullets from Hornady or Sierra.

 

[B!ngo]

Being a physics and math type, you have to be take a closer look at two words that get intertwined when it comes to shooting. Those are 'accuracy' and 'repeatability'.
I'm going to play a bit fast and loose with the terms, and no flames please because there is understandably a lot more detail behind these terms than I can type in a message.

But what often gets cited as 'accuracy' is really 'repeatability'. That is, the ability to hit the same spot (e.g. on paper) from the same distance, under the same conditions, with little variance. That is, when each shot fills the same hole as the prior, that is repeatability.

Accuracy is really hitting the spot that you intended to hit. One time or many times.

The reason people reload is to ensure (near-) perfect consistency shot after shot. An exacting amount of powder, the proper seating of the bullet, centering of the bullet as well, trimming of the case. Anything and everything to ensure consistency will improve repeatability. Five shots through the same hole anywhere on the paper is repeatability.

Accuracy requires excellent sighting in of a scope, a solid stock, reading the wind and weather. Getting those five shots through the same hole in the center of the target is high accuracy.

Anyway, these may not be terms that are often used in the shooting world, but they are used in the statistics and physics world and apply quite well to our sport and/or hobby.

So finally, when you use surplus stuff, the variance of the case/bullet/charge amplified by the disparate aging of the chemistry over time all contribute to greater variance and thus the lack of repeatability. No matter how well the gun is sighted, and how high in quality your gun may be, the inability to shrink the MOA between shots will be profoundly large.

B

 

[BigBore44]

^^Bingo! B!ngo.... Nailed it....almost. The 5 shots through the same hole is not high accuracy. It's consistency. Accuracy is the the ability to repeat that shot not over a short period of time such as a 5 shot group. But a single shot, allow barrel to return to ambient temperature, then repeat. Known commonly as a cold barrel or cold bore shot.

OP,
Your issue is the bullet. When you step up to the higher quality bullets, your accuracy will improve. Assuming that the bullet is seated correctly and your twist rate is correct for the bullet weight and velocity.

 

[evan price]

The cheap bulk military bullets are often either pulls (with slight damage from the pulling process) or else production rejects due being to out of spec for military contract but good enough for civilian target practice if cheap enough.

Figure 2MOA for bulk military ammo anyway, then double that for the out of spec surplus bullets so 4MOA would not be a surprise.

If you want quality, buy some first-run bullets like Hornady, Speer, etc. The surplus stuff is good for blasting ammo.

 

[RainDodger]

Just to add to the findings...

Yesterday at the range I was cutting one ragged hole with my hand loads out of my 20" RRA with a free floated barrel and Wylde chamber. The hand load is a Sierra 60 gr. FBHP "Varminter" (#1375) over 24.2 gr. of H335. Very nice accuracy and repeatability.

I wanted to check the rifle's function with std. .223 inexpensive loads so I shot 10 rounds of PMC "Bronze" with the 55 gr. FMJs. Holy crap.... they hit about 2" from the bull at 8 o'clock, but the group size went to about the size of a large softball. Very poor accuracy and consistency.

You get what you pay for, generally speaking.

 

[Caliper_Mi]

.... they hit about 2" from the bull at 8 o'clock, but the group size went to about the size of a large softball. Very poor accuracy and consistency.

A change in point of impact (POI) is expected when changing to a different brand/load of ammo. PMC has always shot well enough for me, maybe your rifle just doesn't like it.

My best group with these was a 10 shot group at 100 yards that was .25" tall but spread out laterally about 1.75". I am inclined to blame the bullets for most of the dispersion with some being the nut behind the gun.

The bullets are spinning at many thousands of RPM going downrange so the odds of any bullet imperfections causing only a lateral spread are quite low. Lateral spread in a group is often trigger control. Make sure you are squeezing the trigger straight back using the pad of your index finger and holding the trigger back after the shot breaks. Also, take a look at how you have the rifle set when you are shooting groups. Is there anything that could cause varying lateral pressure on the rifle? Are you using any muscle tension to move the sights onto target?

 

[skidooman603]

Listen to RC

 

[juk]

In all honesty, the rest wasn't that great and I haven't been shooting in a long minute. However, the barrel is completely free floating inside of a Samson 15" handgaurd. It is very possible that I am to blame for that odd group. The rest of the groups were circular, somewhere in the neighborhood of 2-3" in diameter.

 

[Art Eatman]

Generally, a group that isn't very high, top to bottom, but is wide in the side-to-side dimension, is caused by a bit of canting of the rifle from shot to shot. It doesn't take very much.

Generally, not always...