55 vs 62 gr

[DarthRevan]

Will the grain count effect how tight your grouping is from a bench fire?
Or is it a quality of barrel, or brand of ammo issue?

Maybe I just need more practice
Does anyone have data to support claim?
I hope it's obvious I mean .223/5.56

 

[92G]

IMO many factors, bullet gr is just one of them.

personally i like 55gr in my 1:9 twist guns. The heavier bullets seem to do better at long range from a tighter twist like 1:7. None of that is surprising i think others observe the same.

That being said i shoot mostly 55gr wolf or XM193 from all my .223 rifles and have had fine results out to 300y.

i almost never shoot match ammo due to cost, though when I have the heavier bullets (70+ gr) seem to do awesome with a tighter twist barrel.

-----

this dude has an amazing set of videos posted.
this one covers twist rate and bullet stability, good video:

https://www.youtube.com/watch?v=Z3h0pMQAFUU

 

[jct61765]

You need alot of practice and figure out what YOUR gun likes better. Are you reloading or using factory ammo?

 

[mac1911]

55 vs 62 of the standard fmj variety will not varry much in actual group size. I dont see it anyway. Point of impact vs point of aim is not really affected for my results. I am not a great shooter. Currently I'm in the high 80s low 90s % . Ex I shot a 468/500 last match. Been averaging in the 450s this year.
Depending on your rifle and ammo will have a huge impact on your group size.
After you can actually shoot a good group. Also consider what the run of the mil 5.56 military ammo is supposed to do..... hit target not shoot tight groups.
If you have a decent shooting 22( for cost saveings only) try shooting one of the appleseed course targets. I'm having trouble finding the links to their targets.
http://appleseedinfo.org/smf/index.php?topic=9833.msg83274#msg83274
Can find links here.
As for 55 vs 62 grain. Your average "Nato" full metal jacket are not great target bullets. Will shoot better than most people can though.
Before I bought my RRA NM and started reloading I was useing my standard A2 rifle. With that rifle I could take ( IMI surplus 5.56) and a SR 1 100 yard rifle target and keep the shots in the black ring shooting prone with a sling.
When I played around with ammo the best groups I could pull out of my regular ARs was about 2" off the rifle rest( lead sled) I sold all but 3 of my ARs.
I have 2 that manufacture claims are 3/4 moa. Off the rest and my reloads I am shooting just over 1moa. Best group I have shot prone and with a sling is 5 shots in a row 1.5" center to center......but that was a good day.
3 largest improvements to my scores.
1. Front sight focus......
2. Dry fire practice.......
3. Breathing control......
Now last time I brought my standard A2 rra rifle out I managed to shoot 20 rounds of wolf into the 10 ring of a SR1 @ 100 yards with 4X's . Good or bad you decide....good for me.

So what rifle are you shooting and with what ammo?
I don't remember exactly and have lost the link. But milspec 5.56m855 standards where 4moa to be good enough for GI. I don't know if those standards have changed with the m855a1 ammo?

 

[bfm]

As mentioned, if you have a 1 in 9 twist, they should be target, not match, accurate. If you have a 1 in 7 twist, try ammo nearer or over 70 gr and see what groups best for you. They are a few companies that do nice loadings of Sierra match BTHP rounds.

Barrel length will also play a bit of a factor. Friends with 20" 1 in 9 barrels seem to get a bit more out of the green tips than I do from my 16" 1 in 9.

 

[DarthRevan]

You need alot of practice and figure out what YOUR gun likes better. Are you reloading or using factory ammo?

Factory

 

[mac1911]

Factory

Here is a link https://rdl.train.army.mil/catalog-...9-B33B4927856C-1308726234899/3-22.9/chap5.htm
has some good info. So basically for GI purposes 2 consecutive 3 shot groups into a 1.5" circle @ 25m is what they look for.
NOTE. above is a grouping exercise not for zeroing your rifle. I for now as long as your shots are hitting close to middle of a target don't worry about adjusting your sights just yet...
There is some decent info on what to expect from a standard AR and a "match" rifle. Also some good group analysis charts