Back to “ye olde format” for this video, but I’ll probably do a mix of “new” and “old” in the future.
A long time ago, I was able to shoot .22s very well, because that was pretty much all I did, all day. I hadn’t shot slowfire with a .22 in years, and decided to see if I was good as I once was. I also compared a 1/16 twist bolt action rifle with a 1/7 twist AR-15 that had a .22LR conversion. Was the 1/7 completely inaccurate, as is often repeated on the internet?
Excellent video. I have been long debating as to whether or not a .22 conversion kit for an ar15 would be worth shooting in a barrel with a 1/7 twist. Seeing your results really makes me want to purchase one sometime in the future.
In the 5.56mm world, the change in the twist from 1:9 to 1:7 was necessary for the increased performance of the M16A2 ammo. The ammo would not stabilize completely in a 1:9 barrel.
And anyone on active duty during the change from M16A1 to M16A2 will tell you quickly that the newer configuration was a real improvement on accuracy.
Sid, wasn’t the 1:7 necessary only for the tracer rounds, rather than the SS109s? Of course it’s definitely a requirement for the newer 70+ grain stuff.
My understanding is that the optimal twist is really dependent on the *length* of the round–which is usually, but not always, proportional to projectile weight.
The M856 tracer, because of its lightweight tracing payload, is considerably longer (~1.1″) than the standard M855 round, and requires the faster 1:7 twist rate for proper stability. If memory serves, 62 gr. tracer and 80 gr. standard projectile are about the same length.
Above I should have said “primarily dependent”, not “really”.
I apologize for the appearance of the following info, but my table did not translate well to this posting format. Read vertically. n/a = data not yet collected.
5.56/.223 Projectile Type
Projectile Length (inches)
Nominal Wt.
Actual Wt.
Comment
1
Sierra FBHP-cb (closed base)
0.571″
40 gr.
40.0 gr.
2
FBHP-cb
0.669″
50 gr.
50.5 gr.
3
BTHP-ob (open base)
0.740″
55 gr.
55.1 gr.
4
M855 NATO
0.900″
62 gr.
61.9 gr.
Green Tip
5
M856 Tracer
1.101″
62 gr.
60.7 gr.
Orange Tip
6
n/a
n/a
69
n/a
7
n/a
0.961″
75 gr.
74.6 gr.
Privi Partisan
8
n/a
n/a
75
n/a
Black Hills
9
n/a
n/a
77
n/a
Black Hills
10
BTHP-ob
1.068″
80 gr.
80.0 gr.
Match
1/12 was the twist for the M16/M16A1.
This video couldn’t have come at a better time: I’ve recently decided to take up rimfire shooting for practice, and have been trying to decide between buying an AR conversion or a dedicated .22LR rifle. There are obviously advantages and drawbacks to each, but it’s good to know that stabilization is not an issue.
Good video. I think it’s interesting because I’ve played around with different ammo in my Marlin 60 over the years, and have found some inconsistencies with what passes for “common knowledge”. Some of the most accurate loads I’ve tried have been supersonic. One that it really seems to like (for accuracy and function) is the Aguila Super Maximum. The cases are actually longer than standard .22 LR, though the OAL seems to be the normal. Most of my testing has been at 50 yards, with some at 100.
Others it’s liked: Aguila SSS; even though it wouldn’t stabilize in my barrel and was leaving keyholes in the paper at 50 yards, it was actually pretty accurate. Wolf Match Target seems to be extremely accurate. I bought a box on a whim when the bulk stuff I’d brought with me was grouping at about 4-6″ at 50 yards. The wind was gusty, so I had some pretty bad horizontal stringing, but the impacts were very close to each other on the vertical, where the stuff before made me feel like I was shooting a shotgun at the target.
I’d actually like to see the SSS load tested in a 1:7 AR. That is a long bullet (if you don’t know, it’s basically a real long 60 grain bullet stuffed into a .22 short case to give .22 LR OAL). It did cycle my Marlin, I’m guessing because the much heavier bullet pushed pressures into the .22 LR range, but it could also be the 35 year old main spring… YMMV.
I shoot the SSS all the time. It’s very accurate out of a 1/7 barrel.
I have been running a CMMG Stainless Steel Kit (basic model) in a 1/9 barrel for sometime now and my results are consistent with yours. CCI Mini Mags seem to shoot well, but I mostly run the 525 & 550 round Federal Bulk packs. Most of my shots are at distances from 7 to 25 yards and accuracy is quite good for a conversion kit IMO.
Recently purchased a S&W M&P 15-22. I’ve only had it out to the range once for a 500 round session (CCI Mini Mag 40gr), but from early indications accuracy from the bench is very good. So far in some speed drills I honestly couldn’t tell much difference between it and a conversion kit. The 15-22 has a functional bolt catch/release which is nice, but is lighter than a standard AR. Overall though I’m quite happy with it and it cleans up alittle easier than the conversion kit.
Wish I could post pix here showing my S&W 15-22 and test targets. Best Mil-style .22 rifle available. Sightron Mil-Dot scope, RRA 2-stage NM trigger (drop-in), MK-9k can. Can hit pretty much anything I can see out to 200 yards with CCI Blazer or CCI Standard Velocity. Contact me if you’d like to give it a try.
Best .22LR ammo deal on the net: 40 gr. CCI Blazer solid at ~3.3 cents per round delivered to Tucson. A fraction of the cost of Mini-Mags or SSS. No duds as in Fed and Rem bulk packs (which are more expensive). 50 round boxes with individual rounds separated in plastic grid.
I like ye olde video style just a bit better. Other than that, good work!
I like old format. It’s not that you’re not good lookin’, it’s that your new format is considerably less engaging and information-dense.
I too, prefer the older format. Still a kickass blog, the only one I follow as a matter of fact.
Thanks, I appreciate that.
I always like your videos. The new format is different, but you still provide good info. Keep up the good work.
Hi Andrew.
Thanks for the great work. This is really the best gun blog out there.
Have you had any issues with shooting a lot of .22lr in a standard at-15 (5.56) with a 1in7 twist? Clogged gas tube,.. etc?
Thanks. Nope…I haven’t, actually.