Diamondback DB15CCB Rifle Journal

[superbeau]

Stamped right on the top of the barrel just back of the flash suppressor.....says "5.56 NATO - 1 in 8 RH twist."

Interesting! How long ago did you buy your rifle?

[duffy]

Less than a month ago and this place moves it's stock pretty fast. My model is a DB15CCMLB.......the Diamondback web site advertises it as a 1 in 8.

[superbeau]

The Diamondback web site advertises it as a 1 in 8.

Well I'm glad DB finally sells 1:8 when they advertise 1:8. For years the DB15 models advertised 1:8 on their website but the guns were actually stamped 1:9 on the barrels. Sounds like that discrepancy has been fixed now.

[duffy]

Yep............

[superbeau]

Well in that case, you shouldn't have any trouble stabilizing 62gr bullets and may have luck higher than that as well. Like you mentioned before, I wonder if that will help or hurt your efforts with lighter bullets like 45-50gr. I hope you'll run some testing at the range and let us all know what you find out :-)

[duffy]

The only two weights I have tried so far are 55 FMJ's and 40 Hornady V-Max. The V-max (hand loads) seem to be more accurate than the 55's, at least at 100 yards.

[superbeau]

Good to know! If you look in my earlier posts, I did some *fairly* extensive ammo testing. I was shocked at how differently ammo would perform across name-brand manufacturers. Even several different types of 50 and 55gr v-max type bullets; some did exceptionally well while others looked shotgun patterns. Unfortunately it's not a cheap exercise but it's kind of fun to try different stuff and see what matches best for your gun. I would have suggested to start with the options I found to be most accurate, but since your barrel is a faster twist than mine, it might not give you that much of a head-start in your research.

[duffy]

I did some internet research on bullet weight vs rifling twist rate and it seems that more twist is preferable to not enough. Too slow of twist will not stabilize the bullet but too much twist for the weight doesn't seem to effect much. I was using the criteria for a 16" barrel.

I have a Howa 1500 in .223 and it has a 1-12 twist. I've only shot the above mentioned bullets in it also.......both seem to be about as accurate.

I have shot a lot of muzzle loaders in the past and the twist rates for them are "important" if not critical. Patched round balls require a long twist rate (1-62 or more) and conical bullets require a tighter twist (1-48 or less). These are relatively slow and very heavy bullets. It is possible to fudge by changing the powder load (ie, shoot conical bullets out of a 1-62 barrel). Using patched round balls out of a 38" 1-62 barrel I was able to get over 2000 fps at 3' from the muzzle. Not bad for a charcoal burner.

Smokeless powder requires more delicate conditions I think. The tools necessary to measure performance are a bit beyond my ability/desire. If it goes "bang" and I hit the target about where I aim I'm happy.

[superbeau]

both seem to be about as accurate

If you have the ability to shoot at longer ranges, you might see more of a difference. My limited understanding of "over spin" is that it creates excess drag and therefore the drop would be greater as the bullet gets further out.

I have a Remington 700 VSSF in 223 that I use on prairie dogs and it's 1:12 twist. Granted it's a long barrel, but there must be a reason that they have a slower twist on those guns versus the ARs that are all in the 1:7-1:9 range. Maybe the faster twist helps stabilize in a shorter barrel. Maybe manufacturers of ARs expect shooters to use heavier bullets. Not sure...

[duffy]

A lot of my prairie dog shooting is 300-500 yards and the range I shoot at has 300 and 800 yard ranges. I zeroed the scope on the Howa at 300 yards and then tried the 800 yard target. The 55's were a bit better at 800 yards (less drop) than the 40's were. That may have been due to the 55's being factory loaded and the 40's a "medium" hand load.

I have not shot any further than 100 yards with the DB........seeing the target with non-magnified sights is getting more difficult the older I get. I'm going to try the 200 yard range the next time I visit the range .....maybe even the 300 just for grins.

[superbeau]

After a year of procrastinating, I finally decided to test my 45-degree offset iron sights. I put these on to help deal with coyotes that seem to always sneak in at 20 yards when my scope is cranked up to 16x looking at an incoming dog on the horizon. If you try to dial the scope down, the coyote will probably bust you. The beauty of the offset sights is that you can just cant the gun to the side and then you're in business for close range. I don't have a lot of experience with iron sights, to be honest. I shot the first time with these sights while standing, freehand, iron sights at 50 yards and this is what happened.



That's plenty good enough for a coyote, so I think my backup sights are in good shape

[pecospuppy]

Yep, good enough.  Looks like you are pulling a little with your trigger hand.  I'm no expert (and maybe you are), but that is what I've been told is the reason for a down and to the left group from a right handed shooter.  If you remove your thumb from around the handle and so you are shooting with your trigger hand thumb on the side of the gun instead of around the handle, you might see your aim improve.  It's worth a try.

[superbeau]

Looks like you are pulling a little with your trigger hand.

It's ironic because I am currently working on improving low/left hits with my pistol shooting. Apparently it's a "thing" and we subconsciously push low/left when we squeeze our hands tighter on the grip in anticipation of the recoil. I blame these rifle hits on shooting off-hand and being a little wobbly. Next time I'm out, I'll try again with the rifle sights in a stable rest. I'd love to get a micro-red dot as my offset sight but I think I'll wait until the prices come down to earth.