New AR Build!

fnuser · Posted: Wed Nov 10, 2010 8:25 pm Post subject: Re: New AR Build!

Elvis,
I'll provide you with non-bias reports if you'lll be patient

slimjim · Posted: Tue Nov 16, 2010 2:46 pm Post subject: Re: New AR Build!

Ok, Dawgdad, Chambered, et all, I need some tips and encouragement. Got out to the range yesterday and finally got to a point in the barrel break-in process where I could shoot some groups between copper treatments. I had just picked up some Remington .223 50gr HPs to try in my S&W M&P with a 16” barrel so thought I’d send those first down the new barrel. The group out of my newly built AR was not impressive. Group is pictured below. Not what I would expect out of a match-grade bull barrel but then again the velocities varied from 3259 to 3410 fps, 24” barrel. Not what you would call hi-grade ammo.

While the barrel copper treatment was in process I shot the same rounds through my M&P (3040 fps avg) and got this pleasing group from an M4 configured AR. I shot some more and continued to get groups like this with my 1.5x scope at 100 yards. Needless to say my heart was in my stomach

slimjim · Posted: Tue Nov 16, 2010 2:48 pm Post subject: Re: New AR Build!

After the cleaning, I went back to the Fiocchi 40gr V-max’s and sent 4 down range. They had shot well from a clean barrel and got this grouping. Not as good as Marty’s .204 but respectable and my heart is not experiencing acid reflux. Cleaned again and sent four Fiochi 69gr SMK Match down range with similar hopes. However, I got a disappointing group. My M&P will shoot the 69gr SMK 1 MOA all day.

Repeat clean and tried my hand-loaded Hornady 75gr A-Max. Not that good. If you through out the 1st fouler shot, I might consider it a respectable start. The 24.5gr of Varget didn’t even show any pressure signs on the primers.

BTW, all these were shot with the gas turned off so essentially was operating a straight-pull bolt action. When I got home, I measured the barrel twist just to make sure it was 1 in 8. I’ve had stranger mistakes made before and with the way it was acting with the 40gr bullets I expected to see the twist come out at 1 in 12. It was right on 1:8 as ordered. Good news is I have 500 rounds of the 40gr V-max!

Any feedback you can provide would be appreciated.

Dawgdad · Posted: Tue Nov 16, 2010 3:18 pm Post subject: Re: New AR Build!

Is the 2.385" COAL measured from the chamber? They need to be .010-.015" off lands for the best results. You cannot get great groups trying to jump them from much further. I get 0.5-1.0MOA in the sweet spot and from as close as .030" the groups open up to pattern size....

Just for grins - try 23.8 Varget... a little slower but they tend to settle down real well in my barrels at 2700 fps.

Also - you will really see the benefit at 300+yards with the A maxes. When your 40 grainers start corkscrewing- these will be just going to sleep.

slimjim · Posted: Tue Nov 16, 2010 8:37 pm Post subject: Re: New AR Build!

Dawgdad wrote:

Is the 2.385" COAL measured from the chamber?

No, this is the recommended COAL from Hornady. Thought I'd just try it for starters while breaking it in. I'll take the time to get within .030".

Dawgdad wrote:

Just for grins - try 23.8 Varget... a little slower but they tend to settle down real well in my barrels at 2700 fps.

Wow, that was a good suggestion! I was thinking of going the other way since the pressure signs were so low and I thought I should be getting more velocity out of it. I'll try that load next outing.

Thanks!!

slimjim · Posted: Tue Nov 16, 2010 10:36 pm Post subject: Re: New AR Build!

Dawgdad wrote:

Is the 2.385" COAL measured from the chamber?

No, this is the recommended COAL from Hornady. Thought I'd just try it for starters while breaking it in. I'll take the time to get within .030".

Dawgdad wrote:

Just for grins - try 23.8 Varget... a little slower but they tend to settle down real well in my barrels at 2700 fps.

Wow, that was a good suggestion! I was thinking of going the other way since the pressure signs were so low and I thought I should be getting more velocity out of it. I'll try that load next outing.

Thanks!!

Elvis · Posted: Tue Nov 16, 2010 11:31 pm Post subject: Re: New AR Build!

looking forward to progress reports. your barrel may settle down and start to shoot better soon all by itself. my buddies 270wsm was crap till it broke in now its a tack driver.

44marty · Posted: Wed Nov 17, 2010 1:13 am Post subject: Re: New AR Build!

You may also want to try a different bullet. The Hdy A-Max have a great reputation, but I have found better results with the V-Max (this I can't explain, and it baffles me) and even better groups with Sierra bullets.

Edit: Have you tried IMR 4064 or IMR 4895 powders?

chambered221 · Posted: Wed Nov 17, 2010 7:21 am Post subject: Re: New AR Build!

The 1.5X scope more than likely added to group size !!!

When doing load development I prefer at least a 12X scope with a fine cross hair. I've got an older Leupold 16X target model I've kept around just for this job. Next time your at the range take a look at how much area your cross hairs cover at a 100 yard target with various scopes set at different powers.
With lower powers it's not uncommon to need a 2" or larger aiming point. What you can't see is actually what part of that dot or square the center point of your cross hairs are on. You could very easily be adding a 1" or better to a group and not even realize it.
When using low powers I prefer a target such as this and concentrate on the cross hair as a whole instead of the center section. In the past I've even made my own in order to have them sized correctly.

Aloysius · Posted: Wed Nov 17, 2010 8:43 am Post subject: Re: New AR Build!

Chamber, you never tried an X-cross for target? I always find it easy to put the +-cross of the optics straight on the X of the target. (but my X-s are not so well formed as your red thingies)

Dawgdad · Posted: Wed Nov 17, 2010 9:46 am Post subject: Re: New AR Build!

lots and lots of choices for bullets and powders.... I hear good things about the IMR 8208XBR too.

4064 and 4895 perform well but I hate sticking lincoln logs in the little bitty case mouth...

SMK 80's are anther proven winner.. Berger VLD's too but sometimes they need a 7 twist to get tight.

Try the 77SMK or 75 hornady BTHP at mag length (2.250") with 24.0gr RE - 15 proven over and over again by some of the best in the nation.

Do not give up on this one yet. If you have a comparator and can get the ogive lenght set up on the sweet spot these will hammer out past 600.

If you do not have a comparator yet... I would work on the 69 and 77SMK's at mag length from 2650-2750 fps range you may get some higher velocities with your longer barrel.

Dawgdad · Posted: Wed Nov 17, 2010 9:46 am Post subject: Re: New AR Build!

Was this barrel cut with the Wylde chamber?

Dawgdad · Posted: Wed Nov 17, 2010 10:07 am Post subject: Re: New AR Build!

You do know what the WOA barrel break in procedure is???

Just shoot it!. I did run a jagged patch of JB paste on the throat and a few passes up the barrel on my 20" varmint barrel but that was it.

Turn the gas on - put a 3x9 or higher power scope on top and shoot a few 10 shot raid fire string through it - let it cool and try your slow fire groups again without cleaning in between. Heresy I know but it works for me.

Also - if you can get more than 100 yards to shoot at - these A-maxes can actually - yes counter intuitive I know - get better at distance.

I have seen 68 hornady match loads that were shooting bug hole 1/2 MOA groups at 100 open up to 1 moa at 200 2 moa at 300 and 3 moa at 600...

While a 75 A max that was 1.5 moa at 100 and 200 went to .8 moa at 300 and 1 moa at 600... it takes those big long pencils a few hundred yards to line out sometimes. Kind of like a dragster spinning its wheels at the starting line then grabbing traction andgoing straight down the track. This is where the higher BC really kicks in.

chambered221 · Posted: Wed Nov 17, 2010 11:23 am Post subject: Re: New AR Build!

Aloysius wrote:

Chamber, you never tried an X-cross for target?

No I haven't..........first time I've heard of such method !!!
I have tried numerous types of aiming points and methods over the years but have always returned to the smallest orange dot that I can still see around the cross-hairs or the bracket method as above.

I just wish I could find more of those 1/4 inch orange dots........only ever seen them once.......bought all of them and they're about gone. Sad

Dawgdad · Posted: Wed Nov 17, 2010 1:07 pm Post subject: Re: New AR Build!

[quote="chambered221...
I just wish I could find more of those 1/4 inch orange dots........only ever seen them once.......bought all of them and they're about gone. :([/quote]

like these?

or these in Red

red 1/4" stickers