My new Whisper & Load Questions
 

So I just finished my first 300 whisper build. Also I've figured out a really cool way to make whisper brass with a dillon trimmer and finally overcame the biggest issue which was the head of the case spinning(and getting torn up) when the cutter first came in contact with the .223 case neck. (I can talk about this more if anyone is interested.)

Here's a pic.
http://img.photobucket.com/albums/v3...300Whisper.jpg

Here's the build spec.
-Noveske 300/221 Fireball 1/8" twist 16" bbl w/ pistol length gas system.
-Noveske BCG.
-Noveske KX3 (Until I get my can.)
-Noveske pinned low profile gas block
-Daniel Defense M4 12.0 Rail
-Tactical Inovations Billet deluxe lower (my first one was better than this one. (It's kinda wobbly even with the tension screw)
-White Oak parts kit.
- RRA 2-stage NM trigger.
-Magpul UBR stock and MIAD grip
-Stag carbine buffer and spring.
-Leupold 4.5-14x40 VX-III (Enough elevation out of all my cheapo scopes for zero.)
-Larue SPR-S mount. (10 MOA of forward cant)

Anyway. I'm feeling pretty good about this project. My first day out with it wasn't seriously disappointing, but I feel I could do better. My load was a bit anemic and not terribly accurate. I had started with a load my buddy had hoping to replicate his results. 9.1gr H110 pushing a 240gr SMK @ 1020ft/s For my build that same load only had them going @ 880ft/s (ES=35 SD=15) and it wasn't enough to lock back the bolt even though it fed all but 2 rounds. Oh yeah. Conditions. So I was roughly at 800ft elevation. Little to no humidity and the temperature was between 25-35 degrees Fahrenheit. Wind was kicking up to about 20 mph, but settled down to an average of about 5-10 mph.

Also, after looking through the photo thread, I noticed that I had loaded my rounds too long at .223 mag length. Since the bullets ogive changes the contour of the feeding geometry of the mag it looks as if it's better to seat them farther back so they don't cant inwards and jam up. (I'll have to do this.)

For my next set of loads, I was thinking I'd start at 11.0gr of H110 and work my way down to 9.5gr with the remainder of my 240gr SMKs. Then do the same with some 220gr SMK's starting at 12.0gr H110 down to 9.5gr. Sound like a good plan? (Looking at the whisper load data this seems all to be well in the safe margin.)

I'm really hoping to get it to function 100% and lock back on an empty mag in the subsonic range. Also, I'm thinking that the cold had a huge effect on the function of the rifle, velocity achieved and overall accuracy due to vertical stringing. H110 has been said to be temp sensitive, and I did notice velocity changes in my other friends AR when he cooked the rounds for too long.

Any advice would be appreciated.:smile:

subsonics and cold temps
 

H110 is pretty temperature sensitive. I had a H110 super sonic load that ran well at 40-45 deg F at a few feet above sea-level. When I tried the gun and load in Arizona at 1000-1200 ft on a 85 deg F day it would blow primers after the third or fourth round. So I suspect that the cold is causing your H110 load to run a bit slow.

320pf

VV N110 For all your subsonic needs.........

Interesting. I see from my burn rate chart that N110 is right next to Lil' Gun and very close to H110. How does it fare when it comes to temp sensitivity? (I have heard that Vihta Vuori pistol powders tend to be less temp sensitive. Since it's Finnish that would make sense.) I'm guessing that loads would be very similar to the H110 loads? I don't currently have an internal ballistics program, but I can get a buddy to run numbers for me.

Any primer recommendations? I was just using Winchester Small Rifle primers, since that's what I've had the best luck with on .223 and even 6.5x47L.

10.0 gr of VV N110 gives me 1052 out of a 16" barrel. It's very stable. It will not drive the supersonic bullets as fast as H110 will. On the subs I get the same velocity with 0.2 grs less.



240 MK

Personally, I am phasing over the lil-gun for my subsonics and discontinuing my H110 use.

VV powders are not available locally and I usually cannot afford to order powder in large enough quantities to make the hazmat fee worth it.


Nice setup though - very professional choice of components.....

Very nice rifle!

I'd be interested in the info on the brass trimming setup.


I tested some loads the other day using 9.4grs of VihtaVuori N110, Federal 205 primers and 220gr Seirra ProHunter projectiles loaded to magazine length. My 5 shot average was around 914fps and was very quite with my YHM Phantom:smile:.I'm using a Pac-Nor Polygonal 8 twist barrel that's 10" in length with the gasblock in the pistol position. I'm not using an adjustable gas system as it seems to run fine.



DISCLAIMER: This load works in MY rifle only! Not responsible if you blow yourself up:grin:

Thanks for the info guys. (And thanks for the compliments on the setup.) I guess I'll have to track down some Lil Gun and some N110.

strycnine- You have a Pacnor AR-15 barrel and it's not a noveske barrel? Weird. Pacnor redirects right to Noveske for their AR-15 barrels on their website.

I can try and make a video of my brass creation process. At the very least I can detail my process.

I'm pretty sure Ron got it direct from PacNor as a blank, then he finished it. Maybe he will chime in.

My 10 1/2" from Ron has a Pacnor 1x8 Polygonal barrel and Paladin 3 way gas block. You have a great looking Rifle.