Got my 300bo pistol built and taken to the range and I must say I'm pretty impressed by the Ranier Ultra Match barrel I put in it.

It's a bargain pistol build, PSA blems and standard UPK/LPK's, psa pistol kit, the only 'nice' parts are the Ranier Ultramatch 10.5" barrel, pistol gas and the Seekins MCSR V2 10" rail.  There's a specwar that will hopefully be released in the next month or two that will go on it.  Waiting sucks.... The optic is a Vortex Strikefire I had laying around, side note the Strikefire is a 4MOA dot non-magnified.  

This is the first real attempt at accuracy, I've only put about 40 rounds through it, most of those were trying to figure out a load that would feed reliably and BHO in super and sub.   This particular load was 15.5gr of 4227 behind a Hornady 150grSP (the 'free' bullets you get for buying hornady products).   It was averaging about 1575 fps with a 50fps md.  Not great but I was looking for a basic plinking load to use up the 150gr'ers I have.   I have yet to even come within sniffing distance of a 'standard' powder for 300BO supers.

Anyway last time I was out I found the 15.5 grains functioned reliably enough I loaded up 30 rounds to test further.  The first 5 round group resulted in the below, note that's at 50 yards not 100 hence the 2 MOA computed size.    Wind was from right to left and could be a partial cause of that flyer or it could just as easily be me.  It is a pistol build after all and I'm not a pro, nor have I recently stayed at a Holiday Inn.  I don't have a wind speed meter, just basing it on a rough formula of flag angle / 4 = wind speed and the movement of the trees I read somewhere.

Sadly after shooting this group I had to go restaple the target, it was windy as... well the target notes are correct.   And while I was walking down range the weapon got blown hard enough to cause it fall off the bag and fell four feet down onto concrete and it hit directly on the on-off switch on the red dot and now there's a void behind the rubber cover where there used to be a push button.  Not a scratch on it anywhere else.  Thank goodness for Vortex's unlimited lifetime warranty.  

Anyway, assuming this wasn't a fluke, I'm pretty happy that when I was looking for a 10"ish inch barrel for my 300BO build the only one in stock was the Ultramatch.

As long as it stabilizes the bullet give your twist rate, barrel length does not really affect precision, especially at 50 yards. I know you weren't shooting match ammo, but I'd honest be disappointed with that group at 50 yards out of a hand-lapped Shilen barrel.

In fairness, he was using a non-magnified 4MOA red dot.  I see far "worse" groups when switching out a fixed 10x for a red dot on the same rifle shooting the same load.

Some folks' eyes just ain't as good as others.  No biggie.

I'm willing to bet that even a 1-4x would shrink that group size down considerably.

I may not be interpreting your statement "come within sniffing distance of a standard powder for 300BO supers" correctly, but I believe I just read somewhere that H110 is a pretty standard powder for supersonic 300 blackout.  I believe it was in a thread where a gentleman was having trouble getting his subs to cycle.

10 rounds 75 yards 5 MOA red dot
I'd put my 16" Daniel Defense barrel up against any.  After putting a 1-4 on it, it routinely does 3/4 MOA at 100

You put a16" barrel on a pistol lower?

Betting he just didn't pay attention to detail when reading. Or he doesn't realize that not shouldering something yields lower accuracy.

Or maybe he's just a dickheaded troll. Who knows.

Most everybody is running a Sig pistol brace on pistol lowers these days, which can be shouldered.  How do we know OP is not doing that.

Even if not using a brace, I would expect a Shilen barrel to do better than that from a bench.  If offhand, that is superb.

And I would tone it down in here before a mod comes along.  You know this is not GD.

Slow your roll, hero.  I went with the facts stated by the OP.  I didn't assume he was using a sig brace, because he didn't say he was using one.  I went with the known fact that a non-shouldered pistol doesn't have the accuracy of a full-on rifle.  Oh and there's also the part where he said "This is the first real attempt at accuracy".  Read it slowly so it sinks in.  

If you prefer to show how awesome you are and talk down about the OP's gun by comparing it to your own, feel free, but it's probably best to observe your own advice regarding GD if that's the case (and it would be wise to note that many people on this forum have shot better groups than the one you posted, at 300 yards, and we could easily turn this into a dick-measuring contest, but I'm due for the 30k service on my car and don't think they'd appreciate me being pants-free in public).  The thread was well on track until you came around and decided to shit all over his Cinnamon Toast Crunch.  2 MOA from a pistol and non-magnified sights is great, and in a gun like a blackout, which isn't considered a "precision" round like 5.56/.223 can be, especially at distance.  2 MOA still yields just a hair over 4" at 200 yards, which is far better than is needed for any hunting situation (unless you're hunting golf balls).  Your input is noted and appreciated, but for OP's use, it seems like he's happy with what he's produced.

I'm even willing to bet that with a bit more load development (and calmer conditions) he can see even better results.  If you have technical information to add, I'm sure it will be well-received.  If you're just going to continue shitting on his thread saying his gun is awful and doesn't shoot worth a shit, feel free to run along and play elsewhere.

Kthx.


Tophatman--sorry he came in here and pulled that crap.  Keep up the load work and maybe look into a magnifier for the dot sight, or maybe a 1-6x scope from primary arms.  They're on the budget side, but will provide a good bit of magnification for range work to maybe shrink that group down even better.

I've noticed my blackout being a lot more susceptible to wind influence than most any round i shoot. Probably due to the lower velocities, but i'm not too savvy on most of the technical parts of shooting so i may be WAY off. For a pistol with only a partially developed load, I say Rock on OP.

I'm not going to argue with you  I agree with the first poster who stated he would be disappointed with those groups out of a Rainier Ultramatch barrel at 50 yards.

OP, load up some 125 gr Ballistic Tips over H110 or W296 and try them.  I'm pretty sure Rainier has a 1 MOA guarantee on their barrels.  

7.5 Rainier Match 50yards pistol.

Honestly none of these groups posted are that big a deal.... Your 12.5 will be super consistent, you just need more precise magnification.

I didn't bother to move the POI below.

Two - 2 shot groups
One - 3 shot group

molar:

That's a nice group. CHF barrels can be very precise. Mind me asking what profile?

Prove it.


http://www.ar15.com/forums/t_1_5/1518887___ARFCOM_1_MOA_ALL_DAY_LONG__Challenge_.html


Welcome to the wall of claim.

That is the S2W (strength to weight) contour.  It is a pretty lightweight build

That was the first load tested out of the barrel.  150 gr Sierra gameking with 14.0 gr AA#9.  That powder is a little too fast for that bullet, though.  Had some failures to lock the bolt back

I'll play.  I'm a good sport.

I'll even enter my Saiga AK with Ultimak and TRS-25 in the 50 yard non-magnified event.  Heads will explode

Saiga AK
50 yards TRS-25 red dot
Golden Tiger 7 rounds

My buddy had a Saiga that was quite the shooter.

Nice shooting.  you should do the contest, but all 5 groups on the paper.

Curiosity question and probably the wrong place:
In archery, stringing of shots horizontally or vertically like exhibited was generally a tuning issue that needed remedied.  I've noticed in the two different photos you posted that stringing seems to be fine for benchrest shooting.  I guess that a group of shots surrounding an intended POI would make more sense to me coming from archery.  What leads to horizontal and/or vertical stringing in rifle shooting?  at 50 yards, wind should have little to no influence on left right (I would think given the small surface area and speed of projectile).

In archery, we tuned for a circular float pattern as small as possible.  I haven't paid any attention to precision rifle/benchrest shooting.  I seemed to see a cicrularfloat when shooting my handgun though.

I'm pretty sure that the vertical stringing exhibited in the first group was due to the crappy mil spec trigger.  That and a 5 MOA dot at 75 yards covers a pretty good bit of the target.

As for the second group, well, its an AK.  Not exactly a benchrest gun, but really accurate as far as AK's go.