300 BLK range report

Moderators: gds, bakerjw, renegade, bamachem

Post Reply
biggjimm
Silent Operator
Posts: 67
Joined: Sun May 01, 2016 9:19 pm

300 BLK range report

Post by biggjimm »

Went back to the range yesterday to continue my search for a load for my 300 BLK.
First of all let me say this, I have always shot for groups & load development from the 100yd bench. However, yesterday was quite windy & I opted to shoot from the 50yd line. An old-timer who hangs out at this particular range scolded me for shooting the 50yd line for load development??? He said most all bullets will be unstable at that close of a distance but will be stabilized & flying true at 100yds????? That sounds both crazy & backwards to what I've been taught & seen for myself. But I'm open to comments & criticism & I've also been wrong before.

Okay on to my results. This was w/ the 150gr FMJ-BT @ 2.050" COL unless otherwise noted. All measurements are center to center. All groups are 5 shots @ 50yds. out of my lead sled solo rest.

H-110- All groups were larger than 1.5" & would not cycle my AR

IMR-4227 was a different story. All groups were under 1.5" & every round cycled my AR.
2nd column is the same loads but @ COL of 2.175" (0.045" jump to rifling which apparently this barrel does not like as well)
14.0gr- 1.030"-- 1.196"
14.5gr- 1.456" -- 1.181"
15.0gr- 0.788" -- 0.802"
15.5gr- 0.365" -- 1.328"
16.0gr- 1.415" -- 1.450"
16.5gr- 0.983" -- 1.363"

All were shot with 10-15mph 90° crosswinds at temps of 75℉-80℉

So now I've got a couple loads to tweak & shoot at 100yds.
FOB
Silent But Deadly
Posts: 205
Joined: Thu Mar 26, 2015 5:37 pm

Re: 300 BLK range report

Post by FOB »

The 15 gr load looks promising.

I do all my initial workups at 50 yards, very little uncertainty on one's hold.

"He said most all bullets will be unstable at that close of a distance but will be stabilized & flying true at 100yds?????"

He'll probably tell you that the bullet doesn't start to rise until about 50 yds. \

Physics is a m'fer.
User avatar
svh
Silent But Deadly
Posts: 556
Joined: Sun Jan 25, 2015 1:55 pm
Location: mid Mo.

Re: 300 BLK range report

Post by svh »

biggjimm wrote:An old-timer who hangs out at this particular range scolded me for shooting the 50yd line for load development??? He said most all bullets will be unstable at that close of a distance but will be stabilized & flying true at 100yds?????
Dang ! I've been doin it wrong this whole time ! :roll:
Cheech, my best friend of 16 years, RIP.
Never trouble trouble till trouble troubles you.
User avatar
rebel
Silent But Deadly
Posts: 7285
Joined: Mon Apr 22, 2013 2:01 pm
Location: Moonshine Country

Re: 300 BLK range report

Post by rebel »

Your ol' timer was speaking of very high BC, boat tail bullets. Most bullets are completely stable at 50, especially a flat base. Even still, from what I understand, a high BC boat tail is not necessarily unstable at that distance, just not achieved it's optimum accuracy - it's least wobble - so to speak.
Just like him, I have my opinions, and right or wrong I think his sucks :lol:
You can't beat the mountain, pilgrim. Mountains got its own way.
popper
Silent But Deadly
Posts: 407
Joined: Tue Apr 15, 2014 2:09 pm

Re: 300 BLK range report

Post by popper »

All the above are partially correct. Any upset in the bullet when it leaves the muzzle gets gyro/aerodynamic stable downrange a bit. Unbalanced bullets will try to go stable but eventually precess into orbit if spun fast enough. The trans-sonic fps depends on nose design, is a lot bigger than most expect and causes bad stuff. Start at 50, go to 100 for good loads, farther if you can.
User avatar
dellet
Silent But Deadly
Posts: 6967
Joined: Fri Nov 30, 2012 1:25 pm

Re: 300 BLK range report

Post by dellet »

popper wrote:All the above are partially correct. Any upset in the bullet when it leaves the muzzle gets gyro/aerodynamic stable downrange a bit. Unbalanced bullets will try to go stable but eventually precess into orbit if spun fast enough. The trans-sonic fps depends on nose design, is a lot bigger than most expect and causes bad stuff. Start at 50, go to 100 for good loads, farther if you can.
I would just add or say differently, that you can spot a bad load at 50, a good load at 100, but your best won't show until you're past 200.
300 Blackout, not just for sub-sonics.
User avatar
drayks
Senior Silent Operator
Posts: 126
Joined: Thu Aug 15, 2013 10:40 am
Location: Western Michigan

Re: 300 BLK range report

Post by drayks »

There may be some validity to the idea of some bullets do not stabilize until quite far from the muzzle. When Armor Piercing rounds were being developed for the .30-06 round in the early 1900's, Colonel Hatcher was astounded when the bullets would only penetrate several inches into hard oak planks close up, but would penetrate through the stacks-more than a foot thick when placed out at 100 yards. This was later attributed to the bullets still wobbling up close and "tumbling". Even with lower velocity at 100 yards much more depth was reached with the bullets traveling "true". drayks
biggjimm
Silent Operator
Posts: 67
Joined: Sun May 01, 2016 9:19 pm

Re: 300 BLK range report

Post by biggjimm »

A lot of interesting thoughts on the matter.
I've always just done my rough load development at 100yds & then I would step up the distance as I tweak the loads. The "tweaking" distance just all depends on what cartridge I happen to be working with & for what purpose.
Sometimes it is seemingly nonsense to some people. Like the time I was working on a 110gr-115gr load for my .357 maximum deer rifles @ 500yds. A couple guys were really heckling me for even having that rifle on the 500yd line. Until they seen me consistently ringing the steels & exploding milk jugs of colored water on the 500yd berm with my lowly ol' Max single shot rifles. Of course I had to explain to them that I didn't deer hunt beyond 200yds with it but punching paper & ringing steel is different.
Now every time I see those guys at the range they always come up to me & respectfully ask me what kind of "crazy" shooting I'm doing today.
User avatar
dellet
Silent But Deadly
Posts: 6967
Joined: Fri Nov 30, 2012 1:25 pm

Re: 300 BLK range report

Post by dellet »

What was your H110 load that would not cycle?

Did it eject and not pickup the next?
300 Blackout, not just for sub-sonics.
biggjimm
Silent Operator
Posts: 67
Joined: Sun May 01, 2016 9:19 pm

Re: 300 BLK range report

Post by biggjimm »

dellet wrote:What was your H110 load that would not cycle?

Did it eject and not pickup the next?

I had loaded a test ladder of H-110 loads from 12.5gr thru 16.0gr & none of them cycled fully.

Yes, they ejected but did not strip the next round. I may need to adjust my gas block a little to run H-110 but it was not near as accurate as the IMR 4227 loads I shot so I'll probably stick with that for this particular bullet anyways. I've got a couple other bullets I want to try out before I settle on a "go to" hunting load.
Post Reply

Who is online

Users browsing this forum: Google [Bot] and 157 guests