6.5 Grendel Load...123 SST vs 120 Gold Dot Velocity "Pressure"

bubbaonpc

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Oct 4, 2015
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143
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Creston, North Carolina
Is anyone else seeing the 123 SST exceeding the velocity of Speer's 120 Gold Dot ?... with all things being equal... Just started finding a load for New Howa Mini Heavy Barrel 20". I broke the barrel in using 120 Gold Dots,120 Power Points and 123 SST's. After break in I loaded up Gold Dots and SST's EQUALLY. Starline Brass NEW...Win. Primers Small Rifle. Sized all brass outta box. Cham and Debur and used K&M Deluxe Hand Primer. Both are loaded to MAG length as OGIVE is too long to fit MAG. Leverevolution, AR Comp, Match Rifle and RL 15. Equal powder in each and I'm seeing 50 FPS faster from the 123's. Where I'm seeing flat primers with 120 Golds...I'm not getting flat primers with the 123's. The Golds measure .263.5 and the SST's are .264. Last load was LeverEvo at 28.8 and 2558fps. Pressure beginning with Golds but SST's look good. What do y'all think? It's no Big Thing, I just find it interesting that a heavier bullet is moving faster...and no pressure signs...but the lighter bullet is showing signs ??
 
In my experience loading for the 6.5 Grendel in the ARs you will run into pressure quicker with the 120 Gold Dot than with most any other cup and core bullet in the 120 to 123 gr range. I mainly use IMR 8208 and I can run a half grain more powder with them than the Gold Dot. Velocity is pretty close to the same with all bullets even through the Gold Dot is burning a half grain less. The 120 Gold Dot has been a very accurate bullet out of both of my ARs. I used it in my 20" barrel rifle at 2550 fps using 28 grs IMR 8208, Hornady case, CCI 450 to kill a deer at 111 yards this past season. Deer was facing me. I placed the bullet in the center of it's chest. It devastated the chest cavity and penetration was about 20" when it exited it's belly. BANG FLOP.
 
Being a bolt gun, I'm not too sure I would worry about it much...bolt guns can handle a lot more pressure than the AR platform.

As I understand it most load data is safe to use in the AR platform...pressures near 55,000...where a bolt gun can take 60,000. Most AR platform shooters should never see any signs of pressure!

I equate chamber pressure with published load data's pressure at X grains of powder. If I see in a loading manual 2789fps has a chamber pressure of 55,000...I only load to that velocity, knowing my pressure will be fairly close to the 55,000 threshold set for the AR platform.

IIRC...the Gold Dot has a raised ring near the base which could raise your pressure some !
 
In my experience loading for the 6.5 Grendel in the ARs you will run into pressure quicker with the 120 Gold Dot than with most any other cup and core bullet in the 120 to 123 gr range. I mainly use IMR 8208 and I can run a half grain more powder with them than the Gold Dot. Velocity is pretty close to the same with all bullets even through the Gold Dot is burning a half grain less. The 120 Gold Dot has been a very accurate bullet out of both of my ARs. I used it in my 20" barrel rifle at 2550 fps using 28 grs IMR 8208, Hornady case, CCI 450 to kill a deer at 111 yards this past season. Deer was facing me. I placed the bullet in the center of it's chest. It devastated the chest cavity and penetration was about 20" when it exited it's belly. BANG FLOP.
Thanks RT, after speaking with a Speer Rep. he said the 120's were "made" for the Grendel and would expand down to 1600 FPS...and of what I've seen in Gel and heard from others, this should be a Deer Slayer for our short range shots in NC Mnts. I fired 20 break in shots using 4 powders with 20 different grain loads and all 20 fit in a 2" circle..so I think they will be really accurate. Gonna try 8208 and 2520 for a lil extra FPS. Thanks again !
 
Being a bolt gun, I'm not too sure I would worry about it much...bolt guns can handle a lot more pressure than the AR platform.

As I understand it most load data is safe to use in the AR platform...pressures near 55,000...where a bolt gun can take 60,000. Most AR platform shooters should never see any signs of pressure!

I equate chamber pressure with published load data's pressure at X grains of powder. If I see in a loading manual 2789fps has a chamber pressure of 55,000...I only load to that velocity, knowing my pressure will be fairly close to the 55,000 threshold set for the AR platform.

IIRC...the Gold Dot has a raised ring near the base which could raise your pressure
some !
Thank you Captn. I'm sure there is something going on. Just found it interesting.. I spoke with Cody B. at Speer and he said the Gold Dots will build up pressure differently than others, and he is correct. I'm like you, I pay mucho attention to the pressures and try and stay below what the Experts find... I really depend on LRH and the guys n gals pushing bullets to the max. 1000's of years experience at my fingertips ! Thanks for your time
 
I load them for my Grendel in AR platform. I believe they have a longer bearing surface than the 123's. I can confirm that the base on the ones I have is .0005" larger than the rest of the bullet. It measures .2645
 
I load them for my Grendel in AR platform. I believe they have a longer bearing surface than the 123's. I can confirm that the base on the ones I have is .0005" larger than the rest of the bullet. It measures .2645
Thank You Gord0, gonna check the bottom, I have noticed the "short " nose and having to shorten my rounds to fit in Mag, where the others OGIVE fit mag. Thanks for your time
 
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