6.5 grendel

[rwilliamson1]

hello everyone


I just finished building a 6.5 Grendel. iv been working on some test loads to achieve maximum accuracy and performance so far I have tried 120gr Hornady a-max with 26GR of H335. they shot alright, they held a group within .75in at 100yds. I tried to load a batch of Hornady 129gr interlock. I used the same powder charge 26gr H335 and apon shooting them and inspecting the brass the primer had a small hole punched deep inside it and there was a large crater from the firing pin. I have never seen this before and I am not sure what the cause is. I know its from pressure but im not sure where its coming from. all my brass have had the same small mark on them about .25in down from the neck and I have not been able to fix it yet. I am hoping that maybe someone has seen these same issues and was able to fix it. im not sure if its from the loads I have been running on some were in the gun if anyone has an idea or has found a better load. the barrel has a 1-8 twist and i havnt found any load data for a Grendel with a 1-8 twist im hoping i just havn't been looking in the right place or someone has some info.

thank you Robert.

 

[112Savage]

I'll venture a guess. You have too much powder in the case for that weight bullet. Hodgdon load manual states a max load for the 123 AMAX as 28.7 grains of H335.
Hornady's latest manual lists 26.4 as max with the 120/123 AMAX. I don't have data for the 129, but in such a small case I would think you should back down to 21 grains of H335 and work back up. Also another choice would be to go to a slower powder like varget or CFE223.
I will say that I have not experimented with the 129 or H335 so I can't directly answer from experience. Also, I apologize if you did work up to the 26 grain level with the 129, you just didn't indicate that you had.

 

[rwilliamson1]

I'll venture a guess. You have too much powder in the case for that weight bullet. Hodgdon load manual states a max load for the 123 AMAX as 28.7 grains of H335.
Hornady's latest manual lists 26.4 as max with the 120/123 AMAX. I don't have data for the 129, but in such a small case I would think you should back down to 21 grains of H335 and work back up. Also another choice would be to go to a slower powder like varget or CFE223.
I will say that I have not experimented with the 129 or H335 so I can't directly answer from experience. Also, I apologize if you did work up to the 26 grain level with the 129, you just didn't indicate that you had.

your right I did not clarify. that was my starting point the only load data I found for the 120 Amax was low of 26 and a high of 28.5 and for the 129 I saw 26 to 29 but I don't know how much was correct so ill probably drop my starting point to 21 or 22. thank you for your help

Robert

 

[drwindmill]

I think for the 120-129 you are much better off using powders like 8208XBR, AR-Comp, CFE 223, or Leverevolution. Leverevolution is pretty available and from my rifles is both accurate and very fast.

 

[woodnut]

The holes in the primers generally says the load is too hot. But, your firing pin just may be either too long or too pointed. Can't say I've heard of that being the case; but in a bolt gun it can happen. As too the spot on the neck, I don't know. Need more info or pictures would be nice.
If you are using 26.4gr. and the new Hornady manual does show it as max; then by all means start over a lot lower!
I'm shooting Accurate 2520 powder with 123 gr. bullets. It's temp. sensitive but very accurate.

 

[Deleted member 46119]

My 6.5 is not complete. My 6 is.

1. Your load is to hot for safety.
2. .75 from a semi is not 'bad', of course there is always room for improvement.
3. I recommend CCI primers, they can take the semi auto hard hitting firing pin better.
4. I never got what I wanted from H335, IIWM, I'd try something else.

Monday I was dinging steel out to 700 with the 6. It's not perfect but getting there. I'm using AR-Comp right now.

The biggest problem is that loaded rounds disappear so fast

 

[vatackdriver]

I expect the dings you are seeing are from the brass deflector. A small PC of Velcro(the soft side) adhered to the brass deflector will solve this but it has never caused me any reloading issues. As for the 335 load, The other powders mentioned will suit you better. H335 seems to work better on the lighter pills from my experience.

 

[joseph]

rwilliamson1,

Take a look here to fix the primer problem:

JP 308 "High Pressure" bolt & primer condition pics on a 6.5CM

joseph