What is the largest bullet anyone has loaded for bolt action 6.5 Grendel

[Dinny]

5.5gr of TB isn't enough powder for the 160gr Hornady RN either. I'm guessing 6gr will clear the barrel but one could probably catch it with a ball mit. More to follow...

Thanks, Dinny

[Klem]

5.5gr of TB isn't enough powder for the 160gr Hornady RN either. I'm guessing 6gr will clear the barrel but one could probably catch it with a ball mit. More to follow...

Thanks, Dinny

Why don't you start at 7 or 8gns of TB with your 160gn Hornady's. With subsonics you start high and work back from there. The peak pressure is way below dangerous so you can afford to go high and work back from there. QL is predicting about 1,050fps from a 16" barrel with 7gn/TB at 56mm OAL. Round nose bullets don't feed as well as pointy nose out of an AR magazine. They also tend to pigeon-toe due to the rib towards the front of the magazine. That is my experience with 300BLK. Stainless steel mags have a less pronounced rib so that will help. Bearing in mind none of these loads will cycle the action. 7.4gn/TB with a 160gn Hornady is your 80% capacity fill threshold for safe loading.

[Dinny]

I'm loading a bolt gun and my COAL is likely shorter than the "book" COAL you have listed. I also have a cutout case that shows the powder level and I have reached a maximum case capacity that I'm comfortable with. Keep in mind, 'my' 80% capacity may not be 'your' 80% capacity. As always,YMMV.

6.5gr clears the barrel and is a bit louder than I expected. I guess shooting my 175gr spitzers is out now.

Thanks, Dinny

[Dinny]

I have another test lot consisting of Hornady 140gr SPs and 6.0gr of TB to test tomorrow morning. If mods believe this to be better suited elsewhere just say the word and I'll keep posting my results elsewhere. If no one is interested, I'll keep my data to myself. Remember, each and every rifle is its own creature. YMMV

Thanks, Dinny

[bj139]

Dinny,
If they don't want you to post here please start a new thread.
I would be interested in what you are finding in testing reduced loads.

[Dinny]

Even the 140s need 6.5gr of TB to consistently clear the barrel. The first one fired fine, the second one stuck 2" from the muzzle. I have a bit more case capacity to work with the 140gr bullet so I'll load some up to 7gr and test them tomorrow.

Thanks, Dinny

[bj139]

Dinny,
How do the primers look?
Any sign of high pressure?

[Dinny]

Dinny,
How do the primers look?
Any sign of high pressure?

Case head expansion, primer flattening, and extraction are all within normal limits. I fell ill with a stomach bug so it may be a few more days before I get back to testing.
Thanks, Dinny

[FW Conch]

There is ABSOLUTELY NO WAY there can be over pressure using Trail Boss. Read the Trail Boss introductory article in the 2008 Hodgdon Annual Manual. The suggestion to not compress Trail Boss is because accuracy is degraded. Compression of Trail Boss does not create an unsafe condition.

This thread has run far afield of the OP's original question.

[Klem]

There is no risk of overpressure when using Trail Boss.

Here is the time/pressure curve for 6.5gns TB behind a 140gn Hornady.



The peak pressure is 20,000lbs which is half the max SAAMI of 52,000. The amount of TB you need to load to reach max peak pressure is 12gns, which can never happen because it is 130% of the case capacity. The max compressed load you could fill is about 9.5gns, which gives 35,000lbs of peak pressure.

If worried about bullets getting stuck in the barrel with TB you can work downward for subsonic test loads, instead of the usual work-up for supersonic. Overpressure is not going to be a problem. The risk of SEE and Flash-Over is. Plus a couple of more peculiar risks like failure to obdurate. Your case fill with 6.5gns is 70% of the available space.

[ricsmall]

Again, start at max and work down. Save time,Powder,pills and you don’t have to beat bullets out of barrel. You will not exceed max pressure with trail boss