300 Ham'r subsonic?

[mattri]

Good Morning All,
Looking at putting together a 300 Ham'r on a Savage 10 platform.
The purpose will be to have a medium powered round that uses common components with the ability to shoot supersonic loads faster than a 300 Blackout and have the option of subsonic loads as well.
It seems most Ham'r barrels are in 1:15 twist for the lighter bullets- I'm thinking a 1:10 to shoot the lighter 120/150gr and heavier 200s.
Thoughts?

[mattri]

100 views!!
Well it sounded like a good idea at the time but after further consideration I just went ahead and ordered a 300 BO barrel.

[Baltimoreed]

I had my 300 blkout rechambered to 300 Ham’r a while back in order to get more gas to run my T20 build. It worked so as soon as my stock gets painted I’ll start load development. Sorry I didn’t see your thread earlier. But no interest in subs. I was disappointed in the blkout and the difficulties in building brass. Ham’r should be easier as you’re not as deep into the donor case. Good luck.

[MUSTANG]

Well - just saw your post and was not aware of the .300 Ham'r round. Did some research and discovered:


The result was the .300 HAMR, which is a modified .223 Remington case necked up to .30-caliber. Well, I know what you’re thinking, that sounds like a .300 Blackout. Yeah, but it’s not. The .300 Blackout uses a much shorter (1.368-inch) case compared to the HAMR’s 1.603-inch case. The short Blackout case was designed to allow for the use of the long and heavy bullets that made it the subsonic wonder cartridge it is. The HAMR on the other hand was designed to do what many imagined the .300 Blackout could do—equal the ballistics of the .30-30 Winchester.

https://www.shootingillustrated.com/content/300-blk-vs-300-hamr-which-is-the-better-cartridge/

https://www.handloadermagazine.com/shooting-the-300-ham-r

A 30-30 ballistic equivalent in an AR Platform is interesting. I have always viewed the .300 Blackout as more of an M-1 Carbine equivalent in an AR Platform. The Handloader magazine article is interesting.

[BK7saum]

I have four 300BLKs; one AR, and 3 bolt guns(one is still a NIB Howa Mini barreled action) Just got a 300 Hamr barrel and built an upper. I have hog and deer hunted with the 300BLK and it is a performer. No shots over 75-100 yards, but it does its job well. i am shooting the Nosler 125 BT. I shoot subsonics in the bolt gun. and typically use the MP 311410 with the deep hollow point. The lighter bullets are quieter than the 220s and 240s, less powder amd gas volume needed.

I am looking forward to seeing how the HAMR perfoms. I have a friend with a HAMR and he is pleased with it. I dont shoot the 300BLK AR much so dont have to worry about confusing magazines. However i will use lancers for the HAMR and Magpul for the BLK.

What I dont like about the HAMR and it is a trade off, is that the long ogive bullets like the Nosler 125 BT do not work with the HAMR in a AR magazine. they are too long and seat too deep.

[mattri]

Thanks for the replies- component availability and general support were about 50% of the reason I went with the BO. I was able to find new brass, dies, trim gauge etc very easily and factory ammo is always out there.
The other 50% was the option to run subs. Again the support is there in components, load data etc and even factory sub ammo so it ended up making sense. Barrel has been ordered, components are on their way- it will be a few weeks but will post more as build progresses.
Very much looking forward to finding a good cast/sub combo.