I'd like to start this thread for information sharing for those currently shooting 300 HAM'R and/or anyone interested in the cartridge. Hopefully it can become a good source of information over time like the 300 HAM'R thread on the Texas Hunting Forum and become a place to post relevant information and answer questions.

Hopefully everyone posting will refrain from personal attacks and caliber bashing and just share experiences and information on the 300 HAM'R cartridge....

Curious why the twist rate is so different from...  that other .308 AR15 cartridge who's name shall not be mentioned...  since the hypersonic bullet weights cover the same range.

Accuracy potential.

1-7/1-8 is optimal for heavy bullets in the 200gr + range

1-13 is optimal for 150gr

1-15 is optimal for 125-135gr

Also the bullets not being over stabilized seems to have a positive effect on terminal performance upon bullet impact on game.

Has anyone found any powder that works better than CFEBLK (perhaps with certain bullets)?  

@BWILSON Do you use anything other than CFEBLK in the ammunition you sell?

I will add two 150gr bullets that will load to proper OAL for magazine feeding.

Hornady Interlock 3031 and Sierra BTSP 2125

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At this point there is nothing better than CFEBLK/WC680 for 125-150gr loads available to either the commercial or OEM markets.

We use WC680 (CFEBLK in 45# kegs) for all but our 95-110gr loads, we use SBR SOCOM for 95gr and some of the 110gr loads at the ammo company. You simply run out of usable powder capacity before you even get to 50,000psi with the 95gr and some 110gr loads. You can't get enough powder in the case and seat the bullet to 2.255" to reach max pressure with CFEBLK with any 95-110gr bullet. As an example a Hornady 110gr SP over 29.9gr of CFEBLK (hot lot #2) is only 52,000psi at 2742fps and shoots great. However we can't load that commercially due to power spill when the machine is indexing. CAUTION: You can easily go over pressure with SBR SOCOM loading 110gr or heavier bullets!!!

I have both 1-15” and 1-13” twist barrels from Wilson. The 1-13” does indeed shoot 150gr bullets a little more accurately, not much though. My pet load 125gr tnt over a near max load of CFE BLK seems to shoot equally well out of both barrels. I haven’t found a powder that is better than CFE so far.

Both barrels are sub-moa with my pet load.

I would be concerned about expansion. The Hornady 3031 has a MV range of 2700-3600 (according to pg 111 of the 10th edition Hornady manual) and also the Sierra Gameking bullets have a reputation for being very tough bullets with thick jackets. On the other hand the Hornady 30303 150gr SST designed for the 300 Savage has a MV range of 2200-3000fps

That was a concern for the Sierra, from their website.


Wasn't sure about the Interlock.  I primarily bought them so I could have something to shoot.  They where on the shelf and they would fit

Does the cannelure line up on that Hornady 3031? I've had good results with Sierra 2130 150 gr. SPT. It's probably too hard for most game but it should smack steel nicely.

No it doesn't, neither does the 30303.

If using CFE there will not be an issue with setback from not crimping. The loads are compressed.  I guess creep could be an issue.

CFE acts just like H110, it likes to be compressed for a good burn.

If things were "normal" I would probably just buy Hot Cores being they are the lowest cost for targets and a good hunting bullet for a do it all round.  I've seen old pricing of around 18 cents apiece.

We've about run through the Hot-Cor's we got when we first got into the Ham'r. I should have picked more up when they were available. I managed to pick up a bunch of 125 TNT's, 135 FTX's, 110 Z-Max's and some 125 Pro-Hunter's before supplies dried up. I have a feeling pricing won't be as good as it was before things got so crazy but hopefully I'm wrong.

I saw a post in another forum that a guy was using H4198 and Reloader 7 in his Ham'r. Will there be any load data for these powders anytime? They may be too slow for light bullets but I would think they'd be good for the 150's. Maybe too bulky? Velocity might not be as good as CFE BLK but since supplies are hard to get having some alternatives would be helpful.

First off unless the St Marks powder plant is out of commission for some reason I doubt that CFEBLK will be any harder to get than any other popular powder due to it's heavy use in the .300BLK. So far we have had no issues obtaining it unlike bullets and primers.

Secondly I keep TERRIBLE notes on loads that don't work, but I went back through what I have in regards to powders that will work to some degree......

Other than CFEBLK and SBR SOCOM most of my experience has been with A1680 since this was the original development powder prior to Hodgdon suggesting I try CFEBLK which was a game changer. So here's the best I can do for now in regards to other powders. Also keep in mind that some of these options other than A1680/N120 may not function guns with intermediate length gas unless they are suppressed.

A1680: The best 2nd choice for 125-135gr loads, you can load to 95% performance with 110-135gr bullets, be careful with 150gr loads
Vit N120: My 3rd choice, I was able to obtain similar velocity to A1680 so it's a viable option
SBR SOCOM: 4th choice is only suitable for 95-110gr loads
H110/W296/N110/LilGun/A5744: Some application for 110gr, easy to go over pressure if your not EXTREMELY careful
A11FS: An option with 110-130gr if your gun will function with it, also easy to go over pressure if your not EXTREMELY careful
LT30/1200-R/N200: My notes only say "not enough powder capacity for full velocity", but further testing might be in order???

So based on the info available to me today.......these are our options for powder under certain conditions listed on my personal order of preference and keeping in mind that I tried these powders early on in the project before I had access to pressure testing.

CFEBLK
A1680
N120
SBR SOCOM (95-110gr only)
LT30
11FS (110-130gr only)

I've not tried R7 or 4198 but I'm pretty confident that the powder bulk issue would be even worse than with some of the others listed above.

As a last note, all bullets of the same weight are not the same when it comes to pressure. Bearing surface, jacket thickness, type of jacket material and construction all can have a substantial effect on how quick a load develops pressure.

As examples:

You can load the Speer 150gr BTSP nearly 75fps faster than the Speer 150gr Gold Dot at the same pressure, the same goes for the Speer 135gr HAM'R BONDED over the Hornady 135gr FTX and the Sierra 125gr SPT PH over the Hornady 125gr FMJ

This will go down as the "Quote of the Year."  At least we can be thankful for the number of different bullets suitable for the 300 HAM'R.  These times also show the value of only needing a barrel for the conversion from 5.56.  Standard AR parts are a lot easier to find.

Bill

Any opinion on these?  

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They will work, just keep the velocity down in the 2250fps range, this bullet builds pressure quicker than some of the other 150gr

Has anyone else tried to load the 125 gr Sierra Gamechangers yet?

I am attempting to work up a load with CFE BLK but am running into case bulging due to powder compression at only about 25 grains of powder.

I haven't shot these yet but I was hoping I could fit more in there. Maybe I don't need to?

Like the Hornady 125gr SST, this bullet is too long and not suitable for the HAM'R. Besides the powder capacity issue, with the bullet seated for a OAL of 2.255" the jump to the rifling kills accuracy. I've buzzed 2/3 of the polymer tip off of the SSTs with a belt sander and got excellent accuracy and good terminal performance on hogs. It would be a very good bullet with a shorter polymer tip.

Thanks, that's what I figured. I'll save these for the 308 and try to find some shorter bullets, or just snip the tips off if I get really desperate.

I was scanning Midways website a few minutes ago and noticed that they are offering 300 HAM'R Starline brass.  AND it is in stock now.

Cheaper at Wilson

Good, I've rather go to the main source.

I got the barrel shop to squeeze in 50 of the 8" pistol barrels in our last 300 HAM'R production run and they are in final finish now, so should be up on the web site for sale next week. If anyone wants to pre-order here's the SKU # and price

TR-300HSBRPG8RT11.25  $224.95

Any plans to do a 12.5" or 13.2?

I have almost pulled the trigger on the 11.3" several times but a slightly longer tube would be my preference for this cartridge.

No plans to add any new barrel SKUs anytime soon

11.3 it is then

125gr pro hunters...

feb 2021

I'm back to trying the Sierra 135 gr match kings, looks like 26.5 gr of CFE BLK is about all that will fit before you run into powder compression issues which I think should be fine.

I haven't worked up that high yet, I just shot a few strings from 24  to 25.5 gr and accuracy was very good with all and no pressure signs so I'll keep going. Using mixed brass and CCI450s right now but will be switching to starline brass after these are all fireformed.

I haven't been this excited about a rifle/cartridge combo in a very long time. It's far superior to 300 Blk for my uses.

Well I went ahead and pulled the trigger on the Wilson 11.3" barrel.

Still playing with the HAMR.

I thought it was interesting that the only thing that made the 135 HPBT work was the boat tail. Otherwise it is a very similar shape and length to the 125 Gamechanger. It's really the only bullet I had on hand that works at all and bullet availability is tenuous right now so I am trying to roll with what I got.

Has anyone been doing OK with non magnum primers and CFE-BLK? My supply of CCI 450s is dwindling...

See pic of the 135 HPBT next to all the bullets that didn't work:

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Attached File

For what it is worth, I have used CCI 400 and see no difference in performance (velocity) between those and the 450's.  However, the 450's do have a stronger cup and I prefer that when dealing with the chance of a slam-fire.

There is more than the length of the bullet in play here. The ogive profile of the nose is also a big factor. If the nose is too pointed, once the bullet is seated to mag length 2.260" max the jump to lead is too far for good accuracy like you see with the Blackout. Bullets like that allow you to load to 2.255" and still be very close to the lead will give the best accuracy and normally give you the most powder space.

The Sierra #2123 135gr HPBT does fit and shoot well, unfortunately Sierra has discontinued it

Not trying to sell you anything, but our bullet seat gage really helps with bullet selection

You are of course right about the ojive shape and the jump to the leade and the long polymer tip.

I guess what surprised me is how much the boat tail helped with avoiding powder crush for a given amount of bullet protrusion into the case.
I really like the 135 HPBT but I see why it got discontinued, it's a very niche bullet and that's why I still have them.

When can I'll just buy the proper bullets but finding them in stock has been a challenge.

Bill,

You say the 1-13 if for 150gr in/or sub freezing temperatures.

Is that true for 125gr-130gr in 20 deg temps?

Looking to build a deer gun for the wife utilizing 125gr SSTs (with the trip shortened) or 130 hot cores.

I currently have a 1-13 twist for 150gr usage.

A 1-15 twist is optimal for 125-130gr for best accuracy and will fully stabilize them under any temperature condition a human is likely to be out in. I've never had an issue with any 150gr, but then about the coldest weather I've ever shot them in was around 20 degrees F

Bill
Quick question, I bought one of your early 7.62x40s 16 in with 1x10 twist. Question is can I have the chamber reamed to the 300hmr? or would this twist be too fast.

Yes it's possible to re-chamber and you should retain whatever accuracy potential you have now

Will a HAM'R reamer completely clean up a Blackout chamber?

The 300 HAM'R is what I hoped the 300 BO would be.

I have a couple boxes of Sierra #2020 bullets, a flat point 125 intended for the 30-30.  Will these work in the HAM'R?  They should be in the right velocity range to be a good hunting bullet.

Yes, but you will still be stuck with the fast 1-7 or 1-8 twist

This isn't an "ideal" bullet, but it will work

Good point.

You have to do your homework on bullets. Find out minimal expansion fps. Then chrono the bullets out of YOUR barrel. Put data in a ballistic app. This way, you know what a particular bullet will do for you.

I just go out and kill hogs with them !!!

How much of an moa loss would that equate to, roughly?

Would pistol length gas create too much pressure without an adj. gas block?

You're asking a question that has no solid answer.  Accuracy will vary from rifle to rifle and bullet type to bullet type.  You should be thinking "How accurate can I make my rifle?" instead of "How bad can it be before I'm too disappointed?"

No way to know what kind of accuracy to expect, any twist faster than a 1-12 is really over stabilizing the suitable bullets

Most .300 BLK bbls are gassed to run with subs non-suppressed which means they are already over gassed when shooting supers, re-chamber to 300 HAM'R and/or add a suppressor and you make the problem worse. We haven't made a test bbl yet, but I'll bet a .300 BLK bbl with a carbine gas system will function fine as a dedicated bbl to shoot supersonic ammo and if you use a 1-13 to 1-15 twist I'll bet it would shoot pretty good.

Thank you. I figured a pistol length gas system could be an issue.

What is it about the .30 cal Ham'r bullet that makes it not like faster twists when a 110g-120g 300blk is fine with those? I presume the bullets lengths are similar.

A 1-15 twist is optimal for best accuracy with 110-130gr bullets, anything faster is over stabilizing the bullets which isn't optimal for best accuracy potential. That said, it's possible for a these light bullets to shoot OK in a fast twist, it's just not optimal. Go the JBMBALLISTICS.COM and run your own #s

Those look great for brush hunting.

I'm curious how they will feed with that shape.