That and action length

We will have NULA M20S rifles out in HAM'R early next year

Thank you Mr.Wilson. I have 1680 on hand. I will give it a try. Those Lehigh bullets have really peaked my interest.

My HAM'R has an 18" SHAW Barrel with M4 Feed Ramp.
I am running 130 Speer HP-V Bullets Seated to an OAL of 2.170 just as Bill recommends.
I started out with a 20 Round Gen 3, 300BLK, P-MAG. The world was Flat and Square, and it run's 100%.
To deer hunt with the HAM'R in Missouri you need a 10 Round or smaller Magazine. This is where the problem surfaced. Pretty much everything you read is about the 300BO. They say with bullets under 150 to just run 223/5.56 magazines, they will run fine. I do not find this to be true with the 300 HAM'R. So far I have used two different 5 Round 223/5.56 Magazines and neither will run. I am not talking a jam now and again, I am talking Will Not Feed Period.

A fellow on AR15.com recommended that I try the Lancer 10 Round, 300BLK Magazines. He has a HAM'R and says that they will run.
I ordered TWO from Midway that may arrive by the end of the week. "With Luck"
What are your experiences with Magazines in the 300 HAM'R?

Bob R

I have used 10, 20,and 30 round Lancer 300 BO mags and NEVER have had a problem. The 10 round mags are ideal for hunting or for use at the shooting bench. I have tried 300 BO P-Mags and they work but I like the metal feed lips on the Lancers. Standard USGI mags work so-so if I under load the capacity. BUT "so-so" isn't good enough.

There are several parts that directly effect the operation of your AR. Use the best parts you can find. Over time minor cost savings disappear, but if your rifle doesn't function 100% of the time it will haunt you every time you pull the trigger!.

agree w/ Graycard...you're going to like the Lancer mags...at the bench and most of my pig hunting I don't need more than 10 rounds and find myself using the Lancers almost all the time. I do have a Pmag 20 rounder than I carry in the case of running into a big sounder. There seems to be enough pressure where I pig hunt those are becoming odd rather than the norm.

Finished my 300 HAM'R rifle and took it to the range today. Very happy with the build.

Running a Wilson Combat 16" Recon Profile Fluted Barrel with 1-13 Twist. Seems to like 130 grain HAM'R Hot-Cor.

Now I need to find a place to hunt some hogs

Pmags have plastic lips that aren't always the correct length or shape, sometimes the follower catches too (tilts). Lancers work fine for my BO, cast or jacketed stuff. I trimmed some Pmags to work but finally gave them to GKs running 223.

I was going through ammo today and noticed that I have some factory loaded TNT that appears to be corroding. It’s stored in the same crate as my other .300 Ham’r rounds (fmj, sp, cc, ftx, hc) but is the only bullet showing anything. Is this fine or a cause for concern?

The picture of your plastic box shows the rubber seal is out of position. If that is how it is when you close the box it would contribute to adding humidity in the box. I have heard that plastic containers are notorious for corrosion but I've never experienced that myself although for long term storage I normally put a silica gel pack in the container. As for the corrosion I've never had any issues shooting those either although if they are really bad I spiff them up with some Flitz or Brasso followed by a wipedown with lighter fluid just to eliminate any residual grit.

The Feeding Problem that I was having delt with Low Capacity (5 & 10 Round) "Hunting Deer in Missouri Legal" 223/5.56 Magazines. Unlike the 300BO with Bullets <150 Grains, the 300 HAM'R did not like 223/5.56 Magazines at all.

I am waiting on the 10 Round Lancers "300BLK" Magazines to show up from Midway. Quite Possibly today. I believe that they will feed, and may very well be my go to magazines for the 300 HAM'R. Most of my shooting is at the Range, and 10 round magazines work just fine for me, except for Two Gun. I do not plan to shoot the 300 HAM'R in the Two Gun Match. I have better options for that.

I will report back on the Lancer Magazines when I get to test them.

Bob R

I understand your frustration. While waiting for my Lancer mags I tried just about every flavor of 5.56 mag and never found one that would reliably feed a HAM'R round no matter what the bullet weight. You will like the reliability of the Lancer mags and as an added bonus they are easy to tell apart from most 5.56 mags.

Primary Arms is probably the largest online provider of all things black rifles. This is always my first stop (more selection and better pricing) than just about everyone.

Lancer 300BO Mags (10-rounds). They are in stock.
[url=https://www.primaryarms.com/lancer-systems-l5-awm-10-round-300-blk-hybrid-magazine-smoke][/url]

We have not seen any feeding issues with D&H, Duramag, Lancer or MagPul Blackout mags, but the Lancer is my favorite.

hamr feeding some pigs a steady diet of 125gr pills

And I thought I had a lot of ammo!

I spent all of opening week at the lease and used the Ham'r all week. I missed a bobcat :sad: and didn't recover 2 pigs but other than that a great time. The buck was hit just on top of the heart and ran maybe 30 yards behing plowing into a tree and going a$$ up

Nice vid DJ!

Looks like a great element dlrz, nice deer!

I did a little load testing over the weekend.
Shaw 18" H-Bar Barrel, 1/15 Twist, Rifle Gas, Non-Adjustable Gas Block.

New Starline 300 HAM'R Cases with the Flash Hole Deburred, and Inside Neck Chamfered only.
Loaded using Redding FL Die Set, No Crimp applied. I do have a Lee Crimp Die that I have not used.
CCI 400 Primers
2.170 OAL
Speer 130 HP-V Bullets

First up was 26.0 grains of CFE Black (New Can)
Average Velocity: 2446 FPS
Extreme Spread: 67 FPS
2457
2436
2445
2413
2480

Next Up, 26.0 Shooters World Blackout (New Can)
Average Velocity: 2437 FPS
Extreme Spread: 45 FPS
NOTE: Not sure what was happening but every round fired gained another 9 to a maximum of 13 fps. I have never had this happen before.
2413
2422
2440
2453
2458
The step Increases in velocity with each shot got my attention. The barrel was not hot to the touch.
I cleaned the barrel at this point. A Donut of Brass came out on the first patch. Jacket Material?
I plan to run by Hunts Long Range and have him take a look down the barrel with a bore scope shortly. He was off deer hunting today.

Last up was 26.0 grains of AA1680 (New Can)
Average Velocity: 2539 FPS
Extreme Spread: 85 FPS
NOTE: This load produced the Highest Velocity, but would not lock the Bolt Open. It failed to strip one round out of the Twenty Five fired. "SCRATCHING HEAD"
Per the Accurate Arms Data also with an 18" Barrel 26.2 only produced 2369 FPS. Per all of my notes on load data for AA1680, this load should have been quite a bit slower than the numbers that I got. I do have a couple older cans of AA1680. I might need to retest with the older powder.
2514
2548
2557
2496
2581

I will probably reload the cases, and do some additional testing for velocity. I may also need to test my Chronograph against another one to check it's accuracy. I have not checked it since I got it back from having some repairs made.

Bob R

CONTINUED:

I am wondering if my barrel is shaving jacket material. AND if this Jacket Material Build-up is applying a crimp to the case when it chambers. The more rounds fired the more jacket material build-up, and the more crimp applied, thus the velocity increase with an increase in Pressure.
Early on with my barrel break in, I got a Brass Donut on a 5 shot cleaning. I was cleaning every five shots until this range trip.
I had not seen another Brass Donut show up on a Patch until this one with a lot more rounds down range. This time I probably had 50 rounds between cleaning's.
I believe a look with a bore scope is the next thing to do. See if I have a square ledge where the bullet hits the rifling, that is shaving jacket material.
I have never had a ring of brass come out on a Patch before on any gun that I have cleaned. This is something new to me.

Bob R

Hi Bob,

Those are some head scratchers. All I can think of is to clean the barrel real well and then bore scope it. Then run 50 rounds through it and inspect with the bore scope again. Personally I use magnum primers all the time and factory crimp all bullets but that should not be your problem. I have extensive experience with the CFE BLK but none of the other powders in the Ham'r.

Oh... and if it's still a new bore it's a good idea to get at least 200 rounds through it before making any changes.

I had something like this happen with my 300 HAM'R Ranger barrel. Velocity and pressure started spiking with no change in loads. I thought the same as you. Cleaned the barrel and it was back to normal. Hasn't happened again. Assumed there may have been something building up copper and would hopefully stop as the barrel broke in. Seems to have as I haven't seen the issue again.

Bob, the Speer 130gr HP is notorious for shaving copper and getting the copper rings, this is why WC disc this load. To reduce this at the time of SAAMI acceptance we changed the lead angle from 45 degrees to 30 degrees to help reduce this issue. Maybe Shaw is using an old spec chamber reamer with the 45 degree? We found this issue to normally go away after 200rds or so.

I can tell that the barrel is getting easier to clean. I have been running Two Wet Patch's (#9), a few Brush Strokes (Brass Brush), another Wet Patch, followed by Two to Three Dry Patch's.

I stopped by Stern Defense yesterday to get another couple Two Stage Triggers on order. I have the Tech swap to the Light Spring, and Bench Test it. One of these Triggers will go in the HAM'R, the other in a 6.5 Grendel that is waiting on a Compass Lake Barrel to get built. Stern Defense make a Cassette Trigger. They market them mainly for PCC Builds, however they do come with a Light Spring for Rifle Builds. So far the last Two have Tested at 2 LB-8 Oz, and 2 LB-9 OZ on the Second Stage.
The Trigger should help a little to shrink groups.

So far the 300 HAM'R is grouping in the 1.0 - 1.5 Inch Range. My last Target for Group had Three in a small cluster, and a couple Left that might be trigger related. Also I have not had a Nice Condition Range Day to shoot it. I am putting up with Wind most every Range Trip. The Multi-Purpose Range (25-200 Yard) faces South. The Sun is starting to be an issue also. I need to add a Beach Towel with a PVC Tubing weight to the bottom of the towel to block the Sun. The shooting line roof is perfect to clamp the towel to. The PVC Tube Weight will keep it from Flopping.

More to come.

Bob R

My case happened when testing 125 TNTs. I wonder if they're prone to this as well(?). Either way, the issue seemed to be self-resolving.