6.5 120 hammer HBC load work up

[PLhunter]

Buddy had a 15 sample pack that didn’t line up right for his PRC mag. So I loaded them up for the creedmoor. This rifle shot the 124 hammer hunters very well.

Powders used were 6.5 Staball and RL-16. All to the same seating depth. Didn’t get close to pressure with RL-16 and nothing but flat primers with Staball. RL-16 was more accurate. Going to try varget after I get some ordered. Also, going to experiment with crimping as the es and sd data wasn’t encouraging

 

[PLhunter]

Ended up getting a new barrel. Took about 6 months longer than I was expecting. The new barrel liked the 120 hbc’s. Here’s the first four down the pipe. About 25 rounds into the barrel.

 

[PLhunter]

Before switching the barrel I saw some promise with Varget, as I ran out of room with other powders. Velocities were low but showed absolutely no pressure.

After about 25 rounds I decided to run a ladder with varget and the 120’s. I know it’s too early to really set a load but it’ll give me a good idea of the powder and bullet combination potential.

39 and 39.3 grains were the above pictured group. Velocities were right around 2800 fps.

Then shot 40.3, 40.7, 41.3, and 41.8.
2 shots each. Grouped together well. Velocities were good but seems like work will need to be done regarding es, and sd. Going to try crimping when I come back to it.

Center low is the hammer load ladder all together. Right is a badlands bd2 ladder. And top is 140 eldm light plinking load I made just to get some down the tube.

 

[PLhunter]

Should note this is with a 19 inch barrel with a 9 inch can on it.

 

[PLhunter]

A little more info. Put a few downrange with Lee factory crimp vs not because my sd and es are still a little high even with great close range accuracy.

Didn’t seem to make a ton of difference. Barrel does appear to be starting to speed up a bit and I did show some light pressure signs. Ejector not smearing but if you look close you can see a slight ring on some.

Charge weight was 41.3 grains.

Crimped 2930, 2942, 2930, 2941, 2948 accuracy was okay but I was shooting quick from a less than ideal position in a truck bed. Probably right around an inch.

Not crimped 2954, 2944, 2933 (.003 neck tension). Accuracy was essentially one oblong hole would never be able to tell it was three shots.

All starline SRP brass.

Going to convert over to my Peterson Brass next. See if I can get a bit more velocity. The starline srp brass is much slower per charge weight with 140 eldm’s.

 

[Andouille]

Interesting results, and nice high velocities! I crimped for a while with 300 WSM amd 30'06 and found it only added more work and lightly damaged necks, so i stopped and focused on neck chamfer and deburr quality, sizing with a bushing die, expanding with a polished mandrel, and shooting for consistent 0.002" interference fit for the bullet. Using these procedures, my SDs with Starline and Lapua brass are typically 6-13 for my tikka 6.5CM, which also has a 19" barrel.

 

[PLhunter]

Interesting results, and nice high velocities! I crimped for a while with 300 WSM amd 30'06 and found it only added more work and lightly damaged necks, so i stopped and focused on neck chamfer and deburr quality, sizing with a bushing die, expanding with a polished mandrel, and shooting for consistent 0.002" interference fit for the bullet. Using these procedures, my SDs with Starline and Lapua brass are typically 6-13 for my tikka 6.5CM, which also has a 19" barrel.

Yeah, looking it back over my crimped load wasn’t really all that bad. ES 18 and SD of 7. But only 5 rounds.

My reloading setup is fairly budget and basic. I did use a friends SAC die to size all the starline brass I have. My regular setup is just a rockchucker and Hornady dies. They work well for some cartridges and not as well for others. My 30-06 maintains very low sd and es spreads with low end prep.

 

[PLhunter]

I went out and did some shooting again with once fired Peterson brass and the hbc. Didn’t have ejector marks but did have some “clickers” 90% of bolt throw was fine but would hang up at the end and pop loose. Fitting with other bullets lower charge weights produced higher velocities in this brass than the srp starline.

I either have a chamber issue, a die issue, or an over pressure issue. Or some combination of all of them. No ejector swipes noted just the difficult finish of the bolt lift to release the case. I think I’ll try lowering charge weights and using a different sizing die first. I think with the 19 inch barrel I need to try to get it to around 2875 to stop seeing intermittent pressure problems.

Results were the following with Peterson brass and federal primers.

40.5 2950 av. More pronounced click
40.2 varget 2945.4 av. 9.1 sd 21.7 es (3 shots)
39.8 varget 2901 avg 10.9 es 25.9 es (4 shots)

Accuracy was generally good to great but I wasn’t shooting for groups. It was absolutely ripping wind so I backed out to 540 yards to test “first round” hit rate on a deer sized target in those conditions with most of the rounds. The ones I shot at 100 were well less than an inch. It was a strong mostly tail wind that would switch from a generally left to right trajectory to an occasional right to left.

I don’t think I was having a great shooting day. A bit sick. The red is the 6.5 creedmoor with 120 hbc two different loads, the blue is an established load with 69.5 hbc in my contender .223. Love that tiny gun. Contender (400 yards) 6.5 creedmoor (540 yards). Winds probably 20-25 mph.