Guns & Outdoors Forum

Never loaded mono-metal bullets. No clue.

One of the reasons I had stopped playing with them in the past was due to not being able to get them to group as tightly as cup and core bullets. That was years ago though. While they are still more costly than cup and core, the cost difference seems to have shrunk some. More places are requiring lead free for hunting so I am slowly trying to find things that work. I prefer cup and core or bonded over mono bullets, but in theory a mono should be better.

The velocity numbers are above book with no noticeable signs of excessive pressure, but groups are less than ideal. I might take the 44.6gr load and play with OAL in 0.020" changes up and down.

Well, test loads are put together. I used the 44.6gr load and put together test rounds from 2.710" to 2.845" OAL in 0.015" increments. 2.710" is book OAL and 2.845" puts the bullet at 0.020" from the maximum length allowed by the chamber. Hopefully I end up with some decent results from this.

Testing didn't go so well today. Toward the end of testing I noticed that the rear scope ring had loosened up on the base. Not knowing when it happened renders the whole test invalid. On a slightly positive note I did find that velocity will shift with seating depth a bit (but not in a linear manner), less than 0.050" of jump results in faint ejector marks on the brass, and over 26 recorded velocities (I didn't write one down apparently) I averaged 3299.7fps. The slowest group was 3276.6 fps and the fastest group was 3331.6 fps.

I will rerun this test with loads covering 2.800 to 2.815 OAL. 2.815 is where I start to see faint ejector marks, but it was only on one piece of brass. That may have been a missed mark from previous testing though.

You seem to be plagued with trials in all your guns.
Who’d you piss off? Never seen someone have so many troubles with so many guns. It shouldn’t be this hard.

Even if it's not as planned it was still a chance to gather information. Looking at the velocities for the 2.800 and 2.815 groups the differences between shots seem the tightest of all the loads. The rings are a QR style due to that being available at the time I purchased rings. There is a high probability that I will change them if I can't figure out a way to make sure they stay right.

I gave up on mono bullets before due to crap groups. I am trying to force myself to get this one figured out. I find cup and core bullets to generally be more forgiving with powder charge differences and seating depth differences.

My employee number at work does end in 666. That may explain some things...

Minor update after the range trip on the weekend. It was cold and that kept the number of people at the range low.

I did drop the charge weight by 0.1gr to bring it to 44.5gr of H4350. This is below book max, but probably actually over where my max should be. I am getting witness marks from the ejector hole on some cases. The mark is there, but not really pronounced, but is not being smeared when the bolt rotates. I have to look really hard to spot the mark on most of the cases I have found it on. These test loads were done with new Starline brass.

Still not where I would like the groups to be, but acceptable for the ranges I would anticipate using it at. Maybe on a warmer day the groups would have been tighter? Who knows for sure. The following would be the two best groups from the test batch.

I forgot. What is your twist rate?

This is a 1:8 twist factory barrel. If I am not mistaken it is about the slowest twist that should be okay with this bullet. Hornady claims that a 1:8 is acceptable with this bullet, but the online stability calculators suggest that faster would be more ideal.

If memory is correct I am also about 150fps over book suggested velocity right now as well. I know I am about 100 fps over book max load suggested velocity, but I wont be pushing a book max load due to some serious ejector marks on brass at much over 44.6gr of H4350 with this brass and bullet. Even at 44.6gr I am getting ejector marks depending on which OAL I go with. 2.785-2.815" was the range that seemed the least likely to produce the faintest ejector mark, but 2.710-2.770" and 2.830-2.845" would produce more noticeable ejector marks with a few that you could actually feel with your fingernail. My max OAL is 2.865". I am not really looking to run a monometal bullet with 0.000" of jump though.

Another range visit and some more results. I wanted to retest the 2.800" and 2.810" OAL loads. I am stil using the same 445.gr H4350 powder charge and new Starline brass. The faint ejector marks and primers tell me to quit pushing and either accept this as it is or start working back down the charge weight path and find the next charge weight that still at least tries to group. Not every case had an ejector mark, but its enough to know im pushing limits a bit. Some required a lot of careful inspection to find, but others were somewhat obvious. None were raised to a point that I could feel it with a finger nail, but you can see it. For reference, my dad's .25-06 was pushing a 90gr CX to about 3350fps today.

I ran two three shot groups with each length.

2.800"

2.810"