Next project : 30 Creedmoor!!! (30-28 Nosler hybrid)

[Mram10us]

Ok, so I need to rename this one too Here is the project and what I'm looking to accomplish:
1. Chamber a 30-28 nosler hybrid (I'll add a drawing soon) while using a 300wsm reamer, 28 nosler go gauge, 28 nosler brass and 300wsm dies

This pic shows the volume comparison between the standard 28 nosler (top) v the hybrid (bottom)

2. Fire cases multiple times to see if the extra case wall that isn't sized (roughly .300") will cause a problem. I chose hornady brass because it is the softest I have to choose from.
3. See if accuracy is par with the 30-28 nosler, etc

Learning from the last project (300 ultra X), I made the headspace slightly shorter, meaning .001" less than Go. Obviously still in the saami spec region, but want to keep virgin brass from having any room to fail.

The rifle components are as follows:
Rem 700 trued up action
Brux 26.5" barrel (was able to chase the threads from the last project and simply remove .270" from the shoulder and tenon dimensions)
Manners eh5
Timney trigger

Next - post results of ladder test with 230 otm and N570 or h1000

edit- a 28 nosler case holds 100.7gr water. This modified case holds 104.2gr for an increase of 3.5%.

 

[Mram10us]

Quick test today of a 215 with 77g r25. 2890fps and didn't blow me up. Later today will be a pressure ladder with speeds for 215s and h1000. Goal is to hit that next speed node around 3100+ with the bit of extra case volume. I'll run the numbers and post the increase, but guessing it is maybe 1%. Not much, but might get to the node with a decrease in pressure

edit: after running the numbers, the extra 3.5% case volume should allow close to 3200fps since we are at 3129 without any signs.

 

[Mram10us]

Left side is the first group of 5. I did a sighter(low left) then shot a 5 shot group. 215 hybrids 77gr r25 f215 gunwerks brass.

Right side is 215, 80-86gr h1000 with f215 3.600" as a close ladder to test speeds. Shot at 106yds

These are the chrono numbers for the h1000 ladder. The first shot at 79(2940fps) was used as a sighted and isn't on the target. Ignore the sd, es, avg, etc. I shot some other stuff after and messed up the numbers.

Brass showed a slight ejector mark on 85 and 86 but bolt lift was normal. Very promising thus far.

Shooting conditions were fair. 4800', 90deg wind 5mph, packed down a foot of snow, 9-13 Harris fully extended, rear bag, prone on ground.

 

[can1010]

promising velocity to start with. how much did you gain in capacity? 3-4 gr should make next node but 3100 is respectable. how is your brass sizing going to work to size the base of the case

 

[Mram10us]

promising velocity to start with. how much did you gain in capacity? 3-4 gr should make next node but 3100 is respectable. how is your brass sizing going to work to size the base of the case

I'll have to run the numbers to see the increase. As for sizing, the goal is partial sizing with a 300 wsm die and I'll know in a few more firings if it becomes an issue. If I have to, I can make a body die but I'm trying to avoid that

After running the numbers, I'm showing 100.7gr of water for a standard 28 nosler case v 104.2gr for this modified case. A 3.5% increase in volume. I posted the numbers above to be easily found

 

[Mram10us]

This pic shows the area not sized by the 300 wsm die (about .650"). That means roughly .500" of case sees the chamber. These nine have been fired twice and resized 3 times. They still feed well.

 

[Mram10us]

Snowing pretty good but got out enough to find the max load for. Slight bolt lift was enough for me to call it good. 86 was 3129 a couple days ago, so it's nice to see it at 3135 today.
86, 86.3 and 86.6 h1000
ADG brass
215 hybrid
f215

Next week when the winds die down, i will do a 2x ladder at 300 or 500 depending on conditions to find the high node

 

[sturner]

Tag

 

[MNbogboy]

Depending on that barrel round count, you still may see more additional speed. Usually they speed up until 100 - 150 rnds.

 

[Mram10us]

Depending on that barrel round count, you still may see more additional speed. Usually they speed up until 100 - 150 rnds.

True. I have over 300 rounds thru it, so I'm guessing it's in its prime

 

[Mram10us]

I made a body sizing die to hit the lower ~.500" if needed. Hopefully I won't need to. Still waiting for a no windy rainy snowy day.....

 

[MNbogboy]

I made a body sizing die to hit the lower ~.500" if needed. Hopefully I won't need to. Still waiting for a no windy rainy snowy day.....

How did you make the body die? Curiosity.

 

[Mram10us]

Threaded a piece of bar stock 7/8-14 on the lower half then bored Out the die to .548". Seems to work well when sizing to .550"

 

[MNbogboy]

Thanks, my thought that a good polished hole of correct diameter would get you there.
Nice work.